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// CodeMirror, copyright (c) by Marijn Haverbeke and others

// Distributed under an MIT license: http://codemirror.net/LICENSE



// This is CodeMirror (http://codemirror.net), a code editor

// implemented in JavaScript on top of the browser's DOM.

//

// You can find some technical background for some of the code below

// at http://marijnhaverbeke.nl/blog/#cm-internals .



(function(mod) {

  if (typeof exports == "object" && typeof module == "object") // CommonJS

    module.exports = mod();

  else if (typeof define == "function" && define.amd) // AMD

    return define([], mod);

  else // Plain browser env

    (this || window).CodeMirror = mod();

})(function() {

  "use strict";



  // BROWSER SNIFFING



  // Kludges for bugs and behavior differences that can't be feature

  // detected are enabled based on userAgent etc sniffing.

  var userAgent = navigator.userAgent;

  var platform = navigator.platform;



  var gecko = /gecko\/\d/i.test(userAgent);

  var ie_upto10 = /MSIE \d/.test(userAgent);

  var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(userAgent);

  var ie = ie_upto10 || ie_11up;

  var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : ie_11up[1]);

  var webkit = /WebKit\//.test(userAgent);

  var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(userAgent);

  var chrome = /Chrome\//.test(userAgent);

  var presto = /Opera\//.test(userAgent);

  var safari = /Apple Computer/.test(navigator.vendor);

  var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(userAgent);

  var phantom = /PhantomJS/.test(userAgent);



  var ios = /AppleWebKit/.test(userAgent) && /Mobile\/\w+/.test(userAgent);

  // This is woefully incomplete. Suggestions for alternative methods welcome.

  var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(userAgent);

  var mac = ios || /Mac/.test(platform);

  var chromeOS = /\bCrOS\b/.test(userAgent);

  var windows = /win/i.test(platform);



  var presto_version = presto && userAgent.match(/Version\/(\d*\.\d*)/);

  if (presto_version) presto_version = Number(presto_version[1]);

  if (presto_version && presto_version >= 15) { presto = false; webkit = true; }

  // Some browsers use the wrong event properties to signal cmd/ctrl on OS X

  var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));

  var captureRightClick = gecko || (ie && ie_version >= 9);



  // Optimize some code when these features are not used.

  var sawReadOnlySpans = false, sawCollapsedSpans = false;



  // EDITOR CONSTRUCTOR



  // A CodeMirror instance represents an editor. This is the object

  // that user code is usually dealing with.



  function CodeMirror(place, options) {

    if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);



    this.options = options = options ? copyObj(options) : {};

    // Determine effective options based on given values and defaults.

    copyObj(defaults, options, false);

    setGuttersForLineNumbers(options);



    var doc = options.value;

    if (typeof doc == "string") doc = new Doc(doc, options.mode, null, options.lineSeparator);

    this.doc = doc;



    var input = new CodeMirror.inputStyles[options.inputStyle](this);

    var display = this.display = new Display(place, doc, input);

    display.wrapper.CodeMirror = this;

    updateGutters(this);

    themeChanged(this);

    if (options.lineWrapping)

      this.display.wrapper.className += " CodeMirror-wrap";

    if (options.autofocus && !mobile) display.input.focus();

    initScrollbars(this);



    this.state = {

      keyMaps: [],  // stores maps added by addKeyMap

      overlays: [], // highlighting overlays, as added by addOverlay

      modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info

      overwrite: false,

      delayingBlurEvent: false,

      focused: false,

      suppressEdits: false, // used to disable editing during key handlers when in readOnly mode

      pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in input.poll

      selectingText: false,

      draggingText: false,

      highlight: new Delayed(), // stores highlight worker timeout

      keySeq: null,  // Unfinished key sequence

      specialChars: null

    };



    var cm = this;



    // Override magic textarea content restore that IE sometimes does

    // on our hidden textarea on reload

    if (ie && ie_version < 11) setTimeout(function() { cm.display.input.reset(true); }, 20);



    registerEventHandlers(this);

    ensureGlobalHandlers();



    startOperation(this);

    this.curOp.forceUpdate = true;

    attachDoc(this, doc);



    if ((options.autofocus && !mobile) || cm.hasFocus())

      setTimeout(bind(onFocus, this), 20);

    else

      onBlur(this);



    for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))

      optionHandlers[opt](this, options[opt], Init);

    maybeUpdateLineNumberWidth(this);

    if (options.finishInit) options.finishInit(this);

    for (var i = 0; i < initHooks.length; ++i) initHooks[i](this);

    endOperation(this);

    // Suppress optimizelegibility in Webkit, since it breaks text

    // measuring on line wrapping boundaries.

    if (webkit && options.lineWrapping &&

        getComputedStyle(display.lineDiv).textRendering == "optimizelegibility")

      display.lineDiv.style.textRendering = "auto";

  }



  // DISPLAY CONSTRUCTOR



  // The display handles the DOM integration, both for input reading

  // and content drawing. It holds references to DOM nodes and

  // display-related state.



  function Display(place, doc, input) {

    var d = this;

    this.input = input;



    // Covers bottom-right square when both scrollbars are present.

    d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");

    d.scrollbarFiller.setAttribute("cm-not-content", "true");

    // Covers bottom of gutter when coverGutterNextToScrollbar is on

    // and h scrollbar is present.

    d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");

    d.gutterFiller.setAttribute("cm-not-content", "true");

    // Will contain the actual code, positioned to cover the viewport.

    d.lineDiv = elt("div", null, "CodeMirror-code");

    // Elements are added to these to represent selection and cursors.

    d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");

    d.cursorDiv = elt("div", null, "CodeMirror-cursors");

    // A visibility: hidden element used to find the size of things.

    d.measure = elt("div", null, "CodeMirror-measure");

    // When lines outside of the viewport are measured, they are drawn in this.

    d.lineMeasure = elt("div", null, "CodeMirror-measure");

    // Wraps everything that needs to exist inside the vertically-padded coordinate system

    d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],

                      null, "position: relative; outline: none");

    // Moved around its parent to cover visible view.

    d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");

    // Set to the height of the document, allowing scrolling.

    d.sizer = elt("div", [d.mover], "CodeMirror-sizer");

    d.sizerWidth = null;

    // Behavior of elts with overflow: auto and padding is

    // inconsistent across browsers. This is used to ensure the

    // scrollable area is big enough.

    d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;");

    // Will contain the gutters, if any.

    d.gutters = elt("div", null, "CodeMirror-gutters");

    d.lineGutter = null;

    // Actual scrollable element.

    d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");

    d.scroller.setAttribute("tabIndex", "-1");

    // The element in which the editor lives.

    d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");



    // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)

    if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }

    if (!webkit && !(gecko && mobile)) d.scroller.draggable = true;



    if (place) {

      if (place.appendChild) place.appendChild(d.wrapper);

      else place(d.wrapper);

    }



    // Current rendered range (may be bigger than the view window).

    d.viewFrom = d.viewTo = doc.first;

    d.reportedViewFrom = d.reportedViewTo = doc.first;

    // Information about the rendered lines.

    d.view = [];

    d.renderedView = null;

    // Holds info about a single rendered line when it was rendered

    // for measurement, while not in view.

    d.externalMeasured = null;

    // Empty space (in pixels) above the view

    d.viewOffset = 0;

    d.lastWrapHeight = d.lastWrapWidth = 0;

    d.updateLineNumbers = null;



    d.nativeBarWidth = d.barHeight = d.barWidth = 0;

    d.scrollbarsClipped = false;



    // Used to only resize the line number gutter when necessary (when

    // the amount of lines crosses a boundary that makes its width change)

    d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;

    // Set to true when a non-horizontal-scrolling line widget is

    // added. As an optimization, line widget aligning is skipped when

    // this is false.

    d.alignWidgets = false;



    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;



    // Tracks the maximum line length so that the horizontal scrollbar

    // can be kept static when scrolling.

    d.maxLine = null;

    d.maxLineLength = 0;

    d.maxLineChanged = false;



    // Used for measuring wheel scrolling granularity

    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;



    // True when shift is held down.

    d.shift = false;



    // Used to track whether anything happened since the context menu

    // was opened.

    d.selForContextMenu = null;



    d.activeTouch = null;



    input.init(d);

  }



  // STATE UPDATES



  // Used to get the editor into a consistent state again when options change.



  function loadMode(cm) {

    cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);

    resetModeState(cm);

  }



  function resetModeState(cm) {

    cm.doc.iter(function(line) {

      if (line.stateAfter) line.stateAfter = null;

      if (line.styles) line.styles = null;

    });

    cm.doc.frontier = cm.doc.first;

    startWorker(cm, 100);

    cm.state.modeGen++;

    if (cm.curOp) regChange(cm);

  }



  function wrappingChanged(cm) {

    if (cm.options.lineWrapping) {

      addClass(cm.display.wrapper, "CodeMirror-wrap");

      cm.display.sizer.style.minWidth = "";

      cm.display.sizerWidth = null;

    } else {

      rmClass(cm.display.wrapper, "CodeMirror-wrap");

      findMaxLine(cm);

    }

    estimateLineHeights(cm);

    regChange(cm);

    clearCaches(cm);

    setTimeout(function(){updateScrollbars(cm);}, 100);

  }



  // Returns a function that estimates the height of a line, to use as

  // first approximation until the line becomes visible (and is thus

  // properly measurable).

  function estimateHeight(cm) {

    var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;

    var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);

    return function(line) {

      if (lineIsHidden(cm.doc, line)) return 0;



      var widgetsHeight = 0;

      if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {

        if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;

      }



      if (wrapping)

        return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;

      else

        return widgetsHeight + th;

    };

  }



  function estimateLineHeights(cm) {

    var doc = cm.doc, est = estimateHeight(cm);

    doc.iter(function(line) {

      var estHeight = est(line);

      if (estHeight != line.height) updateLineHeight(line, estHeight);

    });

  }



  function themeChanged(cm) {

    cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +

      cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");

    clearCaches(cm);

  }



  function guttersChanged(cm) {

    updateGutters(cm);

    regChange(cm);

    setTimeout(function(){alignHorizontally(cm);}, 20);

  }



  // Rebuild the gutter elements, ensure the margin to the left of the

  // code matches their width.

  function updateGutters(cm) {

    var gutters = cm.display.gutters, specs = cm.options.gutters;

    removeChildren(gutters);

    for (var i = 0; i < specs.length; ++i) {

      var gutterClass = specs[i];

      var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));

      if (gutterClass == "CodeMirror-linenumbers") {

        cm.display.lineGutter = gElt;

        gElt.style.width = (cm.display.lineNumWidth || 1) + "px";

      }

    }

    gutters.style.display = i ? "" : "none";

    updateGutterSpace(cm);

  }



  function updateGutterSpace(cm) {

    var width = cm.display.gutters.offsetWidth;

    cm.display.sizer.style.marginLeft = width + "px";

  }



  // Compute the character length of a line, taking into account

  // collapsed ranges (see markText) that might hide parts, and join

  // other lines onto it.

  function lineLength(line) {

    if (line.height == 0) return 0;

    var len = line.text.length, merged, cur = line;

    while (merged = collapsedSpanAtStart(cur)) {

      var found = merged.find(0, true);

      cur = found.from.line;

      len += found.from.ch - found.to.ch;

    }

    cur = line;

    while (merged = collapsedSpanAtEnd(cur)) {

      var found = merged.find(0, true);

      len -= cur.text.length - found.from.ch;

      cur = found.to.line;

      len += cur.text.length - found.to.ch;

    }

    return len;

  }



  // Find the longest line in the document.

  function findMaxLine(cm) {

    var d = cm.display, doc = cm.doc;

    d.maxLine = getLine(doc, doc.first);

    d.maxLineLength = lineLength(d.maxLine);

    d.maxLineChanged = true;

    doc.iter(function(line) {

      var len = lineLength(line);

      if (len > d.maxLineLength) {

        d.maxLineLength = len;

        d.maxLine = line;

      }

    });

  }



  // Make sure the gutters options contains the element

  // "CodeMirror-linenumbers" when the lineNumbers option is true.

  function setGuttersForLineNumbers(options) {

    var found = indexOf(options.gutters, "CodeMirror-linenumbers");

    if (found == -1 && options.lineNumbers) {

      options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);

    } else if (found > -1 && !options.lineNumbers) {

      options.gutters = options.gutters.slice(0);

      options.gutters.splice(found, 1);

    }

  }



  // SCROLLBARS



  // Prepare DOM reads needed to update the scrollbars. Done in one

  // shot to minimize update/measure roundtrips.

  function measureForScrollbars(cm) {

    var d = cm.display, gutterW = d.gutters.offsetWidth;

    var docH = Math.round(cm.doc.height + paddingVert(cm.display));

    return {

      clientHeight: d.scroller.clientHeight,

      viewHeight: d.wrapper.clientHeight,

      scrollWidth: d.scroller.scrollWidth, clientWidth: d.scroller.clientWidth,

      viewWidth: d.wrapper.clientWidth,

      barLeft: cm.options.fixedGutter ? gutterW : 0,

      docHeight: docH,

      scrollHeight: docH + scrollGap(cm) + d.barHeight,

      nativeBarWidth: d.nativeBarWidth,

      gutterWidth: gutterW

    };

  }



  function NativeScrollbars(place, scroll, cm) {

    this.cm = cm;

    var vert = this.vert = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");

    var horiz = this.horiz = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");

    place(vert); place(horiz);



    on(vert, "scroll", function() {

      if (vert.clientHeight) scroll(vert.scrollTop, "vertical");

    });

    on(horiz, "scroll", function() {

      if (horiz.clientWidth) scroll(horiz.scrollLeft, "horizontal");

    });



    this.checkedZeroWidth = false;

    // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).

    if (ie && ie_version < 8) this.horiz.style.minHeight = this.vert.style.minWidth = "18px";

  }



  NativeScrollbars.prototype = copyObj({

    update: function(measure) {

      var needsH = measure.scrollWidth > measure.clientWidth + 1;

      var needsV = measure.scrollHeight > measure.clientHeight + 1;

      var sWidth = measure.nativeBarWidth;



      if (needsV) {

        this.vert.style.display = "block";

        this.vert.style.bottom = needsH ? sWidth + "px" : "0";

        var totalHeight = measure.viewHeight - (needsH ? sWidth : 0);

        // A bug in IE8 can cause this value to be negative, so guard it.

        this.vert.firstChild.style.height =

          Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + "px";

      } else {

        this.vert.style.display = "";

        this.vert.firstChild.style.height = "0";

      }



      if (needsH) {

        this.horiz.style.display = "block";

        this.horiz.style.right = needsV ? sWidth + "px" : "0";

        this.horiz.style.left = measure.barLeft + "px";

        var totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0);

        this.horiz.firstChild.style.width =

          (measure.scrollWidth - measure.clientWidth + totalWidth) + "px";

      } else {

        this.horiz.style.display = "";

        this.horiz.firstChild.style.width = "0";

      }



      if (!this.checkedZeroWidth && measure.clientHeight > 0) {

        if (sWidth == 0) this.zeroWidthHack();

        this.checkedZeroWidth = true;

      }



      return {right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0};

    },

    setScrollLeft: function(pos) {

      if (this.horiz.scrollLeft != pos) this.horiz.scrollLeft = pos;

      if (this.disableHoriz) this.enableZeroWidthBar(this.horiz, this.disableHoriz);

    },

    setScrollTop: function(pos) {

      if (this.vert.scrollTop != pos) this.vert.scrollTop = pos;

      if (this.disableVert) this.enableZeroWidthBar(this.vert, this.disableVert);

    },

    zeroWidthHack: function() {

      var w = mac && !mac_geMountainLion ? "12px" : "18px";

      this.horiz.style.height = this.vert.style.width = w;

      this.horiz.style.pointerEvents = this.vert.style.pointerEvents = "none";

      this.disableHoriz = new Delayed;

      this.disableVert = new Delayed;

    },

    enableZeroWidthBar: function(bar, delay) {

      bar.style.pointerEvents = "auto";

      function maybeDisable() {

        // To find out whether the scrollbar is still visible, we

        // check whether the element under the pixel in the bottom

        // left corner of the scrollbar box is the scrollbar box

        // itself (when the bar is still visible) or its filler child

        // (when the bar is hidden). If it is still visible, we keep

        // it enabled, if it's hidden, we disable pointer events.

        var box = bar.getBoundingClientRect();

        var elt = document.elementFromPoint(box.left + 1, box.bottom - 1);

        if (elt != bar) bar.style.pointerEvents = "none";

        else delay.set(1000, maybeDisable);

      }

      delay.set(1000, maybeDisable);

    },

    clear: function() {

      var parent = this.horiz.parentNode;

      parent.removeChild(this.horiz);

      parent.removeChild(this.vert);

    }

  }, NativeScrollbars.prototype);



  function NullScrollbars() {}



  NullScrollbars.prototype = copyObj({

    update: function() { return {bottom: 0, right: 0}; },

    setScrollLeft: function() {},

    setScrollTop: function() {},

    clear: function() {}

  }, NullScrollbars.prototype);



  CodeMirror.scrollbarModel = {"native": NativeScrollbars, "null": NullScrollbars};



  function initScrollbars(cm) {

    if (cm.display.scrollbars) {

      cm.display.scrollbars.clear();

      if (cm.display.scrollbars.addClass)

        rmClass(cm.display.wrapper, cm.display.scrollbars.addClass);

    }



    cm.display.scrollbars = new CodeMirror.scrollbarModel[cm.options.scrollbarStyle](function(node) {

      cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller);

      // Prevent clicks in the scrollbars from killing focus

      on(node, "mousedown", function() {

        if (cm.state.focused) setTimeout(function() { cm.display.input.focus(); }, 0);

      });

      node.setAttribute("cm-not-content", "true");

    }, function(pos, axis) {

      if (axis == "horizontal") setScrollLeft(cm, pos);

      else setScrollTop(cm, pos);

    }, cm);

    if (cm.display.scrollbars.addClass)

      addClass(cm.display.wrapper, cm.display.scrollbars.addClass);

  }



  function updateScrollbars(cm, measure) {

    if (!measure) measure = measureForScrollbars(cm);

    var startWidth = cm.display.barWidth, startHeight = cm.display.barHeight;

    updateScrollbarsInner(cm, measure);

    for (var i = 0; i < 4 && startWidth != cm.display.barWidth || startHeight != cm.display.barHeight; i++) {

      if (startWidth != cm.display.barWidth && cm.options.lineWrapping)

        updateHeightsInViewport(cm);

      updateScrollbarsInner(cm, measureForScrollbars(cm));

      startWidth = cm.display.barWidth; startHeight = cm.display.barHeight;

    }

  }



  // Re-synchronize the fake scrollbars with the actual size of the

  // content.

  function updateScrollbarsInner(cm, measure) {

    var d = cm.display;

    var sizes = d.scrollbars.update(measure);



    d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px";

    d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px";

    d.heightForcer.style.borderBottom = sizes.bottom + "px solid transparent"



    if (sizes.right && sizes.bottom) {

      d.scrollbarFiller.style.display = "block";

      d.scrollbarFiller.style.height = sizes.bottom + "px";

      d.scrollbarFiller.style.width = sizes.right + "px";

    } else d.scrollbarFiller.style.display = "";

    if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {

      d.gutterFiller.style.display = "block";

      d.gutterFiller.style.height = sizes.bottom + "px";

      d.gutterFiller.style.width = measure.gutterWidth + "px";

    } else d.gutterFiller.style.display = "";

  }



  // Compute the lines that are visible in a given viewport (defaults

  // the the current scroll position). viewport may contain top,

  // height, and ensure (see op.scrollToPos) properties.

  function visibleLines(display, doc, viewport) {

    var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop;

    top = Math.floor(top - paddingTop(display));

    var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight;



    var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);

    // Ensure is a {from: {line, ch}, to: {line, ch}} object, and

    // forces those lines into the viewport (if possible).

    if (viewport && viewport.ensure) {

      var ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line;

      if (ensureFrom < from) {

        from = ensureFrom;

        to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight);

      } else if (Math.min(ensureTo, doc.lastLine()) >= to) {

        from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight);

        to = ensureTo;

      }

    }

    return {from: from, to: Math.max(to, from + 1)};

  }



  // LINE NUMBERS



  // Re-align line numbers and gutter marks to compensate for

  // horizontal scrolling.

  function alignHorizontally(cm) {

    var display = cm.display, view = display.view;

    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;

    var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;

    var gutterW = display.gutters.offsetWidth, left = comp + "px";

    for (var i = 0; i < view.length; i++) if (!view[i].hidden) {

      if (cm.options.fixedGutter) {

        if (view[i].gutter)

          view[i].gutter.style.left = left;

        if (view[i].gutterBackground)

          view[i].gutterBackground.style.left = left;

      }

      var align = view[i].alignable;

      if (align) for (var j = 0; j < align.length; j++)

        align[j].style.left = left;

    }

    if (cm.options.fixedGutter)

      display.gutters.style.left = (comp + gutterW) + "px";

  }



  // Used to ensure that the line number gutter is still the right

  // size for the current document size. Returns true when an update

  // is needed.

  function maybeUpdateLineNumberWidth(cm) {

    if (!cm.options.lineNumbers) return false;

    var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;

    if (last.length != display.lineNumChars) {

      var test = display.measure.appendChild(elt("div", [elt("div", last)],

                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"));

      var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;

      display.lineGutter.style.width = "";

      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1;

      display.lineNumWidth = display.lineNumInnerWidth + padding;

      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;

      display.lineGutter.style.width = display.lineNumWidth + "px";

      updateGutterSpace(cm);

      return true;

    }

    return false;

  }



  function lineNumberFor(options, i) {

    return String(options.lineNumberFormatter(i + options.firstLineNumber));

  }



  // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,

  // but using getBoundingClientRect to get a sub-pixel-accurate

  // result.

  function compensateForHScroll(display) {

    return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;

  }



  // DISPLAY DRAWING



  function DisplayUpdate(cm, viewport, force) {

    var display = cm.display;



    this.viewport = viewport;

    // Store some values that we'll need later (but don't want to force a relayout for)

    this.visible = visibleLines(display, cm.doc, viewport);

    this.editorIsHidden = !display.wrapper.offsetWidth;

    this.wrapperHeight = display.wrapper.clientHeight;

    this.wrapperWidth = display.wrapper.clientWidth;

    this.oldDisplayWidth = displayWidth(cm);

    this.force = force;

    this.dims = getDimensions(cm);

    this.events = [];

  }



  DisplayUpdate.prototype.signal = function(emitter, type) {

    if (hasHandler(emitter, type))

      this.events.push(arguments);

  };

  DisplayUpdate.prototype.finish = function() {

    for (var i = 0; i < this.events.length; i++)

      signal.apply(null, this.events[i]);

  };



  function maybeClipScrollbars(cm) {

    var display = cm.display;

    if (!display.scrollbarsClipped && display.scroller.offsetWidth) {

      display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth;

      display.heightForcer.style.height = scrollGap(cm) + "px";

      display.sizer.style.marginBottom = -display.nativeBarWidth + "px";

      display.sizer.style.borderRightWidth = scrollGap(cm) + "px";

      display.scrollbarsClipped = true;

    }

  }



  // Does the actual updating of the line display. Bails out

  // (returning false) when there is nothing to be done and forced is

  // false.

  function updateDisplayIfNeeded(cm, update) {

    var display = cm.display, doc = cm.doc;



    if (update.editorIsHidden) {

      resetView(cm);

      return false;

    }



    // Bail out if the visible area is already rendered and nothing changed.

    if (!update.force &&

        update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&

        (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&

        display.renderedView == display.view && countDirtyView(cm) == 0)

      return false;



    if (maybeUpdateLineNumberWidth(cm)) {

      resetView(cm);

      update.dims = getDimensions(cm);

    }



    // Compute a suitable new viewport (from & to)

    var end = doc.first + doc.size;

    var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first);

    var to = Math.min(end, update.visible.to + cm.options.viewportMargin);

    if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);

    if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);

    if (sawCollapsedSpans) {

      from = visualLineNo(cm.doc, from);

      to = visualLineEndNo(cm.doc, to);

    }



    var different = from != display.viewFrom || to != display.viewTo ||

      display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth;

    adjustView(cm, from, to);



    display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));

    // Position the mover div to align with the current scroll position

    cm.display.mover.style.top = display.viewOffset + "px";



    var toUpdate = countDirtyView(cm);

    if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view &&

        (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))

      return false;



    // For big changes, we hide the enclosing element during the

    // update, since that speeds up the operations on most browsers.

    var focused = activeElt();

    if (toUpdate > 4) display.lineDiv.style.display = "none";

    patchDisplay(cm, display.updateLineNumbers, update.dims);

    if (toUpdate > 4) display.lineDiv.style.display = "";

    display.renderedView = display.view;

    // There might have been a widget with a focused element that got

    // hidden or updated, if so re-focus it.

    if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();



    // Prevent selection and cursors from interfering with the scroll

    // width and height.

    removeChildren(display.cursorDiv);

    removeChildren(display.selectionDiv);

    display.gutters.style.height = display.sizer.style.minHeight = 0;



    if (different) {

      display.lastWrapHeight = update.wrapperHeight;

      display.lastWrapWidth = update.wrapperWidth;

      startWorker(cm, 400);

    }



    display.updateLineNumbers = null;



    return true;

  }



  function postUpdateDisplay(cm, update) {

    var viewport = update.viewport;



    for (var first = true;; first = false) {

      if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {

        // Clip forced viewport to actual scrollable area.

        if (viewport && viewport.top != null)

          viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top)};

        // Updated line heights might result in the drawn area not

        // actually covering the viewport. Keep looping until it does.

        update.visible = visibleLines(cm.display, cm.doc, viewport);

        if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)

          break;

      }

      if (!updateDisplayIfNeeded(cm, update)) break;

      updateHeightsInViewport(cm);

      var barMeasure = measureForScrollbars(cm);

      updateSelection(cm);

      updateScrollbars(cm, barMeasure);

      setDocumentHeight(cm, barMeasure);

    }



    update.signal(cm, "update", cm);

    if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {

      update.signal(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);

      cm.display.reportedViewFrom = cm.display.viewFrom; cm.display.reportedViewTo = cm.display.viewTo;

    }

  }



  function updateDisplaySimple(cm, viewport) {

    var update = new DisplayUpdate(cm, viewport);

    if (updateDisplayIfNeeded(cm, update)) {

      updateHeightsInViewport(cm);

      postUpdateDisplay(cm, update);

      var barMeasure = measureForScrollbars(cm);

      updateSelection(cm);

      updateScrollbars(cm, barMeasure);

      setDocumentHeight(cm, barMeasure);

      update.finish();

    }

  }



  function setDocumentHeight(cm, measure) {

    cm.display.sizer.style.minHeight = measure.docHeight + "px";

    cm.display.heightForcer.style.top = measure.docHeight + "px";

    cm.display.gutters.style.height = (measure.docHeight + cm.display.barHeight + scrollGap(cm)) + "px";

  }



  // Read the actual heights of the rendered lines, and update their

  // stored heights to match.

  function updateHeightsInViewport(cm) {

    var display = cm.display;

    var prevBottom = display.lineDiv.offsetTop;

    for (var i = 0; i < display.view.length; i++) {

      var cur = display.view[i], height;

      if (cur.hidden) continue;

      if (ie && ie_version < 8) {

        var bot = cur.node.offsetTop + cur.node.offsetHeight;

        height = bot - prevBottom;

        prevBottom = bot;

      } else {

        var box = cur.node.getBoundingClientRect();

        height = box.bottom - box.top;

      }

      var diff = cur.line.height - height;

      if (height < 2) height = textHeight(display);

      if (diff > .001 || diff < -.001) {

        updateLineHeight(cur.line, height);

        updateWidgetHeight(cur.line);

        if (cur.rest) for (var j = 0; j < cur.rest.length; j++)

          updateWidgetHeight(cur.rest[j]);

      }

    }

  }



  // Read and store the height of line widgets associated with the

  // given line.

  function updateWidgetHeight(line) {

    if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)

      line.widgets[i].height = line.widgets[i].node.parentNode.offsetHeight;

  }



  // Do a bulk-read of the DOM positions and sizes needed to draw the

  // view, so that we don't interleave reading and writing to the DOM.

  function getDimensions(cm) {

    var d = cm.display, left = {}, width = {};

    var gutterLeft = d.gutters.clientLeft;

    for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {

      left[cm.options.gutters[i]] = n.offsetLeft + n.clientLeft + gutterLeft;

      width[cm.options.gutters[i]] = n.clientWidth;

    }

    return {fixedPos: compensateForHScroll(d),

            gutterTotalWidth: d.gutters.offsetWidth,

            gutterLeft: left,

            gutterWidth: width,

            wrapperWidth: d.wrapper.clientWidth};

  }



  // Sync the actual display DOM structure with display.view, removing

  // nodes for lines that are no longer in view, and creating the ones

  // that are not there yet, and updating the ones that are out of

  // date.

  function patchDisplay(cm, updateNumbersFrom, dims) {

    var display = cm.display, lineNumbers = cm.options.lineNumbers;

    var container = display.lineDiv, cur = container.firstChild;



    function rm(node) {

      var next = node.nextSibling;

      // Works around a throw-scroll bug in OS X Webkit

      if (webkit && mac && cm.display.currentWheelTarget == node)

        node.style.display = "none";

      else

        node.parentNode.removeChild(node);

      return next;

    }



    var view = display.view, lineN = display.viewFrom;

    // Loop over the elements in the view, syncing cur (the DOM nodes

    // in display.lineDiv) with the view as we go.

    for (var i = 0; i < view.length; i++) {

      var lineView = view[i];

      if (lineView.hidden) {

      } else if (!lineView.node || lineView.node.parentNode != container) { // Not drawn yet

        var node = buildLineElement(cm, lineView, lineN, dims);

        container.insertBefore(node, cur);

      } else { // Already drawn

        while (cur != lineView.node) cur = rm(cur);

        var updateNumber = lineNumbers && updateNumbersFrom != null &&

          updateNumbersFrom <= lineN && lineView.lineNumber;

        if (lineView.changes) {

          if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;

          updateLineForChanges(cm, lineView, lineN, dims);

        }

        if (updateNumber) {

          removeChildren(lineView.lineNumber);

          lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));

        }

        cur = lineView.node.nextSibling;

      }

      lineN += lineView.size;

    }

    while (cur) cur = rm(cur);

  }



  // When an aspect of a line changes, a string is added to

  // lineView.changes. This updates the relevant part of the line's

  // DOM structure.

  function updateLineForChanges(cm, lineView, lineN, dims) {

    for (var j = 0; j < lineView.changes.length; j++) {

      var type = lineView.changes[j];

      if (type == "text") updateLineText(cm, lineView);

      else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);

      else if (type == "class") updateLineClasses(lineView);

      else if (type == "widget") updateLineWidgets(cm, lineView, dims);

    }

    lineView.changes = null;

  }



  // Lines with gutter elements, widgets or a background class need to

  // be wrapped, and have the extra elements added to the wrapper div

  function ensureLineWrapped(lineView) {

    if (lineView.node == lineView.text) {

      lineView.node = elt("div", null, null, "position: relative");

      if (lineView.text.parentNode)

        lineView.text.parentNode.replaceChild(lineView.node, lineView.text);

      lineView.node.appendChild(lineView.text);

      if (ie && ie_version < 8) lineView.node.style.zIndex = 2;

    }

    return lineView.node;

  }



  function updateLineBackground(lineView) {

    var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;

    if (cls) cls += " CodeMirror-linebackground";

    if (lineView.background) {

      if (cls) lineView.background.className = cls;

      else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }

    } else if (cls) {

      var wrap = ensureLineWrapped(lineView);

      lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);

    }

  }



  // Wrapper around buildLineContent which will reuse the structure

  // in display.externalMeasured when possible.

  function getLineContent(cm, lineView) {

    var ext = cm.display.externalMeasured;

    if (ext && ext.line == lineView.line) {

      cm.display.externalMeasured = null;

      lineView.measure = ext.measure;

      return ext.built;

    }

    return buildLineContent(cm, lineView);

  }



  // Redraw the line's text. Interacts with the background and text

  // classes because the mode may output tokens that influence these

  // classes.

  function updateLineText(cm, lineView) {

    var cls = lineView.text.className;

    var built = getLineContent(cm, lineView);

    if (lineView.text == lineView.node) lineView.node = built.pre;

    lineView.text.parentNode.replaceChild(built.pre, lineView.text);

    lineView.text = built.pre;

    if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {

      lineView.bgClass = built.bgClass;

      lineView.textClass = built.textClass;

      updateLineClasses(lineView);

    } else if (cls) {

      lineView.text.className = cls;

    }

  }



  function updateLineClasses(lineView) {

    updateLineBackground(lineView);

    if (lineView.line.wrapClass)

      ensureLineWrapped(lineView).className = lineView.line.wrapClass;

    else if (lineView.node != lineView.text)

      lineView.node.className = "";

    var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;

    lineView.text.className = textClass || "";

  }



  function updateLineGutter(cm, lineView, lineN, dims) {

    if (lineView.gutter) {

      lineView.node.removeChild(lineView.gutter);

      lineView.gutter = null;

    }

    if (lineView.gutterBackground) {

      lineView.node.removeChild(lineView.gutterBackground);

      lineView.gutterBackground = null;

    }

    if (lineView.line.gutterClass) {

      var wrap = ensureLineWrapped(lineView);

      lineView.gutterBackground = elt("div", null, "CodeMirror-gutter-background " + lineView.line.gutterClass,

                                      "left: " + (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) +

                                      "px; width: " + dims.gutterTotalWidth + "px");

      wrap.insertBefore(lineView.gutterBackground, lineView.text);

    }

    var markers = lineView.line.gutterMarkers;

    if (cm.options.lineNumbers || markers) {

      var wrap = ensureLineWrapped(lineView);

      var gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", "left: " +

                                             (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px");

      cm.display.input.setUneditable(gutterWrap);

      wrap.insertBefore(gutterWrap, lineView.text);

      if (lineView.line.gutterClass)

        gutterWrap.className += " " + lineView.line.gutterClass;

      if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))

        lineView.lineNumber = gutterWrap.appendChild(

          elt("div", lineNumberFor(cm.options, lineN),

              "CodeMirror-linenumber CodeMirror-gutter-elt",

              "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "

              + cm.display.lineNumInnerWidth + "px"));

      if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {

        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];

        if (found)

          gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +

                                     dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));

      }

    }

  }



  function updateLineWidgets(cm, lineView, dims) {

    if (lineView.alignable) lineView.alignable = null;

    for (var node = lineView.node.firstChild, next; node; node = next) {

      var next = node.nextSibling;

      if (node.className == "CodeMirror-linewidget")

        lineView.node.removeChild(node);

    }

    insertLineWidgets(cm, lineView, dims);

  }



  // Build a line's DOM representation from scratch

  function buildLineElement(cm, lineView, lineN, dims) {

    var built = getLineContent(cm, lineView);

    lineView.text = lineView.node = built.pre;

    if (built.bgClass) lineView.bgClass = built.bgClass;

    if (built.textClass) lineView.textClass = built.textClass;



    updateLineClasses(lineView);

    updateLineGutter(cm, lineView, lineN, dims);

    insertLineWidgets(cm, lineView, dims);

    return lineView.node;

  }



  // A lineView may contain multiple logical lines (when merged by

  // collapsed spans). The widgets for all of them need to be drawn.

  function insertLineWidgets(cm, lineView, dims) {

    insertLineWidgetsFor(cm, lineView.line, lineView, dims, true);

    if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)

      insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false);

  }



  function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {

    if (!line.widgets) return;

    var wrap = ensureLineWrapped(lineView);

    for (var i = 0, ws = line.widgets; i < ws.length; ++i) {

      var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");

      if (!widget.handleMouseEvents) node.setAttribute("cm-ignore-events", "true");

      positionLineWidget(widget, node, lineView, dims);

      cm.display.input.setUneditable(node);

      if (allowAbove && widget.above)

        wrap.insertBefore(node, lineView.gutter || lineView.text);

      else

        wrap.appendChild(node);

      signalLater(widget, "redraw");

    }

  }



  function positionLineWidget(widget, node, lineView, dims) {

    if (widget.noHScroll) {

      (lineView.alignable || (lineView.alignable = [])).push(node);

      var width = dims.wrapperWidth;

      node.style.left = dims.fixedPos + "px";

      if (!widget.coverGutter) {

        width -= dims.gutterTotalWidth;

        node.style.paddingLeft = dims.gutterTotalWidth + "px";

      }

      node.style.width = width + "px";

    }

    if (widget.coverGutter) {

      node.style.zIndex = 5;

      node.style.position = "relative";

      if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";

    }

  }



  // POSITION OBJECT



  // A Pos instance represents a position within the text.

  var Pos = CodeMirror.Pos = function(line, ch) {

    if (!(this instanceof Pos)) return new Pos(line, ch);

    this.line = line; this.ch = ch;

  };



  // Compare two positions, return 0 if they are the same, a negative

  // number when a is less, and a positive number otherwise.

  var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };



  function copyPos(x) {return Pos(x.line, x.ch);}

  function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }

  function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }



  // INPUT HANDLING



  function ensureFocus(cm) {

    if (!cm.state.focused) { cm.display.input.focus(); onFocus(cm); }

  }



  // This will be set to a {lineWise: bool, text: [string]} object, so

  // that, when pasting, we know what kind of selections the copied

  // text was made out of.

  var lastCopied = null;



  function applyTextInput(cm, inserted, deleted, sel, origin) {

    var doc = cm.doc;

    cm.display.shift = false;

    if (!sel) sel = doc.sel;



    var paste = cm.state.pasteIncoming || origin == "paste";

    var textLines = doc.splitLines(inserted), multiPaste = null

    // When pasing N lines into N selections, insert one line per selection

    if (paste && sel.ranges.length > 1) {

      if (lastCopied && lastCopied.text.join("\n") == inserted) {

        if (sel.ranges.length % lastCopied.text.length == 0) {

          multiPaste = [];

          for (var i = 0; i < lastCopied.text.length; i++)

            multiPaste.push(doc.splitLines(lastCopied.text[i]));

        }

      } else if (textLines.length == sel.ranges.length) {

        multiPaste = map(textLines, function(l) { return [l]; });

      }

    }



    // Normal behavior is to insert the new text into every selection

    for (var i = sel.ranges.length - 1; i >= 0; i--) {

      var range = sel.ranges[i];

      var from = range.from(), to = range.to();

      if (range.empty()) {

        if (deleted && deleted > 0) // Handle deletion

          from = Pos(from.line, from.ch - deleted);

        else if (cm.state.overwrite && !paste) // Handle overwrite

          to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));

        else if (lastCopied && lastCopied.lineWise && lastCopied.text.join("\n") == inserted)

          from = to = Pos(from.line, 0)

      }

      var updateInput = cm.curOp.updateInput;

      var changeEvent = {from: from, to: to, text: multiPaste ? multiPaste[i % multiPaste.length] : textLines,

                         origin: origin || (paste ? "paste" : cm.state.cutIncoming ? "cut" : "+input")};

      makeChange(cm.doc, changeEvent);

      signalLater(cm, "inputRead", cm, changeEvent);

    }

    if (inserted && !paste)

      triggerElectric(cm, inserted);



    ensureCursorVisible(cm);

    cm.curOp.updateInput = updateInput;

    cm.curOp.typing = true;

    cm.state.pasteIncoming = cm.state.cutIncoming = false;

  }



  function handlePaste(e, cm) {

    var pasted = e.clipboardData && e.clipboardData.getData("Text");

    if (pasted) {

      e.preventDefault();

      if (!cm.isReadOnly() && !cm.options.disableInput)

        runInOp(cm, function() { applyTextInput(cm, pasted, 0, null, "paste"); });

      return true;

    }

  }



  function triggerElectric(cm, inserted) {

    // When an 'electric' character is inserted, immediately trigger a reindent

    if (!cm.options.electricChars || !cm.options.smartIndent) return;

    var sel = cm.doc.sel;



    for (var i = sel.ranges.length - 1; i >= 0; i--) {

      var range = sel.ranges[i];

      if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) continue;

      var mode = cm.getModeAt(range.head);

      var indented = false;

      if (mode.electricChars) {

        for (var j = 0; j < mode.electricChars.length; j++)

          if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {

            indented = indentLine(cm, range.head.line, "smart");

            break;

          }

      } else if (mode.electricInput) {

        if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch)))

          indented = indentLine(cm, range.head.line, "smart");

      }

      if (indented) signalLater(cm, "electricInput", cm, range.head.line);

    }

  }



  function copyableRanges(cm) {

    var text = [], ranges = [];

    for (var i = 0; i < cm.doc.sel.ranges.length; i++) {

      var line = cm.doc.sel.ranges[i].head.line;

      var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};

      ranges.push(lineRange);

      text.push(cm.getRange(lineRange.anchor, lineRange.head));

    }

    return {text: text, ranges: ranges};

  }



  function disableBrowserMagic(field, spellcheck) {

    field.setAttribute("autocorrect", "off");

    field.setAttribute("autocapitalize", "off");

    field.setAttribute("spellcheck", !!spellcheck);

  }



  // TEXTAREA INPUT STYLE



  function TextareaInput(cm) {

    this.cm = cm;

    // See input.poll and input.reset

    this.prevInput = "";



    // Flag that indicates whether we expect input to appear real soon

    // now (after some event like 'keypress' or 'input') and are

    // polling intensively.

    this.pollingFast = false;

    // Self-resetting timeout for the poller

    this.polling = new Delayed();

    // Tracks when input.reset has punted to just putting a short

    // string into the textarea instead of the full selection.

    this.inaccurateSelection = false;

    // Used to work around IE issue with selection being forgotten when focus moves away from textarea

    this.hasSelection = false;

    this.composing = null;

  };



  function hiddenTextarea() {

    var te = elt("textarea", null, null, "position: absolute; bottom: -1em; padding: 0; width: 1px; height: 1em; outline: none");

    var div = elt("div", [te], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");

    // The textarea is kept positioned near the cursor to prevent the

    // fact that it'll be scrolled into view on input from scrolling

    // our fake cursor out of view. On webkit, when wrap=off, paste is

    // very slow. So make the area wide instead.

    if (webkit) te.style.width = "1000px";

    else te.setAttribute("wrap", "off");

    // If border: 0; -- iOS fails to open keyboard (issue #1287)

    if (ios) te.style.border = "1px solid black";

    disableBrowserMagic(te);

    return div;

  }



  TextareaInput.prototype = copyObj({

    init: function(display) {

      var input = this, cm = this.cm;



      // Wraps and hides input textarea

      var div = this.wrapper = hiddenTextarea();

      // The semihidden textarea that is focused when the editor is

      // focused, and receives input.

      var te = this.textarea = div.firstChild;

      display.wrapper.insertBefore(div, display.wrapper.firstChild);



      // Needed to hide big blue blinking cursor on Mobile Safari (doesn't seem to work in iOS 8 anymore)

      if (ios) te.style.width = "0px";



      on(te, "input", function() {

        if (ie && ie_version >= 9 && input.hasSelection) input.hasSelection = null;

        input.poll();

      });



      on(te, "paste", function(e) {

        if (signalDOMEvent(cm, e) || handlePaste(e, cm)) return



        cm.state.pasteIncoming = true;

        input.fastPoll();

      });



      function prepareCopyCut(e) {

        if (signalDOMEvent(cm, e)) return

        if (cm.somethingSelected()) {

          lastCopied = {lineWise: false, text: cm.getSelections()};

          if (input.inaccurateSelection) {

            input.prevInput = "";

            input.inaccurateSelection = false;

            te.value = lastCopied.text.join("\n");

            selectInput(te);

          }

        } else if (!cm.options.lineWiseCopyCut) {

          return;

        } else {

          var ranges = copyableRanges(cm);

          lastCopied = {lineWise: true, text: ranges.text};

          if (e.type == "cut") {

            cm.setSelections(ranges.ranges, null, sel_dontScroll);

          } else {

            input.prevInput = "";

            te.value = ranges.text.join("\n");

            selectInput(te);

          }

        }

        if (e.type == "cut") cm.state.cutIncoming = true;

      }

      on(te, "cut", prepareCopyCut);

      on(te, "copy", prepareCopyCut);



      on(display.scroller, "paste", function(e) {

        if (eventInWidget(display, e) || signalDOMEvent(cm, e)) return;

        cm.state.pasteIncoming = true;

        input.focus();

      });



      // Prevent normal selection in the editor (we handle our own)

      on(display.lineSpace, "selectstart", function(e) {

        if (!eventInWidget(display, e)) e_preventDefault(e);

      });



      on(te, "compositionstart", function() {

        var start = cm.getCursor("from");

        if (input.composing) input.composing.range.clear()

        input.composing = {

          start: start,

          range: cm.markText(start, cm.getCursor("to"), {className: "CodeMirror-composing"})

        };

      });

      on(te, "compositionend", function() {

        if (input.composing) {

          input.poll();

          input.composing.range.clear();

          input.composing = null;

        }

      });

    },



    prepareSelection: function() {

      // Redraw the selection and/or cursor

      var cm = this.cm, display = cm.display, doc = cm.doc;

      var result = prepareSelection(cm);



      // Move the hidden textarea near the cursor to prevent scrolling artifacts

      if (cm.options.moveInputWithCursor) {

        var headPos = cursorCoords(cm, doc.sel.primary().head, "div");

        var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();

        result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10,

                                            headPos.top + lineOff.top - wrapOff.top));

        result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10,

                                             headPos.left + lineOff.left - wrapOff.left));

      }



      return result;

    },



    showSelection: function(drawn) {

      var cm = this.cm, display = cm.display;

      removeChildrenAndAdd(display.cursorDiv, drawn.cursors);

      removeChildrenAndAdd(display.selectionDiv, drawn.selection);

      if (drawn.teTop != null) {

        this.wrapper.style.top = drawn.teTop + "px";

        this.wrapper.style.left = drawn.teLeft + "px";

      }

    },



    // Reset the input to correspond to the selection (or to be empty,

    // when not typing and nothing is selected)

    reset: function(typing) {

      if (this.contextMenuPending) return;

      var minimal, selected, cm = this.cm, doc = cm.doc;

      if (cm.somethingSelected()) {

        this.prevInput = "";

        var range = doc.sel.primary();

        minimal = hasCopyEvent &&

          (range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);

        var content = minimal ? "-" : selected || cm.getSelection();

        this.textarea.value = content;

        if (cm.state.focused) selectInput(this.textarea);

        if (ie && ie_version >= 9) this.hasSelection = content;

      } else if (!typing) {

        this.prevInput = this.textarea.value = "";

        if (ie && ie_version >= 9) this.hasSelection = null;

      }

      this.inaccurateSelection = minimal;

    },



    getField: function() { return this.textarea; },



    supportsTouch: function() { return false; },



    focus: function() {

      if (this.cm.options.readOnly != "nocursor" && (!mobile || activeElt() != this.textarea)) {

        try { this.textarea.focus(); }

        catch (e) {} // IE8 will throw if the textarea is display: none or not in DOM

      }

    },



    blur: function() { this.textarea.blur(); },



    resetPosition: function() {

      this.wrapper.style.top = this.wrapper.style.left = 0;

    },



    receivedFocus: function() { this.slowPoll(); },



    // Poll for input changes, using the normal rate of polling. This

    // runs as long as the editor is focused.

    slowPoll: function() {

      var input = this;

      if (input.pollingFast) return;

      input.polling.set(this.cm.options.pollInterval, function() {

        input.poll();

        if (input.cm.state.focused) input.slowPoll();

      });

    },



    // When an event has just come in that is likely to add or change

    // something in the input textarea, we poll faster, to ensure that

    // the change appears on the screen quickly.

    fastPoll: function() {

      var missed = false, input = this;

      input.pollingFast = true;

      function p() {

        var changed = input.poll();

        if (!changed && !missed) {missed = true; input.polling.set(60, p);}

        else {input.pollingFast = false; input.slowPoll();}

      }

      input.polling.set(20, p);

    },



    // Read input from the textarea, and update the document to match.

    // When something is selected, it is present in the textarea, and

    // selected (unless it is huge, in which case a placeholder is

    // used). When nothing is selected, the cursor sits after previously

    // seen text (can be empty), which is stored in prevInput (we must

    // not reset the textarea when typing, because that breaks IME).

    poll: function() {

      var cm = this.cm, input = this.textarea, prevInput = this.prevInput;

      // Since this is called a *lot*, try to bail out as cheaply as

      // possible when it is clear that nothing happened. hasSelection

      // will be the case when there is a lot of text in the textarea,

      // in which case reading its value would be expensive.

      if (this.contextMenuPending || !cm.state.focused ||

          (hasSelection(input) && !prevInput && !this.composing) ||

          cm.isReadOnly() || cm.options.disableInput || cm.state.keySeq)

        return false;



      var text = input.value;

      // If nothing changed, bail.

      if (text == prevInput && !cm.somethingSelected()) return false;

      // Work around nonsensical selection resetting in IE9/10, and

      // inexplicable appearance of private area unicode characters on

      // some key combos in Mac (#2689).

      if (ie && ie_version >= 9 && this.hasSelection === text ||

          mac && /[\uf700-\uf7ff]/.test(text)) {

        cm.display.input.reset();

        return false;

      }



      if (cm.doc.sel == cm.display.selForContextMenu) {

        var first = text.charCodeAt(0);

        if (first == 0x200b && !prevInput) prevInput = "\u200b";

        if (first == 0x21da) { this.reset(); return this.cm.execCommand("undo"); }

      }

      // Find the part of the input that is actually new

      var same = 0, l = Math.min(prevInput.length, text.length);

      while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;



      var self = this;

      runInOp(cm, function() {

        applyTextInput(cm, text.slice(same), prevInput.length - same,

                       null, self.composing ? "*compose" : null);



        // Don't leave long text in the textarea, since it makes further polling slow

        if (text.length > 1000 || text.indexOf("\n") > -1) input.value = self.prevInput = "";

        else self.prevInput = text;



        if (self.composing) {

          self.composing.range.clear();

          self.composing.range = cm.markText(self.composing.start, cm.getCursor("to"),

                                             {className: "CodeMirror-composing"});

        }

      });

      return true;

    },



    ensurePolled: function() {

      if (this.pollingFast && this.poll()) this.pollingFast = false;

    },



    onKeyPress: function() {

      if (ie && ie_version >= 9) this.hasSelection = null;

      this.fastPoll();

    },



    onContextMenu: function(e) {

      var input = this, cm = input.cm, display = cm.display, te = input.textarea;

      var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;

      if (!pos || presto) return; // Opera is difficult.



      // Reset the current text selection only if the click is done outside of the selection

      // and 'resetSelectionOnContextMenu' option is true.

      var reset = cm.options.resetSelectionOnContextMenu;

      if (reset && cm.doc.sel.contains(pos) == -1)

        operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll);



      var oldCSS = te.style.cssText, oldWrapperCSS = input.wrapper.style.cssText;

      input.wrapper.style.cssText = "position: absolute"

      var wrapperBox = input.wrapper.getBoundingClientRect()

      te.style.cssText = "position: absolute; width: 30px; height: 30px; top: " + (e.clientY - wrapperBox.top - 5) +

        "px; left: " + (e.clientX - wrapperBox.left - 5) + "px; z-index: 1000; background: " +

        (ie ? "rgba(255, 255, 255, .05)" : "transparent") +

        "; outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";

      if (webkit) var oldScrollY = window.scrollY; // Work around Chrome issue (#2712)

      display.input.focus();

      if (webkit) window.scrollTo(null, oldScrollY);

      display.input.reset();

      // Adds "Select all" to context menu in FF

      if (!cm.somethingSelected()) te.value = input.prevInput = " ";

      input.contextMenuPending = true;

      display.selForContextMenu = cm.doc.sel;

      clearTimeout(display.detectingSelectAll);



      // Select-all will be greyed out if there's nothing to select, so

      // this adds a zero-width space so that we can later check whether

      // it got selected.

      function prepareSelectAllHack() {

        if (te.selectionStart != null) {

          var selected = cm.somethingSelected();

          var extval = "\u200b" + (selected ? te.value : "");

          te.value = "\u21da"; // Used to catch context-menu undo

          te.value = extval;

          input.prevInput = selected ? "" : "\u200b";

          te.selectionStart = 1; te.selectionEnd = extval.length;

          // Re-set this, in case some other handler touched the

          // selection in the meantime.

          display.selForContextMenu = cm.doc.sel;

        }

      }

      function rehide() {

        input.contextMenuPending = false;

        input.wrapper.style.cssText = oldWrapperCSS

        te.style.cssText = oldCSS;

        if (ie && ie_version < 9) display.scrollbars.setScrollTop(display.scroller.scrollTop = scrollPos);



        // Try to detect the user choosing select-all

        if (te.selectionStart != null) {

          if (!ie || (ie && ie_version < 9)) prepareSelectAllHack();

          var i = 0, poll = function() {

            if (display.selForContextMenu == cm.doc.sel && te.selectionStart == 0 &&

                te.selectionEnd > 0 && input.prevInput == "\u200b")

              operation(cm, commands.selectAll)(cm);

            else if (i++ < 10) display.detectingSelectAll = setTimeout(poll, 500);

            else display.input.reset();

          };

          display.detectingSelectAll = setTimeout(poll, 200);

        }

      }



      if (ie && ie_version >= 9) prepareSelectAllHack();

      if (captureRightClick) {

        e_stop(e);

        var mouseup = function() {

          off(window, "mouseup", mouseup);

          setTimeout(rehide, 20);

        };

        on(window, "mouseup", mouseup);

      } else {

        setTimeout(rehide, 50);

      }

    },



    readOnlyChanged: function(val) {

      if (!val) this.reset();

    },



    setUneditable: nothing,



    needsContentAttribute: false

  }, TextareaInput.prototype);



  // CONTENTEDITABLE INPUT STYLE



  function ContentEditableInput(cm) {

    this.cm = cm;

    this.lastAnchorNode = this.lastAnchorOffset = this.lastFocusNode = this.lastFocusOffset = null;

    this.polling = new Delayed();

    this.gracePeriod = false;

  }



  ContentEditableInput.prototype = copyObj({

    init: function(display) {

      var input = this, cm = input.cm;

      var div = input.div = display.lineDiv;

      disableBrowserMagic(div, cm.options.spellcheck);



      on(div, "paste", function(e) {

        if (signalDOMEvent(cm, e) || handlePaste(e, cm)) return

        // IE doesn't fire input events, so we schedule a read for the pasted content in this way

        if (ie_version <= 11) setTimeout(operation(cm, function() {

          if (!input.pollContent()) regChange(cm);

        }), 20)

      })



      on(div, "compositionstart", function(e) {

        var data = e.data;

        input.composing = {sel: cm.doc.sel, data: data, startData: data};

        if (!data) return;

        var prim = cm.doc.sel.primary();

        var line = cm.getLine(prim.head.line);

        var found = line.indexOf(data, Math.max(0, prim.head.ch - data.length));

        if (found > -1 && found <= prim.head.ch)

          input.composing.sel = simpleSelection(Pos(prim.head.line, found),

                                                Pos(prim.head.line, found + data.length));

      });

      on(div, "compositionupdate", function(e) {

        input.composing.data = e.data;

      });

      on(div, "compositionend", function(e) {

        var ours = input.composing;

        if (!ours) return;

        if (e.data != ours.startData && !/\u200b/.test(e.data))

          ours.data = e.data;

        // Need a small delay to prevent other code (input event,

        // selection polling) from doing damage when fired right after

        // compositionend.

        setTimeout(function() {

          if (!ours.handled)

            input.applyComposition(ours);

          if (input.composing == ours)

            input.composing = null;

        }, 50);

      });



      on(div, "touchstart", function() {

        input.forceCompositionEnd();

      });



      on(div, "input", function() {

        if (input.composing) return;

        if (cm.isReadOnly() || !input.pollContent())

          runInOp(input.cm, function() {regChange(cm);});

      });



      function onCopyCut(e) {

        if (signalDOMEvent(cm, e)) return

        if (cm.somethingSelected()) {

          lastCopied = {lineWise: false, text: cm.getSelections()};

          if (e.type == "cut") cm.replaceSelection("", null, "cut");

        } else if (!cm.options.lineWiseCopyCut) {

          return;

        } else {

          var ranges = copyableRanges(cm);

          lastCopied = {lineWise: true, text: ranges.text};

          if (e.type == "cut") {

            cm.operation(function() {

              cm.setSelections(ranges.ranges, 0, sel_dontScroll);

              cm.replaceSelection("", null, "cut");

            });

          }

        }

        if (e.clipboardData) {

          e.clipboardData.clearData();

          var content = lastCopied.text.join("\n")

          // iOS exposes the clipboard API, but seems to discard content inserted into it

          e.clipboardData.setData("Text", content);

          if (e.clipboardData.getData("Text") == content) {

            e.preventDefault();

            return

          }

        }

        // Old-fashioned briefly-focus-a-textarea hack

        var kludge = hiddenTextarea(), te = kludge.firstChild;

        cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild);

        te.value = lastCopied.text.join("\n");

        var hadFocus = document.activeElement;

        selectInput(te);

        setTimeout(function() {

          cm.display.lineSpace.removeChild(kludge);

          hadFocus.focus();

          if (hadFocus == div) input.showPrimarySelection()

        }, 50);

      }

      on(div, "copy", onCopyCut);

      on(div, "cut", onCopyCut);

    },



    prepareSelection: function() {

      var result = prepareSelection(this.cm, false);

      result.focus = this.cm.state.focused;

      return result;

    },



    showSelection: function(info, takeFocus) {

      if (!info || !this.cm.display.view.length) return;

      if (info.focus || takeFocus) this.showPrimarySelection();

      this.showMultipleSelections(info);

    },



    showPrimarySelection: function() {

      var sel = window.getSelection(), prim = this.cm.doc.sel.primary();

      var curAnchor = domToPos(this.cm, sel.anchorNode, sel.anchorOffset);

      var curFocus = domToPos(this.cm, sel.focusNode, sel.focusOffset);

      if (curAnchor && !curAnchor.bad && curFocus && !curFocus.bad &&

          cmp(minPos(curAnchor, curFocus), prim.from()) == 0 &&

          cmp(maxPos(curAnchor, curFocus), prim.to()) == 0)

        return;



      var start = posToDOM(this.cm, prim.from());

      var end = posToDOM(this.cm, prim.to());

      if (!start && !end) return;



      var view = this.cm.display.view;

      var old = sel.rangeCount && sel.getRangeAt(0);

      if (!start) {

        start = {node: view[0].measure.map[2], offset: 0};

      } else if (!end) { // FIXME dangerously hacky

        var measure = view[view.length - 1].measure;

        var map = measure.maps ? measure.maps[measure.maps.length - 1] : measure.map;

        end = {node: map[map.length - 1], offset: map[map.length - 2] - map[map.length - 3]};

      }



      try { var rng = range(start.node, start.offset, end.offset, end.node); }

      catch(e) {} // Our model of the DOM might be outdated, in which case the range we try to set can be impossible

      if (rng) {

        if (!gecko && this.cm.state.focused) {

          sel.collapse(start.node, start.offset);

          if (!rng.collapsed) sel.addRange(rng);

        } else {

          sel.removeAllRanges();

          sel.addRange(rng);

        }

        if (old && sel.anchorNode == null) sel.addRange(old);

        else if (gecko) this.startGracePeriod();

      }

      this.rememberSelection();

    },



    startGracePeriod: function() {

      var input = this;

      clearTimeout(this.gracePeriod);

      this.gracePeriod = setTimeout(function() {

        input.gracePeriod = false;

        if (input.selectionChanged())

          input.cm.operation(function() { input.cm.curOp.selectionChanged = true; });

      }, 20);

    },



    showMultipleSelections: function(info) {

      removeChildrenAndAdd(this.cm.display.cursorDiv, info.cursors);

      removeChildrenAndAdd(this.cm.display.selectionDiv, info.selection);

    },



    rememberSelection: function() {

      var sel = window.getSelection();

      this.lastAnchorNode = sel.anchorNode; this.lastAnchorOffset = sel.anchorOffset;

      this.lastFocusNode = sel.focusNode; this.lastFocusOffset = sel.focusOffset;

    },



    selectionInEditor: function() {

      var sel = window.getSelection();

      if (!sel.rangeCount) return false;

      var node = sel.getRangeAt(0).commonAncestorContainer;

      return contains(this.div, node);

    },



    focus: function() {

      if (this.cm.options.readOnly != "nocursor") this.div.focus();

    },

    blur: function() { this.div.blur(); },

    getField: function() { return this.div; },



    supportsTouch: function() { return true; },



    receivedFocus: function() {

      var input = this;

      if (this.selectionInEditor())

        this.pollSelection();

      else

        runInOp(this.cm, function() { input.cm.curOp.selectionChanged = true; });



      function poll() {

        if (input.cm.state.focused) {

          input.pollSelection();

          input.polling.set(input.cm.options.pollInterval, poll);

        }

      }

      this.polling.set(this.cm.options.pollInterval, poll);

    },



    selectionChanged: function() {

      var sel = window.getSelection();

      return sel.anchorNode != this.lastAnchorNode || sel.anchorOffset != this.lastAnchorOffset ||

        sel.focusNode != this.lastFocusNode || sel.focusOffset != this.lastFocusOffset;

    },



    pollSelection: function() {

      if (!this.composing && !this.gracePeriod && this.selectionChanged()) {

        var sel = window.getSelection(), cm = this.cm;

        this.rememberSelection();

        var anchor = domToPos(cm, sel.anchorNode, sel.anchorOffset);

        var head = domToPos(cm, sel.focusNode, sel.focusOffset);

        if (anchor && head) runInOp(cm, function() {

          setSelection(cm.doc, simpleSelection(anchor, head), sel_dontScroll);

          if (anchor.bad || head.bad) cm.curOp.selectionChanged = true;

        });

      }

    },



    pollContent: function() {

      var cm = this.cm, display = cm.display, sel = cm.doc.sel.primary();

      var from = sel.from(), to = sel.to();

      if (from.line < display.viewFrom || to.line > display.viewTo - 1) return false;



      var fromIndex;

      if (from.line == display.viewFrom || (fromIndex = findViewIndex(cm, from.line)) == 0) {

        var fromLine = lineNo(display.view[0].line);

        var fromNode = display.view[0].node;

      } else {

        var fromLine = lineNo(display.view[fromIndex].line);

        var fromNode = display.view[fromIndex - 1].node.nextSibling;

      }

      var toIndex = findViewIndex(cm, to.line);

      if (toIndex == display.view.length - 1) {

        var toLine = display.viewTo - 1;

        var toNode = display.lineDiv.lastChild;

      } else {

        var toLine = lineNo(display.view[toIndex + 1].line) - 1;

        var toNode = display.view[toIndex + 1].node.previousSibling;

      }



      var newText = cm.doc.splitLines(domTextBetween(cm, fromNode, toNode, fromLine, toLine));

      var oldText = getBetween(cm.doc, Pos(fromLine, 0), Pos(toLine, getLine(cm.doc, toLine).text.length));

      while (newText.length > 1 && oldText.length > 1) {

        if (lst(newText) == lst(oldText)) { newText.pop(); oldText.pop(); toLine--; }

        else if (newText[0] == oldText[0]) { newText.shift(); oldText.shift(); fromLine++; }

        else break;

      }



      var cutFront = 0, cutEnd = 0;

      var newTop = newText[0], oldTop = oldText[0], maxCutFront = Math.min(newTop.length, oldTop.length);

      while (cutFront < maxCutFront && newTop.charCodeAt(cutFront) == oldTop.charCodeAt(cutFront))

        ++cutFront;

      var newBot = lst(newText), oldBot = lst(oldText);

      var maxCutEnd = Math.min(newBot.length - (newText.length == 1 ? cutFront : 0),

                               oldBot.length - (oldText.length == 1 ? cutFront : 0));

      while (cutEnd < maxCutEnd &&

             newBot.charCodeAt(newBot.length - cutEnd - 1) == oldBot.charCodeAt(oldBot.length - cutEnd - 1))

        ++cutEnd;



      newText[newText.length - 1] = newBot.slice(0, newBot.length - cutEnd);

      newText[0] = newText[0].slice(cutFront);



      var chFrom = Pos(fromLine, cutFront);

      var chTo = Pos(toLine, oldText.length ? lst(oldText).length - cutEnd : 0);

      if (newText.length > 1 || newText[0] || cmp(chFrom, chTo)) {

        replaceRange(cm.doc, newText, chFrom, chTo, "+input");

        return true;

      }

    },



    ensurePolled: function() {

      this.forceCompositionEnd();

    },

    reset: function() {

      this.forceCompositionEnd();

    },

    forceCompositionEnd: function() {

      if (!this.composing || this.composing.handled) return;

      this.applyComposition(this.composing);

      this.composing.handled = true;

      this.div.blur();

      this.div.focus();

    },

    applyComposition: function(composing) {

      if (this.cm.isReadOnly())

        operation(this.cm, regChange)(this.cm)

      else if (composing.data && composing.data != composing.startData)

        operation(this.cm, applyTextInput)(this.cm, composing.data, 0, composing.sel);

    },



    setUneditable: function(node) {

      node.contentEditable = "false"

    },



    onKeyPress: function(e) {

      e.preventDefault();

      if (!this.cm.isReadOnly())

        operation(this.cm, applyTextInput)(this.cm, String.fromCharCode(e.charCode == null ? e.keyCode : e.charCode), 0);

    },



    readOnlyChanged: function(val) {

      this.div.contentEditable = String(val != "nocursor")

    },



    onContextMenu: nothing,

    resetPosition: nothing,



    needsContentAttribute: true

  }, ContentEditableInput.prototype);



  function posToDOM(cm, pos) {

    var view = findViewForLine(cm, pos.line);

    if (!view || view.hidden) return null;

    var line = getLine(cm.doc, pos.line);

    var info = mapFromLineView(view, line, pos.line);



    var order = getOrder(line), side = "left";

    if (order) {

      var partPos = getBidiPartAt(order, pos.ch);

      side = partPos % 2 ? "right" : "left";

    }

    var result = nodeAndOffsetInLineMap(info.map, pos.ch, side);

    result.offset = result.collapse == "right" ? result.end : result.start;

    return result;

  }



  function badPos(pos, bad) { if (bad) pos.bad = true; return pos; }



  function domToPos(cm, node, offset) {

    var lineNode;

    if (node == cm.display.lineDiv) {

      lineNode = cm.display.lineDiv.childNodes[offset];

      if (!lineNode) return badPos(cm.clipPos(Pos(cm.display.viewTo - 1)), true);

      node = null; offset = 0;

    } else {

      for (lineNode = node;; lineNode = lineNode.parentNode) {

        if (!lineNode || lineNode == cm.display.lineDiv) return null;

        if (lineNode.parentNode && lineNode.parentNode == cm.display.lineDiv) break;

      }

    }

    for (var i = 0; i < cm.display.view.length; i++) {

      var lineView = cm.display.view[i];

      if (lineView.node == lineNode)

        return locateNodeInLineView(lineView, node, offset);

    }

  }



  function locateNodeInLineView(lineView, node, offset) {

    var wrapper = lineView.text.firstChild, bad = false;

    if (!node || !contains(wrapper, node)) return badPos(Pos(lineNo(lineView.line), 0), true);

    if (node == wrapper) {

      bad = true;

      node = wrapper.childNodes[offset];

      offset = 0;

      if (!node) {

        var line = lineView.rest ? lst(lineView.rest) : lineView.line;

        return badPos(Pos(lineNo(line), line.text.length), bad);

      }

    }



    var textNode = node.nodeType == 3 ? node : null, topNode = node;

    if (!textNode && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {

      textNode = node.firstChild;

      if (offset) offset = textNode.nodeValue.length;

    }

    while (topNode.parentNode != wrapper) topNode = topNode.parentNode;

    var measure = lineView.measure, maps = measure.maps;



    function find(textNode, topNode, offset) {

      for (var i = -1; i < (maps ? maps.length : 0); i++) {

        var map = i < 0 ? measure.map : maps[i];

        for (var j = 0; j < map.length; j += 3) {

          var curNode = map[j + 2];

          if (curNode == textNode || curNode == topNode) {

            var line = lineNo(i < 0 ? lineView.line : lineView.rest[i]);

            var ch = map[j] + offset;

            if (offset < 0 || curNode != textNode) ch = map[j + (offset ? 1 : 0)];

            return Pos(line, ch);

          }

        }

      }

    }

    var found = find(textNode, topNode, offset);

    if (found) return badPos(found, bad);



    // FIXME this is all really shaky. might handle the few cases it needs to handle, but likely to cause problems

    for (var after = topNode.nextSibling, dist = textNode ? textNode.nodeValue.length - offset : 0; after; after = after.nextSibling) {

      found = find(after, after.firstChild, 0);

      if (found)

        return badPos(Pos(found.line, found.ch - dist), bad);

      else

        dist += after.textContent.length;

    }

    for (var before = topNode.previousSibling, dist = offset; before; before = before.previousSibling) {

      found = find(before, before.firstChild, -1);

      if (found)

        return badPos(Pos(found.line, found.ch + dist), bad);

      else

        dist += before.textContent.length;

    }

  }



  function domTextBetween(cm, from, to, fromLine, toLine) {

    var text = "", closing = false, lineSep = cm.doc.lineSeparator();

    function recognizeMarker(id) { return function(marker) { return marker.id == id; }; }

    function walk(node) {

      if (node.nodeType == 1) {

        var cmText = node.getAttribute("cm-text");

        if (cmText != null) {

          if (cmText == "") cmText = node.textContent.replace(/\u200b/g, "");

          text += cmText;

          return;

        }

        var markerID = node.getAttribute("cm-marker"), range;

        if (markerID) {

          var found = cm.findMarks(Pos(fromLine, 0), Pos(toLine + 1, 0), recognizeMarker(+markerID));

          if (found.length && (range = found[0].find()))

            text += getBetween(cm.doc, range.from, range.to).join(lineSep);

          return;

        }

        if (node.getAttribute("contenteditable") == "false") return;

        for (var i = 0; i < node.childNodes.length; i++)

          walk(node.childNodes[i]);

        if (/^(pre|div|p)$/i.test(node.nodeName))

          closing = true;

      } else if (node.nodeType == 3) {

        var val = node.nodeValue;

        if (!val) return;

        if (closing) {

          text += lineSep;

          closing = false;

        }

        text += val;

      }

    }

    for (;;) {

      walk(from);

      if (from == to) break;

      from = from.nextSibling;

    }

    return text;

  }



  CodeMirror.inputStyles = {"textarea": TextareaInput, "contenteditable": ContentEditableInput};



  // SELECTION / CURSOR



  // Selection objects are immutable. A new one is created every time

  // the selection changes. A selection is one or more non-overlapping

  // (and non-touching) ranges, sorted, and an integer that indicates

  // which one is the primary selection (the one that's scrolled into

  // view, that getCursor returns, etc).

  function Selection(ranges, primIndex) {

    this.ranges = ranges;

    this.primIndex = primIndex;

  }



  Selection.prototype = {

    primary: function() { return this.ranges[this.primIndex]; },

    equals: function(other) {

      if (other == this) return true;

      if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;

      for (var i = 0; i < this.ranges.length; i++) {

        var here = this.ranges[i], there = other.ranges[i];

        if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;

      }

      return true;

    },

    deepCopy: function() {

      for (var out = [], i = 0; i < this.ranges.length; i++)

        out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));

      return new Selection(out, this.primIndex);

    },

    somethingSelected: function() {

      for (var i = 0; i < this.ranges.length; i++)

        if (!this.ranges[i].empty()) return true;

      return false;

    },

    contains: function(pos, end) {

      if (!end) end = pos;

      for (var i = 0; i < this.ranges.length; i++) {

        var range = this.ranges[i];

        if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)

          return i;

      }

      return -1;

    }

  };



  function Range(anchor, head) {

    this.anchor = anchor; this.head = head;

  }



  Range.prototype = {

    from: function() { return minPos(this.anchor, this.head); },

    to: function() { return maxPos(this.anchor, this.head); },

    empty: function() {

      return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;

    }

  };



  // Take an unsorted, potentially overlapping set of ranges, and

  // build a selection out of it. 'Consumes' ranges array (modifying

  // it).

  function normalizeSelection(ranges, primIndex) {

    var prim = ranges[primIndex];

    ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });

    primIndex = indexOf(ranges, prim);

    for (var i = 1; i < ranges.length; i++) {

      var cur = ranges[i], prev = ranges[i - 1];

      if (cmp(prev.to(), cur.from()) >= 0) {

        var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());

        var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;

        if (i <= primIndex) --primIndex;

        ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));

      }

    }

    return new Selection(ranges, primIndex);

  }



  function simpleSelection(anchor, head) {

    return new Selection([new Range(anchor, head || anchor)], 0);

  }



  // Most of the external API clips given positions to make sure they

  // actually exist within the document.

  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}

  function clipPos(doc, pos) {

    if (pos.line < doc.first) return Pos(doc.first, 0);

    var last = doc.first + doc.size - 1;

    if (pos.line > last) return Pos(last, getLine(doc, last).text.length);

    return clipToLen(pos, getLine(doc, pos.line).text.length);

  }

  function clipToLen(pos, linelen) {

    var ch = pos.ch;

    if (ch == null || ch > linelen) return Pos(pos.line, linelen);

    else if (ch < 0) return Pos(pos.line, 0);

    else return pos;

  }

  function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}

  function clipPosArray(doc, array) {

    for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);

    return out;

  }



  // SELECTION UPDATES



  // The 'scroll' parameter given to many of these indicated whether

  // the new cursor position should be scrolled into view after

  // modifying the selection.



  // If shift is held or the extend flag is set, extends a range to

  // include a given position (and optionally a second position).

  // Otherwise, simply returns the range between the given positions.

  // Used for cursor motion and such.

  function extendRange(doc, range, head, other) {

    if (doc.cm && doc.cm.display.shift || doc.extend) {

      var anchor = range.anchor;

      if (other) {

        var posBefore = cmp(head, anchor) < 0;

        if (posBefore != (cmp(other, anchor) < 0)) {

          anchor = head;

          head = other;

        } else if (posBefore != (cmp(head, other) < 0)) {

          head = other;

        }

      }

      return new Range(anchor, head);

    } else {

      return new Range(other || head, head);

    }

  }



  // Extend the primary selection range, discard the rest.

  function extendSelection(doc, head, other, options) {

    setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);

  }



  // Extend all selections (pos is an array of selections with length

  // equal the number of selections)

  function extendSelections(doc, heads, options) {

    for (var out = [], i = 0; i < doc.sel.ranges.length; i++)

      out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);

    var newSel = normalizeSelection(out, doc.sel.primIndex);

    setSelection(doc, newSel, options);

  }



  // Updates a single range in the selection.

  function replaceOneSelection(doc, i, range, options) {

    var ranges = doc.sel.ranges.slice(0);

    ranges[i] = range;

    setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);

  }



  // Reset the selection to a single range.

  function setSimpleSelection(doc, anchor, head, options) {

    setSelection(doc, simpleSelection(anchor, head), options);

  }



  // Give beforeSelectionChange handlers a change to influence a

  // selection update.

  function filterSelectionChange(doc, sel, options) {

    var obj = {

      ranges: sel.ranges,

      update: function(ranges) {

        this.ranges = [];

        for (var i = 0; i < ranges.length; i++)

          this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),

                                     clipPos(doc, ranges[i].head));

      },

      origin: options && options.origin

    };

    signal(doc, "beforeSelectionChange", doc, obj);

    if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);

    if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);

    else return sel;

  }



  function setSelectionReplaceHistory(doc, sel, options) {

    var done = doc.history.done, last = lst(done);

    if (last && last.ranges) {

      done[done.length - 1] = sel;

      setSelectionNoUndo(doc, sel, options);

    } else {

      setSelection(doc, sel, options);

    }

  }



  // Set a new selection.

  function setSelection(doc, sel, options) {

    setSelectionNoUndo(doc, sel, options);

    addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);

  }



  function setSelectionNoUndo(doc, sel, options) {

    if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))

      sel = filterSelectionChange(doc, sel, options);



    var bias = options && options.bias ||

      (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);

    setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));



    if (!(options && options.scroll === false) && doc.cm)

      ensureCursorVisible(doc.cm);

  }



  function setSelectionInner(doc, sel) {

    if (sel.equals(doc.sel)) return;



    doc.sel = sel;



    if (doc.cm) {

      doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;

      signalCursorActivity(doc.cm);

    }

    signalLater(doc, "cursorActivity", doc);

  }



  // Verify that the selection does not partially select any atomic

  // marked ranges.

  function reCheckSelection(doc) {

    setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);

  }



  // Return a selection that does not partially select any atomic

  // ranges.

  function skipAtomicInSelection(doc, sel, bias, mayClear) {

    var out;

    for (var i = 0; i < sel.ranges.length; i++) {

      var range = sel.ranges[i];

      var old = sel.ranges.length == doc.sel.ranges.length && doc.sel.ranges[i];

      var newAnchor = skipAtomic(doc, range.anchor, old && old.anchor, bias, mayClear);

      var newHead = skipAtomic(doc, range.head, old && old.head, bias, mayClear);

      if (out || newAnchor != range.anchor || newHead != range.head) {

        if (!out) out = sel.ranges.slice(0, i);

        out[i] = new Range(newAnchor, newHead);

      }

    }

    return out ? normalizeSelection(out, sel.primIndex) : sel;

  }



  function skipAtomicInner(doc, pos, oldPos, dir, mayClear) {

    var line = getLine(doc, pos.line);

    if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {

      var sp = line.markedSpans[i], m = sp.marker;

      if ((sp.from == null || (m.inclusiveLeft ? sp.from <= pos.ch : sp.from < pos.ch)) &&

          (sp.to == null || (m.inclusiveRight ? sp.to >= pos.ch : sp.to > pos.ch))) {

        if (mayClear) {

          signal(m, "beforeCursorEnter");

          if (m.explicitlyCleared) {

            if (!line.markedSpans) break;

            else {--i; continue;}

          }

        }

        if (!m.atomic) continue;



        if (oldPos) {

          var near = m.find(dir < 0 ? 1 : -1), diff;

          if (dir < 0 ? m.inclusiveRight : m.inclusiveLeft)

            near = movePos(doc, near, -dir, near && near.line == pos.line ? line : null);

          if (near && near.line == pos.line && (diff = cmp(near, oldPos)) && (dir < 0 ? diff < 0 : diff > 0))

            return skipAtomicInner(doc, near, pos, dir, mayClear);

        }



        var far = m.find(dir < 0 ? -1 : 1);

        if (dir < 0 ? m.inclusiveLeft : m.inclusiveRight)

          far = movePos(doc, far, dir, far.line == pos.line ? line : null);

        return far ? skipAtomicInner(doc, far, pos, dir, mayClear) : null;

      }

    }

    return pos;

  }



  // Ensure a given position is not inside an atomic range.

  function skipAtomic(doc, pos, oldPos, bias, mayClear) {

    var dir = bias || 1;

    var found = skipAtomicInner(doc, pos, oldPos, dir, mayClear) ||

        (!mayClear && skipAtomicInner(doc, pos, oldPos, dir, true)) ||

        skipAtomicInner(doc, pos, oldPos, -dir, mayClear) ||

        (!mayClear && skipAtomicInner(doc, pos, oldPos, -dir, true));

    if (!found) {

      doc.cantEdit = true;

      return Pos(doc.first, 0);

    }

    return found;

  }



  function movePos(doc, pos, dir, line) {

    if (dir < 0 && pos.ch == 0) {

      if (pos.line > doc.first) return clipPos(doc, Pos(pos.line - 1));

      else return null;

    } else if (dir > 0 && pos.ch == (line || getLine(doc, pos.line)).text.length) {

      if (pos.line < doc.first + doc.size - 1) return Pos(pos.line + 1, 0);

      else return null;

    } else {

      return new Pos(pos.line, pos.ch + dir);

    }

  }



  // SELECTION DRAWING



  function updateSelection(cm) {

    cm.display.input.showSelection(cm.display.input.prepareSelection());

  }



  function prepareSelection(cm, primary) {

    var doc = cm.doc, result = {};

    var curFragment = result.cursors = document.createDocumentFragment();

    var selFragment = result.selection = document.createDocumentFragment();



    for (var i = 0; i < doc.sel.ranges.length; i++) {

      if (primary === false && i == doc.sel.primIndex) continue;

      var range = doc.sel.ranges[i];

      if (range.from().line >= cm.display.viewTo || range.to().line < cm.display.viewFrom) continue;

      var collapsed = range.empty();

      if (collapsed || cm.options.showCursorWhenSelecting)

        drawSelectionCursor(cm, range.head, curFragment);

      if (!collapsed)

        drawSelectionRange(cm, range, selFragment);

    }

    return result;

  }



  // Draws a cursor for the given range

  function drawSelectionCursor(cm, head, output) {

    var pos = cursorCoords(cm, head, "div", null, null, !cm.options.singleCursorHeightPerLine);



    var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));

    cursor.style.left = pos.left + "px";

    cursor.style.top = pos.top + "px";

    cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";



    if (pos.other) {

      // Secondary cursor, shown when on a 'jump' in bi-directional text

      var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));

      otherCursor.style.display = "";

      otherCursor.style.left = pos.other.left + "px";

      otherCursor.style.top = pos.other.top + "px";

      otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";

    }

  }



  // Draws the given range as a highlighted selection

  function drawSelectionRange(cm, range, output) {

    var display = cm.display, doc = cm.doc;

    var fragment = document.createDocumentFragment();

    var padding = paddingH(cm.display), leftSide = padding.left;

    var rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right;



    function add(left, top, width, bottom) {

      if (top < 0) top = 0;

      top = Math.round(top);

      bottom = Math.round(bottom);

      fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +

                               "px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +

                               "px; height: " + (bottom - top) + "px"));

    }



    function drawForLine(line, fromArg, toArg) {

      var lineObj = getLine(doc, line);

      var lineLen = lineObj.text.length;

      var start, end;

      function coords(ch, bias) {

        return charCoords(cm, Pos(line, ch), "div", lineObj, bias);

      }



      iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {

        var leftPos = coords(from, "left"), rightPos, left, right;

        if (from == to) {

          rightPos = leftPos;

          left = right = leftPos.left;

        } else {

          rightPos = coords(to - 1, "right");

          if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }

          left = leftPos.left;

          right = rightPos.right;

        }

        if (fromArg == null && from == 0) left = leftSide;

        if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part

          add(left, leftPos.top, null, leftPos.bottom);

          left = leftSide;

          if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);

        }

        if (toArg == null && to == lineLen) right = rightSide;

        if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)

          start = leftPos;

        if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)

          end = rightPos;

        if (left < leftSide + 1) left = leftSide;

        add(left, rightPos.top, right - left, rightPos.bottom);

      });

      return {start: start, end: end};

    }



    var sFrom = range.from(), sTo = range.to();

    if (sFrom.line == sTo.line) {

      drawForLine(sFrom.line, sFrom.ch, sTo.ch);

    } else {

      var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);

      var singleVLine = visualLine(fromLine) == visualLine(toLine);

      var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;

      var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;

      if (singleVLine) {

        if (leftEnd.top < rightStart.top - 2) {

          add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);

          add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);

        } else {

          add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);

        }

      }

      if (leftEnd.bottom < rightStart.top)

        add(leftSide, leftEnd.bottom, null, rightStart.top);

    }



    output.appendChild(fragment);

  }



  // Cursor-blinking

  function restartBlink(cm) {

    if (!cm.state.focused) return;

    var display = cm.display;

    clearInterval(display.blinker);

    var on = true;

    display.cursorDiv.style.visibility = "";

    if (cm.options.cursorBlinkRate > 0)

      display.blinker = setInterval(function() {

        display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";

      }, cm.options.cursorBlinkRate);

    else if (cm.options.cursorBlinkRate < 0)

      display.cursorDiv.style.visibility = "hidden";

  }



  // HIGHLIGHT WORKER



  function startWorker(cm, time) {

    if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)

      cm.state.highlight.set(time, bind(highlightWorker, cm));

  }



  function highlightWorker(cm) {

    var doc = cm.doc;

    if (doc.frontier < doc.first) doc.frontier = doc.first;

    if (doc.frontier >= cm.display.viewTo) return;

    var end = +new Date + cm.options.workTime;

    var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));

    var changedLines = [];



    doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {

      if (doc.frontier >= cm.display.viewFrom) { // Visible

        var oldStyles = line.styles, tooLong = line.text.length > cm.options.maxHighlightLength;

        var highlighted = highlightLine(cm, line, tooLong ? copyState(doc.mode, state) : state, true);

        line.styles = highlighted.styles;

        var oldCls = line.styleClasses, newCls = highlighted.classes;

        if (newCls) line.styleClasses = newCls;

        else if (oldCls) line.styleClasses = null;

        var ischange = !oldStyles || oldStyles.length != line.styles.length ||

          oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);

        for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];

        if (ischange) changedLines.push(doc.frontier);

        line.stateAfter = tooLong ? state : copyState(doc.mode, state);

      } else {

        if (line.text.length <= cm.options.maxHighlightLength)

          processLine(cm, line.text, state);

        line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;

      }

      ++doc.frontier;

      if (+new Date > end) {

        startWorker(cm, cm.options.workDelay);

        return true;

      }

    });

    if (changedLines.length) runInOp(cm, function() {

      for (var i = 0; i < changedLines.length; i++)

        regLineChange(cm, changedLines[i], "text");

    });

  }



  // Finds the line to start with when starting a parse. Tries to

  // find a line with a stateAfter, so that it can start with a

  // valid state. If that fails, it returns the line with the

  // smallest indentation, which tends to need the least context to

  // parse correctly.

  function findStartLine(cm, n, precise) {

    var minindent, minline, doc = cm.doc;

    var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);

    for (var search = n; search > lim; --search) {

      if (search <= doc.first) return doc.first;

      var line = getLine(doc, search - 1);

      if (line.stateAfter && (!precise || search <= doc.frontier)) return search;

      var indented = countColumn(line.text, null, cm.options.tabSize);

      if (minline == null || minindent > indented) {

        minline = search - 1;

        minindent = indented;

      }

    }

    return minline;

  }



  function getStateBefore(cm, n, precise) {

    var doc = cm.doc, display = cm.display;

    if (!doc.mode.startState) return true;

    var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;

    if (!state) state = startState(doc.mode);

    else state = copyState(doc.mode, state);

    doc.iter(pos, n, function(line) {

      processLine(cm, line.text, state);

      var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;

      line.stateAfter = save ? copyState(doc.mode, state) : null;

      ++pos;

    });

    if (precise) doc.frontier = pos;

    return state;

  }



  // POSITION MEASUREMENT



  function paddingTop(display) {return display.lineSpace.offsetTop;}

  function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}

  function paddingH(display) {

    if (display.cachedPaddingH) return display.cachedPaddingH;

    var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));

    var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;

    var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};

    if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;

    return data;

  }



  function scrollGap(cm) { return scrollerGap - cm.display.nativeBarWidth; }

  function displayWidth(cm) {

    return cm.display.scroller.clientWidth - scrollGap(cm) - cm.display.barWidth;

  }

  function displayHeight(cm) {

    return cm.display.scroller.clientHeight - scrollGap(cm) - cm.display.barHeight;

  }



  // Ensure the lineView.wrapping.heights array is populated. This is

  // an array of bottom offsets for the lines that make up a drawn

  // line. When lineWrapping is on, there might be more than one

  // height.

  function ensureLineHeights(cm, lineView, rect) {

    var wrapping = cm.options.lineWrapping;

    var curWidth = wrapping && displayWidth(cm);

    if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {

      var heights = lineView.measure.heights = [];

      if (wrapping) {

        lineView.measure.width = curWidth;

        var rects = lineView.text.firstChild.getClientRects();

        for (var i = 0; i < rects.length - 1; i++) {

          var cur = rects[i], next = rects[i + 1];

          if (Math.abs(cur.bottom - next.bottom) > 2)

            heights.push((cur.bottom + next.top) / 2 - rect.top);

        }

      }

      heights.push(rect.bottom - rect.top);

    }

  }



  // Find a line map (mapping character offsets to text nodes) and a

  // measurement cache for the given line number. (A line view might

  // contain multiple lines when collapsed ranges are present.)

  function mapFromLineView(lineView, line, lineN) {

    if (lineView.line == line)

      return {map: lineView.measure.map, cache: lineView.measure.cache};

    for (var i = 0; i < lineView.rest.length; i++)

      if (lineView.rest[i] == line)

        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};

    for (var i = 0; i < lineView.rest.length; i++)

      if (lineNo(lineView.rest[i]) > lineN)

        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};

  }



  // Render a line into the hidden node display.externalMeasured. Used

  // when measurement is needed for a line that's not in the viewport.

  function updateExternalMeasurement(cm, line) {

    line = visualLine(line);

    var lineN = lineNo(line);

    var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);

    view.lineN = lineN;

    var built = view.built = buildLineContent(cm, view);

    view.text = built.pre;

    removeChildrenAndAdd(cm.display.lineMeasure, built.pre);

    return view;

  }



  // Get a {top, bottom, left, right} box (in line-local coordinates)

  // for a given character.

  function measureChar(cm, line, ch, bias) {

    return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);

  }



  // Find a line view that corresponds to the given line number.

  function findViewForLine(cm, lineN) {

    if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)

      return cm.display.view[findViewIndex(cm, lineN)];

    var ext = cm.display.externalMeasured;

    if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)

      return ext;

  }



  // Measurement can be split in two steps, the set-up work that

  // applies to the whole line, and the measurement of the actual

  // character. Functions like coordsChar, that need to do a lot of

  // measurements in a row, can thus ensure that the set-up work is

  // only done once.

  function prepareMeasureForLine(cm, line) {

    var lineN = lineNo(line);

    var view = findViewForLine(cm, lineN);

    if (view && !view.text) {

      view = null;

    } else if (view && view.changes) {

      updateLineForChanges(cm, view, lineN, getDimensions(cm));

      cm.curOp.forceUpdate = true;

    }

    if (!view)

      view = updateExternalMeasurement(cm, line);



    var info = mapFromLineView(view, line, lineN);

    return {

      line: line, view: view, rect: null,

      map: info.map, cache: info.cache, before: info.before,

      hasHeights: false

    };

  }



  // Given a prepared measurement object, measures the position of an

  // actual character (or fetches it from the cache).

  function measureCharPrepared(cm, prepared, ch, bias, varHeight) {

    if (prepared.before) ch = -1;

    var key = ch + (bias || ""), found;

    if (prepared.cache.hasOwnProperty(key)) {

      found = prepared.cache[key];

    } else {

      if (!prepared.rect)

        prepared.rect = prepared.view.text.getBoundingClientRect();

      if (!prepared.hasHeights) {

        ensureLineHeights(cm, prepared.view, prepared.rect);

        prepared.hasHeights = true;

      }

      found = measureCharInner(cm, prepared, ch, bias);

      if (!found.bogus) prepared.cache[key] = found;

    }

    return {left: found.left, right: found.right,

            top: varHeight ? found.rtop : found.top,

            bottom: varHeight ? found.rbottom : found.bottom};

  }



  var nullRect = {left: 0, right: 0, top: 0, bottom: 0};



  function nodeAndOffsetInLineMap(map, ch, bias) {

    var node, start, end, collapse;

    // First, search the line map for the text node corresponding to,

    // or closest to, the target character.

    for (var i = 0; i < map.length; i += 3) {

      var mStart = map[i], mEnd = map[i + 1];

      if (ch < mStart) {

        start = 0; end = 1;

        collapse = "left";

      } else if (ch < mEnd) {

        start = ch - mStart;

        end = start + 1;

      } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {

        end = mEnd - mStart;

        start = end - 1;

        if (ch >= mEnd) collapse = "right";

      }

      if (start != null) {

        node = map[i + 2];

        if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))

          collapse = bias;

        if (bias == "left" && start == 0)

          while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {

            node = map[(i -= 3) + 2];

            collapse = "left";

          }

        if (bias == "right" && start == mEnd - mStart)

          while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {

            node = map[(i += 3) + 2];

            collapse = "right";

          }

        break;

      }

    }

    return {node: node, start: start, end: end, collapse: collapse, coverStart: mStart, coverEnd: mEnd};

  }



  function getUsefulRect(rects, bias) {

    var rect = nullRect

    if (bias == "left") for (var i = 0; i < rects.length; i++) {

      if ((rect = rects[i]).left != rect.right) break

    } else for (var i = rects.length - 1; i >= 0; i--) {

      if ((rect = rects[i]).left != rect.right) break

    }

    return rect

  }



  function measureCharInner(cm, prepared, ch, bias) {

    var place = nodeAndOffsetInLineMap(prepared.map, ch, bias);

    var node = place.node, start = place.start, end = place.end, collapse = place.collapse;



    var rect;

    if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.

      for (var i = 0; i < 4; i++) { // Retry a maximum of 4 times when nonsense rectangles are returned

        while (start && isExtendingChar(prepared.line.text.charAt(place.coverStart + start))) --start;

        while (place.coverStart + end < place.coverEnd && isExtendingChar(prepared.line.text.charAt(place.coverStart + end))) ++end;

        if (ie && ie_version < 9 && start == 0 && end == place.coverEnd - place.coverStart)

          rect = node.parentNode.getBoundingClientRect();

        else

          rect = getUsefulRect(range(node, start, end).getClientRects(), bias)

        if (rect.left || rect.right || start == 0) break;

        end = start;

        start = start - 1;

        collapse = "right";

      }

      if (ie && ie_version < 11) rect = maybeUpdateRectForZooming(cm.display.measure, rect);

    } else { // If it is a widget, simply get the box for the whole widget.

      if (start > 0) collapse = bias = "right";

      var rects;

      if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)

        rect = rects[bias == "right" ? rects.length - 1 : 0];

      else

        rect = node.getBoundingClientRect();

    }

    if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {

      var rSpan = node.parentNode.getClientRects()[0];

      if (rSpan)

        rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};

      else

        rect = nullRect;

    }



    var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;

    var mid = (rtop + rbot) / 2;

    var heights = prepared.view.measure.heights;

    for (var i = 0; i < heights.length - 1; i++)

      if (mid < heights[i]) break;

    var top = i ? heights[i - 1] : 0, bot = heights[i];

    var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,

                  right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,

                  top: top, bottom: bot};

    if (!rect.left && !rect.right) result.bogus = true;

    if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }



    return result;

  }



  // Work around problem with bounding client rects on ranges being

  // returned incorrectly when zoomed on IE10 and below.

  function maybeUpdateRectForZooming(measure, rect) {

    if (!window.screen || screen.logicalXDPI == null ||

        screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure))

      return rect;

    var scaleX = screen.logicalXDPI / screen.deviceXDPI;

    var scaleY = screen.logicalYDPI / screen.deviceYDPI;

    return {left: rect.left * scaleX, right: rect.right * scaleX,

            top: rect.top * scaleY, bottom: rect.bottom * scaleY};

  }



  function clearLineMeasurementCacheFor(lineView) {

    if (lineView.measure) {

      lineView.measure.cache = {};

      lineView.measure.heights = null;

      if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)

        lineView.measure.caches[i] = {};

    }

  }



  function clearLineMeasurementCache(cm) {

    cm.display.externalMeasure = null;

    removeChildren(cm.display.lineMeasure);

    for (var i = 0; i < cm.display.view.length; i++)

      clearLineMeasurementCacheFor(cm.display.view[i]);

  }



  function clearCaches(cm) {

    clearLineMeasurementCache(cm);

    cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;

    if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;

    cm.display.lineNumChars = null;

  }



  function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }

  function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }



  // Converts a {top, bottom, left, right} box from line-local

  // coordinates into another coordinate system. Context may be one of

  // "line", "div" (display.lineDiv), "local"/null (editor), "window",

  // or "page".

  function intoCoordSystem(cm, lineObj, rect, context) {

    if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {

      var size = widgetHeight(lineObj.widgets[i]);

      rect.top += size; rect.bottom += size;

    }

    if (context == "line") return rect;

    if (!context) context = "local";

    var yOff = heightAtLine(lineObj);

    if (context == "local") yOff += paddingTop(cm.display);

    else yOff -= cm.display.viewOffset;

    if (context == "page" || context == "window") {

      var lOff = cm.display.lineSpace.getBoundingClientRect();

      yOff += lOff.top + (context == "window" ? 0 : pageScrollY());

      var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());

      rect.left += xOff; rect.right += xOff;

    }

    rect.top += yOff; rect.bottom += yOff;

    return rect;

  }



  // Coverts a box from "div" coords to another coordinate system.

  // Context may be "window", "page", "div", or "local"/null.

  function fromCoordSystem(cm, coords, context) {

    if (context == "div") return coords;

    var left = coords.left, top = coords.top;

    // First move into "page" coordinate system

    if (context == "page") {

      left -= pageScrollX();

      top -= pageScrollY();

    } else if (context == "local" || !context) {

      var localBox = cm.display.sizer.getBoundingClientRect();

      left += localBox.left;

      top += localBox.top;

    }



    var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();

    return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};

  }



  function charCoords(cm, pos, context, lineObj, bias) {

    if (!lineObj) lineObj = getLine(cm.doc, pos.line);

    return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);

  }



  // Returns a box for a given cursor position, which may have an

  // 'other' property containing the position of the secondary cursor

  // on a bidi boundary.

  function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {

    lineObj = lineObj || getLine(cm.doc, pos.line);

    if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);

    function get(ch, right) {

      var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);

      if (right) m.left = m.right; else m.right = m.left;

      return intoCoordSystem(cm, lineObj, m, context);

    }

    function getBidi(ch, partPos) {

      var part = order[partPos], right = part.level % 2;

      if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {

        part = order[--partPos];

        ch = bidiRight(part) - (part.level % 2 ? 0 : 1);

        right = true;

      } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {

        part = order[++partPos];

        ch = bidiLeft(part) - part.level % 2;

        right = false;

      }

      if (right && ch == part.to && ch > part.from) return get(ch - 1);

      return get(ch, right);

    }

    var order = getOrder(lineObj), ch = pos.ch;

    if (!order) return get(ch);

    var partPos = getBidiPartAt(order, ch);

    var val = getBidi(ch, partPos);

    if (bidiOther != null) val.other = getBidi(ch, bidiOther);

    return val;

  }



  // Used to cheaply estimate the coordinates for a position. Used for

  // intermediate scroll updates.

  function estimateCoords(cm, pos) {

    var left = 0, pos = clipPos(cm.doc, pos);

    if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;

    var lineObj = getLine(cm.doc, pos.line);

    var top = heightAtLine(lineObj) + paddingTop(cm.display);

    return {left: left, right: left, top: top, bottom: top + lineObj.height};

  }



  // Positions returned by coordsChar contain some extra information.

  // xRel is the relative x position of the input coordinates compared

  // to the found position (so xRel > 0 means the coordinates are to

  // the right of the character position, for example). When outside

  // is true, that means the coordinates lie outside the line's

  // vertical range.

  function PosWithInfo(line, ch, outside, xRel) {

    var pos = Pos(line, ch);

    pos.xRel = xRel;

    if (outside) pos.outside = true;

    return pos;

  }



  // Compute the character position closest to the given coordinates.

  // Input must be lineSpace-local ("div" coordinate system).

  function coordsChar(cm, x, y) {

    var doc = cm.doc;

    y += cm.display.viewOffset;

    if (y < 0) return PosWithInfo(doc.first, 0, true, -1);

    var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;

    if (lineN > last)

      return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);

    if (x < 0) x = 0;



    var lineObj = getLine(doc, lineN);

    for (;;) {

      var found = coordsCharInner(cm, lineObj, lineN, x, y);

      var merged = collapsedSpanAtEnd(lineObj);

      var mergedPos = merged && merged.find(0, true);

      if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))

        lineN = lineNo(lineObj = mergedPos.to.line);

      else

        return found;

    }

  }



  function coordsCharInner(cm, lineObj, lineNo, x, y) {

    var innerOff = y - heightAtLine(lineObj);

    var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;

    var preparedMeasure = prepareMeasureForLine(cm, lineObj);



    function getX(ch) {

      var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);

      wrongLine = true;

      if (innerOff > sp.bottom) return sp.left - adjust;

      else if (innerOff < sp.top) return sp.left + adjust;

      else wrongLine = false;

      return sp.left;

    }



    var bidi = getOrder(lineObj), dist = lineObj.text.length;

    var from = lineLeft(lineObj), to = lineRight(lineObj);

    var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;



    if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);

    // Do a binary search between these bounds.

    for (;;) {

      if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {

        var ch = x < fromX || x - fromX <= toX - x ? from : to;

        var outside = ch == from ? fromOutside : toOutside

        var xDiff = x - (ch == from ? fromX : toX);

        // This is a kludge to handle the case where the coordinates

        // are after a line-wrapped line. We should replace it with a

        // more general handling of cursor positions around line

        // breaks. (Issue #4078)

        if (toOutside && !bidi && !/\s/.test(lineObj.text.charAt(ch)) && xDiff > 0 &&

            ch < lineObj.text.length && preparedMeasure.view.measure.heights.length > 1) {

          var charSize = measureCharPrepared(cm, preparedMeasure, ch, "right");

          if (innerOff <= charSize.bottom && innerOff >= charSize.top && Math.abs(x - charSize.right) < xDiff) {

            outside = false

            ch++

            xDiff = x - charSize.right

          }

        }

        while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;

        var pos = PosWithInfo(lineNo, ch, outside, xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);

        return pos;

      }

      var step = Math.ceil(dist / 2), middle = from + step;

      if (bidi) {

        middle = from;

        for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);

      }

      var middleX = getX(middle);

      if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}

      else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}

    }

  }



  var measureText;

  // Compute the default text height.

  function textHeight(display) {

    if (display.cachedTextHeight != null) return display.cachedTextHeight;

    if (measureText == null) {

      measureText = elt("pre");

      // Measure a bunch of lines, for browsers that compute

      // fractional heights.

      for (var i = 0; i < 49; ++i) {

        measureText.appendChild(document.createTextNode("x"));

        measureText.appendChild(elt("br"));

      }

      measureText.appendChild(document.createTextNode("x"));

    }

    removeChildrenAndAdd(display.measure, measureText);

    var height = measureText.offsetHeight / 50;

    if (height > 3) display.cachedTextHeight = height;

    removeChildren(display.measure);

    return height || 1;

  }



  // Compute the default character width.

  function charWidth(display) {

    if (display.cachedCharWidth != null) return display.cachedCharWidth;

    var anchor = elt("span", "xxxxxxxxxx");

    var pre = elt("pre", [anchor]);

    removeChildrenAndAdd(display.measure, pre);

    var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;

    if (width > 2) display.cachedCharWidth = width;

    return width || 10;

  }



  // OPERATIONS



  // Operations are used to wrap a series of changes to the editor

  // state in such a way that each change won't have to update the

  // cursor and display (which would be awkward, slow, and

  // error-prone). Instead, display updates are batched and then all

  // combined and executed at once.



  var operationGroup = null;



  var nextOpId = 0;

  // Start a new operation.

  function startOperation(cm) {

    cm.curOp = {

      cm: cm,

      viewChanged: false,      // Flag that indicates that lines might need to be redrawn

      startHeight: cm.doc.height, // Used to detect need to update scrollbar

      forceUpdate: false,      // Used to force a redraw

      updateInput: null,       // Whether to reset the input textarea

      typing: false,           // Whether this reset should be careful to leave existing text (for compositing)

      changeObjs: null,        // Accumulated changes, for firing change events

      cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on

      cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already

      selectionChanged: false, // Whether the selection needs to be redrawn

      updateMaxLine: false,    // Set when the widest line needs to be determined anew

      scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet

      scrollToPos: null,       // Used to scroll to a specific position

      focus: false,

      id: ++nextOpId           // Unique ID

    };

    if (operationGroup) {

      operationGroup.ops.push(cm.curOp);

    } else {

      cm.curOp.ownsGroup = operationGroup = {

        ops: [cm.curOp],

        delayedCallbacks: []

      };

    }

  }



  function fireCallbacksForOps(group) {

    // Calls delayed callbacks and cursorActivity handlers until no

    // new ones appear

    var callbacks = group.delayedCallbacks, i = 0;

    do {

      for (; i < callbacks.length; i++)

        callbacks[i].call(null);

      for (var j = 0; j < group.ops.length; j++) {

        var op = group.ops[j];

        if (op.cursorActivityHandlers)

          while (op.cursorActivityCalled < op.cursorActivityHandlers.length)

            op.cursorActivityHandlers[op.cursorActivityCalled++].call(null, op.cm);

      }

    } while (i < callbacks.length);

  }



  // Finish an operation, updating the display and signalling delayed events

  function endOperation(cm) {

    var op = cm.curOp, group = op.ownsGroup;

    if (!group) return;



    try { fireCallbacksForOps(group); }

    finally {

      operationGroup = null;

      for (var i = 0; i < group.ops.length; i++)

        group.ops[i].cm.curOp = null;

      endOperations(group);

    }

  }



  // The DOM updates done when an operation finishes are batched so

  // that the minimum number of relayouts are required.

  function endOperations(group) {

    var ops = group.ops;

    for (var i = 0; i < ops.length; i++) // Read DOM

      endOperation_R1(ops[i]);

    for (var i = 0; i < ops.length; i++) // Write DOM (maybe)

      endOperation_W1(ops[i]);

    for (var i = 0; i < ops.length; i++) // Read DOM

      endOperation_R2(ops[i]);

    for (var i = 0; i < ops.length; i++) // Write DOM (maybe)

      endOperation_W2(ops[i]);

    for (var i = 0; i < ops.length; i++) // Read DOM

      endOperation_finish(ops[i]);

  }



  function endOperation_R1(op) {

    var cm = op.cm, display = cm.display;

    maybeClipScrollbars(cm);

    if (op.updateMaxLine) findMaxLine(cm);



    op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||

      op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||

                         op.scrollToPos.to.line >= display.viewTo) ||

      display.maxLineChanged && cm.options.lineWrapping;

    op.update = op.mustUpdate &&

      new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);

  }



  function endOperation_W1(op) {

    op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update);

  }



  function endOperation_R2(op) {

    var cm = op.cm, display = cm.display;

    if (op.updatedDisplay) updateHeightsInViewport(cm);



    op.barMeasure = measureForScrollbars(cm);



    // If the max line changed since it was last measured, measure it,

    // and ensure the document's width matches it.

    // updateDisplay_W2 will use these properties to do the actual resizing

    if (display.maxLineChanged && !cm.options.lineWrapping) {

      op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3;

      cm.display.sizerWidth = op.adjustWidthTo;

      op.barMeasure.scrollWidth =

        Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth);

      op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm));

    }



    if (op.updatedDisplay || op.selectionChanged)

      op.preparedSelection = display.input.prepareSelection(op.focus);

  }



  function endOperation_W2(op) {

    var cm = op.cm;



    if (op.adjustWidthTo != null) {

      cm.display.sizer.style.minWidth = op.adjustWidthTo + "px";

      if (op.maxScrollLeft < cm.doc.scrollLeft)

        setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true);

      cm.display.maxLineChanged = false;

    }



    var takeFocus = op.focus && op.focus == activeElt() && (!document.hasFocus || document.hasFocus())

    if (op.preparedSelection)

      cm.display.input.showSelection(op.preparedSelection, takeFocus);

    if (op.updatedDisplay || op.startHeight != cm.doc.height)

      updateScrollbars(cm, op.barMeasure);

    if (op.updatedDisplay)

      setDocumentHeight(cm, op.barMeasure);



    if (op.selectionChanged) restartBlink(cm);



    if (cm.state.focused && op.updateInput)

      cm.display.input.reset(op.typing);

    if (takeFocus) ensureFocus(op.cm);

  }



  function endOperation_finish(op) {

    var cm = op.cm, display = cm.display, doc = cm.doc;



    if (op.updatedDisplay) postUpdateDisplay(cm, op.update);



    // Abort mouse wheel delta measurement, when scrolling explicitly

    if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))

      display.wheelStartX = display.wheelStartY = null;



    // Propagate the scroll position to the actual DOM scroller

    if (op.scrollTop != null && (display.scroller.scrollTop != op.scrollTop || op.forceScroll)) {

      doc.scrollTop = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));

      display.scrollbars.setScrollTop(doc.scrollTop);

      display.scroller.scrollTop = doc.scrollTop;

    }

    if (op.scrollLeft != null && (display.scroller.scrollLeft != op.scrollLeft || op.forceScroll)) {

      doc.scrollLeft = Math.max(0, Math.min(display.scroller.scrollWidth - display.scroller.clientWidth, op.scrollLeft));

      display.scrollbars.setScrollLeft(doc.scrollLeft);

      display.scroller.scrollLeft = doc.scrollLeft;

      alignHorizontally(cm);

    }

    // If we need to scroll a specific position into view, do so.

    if (op.scrollToPos) {

      var coords = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),

                                     clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin);

      if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);

    }



    // Fire events for markers that are hidden/unidden by editing or

    // undoing

    var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;

    if (hidden) for (var i = 0; i < hidden.length; ++i)

      if (!hidden[i].lines.length) signal(hidden[i], "hide");

    if (unhidden) for (var i = 0; i < unhidden.length; ++i)

      if (unhidden[i].lines.length) signal(unhidden[i], "unhide");



    if (display.wrapper.offsetHeight)

      doc.scrollTop = cm.display.scroller.scrollTop;



    // Fire change events, and delayed event handlers

    if (op.changeObjs)

      signal(cm, "changes", cm, op.changeObjs);

    if (op.update)

      op.update.finish();

  }



  // Run the given function in an operation

  function runInOp(cm, f) {

    if (cm.curOp) return f();

    startOperation(cm);

    try { return f(); }

    finally { endOperation(cm); }

  }

  // Wraps a function in an operation. Returns the wrapped function.

  function operation(cm, f) {

    return function() {

      if (cm.curOp) return f.apply(cm, arguments);

      startOperation(cm);

      try { return f.apply(cm, arguments); }

      finally { endOperation(cm); }

    };

  }

  // Used to add methods to editor and doc instances, wrapping them in

  // operations.

  function methodOp(f) {

    return function() {

      if (this.curOp) return f.apply(this, arguments);

      startOperation(this);

      try { return f.apply(this, arguments); }

      finally { endOperation(this); }

    };

  }

  function docMethodOp(f) {

    return function() {

      var cm = this.cm;

      if (!cm || cm.curOp) return f.apply(this, arguments);

      startOperation(cm);

      try { return f.apply(this, arguments); }

      finally { endOperation(cm); }

    };

  }



  // VIEW TRACKING



  // These objects are used to represent the visible (currently drawn)

  // part of the document. A LineView may correspond to multiple

  // logical lines, if those are connected by collapsed ranges.

  function LineView(doc, line, lineN) {

    // The starting line

    this.line = line;

    // Continuing lines, if any

    this.rest = visualLineContinued(line);

    // Number of logical lines in this visual line

    this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;

    this.node = this.text = null;

    this.hidden = lineIsHidden(doc, line);

  }



  // Create a range of LineView objects for the given lines.

  function buildViewArray(cm, from, to) {

    var array = [], nextPos;

    for (var pos = from; pos < to; pos = nextPos) {

      var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);

      nextPos = pos + view.size;

      array.push(view);

    }

    return array;

  }



  // Updates the display.view data structure for a given change to the

  // document. From and to are in pre-change coordinates. Lendiff is

  // the amount of lines added or subtracted by the change. This is

  // used for changes that span multiple lines, or change the way

  // lines are divided into visual lines. regLineChange (below)

  // registers single-line changes.

  function regChange(cm, from, to, lendiff) {

    if (from == null) from = cm.doc.first;

    if (to == null) to = cm.doc.first + cm.doc.size;

    if (!lendiff) lendiff = 0;



    var display = cm.display;

    if (lendiff && to < display.viewTo &&

        (display.updateLineNumbers == null || display.updateLineNumbers > from))

      display.updateLineNumbers = from;



    cm.curOp.viewChanged = true;



    if (from >= display.viewTo) { // Change after

      if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)

        resetView(cm);

    } else if (to <= display.viewFrom) { // Change before

      if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {

        resetView(cm);

      } else {

        display.viewFrom += lendiff;

        display.viewTo += lendiff;

      }

    } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap

      resetView(cm);

    } else if (from <= display.viewFrom) { // Top overlap

      var cut = viewCuttingPoint(cm, to, to + lendiff, 1);

      if (cut) {

        display.view = display.view.slice(cut.index);

        display.viewFrom = cut.lineN;

        display.viewTo += lendiff;

      } else {

        resetView(cm);

      }

    } else if (to >= display.viewTo) { // Bottom overlap

      var cut = viewCuttingPoint(cm, from, from, -1);

      if (cut) {

        display.view = display.view.slice(0, cut.index);

        display.viewTo = cut.lineN;

      } else {

        resetView(cm);

      }

    } else { // Gap in the middle

      var cutTop = viewCuttingPoint(cm, from, from, -1);

      var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);

      if (cutTop && cutBot) {

        display.view = display.view.slice(0, cutTop.index)

          .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))

          .concat(display.view.slice(cutBot.index));

        display.viewTo += lendiff;

      } else {

        resetView(cm);

      }

    }



    var ext = display.externalMeasured;

    if (ext) {

      if (to < ext.lineN)

        ext.lineN += lendiff;

      else if (from < ext.lineN + ext.size)

        display.externalMeasured = null;

    }

  }



  // Register a change to a single line. Type must be one of "text",

  // "gutter", "class", "widget"

  function regLineChange(cm, line, type) {

    cm.curOp.viewChanged = true;

    var display = cm.display, ext = cm.display.externalMeasured;

    if (ext && line >= ext.lineN && line < ext.lineN + ext.size)

      display.externalMeasured = null;



    if (line < display.viewFrom || line >= display.viewTo) return;

    var lineView = display.view[findViewIndex(cm, line)];

    if (lineView.node == null) return;

    var arr = lineView.changes || (lineView.changes = []);

    if (indexOf(arr, type) == -1) arr.push(type);

  }



  // Clear the view.

  function resetView(cm) {

    cm.display.viewFrom = cm.display.viewTo = cm.doc.first;

    cm.display.view = [];

    cm.display.viewOffset = 0;

  }



  // Find the view element corresponding to a given line. Return null

  // when the line isn't visible.

  function findViewIndex(cm, n) {

    if (n >= cm.display.viewTo) return null;

    n -= cm.display.viewFrom;

    if (n < 0) return null;

    var view = cm.display.view;

    for (var i = 0; i < view.length; i++) {

      n -= view[i].size;

      if (n < 0) return i;

    }

  }



  function viewCuttingPoint(cm, oldN, newN, dir) {

    var index = findViewIndex(cm, oldN), diff, view = cm.display.view;

    if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)

      return {index: index, lineN: newN};

    for (var i = 0, n = cm.display.viewFrom; i < index; i++)

      n += view[i].size;

    if (n != oldN) {

      if (dir > 0) {

        if (index == view.length - 1) return null;

        diff = (n + view[index].size) - oldN;

        index++;

      } else {

        diff = n - oldN;

      }

      oldN += diff; newN += diff;

    }

    while (visualLineNo(cm.doc, newN) != newN) {

      if (index == (dir < 0 ? 0 : view.length - 1)) return null;

      newN += dir * view[index - (dir < 0 ? 1 : 0)].size;

      index += dir;

    }

    return {index: index, lineN: newN};

  }



  // Force the view to cover a given range, adding empty view element

  // or clipping off existing ones as needed.

  function adjustView(cm, from, to) {

    var display = cm.display, view = display.view;

    if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {

      display.view = buildViewArray(cm, from, to);

      display.viewFrom = from;

    } else {

      if (display.viewFrom > from)

        display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);

      else if (display.viewFrom < from)

        display.view = display.view.slice(findViewIndex(cm, from));

      display.viewFrom = from;

      if (display.viewTo < to)

        display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));

      else if (display.viewTo > to)

        display.view = display.view.slice(0, findViewIndex(cm, to));

    }

    display.viewTo = to;

  }



  // Count the number of lines in the view whose DOM representation is

  // out of date (or nonexistent).

  function countDirtyView(cm) {

    var view = cm.display.view, dirty = 0;

    for (var i = 0; i < view.length; i++) {

      var lineView = view[i];

      if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;

    }

    return dirty;

  }



  // EVENT HANDLERS



  // Attach the necessary event handlers when initializing the editor

  function registerEventHandlers(cm) {

    var d = cm.display;

    on(d.scroller, "mousedown", operation(cm, onMouseDown));

    // Older IE's will not fire a second mousedown for a double click

    if (ie && ie_version < 11)

      on(d.scroller, "dblclick", operation(cm, function(e) {

        if (signalDOMEvent(cm, e)) return;

        var pos = posFromMouse(cm, e);

        if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;

        e_preventDefault(e);

        var word = cm.findWordAt(pos);

        extendSelection(cm.doc, word.anchor, word.head);

      }));

    else

      on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });

    // Some browsers fire contextmenu *after* opening the menu, at

    // which point we can't mess with it anymore. Context menu is

    // handled in onMouseDown for these browsers.

    if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});



    // Used to suppress mouse event handling when a touch happens

    var touchFinished, prevTouch = {end: 0};

    function finishTouch() {

      if (d.activeTouch) {

        touchFinished = setTimeout(function() {d.activeTouch = null;}, 1000);

        prevTouch = d.activeTouch;

        prevTouch.end = +new Date;

      }

    };

    function isMouseLikeTouchEvent(e) {

      if (e.touches.length != 1) return false;

      var touch = e.touches[0];

      return touch.radiusX <= 1 && touch.radiusY <= 1;

    }

    function farAway(touch, other) {

      if (other.left == null) return true;

      var dx = other.left - touch.left, dy = other.top - touch.top;

      return dx * dx + dy * dy > 20 * 20;

    }

    on(d.scroller, "touchstart", function(e) {

      if (!signalDOMEvent(cm, e) && !isMouseLikeTouchEvent(e)) {

        clearTimeout(touchFinished);

        var now = +new Date;

        d.activeTouch = {start: now, moved: false,

                         prev: now - prevTouch.end <= 300 ? prevTouch : null};

        if (e.touches.length == 1) {

          d.activeTouch.left = e.touches[0].pageX;

          d.activeTouch.top = e.touches[0].pageY;

        }

      }

    });

    on(d.scroller, "touchmove", function() {

      if (d.activeTouch) d.activeTouch.moved = true;

    });

    on(d.scroller, "touchend", function(e) {

      var touch = d.activeTouch;

      if (touch && !eventInWidget(d, e) && touch.left != null &&

          !touch.moved && new Date - touch.start < 300) {

        var pos = cm.coordsChar(d.activeTouch, "page"), range;

        if (!touch.prev || farAway(touch, touch.prev)) // Single tap

          range = new Range(pos, pos);

        else if (!touch.prev.prev || farAway(touch, touch.prev.prev)) // Double tap

          range = cm.findWordAt(pos);

        else // Triple tap

          range = new Range(Pos(pos.line, 0), clipPos(cm.doc, Pos(pos.line + 1, 0)));

        cm.setSelection(range.anchor, range.head);

        cm.focus();

        e_preventDefault(e);

      }

      finishTouch();

    });

    on(d.scroller, "touchcancel", finishTouch);



    // Sync scrolling between fake scrollbars and real scrollable

    // area, ensure viewport is updated when scrolling.

    on(d.scroller, "scroll", function() {

      if (d.scroller.clientHeight) {

        setScrollTop(cm, d.scroller.scrollTop);

        setScrollLeft(cm, d.scroller.scrollLeft, true);

        signal(cm, "scroll", cm);

      }

    });



    // Listen to wheel events in order to try and update the viewport on time.

    on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});

    on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});



    // Prevent wrapper from ever scrolling

    on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });



    d.dragFunctions = {

      enter: function(e) {if (!signalDOMEvent(cm, e)) e_stop(e);},

      over: function(e) {if (!signalDOMEvent(cm, e)) { onDragOver(cm, e); e_stop(e); }},

      start: function(e){onDragStart(cm, e);},

      drop: operation(cm, onDrop),

      leave: function(e) {if (!signalDOMEvent(cm, e)) { clearDragCursor(cm); }}

    };



    var inp = d.input.getField();

    on(inp, "keyup", function(e) { onKeyUp.call(cm, e); });

    on(inp, "keydown", operation(cm, onKeyDown));

    on(inp, "keypress", operation(cm, onKeyPress));

    on(inp, "focus", function (e) { onFocus(cm, e); });

    on(inp, "blur", function (e) { onBlur(cm, e); });

  }



  function dragDropChanged(cm, value, old) {

    var wasOn = old && old != CodeMirror.Init;

    if (!value != !wasOn) {

      var funcs = cm.display.dragFunctions;

      var toggle = value ? on : off;

      toggle(cm.display.scroller, "dragstart", funcs.start);

      toggle(cm.display.scroller, "dragenter", funcs.enter);

      toggle(cm.display.scroller, "dragover", funcs.over);

      toggle(cm.display.scroller, "dragleave", funcs.leave);

      toggle(cm.display.scroller, "drop", funcs.drop);

    }

  }



  // Called when the window resizes

  function onResize(cm) {

    var d = cm.display;

    if (d.lastWrapHeight == d.wrapper.clientHeight && d.lastWrapWidth == d.wrapper.clientWidth)

      return;

    // Might be a text scaling operation, clear size caches.

    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;

    d.scrollbarsClipped = false;

    cm.setSize();

  }



  // MOUSE EVENTS



  // Return true when the given mouse event happened in a widget

  function eventInWidget(display, e) {

    for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {

      if (!n || (n.nodeType == 1 && n.getAttribute("cm-ignore-events") == "true") ||

          (n.parentNode == display.sizer && n != display.mover))

        return true;

    }

  }



  // Given a mouse event, find the corresponding position. If liberal

  // is false, it checks whether a gutter or scrollbar was clicked,

  // and returns null if it was. forRect is used by rectangular

  // selections, and tries to estimate a character position even for

  // coordinates beyond the right of the text.

  function posFromMouse(cm, e, liberal, forRect) {

    var display = cm.display;

    if (!liberal && e_target(e).getAttribute("cm-not-content") == "true") return null;



    var x, y, space = display.lineSpace.getBoundingClientRect();

    // Fails unpredictably on IE[67] when mouse is dragged around quickly.

    try { x = e.clientX - space.left; y = e.clientY - space.top; }

    catch (e) { return null; }

    var coords = coordsChar(cm, x, y), line;

    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {

      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;

      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));

    }

    return coords;

  }



  // A mouse down can be a single click, double click, triple click,

  // start of selection drag, start of text drag, new cursor

  // (ctrl-click), rectangle drag (alt-drag), or xwin

  // middle-click-paste. Or it might be a click on something we should

  // not interfere with, such as a scrollbar or widget.

  function onMouseDown(e) {

    var cm = this, display = cm.display;

    if (signalDOMEvent(cm, e) || display.activeTouch && display.input.supportsTouch()) return;

    display.shift = e.shiftKey;



    if (eventInWidget(display, e)) {

      if (!webkit) {

        // Briefly turn off draggability, to allow widgets to do

        // normal dragging things.

        display.scroller.draggable = false;

        setTimeout(function(){display.scroller.draggable = true;}, 100);

      }

      return;

    }

    if (clickInGutter(cm, e)) return;

    var start = posFromMouse(cm, e);

    window.focus();



    switch (e_button(e)) {

    case 1:

      // #3261: make sure, that we're not starting a second selection

      if (cm.state.selectingText)

        cm.state.selectingText(e);

      else if (start)

        leftButtonDown(cm, e, start);

      else if (e_target(e) == display.scroller)

        e_preventDefault(e);

      break;

    case 2:

      if (webkit) cm.state.lastMiddleDown = +new Date;

      if (start) extendSelection(cm.doc, start);

      setTimeout(function() {display.input.focus();}, 20);

      e_preventDefault(e);

      break;

    case 3:

      if (captureRightClick) onContextMenu(cm, e);

      else delayBlurEvent(cm);

      break;

    }

  }



  var lastClick, lastDoubleClick;

  function leftButtonDown(cm, e, start) {

    if (ie) setTimeout(bind(ensureFocus, cm), 0);

    else cm.curOp.focus = activeElt();



    var now = +new Date, type;

    if (lastDoubleClick && lastDoubleClick.time > now - 400 && cmp(lastDoubleClick.pos, start) == 0) {

      type = "triple";

    } else if (lastClick && lastClick.time > now - 400 && cmp(lastClick.pos, start) == 0) {

      type = "double";

      lastDoubleClick = {time: now, pos: start};

    } else {

      type = "single";

      lastClick = {time: now, pos: start};

    }



    var sel = cm.doc.sel, modifier = mac ? e.metaKey : e.ctrlKey, contained;

    if (cm.options.dragDrop && dragAndDrop && !cm.isReadOnly() &&

        type == "single" && (contained = sel.contains(start)) > -1 &&

        (cmp((contained = sel.ranges[contained]).from(), start) < 0 || start.xRel > 0) &&

        (cmp(contained.to(), start) > 0 || start.xRel < 0))

      leftButtonStartDrag(cm, e, start, modifier);

    else

      leftButtonSelect(cm, e, start, type, modifier);

  }



  // Start a text drag. When it ends, see if any dragging actually

  // happen, and treat as a click if it didn't.

  function leftButtonStartDrag(cm, e, start, modifier) {

    var display = cm.display, startTime = +new Date;

    var dragEnd = operation(cm, function(e2) {

      if (webkit) display.scroller.draggable = false;

      cm.state.draggingText = false;

      off(document, "mouseup", dragEnd);

      off(display.scroller, "drop", dragEnd);

      if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {

        e_preventDefault(e2);

        if (!modifier && +new Date - 200 < startTime)

          extendSelection(cm.doc, start);

        // Work around unexplainable focus problem in IE9 (#2127) and Chrome (#3081)

        if (webkit || ie && ie_version == 9)

          setTimeout(function() {document.body.focus(); display.input.focus();}, 20);

        else

          display.input.focus();

      }

    });

    // Let the drag handler handle this.

    if (webkit) display.scroller.draggable = true;

    cm.state.draggingText = dragEnd;

    dragEnd.copy = mac ? e.altKey : e.ctrlKey

    // IE's approach to draggable

    if (display.scroller.dragDrop) display.scroller.dragDrop();

    on(document, "mouseup", dragEnd);

    on(display.scroller, "drop", dragEnd);

  }



  // Normal selection, as opposed to text dragging.

  function leftButtonSelect(cm, e, start, type, addNew) {

    var display = cm.display, doc = cm.doc;

    e_preventDefault(e);



    var ourRange, ourIndex, startSel = doc.sel, ranges = startSel.ranges;

    if (addNew && !e.shiftKey) {

      ourIndex = doc.sel.contains(start);

      if (ourIndex > -1)

        ourRange = ranges[ourIndex];

      else

        ourRange = new Range(start, start);

    } else {

      ourRange = doc.sel.primary();

      ourIndex = doc.sel.primIndex;

    }



    if (chromeOS ? e.shiftKey && e.metaKey : e.altKey) {

      type = "rect";

      if (!addNew) ourRange = new Range(start, start);

      start = posFromMouse(cm, e, true, true);

      ourIndex = -1;

    } else if (type == "double") {

      var word = cm.findWordAt(start);

      if (cm.display.shift || doc.extend)

        ourRange = extendRange(doc, ourRange, word.anchor, word.head);

      else

        ourRange = word;

    } else if (type == "triple") {

      var line = new Range(Pos(start.line, 0), clipPos(doc, Pos(start.line + 1, 0)));

      if (cm.display.shift || doc.extend)

        ourRange = extendRange(doc, ourRange, line.anchor, line.head);

      else

        ourRange = line;

    } else {

      ourRange = extendRange(doc, ourRange, start);

    }



    if (!addNew) {

      ourIndex = 0;

      setSelection(doc, new Selection([ourRange], 0), sel_mouse);

      startSel = doc.sel;

    } else if (ourIndex == -1) {

      ourIndex = ranges.length;

      setSelection(doc, normalizeSelection(ranges.concat([ourRange]), ourIndex),

                   {scroll: false, origin: "*mouse"});

    } else if (ranges.length > 1 && ranges[ourIndex].empty() && type == "single" && !e.shiftKey) {

      setSelection(doc, normalizeSelection(ranges.slice(0, ourIndex).concat(ranges.slice(ourIndex + 1)), 0),

                   {scroll: false, origin: "*mouse"});

      startSel = doc.sel;

    } else {

      replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);

    }



    var lastPos = start;

    function extendTo(pos) {

      if (cmp(lastPos, pos) == 0) return;

      lastPos = pos;



      if (type == "rect") {

        var ranges = [], tabSize = cm.options.tabSize;

        var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);

        var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);

        var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);

        for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));

             line <= end; line++) {

          var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);

          if (left == right)

            ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)));

          else if (text.length > leftPos)

            ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))));

        }

        if (!ranges.length) ranges.push(new Range(start, start));

        setSelection(doc, normalizeSelection(startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex),

                     {origin: "*mouse", scroll: false});

        cm.scrollIntoView(pos);

      } else {

        var oldRange = ourRange;

        var anchor = oldRange.anchor, head = pos;

        if (type != "single") {

          if (type == "double")

            var range = cm.findWordAt(pos);

          else

            var range = new Range(Pos(pos.line, 0), clipPos(doc, Pos(pos.line + 1, 0)));

          if (cmp(range.anchor, anchor) > 0) {

            head = range.head;

            anchor = minPos(oldRange.from(), range.anchor);

          } else {

            head = range.anchor;

            anchor = maxPos(oldRange.to(), range.head);

          }

        }

        var ranges = startSel.ranges.slice(0);

        ranges[ourIndex] = new Range(clipPos(doc, anchor), head);

        setSelection(doc, normalizeSelection(ranges, ourIndex), sel_mouse);

      }

    }



    var editorSize = display.wrapper.getBoundingClientRect();

    // Used to ensure timeout re-tries don't fire when another extend

    // happened in the meantime (clearTimeout isn't reliable -- at

    // least on Chrome, the timeouts still happen even when cleared,

    // if the clear happens after their scheduled firing time).

    var counter = 0;



    function extend(e) {

      var curCount = ++counter;

      var cur = posFromMouse(cm, e, true, type == "rect");

      if (!cur) return;

      if (cmp(cur, lastPos) != 0) {

        cm.curOp.focus = activeElt();

        extendTo(cur);

        var visible = visibleLines(display, doc);

        if (cur.line >= visible.to || cur.line < visible.from)

          setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);

      } else {

        var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;

        if (outside) setTimeout(operation(cm, function() {

          if (counter != curCount) return;

          display.scroller.scrollTop += outside;

          extend(e);

        }), 50);

      }

    }



    function done(e) {

      cm.state.selectingText = false;

      counter = Infinity;

      e_preventDefault(e);

      display.input.focus();

      off(document, "mousemove", move);

      off(document, "mouseup", up);

      doc.history.lastSelOrigin = null;

    }



    var move = operation(cm, function(e) {

      if (!e_button(e)) done(e);

      else extend(e);

    });

    var up = operation(cm, done);

    cm.state.selectingText = up;

    on(document, "mousemove", move);

    on(document, "mouseup", up);

  }



  // Determines whether an event happened in the gutter, and fires the

  // handlers for the corresponding event.

  function gutterEvent(cm, e, type, prevent) {

    try { var mX = e.clientX, mY = e.clientY; }

    catch(e) { return false; }

    if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false;

    if (prevent) e_preventDefault(e);



    var display = cm.display;

    var lineBox = display.lineDiv.getBoundingClientRect();



    if (mY > lineBox.bottom || !hasHandler(cm, type)) return e_defaultPrevented(e);

    mY -= lineBox.top - display.viewOffset;



    for (var i = 0; i < cm.options.gutters.length; ++i) {

      var g = display.gutters.childNodes[i];

      if (g && g.getBoundingClientRect().right >= mX) {

        var line = lineAtHeight(cm.doc, mY);

        var gutter = cm.options.gutters[i];

        signal(cm, type, cm, line, gutter, e);

        return e_defaultPrevented(e);

      }

    }

  }



  function clickInGutter(cm, e) {

    return gutterEvent(cm, e, "gutterClick", true);

  }



  // Kludge to work around strange IE behavior where it'll sometimes

  // re-fire a series of drag-related events right after the drop (#1551)

  var lastDrop = 0;



  function onDrop(e) {

    var cm = this;

    clearDragCursor(cm);

    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))

      return;

    e_preventDefault(e);

    if (ie) lastDrop = +new Date;

    var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;

    if (!pos || cm.isReadOnly()) return;

    // Might be a file drop, in which case we simply extract the text

    // and insert it.

    if (files && files.length && window.FileReader && window.File) {

      var n = files.length, text = Array(n), read = 0;

      var loadFile = function(file, i) {

        if (cm.options.allowDropFileTypes &&

            indexOf(cm.options.allowDropFileTypes, file.type) == -1)

          return;



        var reader = new FileReader;

        reader.onload = operation(cm, function() {

          var content = reader.result;

          if (/[\x00-\x08\x0e-\x1f]{2}/.test(content)) content = "";

          text[i] = content;

          if (++read == n) {

            pos = clipPos(cm.doc, pos);

            var change = {from: pos, to: pos,

                          text: cm.doc.splitLines(text.join(cm.doc.lineSeparator())),

                          origin: "paste"};

            makeChange(cm.doc, change);

            setSelectionReplaceHistory(cm.doc, simpleSelection(pos, changeEnd(change)));

          }

        });

        reader.readAsText(file);

      };

      for (var i = 0; i < n; ++i) loadFile(files[i], i);

    } else { // Normal drop

      // Don't do a replace if the drop happened inside of the selected text.

      if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {

        cm.state.draggingText(e);

        // Ensure the editor is re-focused

        setTimeout(function() {cm.display.input.focus();}, 20);

        return;

      }

      try {

        var text = e.dataTransfer.getData("Text");

        if (text) {

          if (cm.state.draggingText && !cm.state.draggingText.copy)

            var selected = cm.listSelections();

          setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));

          if (selected) for (var i = 0; i < selected.length; ++i)

            replaceRange(cm.doc, "", selected[i].anchor, selected[i].head, "drag");

          cm.replaceSelection(text, "around", "paste");

          cm.display.input.focus();

        }

      }

      catch(e){}

    }

  }



  function onDragStart(cm, e) {

    if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }

    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;



    e.dataTransfer.setData("Text", cm.getSelection());

    e.dataTransfer.effectAllowed = "copyMove"



    // Use dummy image instead of default browsers image.

    // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.

    if (e.dataTransfer.setDragImage && !safari) {

      var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");

      img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";

      if (presto) {

        img.width = img.height = 1;

        cm.display.wrapper.appendChild(img);

        // Force a relayout, or Opera won't use our image for some obscure reason

        img._top = img.offsetTop;

      }

      e.dataTransfer.setDragImage(img, 0, 0);

      if (presto) img.parentNode.removeChild(img);

    }

  }



  function onDragOver(cm, e) {

    var pos = posFromMouse(cm, e);

    if (!pos) return;

    var frag = document.createDocumentFragment();

    drawSelectionCursor(cm, pos, frag);

    if (!cm.display.dragCursor) {

      cm.display.dragCursor = elt("div", null, "CodeMirror-cursors CodeMirror-dragcursors");

      cm.display.lineSpace.insertBefore(cm.display.dragCursor, cm.display.cursorDiv);

    }

    removeChildrenAndAdd(cm.display.dragCursor, frag);

  }



  function clearDragCursor(cm) {

    if (cm.display.dragCursor) {

      cm.display.lineSpace.removeChild(cm.display.dragCursor);

      cm.display.dragCursor = null;

    }

  }



  // SCROLL EVENTS



  // Sync the scrollable area and scrollbars, ensure the viewport

  // covers the visible area.

  function setScrollTop(cm, val) {

    if (Math.abs(cm.doc.scrollTop - val) < 2) return;

    cm.doc.scrollTop = val;

    if (!gecko) updateDisplaySimple(cm, {top: val});

    if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;

    cm.display.scrollbars.setScrollTop(val);

    if (gecko) updateDisplaySimple(cm);

    startWorker(cm, 100);

  }

  // Sync scroller and scrollbar, ensure the gutter elements are

  // aligned.

  function setScrollLeft(cm, val, isScroller) {

    if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;

    val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);

    cm.doc.scrollLeft = val;

    alignHorizontally(cm);

    if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;

    cm.display.scrollbars.setScrollLeft(val);

  }



  // Since the delta values reported on mouse wheel events are

  // unstandardized between browsers and even browser versions, and

  // generally horribly unpredictable, this code starts by measuring

  // the scroll effect that the first few mouse wheel events have,

  // and, from that, detects the way it can convert deltas to pixel

  // offsets afterwards.

  //

  // The reason we want to know the amount a wheel event will scroll

  // is that it gives us a chance to update the display before the

  // actual scrolling happens, reducing flickering.



  var wheelSamples = 0, wheelPixelsPerUnit = null;

  // Fill in a browser-detected starting value on browsers where we

  // know one. These don't have to be accurate -- the result of them

  // being wrong would just be a slight flicker on the first wheel

  // scroll (if it is large enough).

  if (ie) wheelPixelsPerUnit = -.53;

  else if (gecko) wheelPixelsPerUnit = 15;

  else if (chrome) wheelPixelsPerUnit = -.7;

  else if (safari) wheelPixelsPerUnit = -1/3;



  var wheelEventDelta = function(e) {

    var dx = e.wheelDeltaX, dy = e.wheelDeltaY;

    if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;

    if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;

    else if (dy == null) dy = e.wheelDelta;

    return {x: dx, y: dy};

  };

  CodeMirror.wheelEventPixels = function(e) {

    var delta = wheelEventDelta(e);

    delta.x *= wheelPixelsPerUnit;

    delta.y *= wheelPixelsPerUnit;

    return delta;

  };



  function onScrollWheel(cm, e) {

    var delta = wheelEventDelta(e), dx = delta.x, dy = delta.y;



    var display = cm.display, scroll = display.scroller;

    // Quit if there's nothing to scroll here

    var canScrollX = scroll.scrollWidth > scroll.clientWidth;

    var canScrollY = scroll.scrollHeight > scroll.clientHeight;

    if (!(dx && canScrollX || dy && canScrollY)) return;



    // Webkit browsers on OS X abort momentum scrolls when the target

    // of the scroll event is removed from the scrollable element.

    // This hack (see related code in patchDisplay) makes sure the

    // element is kept around.

    if (dy && mac && webkit) {

      outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {

        for (var i = 0; i < view.length; i++) {

          if (view[i].node == cur) {

            cm.display.currentWheelTarget = cur;

            break outer;

          }

        }

      }

    }



    // On some browsers, horizontal scrolling will cause redraws to

    // happen before the gutter has been realigned, causing it to

    // wriggle around in a most unseemly way. When we have an

    // estimated pixels/delta value, we just handle horizontal

    // scrolling entirely here. It'll be slightly off from native, but

    // better than glitching out.

    if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {

      if (dy && canScrollY)

        setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));

      setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));

      // Only prevent default scrolling if vertical scrolling is

      // actually possible. Otherwise, it causes vertical scroll

      // jitter on OSX trackpads when deltaX is small and deltaY

      // is large (issue #3579)

      if (!dy || (dy && canScrollY))

        e_preventDefault(e);

      display.wheelStartX = null; // Abort measurement, if in progress

      return;

    }



    // 'Project' the visible viewport to cover the area that is being

    // scrolled into view (if we know enough to estimate it).

    if (dy && wheelPixelsPerUnit != null) {

      var pixels = dy * wheelPixelsPerUnit;

      var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;

      if (pixels < 0) top = Math.max(0, top + pixels - 50);

      else bot = Math.min(cm.doc.height, bot + pixels + 50);

      updateDisplaySimple(cm, {top: top, bottom: bot});

    }



    if (wheelSamples < 20) {

      if (display.wheelStartX == null) {

        display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;

        display.wheelDX = dx; display.wheelDY = dy;

        setTimeout(function() {

          if (display.wheelStartX == null) return;

          var movedX = scroll.scrollLeft - display.wheelStartX;

          var movedY = scroll.scrollTop - display.wheelStartY;

          var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||

            (movedX && display.wheelDX && movedX / display.wheelDX);

          display.wheelStartX = display.wheelStartY = null;

          if (!sample) return;

          wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);

          ++wheelSamples;

        }, 200);

      } else {

        display.wheelDX += dx; display.wheelDY += dy;

      }

    }

  }



  // KEY EVENTS



  // Run a handler that was bound to a key.

  function doHandleBinding(cm, bound, dropShift) {

    if (typeof bound == "string") {

      bound = commands[bound];

      if (!bound) return false;

    }

    // Ensure previous input has been read, so that the handler sees a

    // consistent view of the document

    cm.display.input.ensurePolled();

    var prevShift = cm.display.shift, done = false;

    try {

      if (cm.isReadOnly()) cm.state.suppressEdits = true;

      if (dropShift) cm.display.shift = false;

      done = bound(cm) != Pass;

    } finally {

      cm.display.shift = prevShift;

      cm.state.suppressEdits = false;

    }

    return done;

  }



  function lookupKeyForEditor(cm, name, handle) {

    for (var i = 0; i < cm.state.keyMaps.length; i++) {

      var result = lookupKey(name, cm.state.keyMaps[i], handle, cm);

      if (result) return result;

    }

    return (cm.options.extraKeys && lookupKey(name, cm.options.extraKeys, handle, cm))

      || lookupKey(name, cm.options.keyMap, handle, cm);

  }



  var stopSeq = new Delayed;

  function dispatchKey(cm, name, e, handle) {

    var seq = cm.state.keySeq;

    if (seq) {

      if (isModifierKey(name)) return "handled";

      stopSeq.set(50, function() {

        if (cm.state.keySeq == seq) {

          cm.state.keySeq = null;

          cm.display.input.reset();

        }

      });

      name = seq + " " + name;

    }

    var result = lookupKeyForEditor(cm, name, handle);



    if (result == "multi")

      cm.state.keySeq = name;

    if (result == "handled")

      signalLater(cm, "keyHandled", cm, name, e);



    if (result == "handled" || result == "multi") {

      e_preventDefault(e);

      restartBlink(cm);

    }



    if (seq && !result && /\'$/.test(name)) {

      e_preventDefault(e);

      return true;

    }

    return !!result;

  }



  // Handle a key from the keydown event.

  function handleKeyBinding(cm, e) {

    var name = keyName(e, true);

    if (!name) return false;



    if (e.shiftKey && !cm.state.keySeq) {

      // First try to resolve full name (including 'Shift-'). Failing

      // that, see if there is a cursor-motion command (starting with

      // 'go') bound to the keyname without 'Shift-'.

      return dispatchKey(cm, "Shift-" + name, e, function(b) {return doHandleBinding(cm, b, true);})

          || dispatchKey(cm, name, e, function(b) {

               if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)

                 return doHandleBinding(cm, b);

             });

    } else {

      return dispatchKey(cm, name, e, function(b) { return doHandleBinding(cm, b); });

    }

  }



  // Handle a key from the keypress event

  function handleCharBinding(cm, e, ch) {

    return dispatchKey(cm, "'" + ch + "'", e,

                       function(b) { return doHandleBinding(cm, b, true); });

  }



  var lastStoppedKey = null;

  function onKeyDown(e) {

    var cm = this;

    cm.curOp.focus = activeElt();

    if (signalDOMEvent(cm, e)) return;

    // IE does strange things with escape.

    if (ie && ie_version < 11 && e.keyCode == 27) e.returnValue = false;

    var code = e.keyCode;

    cm.display.shift = code == 16 || e.shiftKey;

    var handled = handleKeyBinding(cm, e);

    if (presto) {

      lastStoppedKey = handled ? code : null;

      // Opera has no cut event... we try to at least catch the key combo

      if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))

        cm.replaceSelection("", null, "cut");

    }



    // Turn mouse into crosshair when Alt is held on Mac.

    if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))

      showCrossHair(cm);

  }



  function showCrossHair(cm) {

    var lineDiv = cm.display.lineDiv;

    addClass(lineDiv, "CodeMirror-crosshair");



    function up(e) {

      if (e.keyCode == 18 || !e.altKey) {

        rmClass(lineDiv, "CodeMirror-crosshair");

        off(document, "keyup", up);

        off(document, "mouseover", up);

      }

    }

    on(document, "keyup", up);

    on(document, "mouseover", up);

  }



  function onKeyUp(e) {

    if (e.keyCode == 16) this.doc.sel.shift = false;

    signalDOMEvent(this, e);

  }



  function onKeyPress(e) {

    var cm = this;

    if (eventInWidget(cm.display, e) || signalDOMEvent(cm, e) || e.ctrlKey && !e.altKey || mac && e.metaKey) return;

    var keyCode = e.keyCode, charCode = e.charCode;

    if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}

    if ((presto && (!e.which || e.which < 10)) && handleKeyBinding(cm, e)) return;

    var ch = String.fromCharCode(charCode == null ? keyCode : charCode);

    if (handleCharBinding(cm, e, ch)) return;

    cm.display.input.onKeyPress(e);

  }



  // FOCUS/BLUR EVENTS



  function delayBlurEvent(cm) {

    cm.state.delayingBlurEvent = true;

    setTimeout(function() {

      if (cm.state.delayingBlurEvent) {

        cm.state.delayingBlurEvent = false;

        onBlur(cm);

      }

    }, 100);

  }



  function onFocus(cm, e) {

    if (cm.state.delayingBlurEvent) cm.state.delayingBlurEvent = false;



    if (cm.options.readOnly == "nocursor") return;

    if (!cm.state.focused) {

      signal(cm, "focus", cm, e);

      cm.state.focused = true;

      addClass(cm.display.wrapper, "CodeMirror-focused");

      // This test prevents this from firing when a context

      // menu is closed (since the input reset would kill the

      // select-all detection hack)

      if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {

        cm.display.input.reset();

        if (webkit) setTimeout(function() { cm.display.input.reset(true); }, 20); // Issue #1730

      }

      cm.display.input.receivedFocus();

    }

    restartBlink(cm);

  }

  function onBlur(cm, e) {

    if (cm.state.delayingBlurEvent) return;



    if (cm.state.focused) {

      signal(cm, "blur", cm, e);

      cm.state.focused = false;

      rmClass(cm.display.wrapper, "CodeMirror-focused");

    }

    clearInterval(cm.display.blinker);

    setTimeout(function() {if (!cm.state.focused) cm.display.shift = false;}, 150);

  }



  // CONTEXT MENU HANDLING



  // To make the context menu work, we need to briefly unhide the

  // textarea (making it as unobtrusive as possible) to let the

  // right-click take effect on it.

  function onContextMenu(cm, e) {

    if (eventInWidget(cm.display, e) || contextMenuInGutter(cm, e)) return;

    if (signalDOMEvent(cm, e, "contextmenu")) return;

    cm.display.input.onContextMenu(e);

  }



  function contextMenuInGutter(cm, e) {

    if (!hasHandler(cm, "gutterContextMenu")) return false;

    return gutterEvent(cm, e, "gutterContextMenu", false);

  }



  // UPDATING



  // Compute the position of the end of a change (its 'to' property

  // refers to the pre-change end).

  var changeEnd = CodeMirror.changeEnd = function(change) {

    if (!change.text) return change.to;

    return Pos(change.from.line + change.text.length - 1,

               lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));

  };



  // Adjust a position to refer to the post-change position of the

  // same text, or the end of the change if the change covers it.

  function adjustForChange(pos, change) {

    if (cmp(pos, change.from) < 0) return pos;

    if (cmp(pos, change.to) <= 0) return changeEnd(change);



    var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;

    if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;

    return Pos(line, ch);

  }



  function computeSelAfterChange(doc, change) {

    var out = [];

    for (var i = 0; i < doc.sel.ranges.length; i++) {

      var range = doc.sel.ranges[i];

      out.push(new Range(adjustForChange(range.anchor, change),

                         adjustForChange(range.head, change)));

    }

    return normalizeSelection(out, doc.sel.primIndex);

  }



  function offsetPos(pos, old, nw) {

    if (pos.line == old.line)

      return Pos(nw.line, pos.ch - old.ch + nw.ch);

    else

      return Pos(nw.line + (pos.line - old.line), pos.ch);

  }



  // Used by replaceSelections to allow moving the selection to the

  // start or around the replaced test. Hint may be "start" or "around".

  function computeReplacedSel(doc, changes, hint) {

    var out = [];

    var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;

    for (var i = 0; i < changes.length; i++) {

      var change = changes[i];

      var from = offsetPos(change.from, oldPrev, newPrev);

      var to = offsetPos(changeEnd(change), oldPrev, newPrev);

      oldPrev = change.to;

      newPrev = to;

      if (hint == "around") {

        var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;

        out[i] = new Range(inv ? to : from, inv ? from : to);

      } else {

        out[i] = new Range(from, from);

      }

    }

    return new Selection(out, doc.sel.primIndex);

  }



  // Allow "beforeChange" event handlers to influence a change

  function filterChange(doc, change, update) {

    var obj = {

      canceled: false,

      from: change.from,

      to: change.to,

      text: change.text,

      origin: change.origin,

      cancel: function() { this.canceled = true; }

    };

    if (update) obj.update = function(from, to, text, origin) {

      if (from) this.from = clipPos(doc, from);

      if (to) this.to = clipPos(doc, to);

      if (text) this.text = text;

      if (origin !== undefined) this.origin = origin;

    };

    signal(doc, "beforeChange", doc, obj);

    if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);



    if (obj.canceled) return null;

    return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};

  }



  // Apply a change to a document, and add it to the document's

  // history, and propagating it to all linked documents.

  function makeChange(doc, change, ignoreReadOnly) {

    if (doc.cm) {

      if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly);

      if (doc.cm.state.suppressEdits) return;

    }



    if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {

      change = filterChange(doc, change, true);

      if (!change) return;

    }



    // Possibly split or suppress the update based on the presence

    // of read-only spans in its range.

    var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);

    if (split) {

      for (var i = split.length - 1; i >= 0; --i)

        makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text});

    } else {

      makeChangeInner(doc, change);

    }

  }



  function makeChangeInner(doc, change) {

    if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) return;

    var selAfter = computeSelAfterChange(doc, change);

    addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);



    makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));

    var rebased = [];



    linkedDocs(doc, function(doc, sharedHist) {

      if (!sharedHist && indexOf(rebased, doc.history) == -1) {

        rebaseHist(doc.history, change);

        rebased.push(doc.history);

      }

      makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));

    });

  }



  // Revert a change stored in a document's history.

  function makeChangeFromHistory(doc, type, allowSelectionOnly) {

    if (doc.cm && doc.cm.state.suppressEdits && !allowSelectionOnly) return;



    var hist = doc.history, event, selAfter = doc.sel;

    var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;



    // Verify that there is a useable event (so that ctrl-z won't

    // needlessly clear selection events)

    for (var i = 0; i < source.length; i++) {

      event = source[i];

      if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)

        break;

    }

    if (i == source.length) return;

    hist.lastOrigin = hist.lastSelOrigin = null;



    for (;;) {

      event = source.pop();

      if (event.ranges) {

        pushSelectionToHistory(event, dest);

        if (allowSelectionOnly && !event.equals(doc.sel)) {

          setSelection(doc, event, {clearRedo: false});

          return;

        }

        selAfter = event;

      }

      else break;

    }



    // Build up a reverse change object to add to the opposite history

    // stack (redo when undoing, and vice versa).

    var antiChanges = [];

    pushSelectionToHistory(selAfter, dest);

    dest.push({changes: antiChanges, generation: hist.generation});

    hist.generation = event.generation || ++hist.maxGeneration;



    var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");



    for (var i = event.changes.length - 1; i >= 0; --i) {

      var change = event.changes[i];

      change.origin = type;

      if (filter && !filterChange(doc, change, false)) {

        source.length = 0;

        return;

      }



      antiChanges.push(historyChangeFromChange(doc, change));



      var after = i ? computeSelAfterChange(doc, change) : lst(source);

      makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));

      if (!i && doc.cm) doc.cm.scrollIntoView({from: change.from, to: changeEnd(change)});

      var rebased = [];



      // Propagate to the linked documents

      linkedDocs(doc, function(doc, sharedHist) {

        if (!sharedHist && indexOf(rebased, doc.history) == -1) {

          rebaseHist(doc.history, change);

          rebased.push(doc.history);

        }

        makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));

      });

    }

  }



  // Sub-views need their line numbers shifted when text is added

  // above or below them in the parent document.

  function shiftDoc(doc, distance) {

    if (distance == 0) return;

    doc.first += distance;

    doc.sel = new Selection(map(doc.sel.ranges, function(range) {

      return new Range(Pos(range.anchor.line + distance, range.anchor.ch),

                       Pos(range.head.line + distance, range.head.ch));

    }), doc.sel.primIndex);

    if (doc.cm) {

      regChange(doc.cm, doc.first, doc.first - distance, distance);

      for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++)

        regLineChange(doc.cm, l, "gutter");

    }

  }



  // More lower-level change function, handling only a single document

  // (not linked ones).

  function makeChangeSingleDoc(doc, change, selAfter, spans) {

    if (doc.cm && !doc.cm.curOp)

      return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);



    if (change.to.line < doc.first) {

      shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));

      return;

    }

    if (change.from.line > doc.lastLine()) return;



    // Clip the change to the size of this doc

    if (change.from.line < doc.first) {

      var shift = change.text.length - 1 - (doc.first - change.from.line);

      shiftDoc(doc, shift);

      change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),

                text: [lst(change.text)], origin: change.origin};

    }

    var last = doc.lastLine();

    if (change.to.line > last) {

      change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),

                text: [change.text[0]], origin: change.origin};

    }



    change.removed = getBetween(doc, change.from, change.to);



    if (!selAfter) selAfter = computeSelAfterChange(doc, change);

    if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans);

    else updateDoc(doc, change, spans);

    setSelectionNoUndo(doc, selAfter, sel_dontScroll);

  }



  // Handle the interaction of a change to a document with the editor

  // that this document is part of.

  function makeChangeSingleDocInEditor(cm, change, spans) {

    var doc = cm.doc, display = cm.display, from = change.from, to = change.to;



    var recomputeMaxLength = false, checkWidthStart = from.line;

    if (!cm.options.lineWrapping) {

      checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));

      doc.iter(checkWidthStart, to.line + 1, function(line) {

        if (line == display.maxLine) {

          recomputeMaxLength = true;

          return true;

        }

      });

    }



    if (doc.sel.contains(change.from, change.to) > -1)

      signalCursorActivity(cm);



    updateDoc(doc, change, spans, estimateHeight(cm));



    if (!cm.options.lineWrapping) {

      doc.iter(checkWidthStart, from.line + change.text.length, function(line) {

        var len = lineLength(line);

        if (len > display.maxLineLength) {

          display.maxLine = line;

          display.maxLineLength = len;

          display.maxLineChanged = true;

          recomputeMaxLength = false;

        }

      });

      if (recomputeMaxLength) cm.curOp.updateMaxLine = true;

    }



    // Adjust frontier, schedule worker

    doc.frontier = Math.min(doc.frontier, from.line);

    startWorker(cm, 400);



    var lendiff = change.text.length - (to.line - from.line) - 1;

    // Remember that these lines changed, for updating the display

    if (change.full)

      regChange(cm);

    else if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))

      regLineChange(cm, from.line, "text");

    else

      regChange(cm, from.line, to.line + 1, lendiff);



    var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");

    if (changeHandler || changesHandler) {

      var obj = {

        from: from, to: to,

        text: change.text,

        removed: change.removed,

        origin: change.origin

      };

      if (changeHandler) signalLater(cm, "change", cm, obj);

      if (changesHandler) (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj);

    }

    cm.display.selForContextMenu = null;

  }



  function replaceRange(doc, code, from, to, origin) {

    if (!to) to = from;

    if (cmp(to, from) < 0) { var tmp = to; to = from; from = tmp; }

    if (typeof code == "string") code = doc.splitLines(code);

    makeChange(doc, {from: from, to: to, text: code, origin: origin});

  }



  // SCROLLING THINGS INTO VIEW



  // If an editor sits on the top or bottom of the window, partially

  // scrolled out of view, this ensures that the cursor is visible.

  function maybeScrollWindow(cm, coords) {

    if (signalDOMEvent(cm, "scrollCursorIntoView")) return;



    var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;

    if (coords.top + box.top < 0) doScroll = true;

    else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;

    if (doScroll != null && !phantom) {

      var scrollNode = elt("div", "\u200b", null, "position: absolute; top: " +

                           (coords.top - display.viewOffset - paddingTop(cm.display)) + "px; height: " +

                           (coords.bottom - coords.top + scrollGap(cm) + display.barHeight) + "px; left: " +

                           coords.left + "px; width: 2px;");

      cm.display.lineSpace.appendChild(scrollNode);

      scrollNode.scrollIntoView(doScroll);

      cm.display.lineSpace.removeChild(scrollNode);

    }

  }



  // Scroll a given position into view (immediately), verifying that

  // it actually became visible (as line heights are accurately

  // measured, the position of something may 'drift' during drawing).

  function scrollPosIntoView(cm, pos, end, margin) {

    if (margin == null) margin = 0;

    for (var limit = 0; limit < 5; limit++) {

      var changed = false, coords = cursorCoords(cm, pos);

      var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);

      var scrollPos = calculateScrollPos(cm, Math.min(coords.left, endCoords.left),

                                         Math.min(coords.top, endCoords.top) - margin,

                                         Math.max(coords.left, endCoords.left),

                                         Math.max(coords.bottom, endCoords.bottom) + margin);

      var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;

      if (scrollPos.scrollTop != null) {

        setScrollTop(cm, scrollPos.scrollTop);

        if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;

      }

      if (scrollPos.scrollLeft != null) {

        setScrollLeft(cm, scrollPos.scrollLeft);

        if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;

      }

      if (!changed) break;

    }

    return coords;

  }



  // Scroll a given set of coordinates into view (immediately).

  function scrollIntoView(cm, x1, y1, x2, y2) {

    var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);

    if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);

    if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);

  }



  // Calculate a new scroll position needed to scroll the given

  // rectangle into view. Returns an object with scrollTop and

  // scrollLeft properties. When these are undefined, the

  // vertical/horizontal position does not need to be adjusted.

  function calculateScrollPos(cm, x1, y1, x2, y2) {

    var display = cm.display, snapMargin = textHeight(cm.display);

    if (y1 < 0) y1 = 0;

    var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;

    var screen = displayHeight(cm), result = {};

    if (y2 - y1 > screen) y2 = y1 + screen;

    var docBottom = cm.doc.height + paddingVert(display);

    var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;

    if (y1 < screentop) {

      result.scrollTop = atTop ? 0 : y1;

    } else if (y2 > screentop + screen) {

      var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);

      if (newTop != screentop) result.scrollTop = newTop;

    }



    var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;

    var screenw = displayWidth(cm) - (cm.options.fixedGutter ? display.gutters.offsetWidth : 0);

    var tooWide = x2 - x1 > screenw;

    if (tooWide) x2 = x1 + screenw;

    if (x1 < 10)

      result.scrollLeft = 0;

    else if (x1 < screenleft)

      result.scrollLeft = Math.max(0, x1 - (tooWide ? 0 : 10));

    else if (x2 > screenw + screenleft - 3)

      result.scrollLeft = x2 + (tooWide ? 0 : 10) - screenw;

    return result;

  }



  // Store a relative adjustment to the scroll position in the current

  // operation (to be applied when the operation finishes).

  function addToScrollPos(cm, left, top) {

    if (left != null || top != null) resolveScrollToPos(cm);

    if (left != null)

      cm.curOp.scrollLeft = (cm.curOp.scrollLeft == null ? cm.doc.scrollLeft : cm.curOp.scrollLeft) + left;

    if (top != null)

      cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;

  }



  // Make sure that at the end of the operation the current cursor is

  // shown.

  function ensureCursorVisible(cm) {

    resolveScrollToPos(cm);

    var cur = cm.getCursor(), from = cur, to = cur;

    if (!cm.options.lineWrapping) {

      from = cur.ch ? Pos(cur.line, cur.ch - 1) : cur;

      to = Pos(cur.line, cur.ch + 1);

    }

    cm.curOp.scrollToPos = {from: from, to: to, margin: cm.options.cursorScrollMargin, isCursor: true};

  }



  // When an operation has its scrollToPos property set, and another

  // scroll action is applied before the end of the operation, this

  // 'simulates' scrolling that position into view in a cheap way, so

  // that the effect of intermediate scroll commands is not ignored.

  function resolveScrollToPos(cm) {

    var range = cm.curOp.scrollToPos;

    if (range) {

      cm.curOp.scrollToPos = null;

      var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);

      var sPos = calculateScrollPos(cm, Math.min(from.left, to.left),

                                    Math.min(from.top, to.top) - range.margin,

                                    Math.max(from.right, to.right),

                                    Math.max(from.bottom, to.bottom) + range.margin);

      cm.scrollTo(sPos.scrollLeft, sPos.scrollTop);

    }

  }



  // API UTILITIES



  // Indent the given line. The how parameter can be "smart",

  // "add"/null, "subtract", or "prev". When aggressive is false

  // (typically set to true for forced single-line indents), empty

  // lines are not indented, and places where the mode returns Pass

  // are left alone.

  function indentLine(cm, n, how, aggressive) {

    var doc = cm.doc, state;

    if (how == null) how = "add";

    if (how == "smart") {

      // Fall back to "prev" when the mode doesn't have an indentation

      // method.

      if (!doc.mode.indent) how = "prev";

      else state = getStateBefore(cm, n);

    }



    var tabSize = cm.options.tabSize;

    var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);

    if (line.stateAfter) line.stateAfter = null;

    var curSpaceString = line.text.match(/^\s*/)[0], indentation;

    if (!aggressive && !/\S/.test(line.text)) {

      indentation = 0;

      how = "not";

    } else if (how == "smart") {

      indentation = doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);

      if (indentation == Pass || indentation > 150) {

        if (!aggressive) return;

        how = "prev";

      }

    }

    if (how == "prev") {

      if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);

      else indentation = 0;

    } else if (how == "add") {

      indentation = curSpace + cm.options.indentUnit;

    } else if (how == "subtract") {

      indentation = curSpace - cm.options.indentUnit;

    } else if (typeof how == "number") {

      indentation = curSpace + how;

    }

    indentation = Math.max(0, indentation);



    var indentString = "", pos = 0;

    if (cm.options.indentWithTabs)

      for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}

    if (pos < indentation) indentString += spaceStr(indentation - pos);



    if (indentString != curSpaceString) {

      replaceRange(doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");

      line.stateAfter = null;

      return true;

    } else {

      // Ensure that, if the cursor was in the whitespace at the start

      // of the line, it is moved to the end of that space.

      for (var i = 0; i < doc.sel.ranges.length; i++) {

        var range = doc.sel.ranges[i];

        if (range.head.line == n && range.head.ch < curSpaceString.length) {

          var pos = Pos(n, curSpaceString.length);

          replaceOneSelection(doc, i, new Range(pos, pos));

          break;

        }

      }

    }

  }



  // Utility for applying a change to a line by handle or number,

  // returning the number and optionally registering the line as

  // changed.

  function changeLine(doc, handle, changeType, op) {

    var no = handle, line = handle;

    if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));

    else no = lineNo(handle);

    if (no == null) return null;

    if (op(line, no) && doc.cm) regLineChange(doc.cm, no, changeType);

    return line;

  }



  // Helper for deleting text near the selection(s), used to implement

  // backspace, delete, and similar functionality.

  function deleteNearSelection(cm, compute) {

    var ranges = cm.doc.sel.ranges, kill = [];

    // Build up a set of ranges to kill first, merging overlapping

    // ranges.

    for (var i = 0; i < ranges.length; i++) {

      var toKill = compute(ranges[i]);

      while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {

        var replaced = kill.pop();

        if (cmp(replaced.from, toKill.from) < 0) {

          toKill.from = replaced.from;

          break;

        }

      }

      kill.push(toKill);

    }

    // Next, remove those actual ranges.

    runInOp(cm, function() {

      for (var i = kill.length - 1; i >= 0; i--)

        replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete");

      ensureCursorVisible(cm);

    });

  }



  // Used for horizontal relative motion. Dir is -1 or 1 (left or

  // right), unit can be "char", "column" (like char, but doesn't

  // cross line boundaries), "word" (across next word), or "group" (to

  // the start of next group of word or non-word-non-whitespace

  // chars). The visually param controls whether, in right-to-left

  // text, direction 1 means to move towards the next index in the

  // string, or towards the character to the right of the current

  // position. The resulting position will have a hitSide=true

  // property if it reached the end of the document.

  function findPosH(doc, pos, dir, unit, visually) {

    var line = pos.line, ch = pos.ch, origDir = dir;

    var lineObj = getLine(doc, line);

    function findNextLine() {

      var l = line + dir;

      if (l < doc.first || l >= doc.first + doc.size) return false

      line = l;

      return lineObj = getLine(doc, l);

    }

    function moveOnce(boundToLine) {

      var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);

      if (next == null) {

        if (!boundToLine && findNextLine()) {

          if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);

          else ch = dir < 0 ? lineObj.text.length : 0;

        } else return false

      } else ch = next;

      return true;

    }



    if (unit == "char") {

      moveOnce()

    } else if (unit == "column") {

      moveOnce(true)

    } else if (unit == "word" || unit == "group") {

      var sawType = null, group = unit == "group";

      var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");

      for (var first = true;; first = false) {

        if (dir < 0 && !moveOnce(!first)) break;

        var cur = lineObj.text.charAt(ch) || "\n";

        var type = isWordChar(cur, helper) ? "w"

          : group && cur == "\n" ? "n"

          : !group || /\s/.test(cur) ? null

          : "p";

        if (group && !first && !type) type = "s";

        if (sawType && sawType != type) {

          if (dir < 0) {dir = 1; moveOnce();}

          break;

        }



        if (type) sawType = type;

        if (dir > 0 && !moveOnce(!first)) break;

      }

    }

    var result = skipAtomic(doc, Pos(line, ch), pos, origDir, true);

    if (!cmp(pos, result)) result.hitSide = true;

    return result;

  }



  // For relative vertical movement. Dir may be -1 or 1. Unit can be

  // "page" or "line". The resulting position will have a hitSide=true

  // property if it reached the end of the document.

  function findPosV(cm, pos, dir, unit) {

    var doc = cm.doc, x = pos.left, y;

    if (unit == "page") {

      var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);

      var moveAmount = Math.max(pageSize - .5 * textHeight(cm.display), 3);

      y = (dir > 0 ? pos.bottom : pos.top) + dir * moveAmount;

    } else if (unit == "line") {

      y = dir > 0 ? pos.bottom + 3 : pos.top - 3;

    }

    for (;;) {

      var target = coordsChar(cm, x, y);

      if (!target.outside) break;

      if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }

      y += dir * 5;

    }

    return target;

  }



  // EDITOR METHODS



  // The publicly visible API. Note that methodOp(f) means

  // 'wrap f in an operation, performed on its `this` parameter'.



  // This is not the complete set of editor methods. Most of the

  // methods defined on the Doc type are also injected into

  // CodeMirror.prototype, for backwards compatibility and

  // convenience.



  CodeMirror.prototype = {

    constructor: CodeMirror,

    focus: function(){window.focus(); this.display.input.focus();},



    setOption: function(option, value) {

      var options = this.options, old = options[option];

      if (options[option] == value && option != "mode") return;

      options[option] = value;

      if (optionHandlers.hasOwnProperty(option))

        operation(this, optionHandlers[option])(this, value, old);

    },



    getOption: function(option) {return this.options[option];},

    getDoc: function() {return this.doc;},



    addKeyMap: function(map, bottom) {

      this.state.keyMaps[bottom ? "push" : "unshift"](getKeyMap(map));

    },

    removeKeyMap: function(map) {

      var maps = this.state.keyMaps;

      for (var i = 0; i < maps.length; ++i)

        if (maps[i] == map || maps[i].name == map) {

          maps.splice(i, 1);

          return true;

        }

    },



    addOverlay: methodOp(function(spec, options) {

      var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);

      if (mode.startState) throw new Error("Overlays may not be stateful.");

      insertSorted(this.state.overlays,

                   {mode: mode, modeSpec: spec, opaque: options && options.opaque,

                    priority: (options && options.priority) || 0},

                   function(overlay) { return overlay.priority })

      this.state.modeGen++;

      regChange(this);

    }),

    removeOverlay: methodOp(function(spec) {

      var overlays = this.state.overlays;

      for (var i = 0; i < overlays.length; ++i) {

        var cur = overlays[i].modeSpec;

        if (cur == spec || typeof spec == "string" && cur.name == spec) {

          overlays.splice(i, 1);

          this.state.modeGen++;

          regChange(this);

          return;

        }

      }

    }),



    indentLine: methodOp(function(n, dir, aggressive) {

      if (typeof dir != "string" && typeof dir != "number") {

        if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";

        else dir = dir ? "add" : "subtract";

      }

      if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);

    }),

    indentSelection: methodOp(function(how) {

      var ranges = this.doc.sel.ranges, end = -1;

      for (var i = 0; i < ranges.length; i++) {

        var range = ranges[i];

        if (!range.empty()) {

          var from = range.from(), to = range.to();

          var start = Math.max(end, from.line);

          end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;

          for (var j = start; j < end; ++j)

            indentLine(this, j, how);

          var newRanges = this.doc.sel.ranges;

          if (from.ch == 0 && ranges.length == newRanges.length && newRanges[i].from().ch > 0)

            replaceOneSelection(this.doc, i, new Range(from, newRanges[i].to()), sel_dontScroll);

        } else if (range.head.line > end) {

          indentLine(this, range.head.line, how, true);

          end = range.head.line;

          if (i == this.doc.sel.primIndex) ensureCursorVisible(this);

        }

      }

    }),



    // Fetch the parser token for a given character. Useful for hacks

    // that want to inspect the mode state (say, for completion).

    getTokenAt: function(pos, precise) {

      return takeToken(this, pos, precise);

    },



    getLineTokens: function(line, precise) {

      return takeToken(this, Pos(line), precise, true);

    },



    getTokenTypeAt: function(pos) {

      pos = clipPos(this.doc, pos);

      var styles = getLineStyles(this, getLine(this.doc, pos.line));

      var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;

      var type;

      if (ch == 0) type = styles[2];

      else for (;;) {

        var mid = (before + after) >> 1;

        if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;

        else if (styles[mid * 2 + 1] < ch) before = mid + 1;

        else { type = styles[mid * 2 + 2]; break; }

      }

      var cut = type ? type.indexOf("cm-overlay ") : -1;

      return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1);

    },



    getModeAt: function(pos) {

      var mode = this.doc.mode;

      if (!mode.innerMode) return mode;

      return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;

    },



    getHelper: function(pos, type) {

      return this.getHelpers(pos, type)[0];

    },



    getHelpers: function(pos, type) {

      var found = [];

      if (!helpers.hasOwnProperty(type)) return found;

      var help = helpers[type], mode = this.getModeAt(pos);

      if (typeof mode[type] == "string") {

        if (help[mode[type]]) found.push(help[mode[type]]);

      } else if (mode[type]) {

        for (var i = 0; i < mode[type].length; i++) {

          var val = help[mode[type][i]];

          if (val) found.push(val);

        }

      } else if (mode.helperType && help[mode.helperType]) {

        found.push(help[mode.helperType]);

      } else if (help[mode.name]) {

        found.push(help[mode.name]);

      }

      for (var i = 0; i < help._global.length; i++) {

        var cur = help._global[i];

        if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)

          found.push(cur.val);

      }

      return found;

    },



    getStateAfter: function(line, precise) {

      var doc = this.doc;

      line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);

      return getStateBefore(this, line + 1, precise);

    },



    cursorCoords: function(start, mode) {

      var pos, range = this.doc.sel.primary();

      if (start == null) pos = range.head;

      else if (typeof start == "object") pos = clipPos(this.doc, start);

      else pos = start ? range.from() : range.to();

      return cursorCoords(this, pos, mode || "page");

    },



    charCoords: function(pos, mode) {

      return charCoords(this, clipPos(this.doc, pos), mode || "page");

    },



    coordsChar: function(coords, mode) {

      coords = fromCoordSystem(this, coords, mode || "page");

      return coordsChar(this, coords.left, coords.top);

    },



    lineAtHeight: function(height, mode) {

      height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;

      return lineAtHeight(this.doc, height + this.display.viewOffset);

    },

    heightAtLine: function(line, mode) {

      var end = false, lineObj;

      if (typeof line == "number") {

        var last = this.doc.first + this.doc.size - 1;

        if (line < this.doc.first) line = this.doc.first;

        else if (line > last) { line = last; end = true; }

        lineObj = getLine(this.doc, line);

      } else {

        lineObj = line;

      }

      return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page").top +

        (end ? this.doc.height - heightAtLine(lineObj) : 0);

    },



    defaultTextHeight: function() { return textHeight(this.display); },

    defaultCharWidth: function() { return charWidth(this.display); },



    setGutterMarker: methodOp(function(line, gutterID, value) {

      return changeLine(this.doc, line, "gutter", function(line) {

        var markers = line.gutterMarkers || (line.gutterMarkers = {});

        markers[gutterID] = value;

        if (!value && isEmpty(markers)) line.gutterMarkers = null;

        return true;

      });

    }),



    clearGutter: methodOp(function(gutterID) {

      var cm = this, doc = cm.doc, i = doc.first;

      doc.iter(function(line) {

        if (line.gutterMarkers && line.gutterMarkers[gutterID]) {

          line.gutterMarkers[gutterID] = null;

          regLineChange(cm, i, "gutter");

          if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;

        }

        ++i;

      });

    }),



    lineInfo: function(line) {

      if (typeof line == "number") {

        if (!isLine(this.doc, line)) return null;

        var n = line;

        line = getLine(this.doc, line);

        if (!line) return null;

      } else {

        var n = lineNo(line);

        if (n == null) return null;

      }

      return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,

              textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,

              widgets: line.widgets};

    },



    getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo};},



    addWidget: function(pos, node, scroll, vert, horiz) {

      var display = this.display;

      pos = cursorCoords(this, clipPos(this.doc, pos));

      var top = pos.bottom, left = pos.left;

      node.style.position = "absolute";

      node.setAttribute("cm-ignore-events", "true");

      this.display.input.setUneditable(node);

      display.sizer.appendChild(node);

      if (vert == "over") {

        top = pos.top;

      } else if (vert == "above" || vert == "near") {

        var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),

        hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);

        // Default to positioning above (if specified and possible); otherwise default to positioning below

        if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)

          top = pos.top - node.offsetHeight;

        else if (pos.bottom + node.offsetHeight <= vspace)

          top = pos.bottom;

        if (left + node.offsetWidth > hspace)

          left = hspace - node.offsetWidth;

      }

      node.style.top = top + "px";

      node.style.left = node.style.right = "";

      if (horiz == "right") {

        left = display.sizer.clientWidth - node.offsetWidth;

        node.style.right = "0px";

      } else {

        if (horiz == "left") left = 0;

        else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;

        node.style.left = left + "px";

      }

      if (scroll)

        scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);

    },



    triggerOnKeyDown: methodOp(onKeyDown),

    triggerOnKeyPress: methodOp(onKeyPress),

    triggerOnKeyUp: onKeyUp,



    execCommand: function(cmd) {

      if (commands.hasOwnProperty(cmd))

        return commands[cmd].call(null, this);

    },



    triggerElectric: methodOp(function(text) { triggerElectric(this, text); }),



    findPosH: function(from, amount, unit, visually) {

      var dir = 1;

      if (amount < 0) { dir = -1; amount = -amount; }

      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {

        cur = findPosH(this.doc, cur, dir, unit, visually);

        if (cur.hitSide) break;

      }

      return cur;

    },



    moveH: methodOp(function(dir, unit) {

      var cm = this;

      cm.extendSelectionsBy(function(range) {

        if (cm.display.shift || cm.doc.extend || range.empty())

          return findPosH(cm.doc, range.head, dir, unit, cm.options.rtlMoveVisually);

        else

          return dir < 0 ? range.from() : range.to();

      }, sel_move);

    }),



    deleteH: methodOp(function(dir, unit) {

      var sel = this.doc.sel, doc = this.doc;

      if (sel.somethingSelected())

        doc.replaceSelection("", null, "+delete");

      else

        deleteNearSelection(this, function(range) {

          var other = findPosH(doc, range.head, dir, unit, false);

          return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other};

        });

    }),



    findPosV: function(from, amount, unit, goalColumn) {

      var dir = 1, x = goalColumn;

      if (amount < 0) { dir = -1; amount = -amount; }

      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {

        var coords = cursorCoords(this, cur, "div");

        if (x == null) x = coords.left;

        else coords.left = x;

        cur = findPosV(this, coords, dir, unit);

        if (cur.hitSide) break;

      }

      return cur;

    },



    moveV: methodOp(function(dir, unit) {

      var cm = this, doc = this.doc, goals = [];

      var collapse = !cm.display.shift && !doc.extend && doc.sel.somethingSelected();

      doc.extendSelectionsBy(function(range) {

        if (collapse)

          return dir < 0 ? range.from() : range.to();

        var headPos = cursorCoords(cm, range.head, "div");

        if (range.goalColumn != null) headPos.left = range.goalColumn;

        goals.push(headPos.left);

        var pos = findPosV(cm, headPos, dir, unit);

        if (unit == "page" && range == doc.sel.primary())

          addToScrollPos(cm, null, charCoords(cm, pos, "div").top - headPos.top);

        return pos;

      }, sel_move);

      if (goals.length) for (var i = 0; i < doc.sel.ranges.length; i++)

        doc.sel.ranges[i].goalColumn = goals[i];

    }),



    // Find the word at the given position (as returned by coordsChar).

    findWordAt: function(pos) {

      var doc = this.doc, line = getLine(doc, pos.line).text;

      var start = pos.ch, end = pos.ch;

      if (line) {

        var helper = this.getHelper(pos, "wordChars");

        if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;

        var startChar = line.charAt(start);

        var check = isWordChar(startChar, helper)

          ? function(ch) { return isWordChar(ch, helper); }

          : /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}

          : function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};

        while (start > 0 && check(line.charAt(start - 1))) --start;

        while (end < line.length && check(line.charAt(end))) ++end;

      }

      return new Range(Pos(pos.line, start), Pos(pos.line, end));

    },



    toggleOverwrite: function(value) {

      if (value != null && value == this.state.overwrite) return;

      if (this.state.overwrite = !this.state.overwrite)

        addClass(this.display.cursorDiv, "CodeMirror-overwrite");

      else

        rmClass(this.display.cursorDiv, "CodeMirror-overwrite");



      signal(this, "overwriteToggle", this, this.state.overwrite);

    },

    hasFocus: function() { return this.display.input.getField() == activeElt(); },

    isReadOnly: function() { return !!(this.options.readOnly || this.doc.cantEdit); },



    scrollTo: methodOp(function(x, y) {

      if (x != null || y != null) resolveScrollToPos(this);

      if (x != null) this.curOp.scrollLeft = x;

      if (y != null) this.curOp.scrollTop = y;

    }),

    getScrollInfo: function() {

      var scroller = this.display.scroller;

      return {left: scroller.scrollLeft, top: scroller.scrollTop,

              height: scroller.scrollHeight - scrollGap(this) - this.display.barHeight,

              width: scroller.scrollWidth - scrollGap(this) - this.display.barWidth,

              clientHeight: displayHeight(this), clientWidth: displayWidth(this)};

    },



    scrollIntoView: methodOp(function(range, margin) {

      if (range == null) {

        range = {from: this.doc.sel.primary().head, to: null};

        if (margin == null) margin = this.options.cursorScrollMargin;

      } else if (typeof range == "number") {

        range = {from: Pos(range, 0), to: null};

      } else if (range.from == null) {

        range = {from: range, to: null};

      }

      if (!range.to) range.to = range.from;

      range.margin = margin || 0;



      if (range.from.line != null) {

        resolveScrollToPos(this);

        this.curOp.scrollToPos = range;

      } else {

        var sPos = calculateScrollPos(this, Math.min(range.from.left, range.to.left),

                                      Math.min(range.from.top, range.to.top) - range.margin,

                                      Math.max(range.from.right, range.to.right),

                                      Math.max(range.from.bottom, range.to.bottom) + range.margin);

        this.scrollTo(sPos.scrollLeft, sPos.scrollTop);

      }

    }),



    setSize: methodOp(function(width, height) {

      var cm = this;

      function interpret(val) {

        return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;

      }

      if (width != null) cm.display.wrapper.style.width = interpret(width);

      if (height != null) cm.display.wrapper.style.height = interpret(height);

      if (cm.options.lineWrapping) clearLineMeasurementCache(this);

      var lineNo = cm.display.viewFrom;

      cm.doc.iter(lineNo, cm.display.viewTo, function(line) {

        if (line.widgets) for (var i = 0; i < line.widgets.length; i++)

          if (line.widgets[i].noHScroll) { regLineChange(cm, lineNo, "widget"); break; }

        ++lineNo;

      });

      cm.curOp.forceUpdate = true;

      signal(cm, "refresh", this);

    }),



    operation: function(f){return runInOp(this, f);},



    refresh: methodOp(function() {

      var oldHeight = this.display.cachedTextHeight;

      regChange(this);

      this.curOp.forceUpdate = true;

      clearCaches(this);

      this.scrollTo(this.doc.scrollLeft, this.doc.scrollTop);

      updateGutterSpace(this);

      if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)

        estimateLineHeights(this);

      signal(this, "refresh", this);

    }),



    swapDoc: methodOp(function(doc) {

      var old = this.doc;

      old.cm = null;

      attachDoc(this, doc);

      clearCaches(this);

      this.display.input.reset();

      this.scrollTo(doc.scrollLeft, doc.scrollTop);

      this.curOp.forceScroll = true;

      signalLater(this, "swapDoc", this, old);

      return old;

    }),



    getInputField: function(){return this.display.input.getField();},

    getWrapperElement: function(){return this.display.wrapper;},

    getScrollerElement: function(){return this.display.scroller;},

    getGutterElement: function(){return this.display.gutters;}

  };

  eventMixin(CodeMirror);



  // OPTION DEFAULTS



  // The default configuration options.

  var defaults = CodeMirror.defaults = {};

  // Functions to run when options are changed.

  var optionHandlers = CodeMirror.optionHandlers = {};



  function option(name, deflt, handle, notOnInit) {

    CodeMirror.defaults[name] = deflt;

    if (handle) optionHandlers[name] =

      notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;

  }



  // Passed to option handlers when there is no old value.

  var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};



  // These two are, on init, called from the constructor because they

  // have to be initialized before the editor can start at all.

  option("value", "", function(cm, val) {

    cm.setValue(val);

  }, true);

  option("mode", null, function(cm, val) {

    cm.doc.modeOption = val;

    loadMode(cm);

  }, true);



  option("indentUnit", 2, loadMode, true);

  option("indentWithTabs", false);

  option("smartIndent", true);

  option("tabSize", 4, function(cm) {

    resetModeState(cm);

    clearCaches(cm);

    regChange(cm);

  }, true);

  option("lineSeparator", null, function(cm, val) {

    cm.doc.lineSep = val;

    if (!val) return;

    var newBreaks = [], lineNo = cm.doc.first;

    cm.doc.iter(function(line) {

      for (var pos = 0;;) {

        var found = line.text.indexOf(val, pos);

        if (found == -1) break;

        pos = found + val.length;

        newBreaks.push(Pos(lineNo, found));

      }

      lineNo++;

    });

    for (var i = newBreaks.length - 1; i >= 0; i--)

      replaceRange(cm.doc, val, newBreaks[i], Pos(newBreaks[i].line, newBreaks[i].ch + val.length))

  });

  option("specialChars", /[\u0000-\u001f\u007f\u00ad\u200b-\u200f\u2028\u2029\ufeff]/g, function(cm, val, old) {

    cm.state.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");

    if (old != CodeMirror.Init) cm.refresh();

  });

  option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function(cm) {cm.refresh();}, true);

  option("electricChars", true);

  option("inputStyle", mobile ? "contenteditable" : "textarea", function() {

    throw new Error("inputStyle can not (yet) be changed in a running editor"); // FIXME

  }, true);

  option("spellcheck", false, function(cm, val) {

    cm.getInputField().spellcheck = val

  }, true);

  option("rtlMoveVisually", !windows);

  option("wholeLineUpdateBefore", true);



  option("theme", "default", function(cm) {

    themeChanged(cm);

    guttersChanged(cm);

  }, true);

  option("keyMap", "default", function(cm, val, old) {

    var next = getKeyMap(val);

    var prev = old != CodeMirror.Init && getKeyMap(old);

    if (prev && prev.detach) prev.detach(cm, next);

    if (next.attach) next.attach(cm, prev || null);

  });

  option("extraKeys", null);



  option("lineWrapping", false, wrappingChanged, true);

  option("gutters", [], function(cm) {

    setGuttersForLineNumbers(cm.options);

    guttersChanged(cm);

  }, true);

  option("fixedGutter", true, function(cm, val) {

    cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";

    cm.refresh();

  }, true);

  option("coverGutterNextToScrollbar", false, function(cm) {updateScrollbars(cm);}, true);

  option("scrollbarStyle", "native", function(cm) {

    initScrollbars(cm);

    updateScrollbars(cm);

    cm.display.scrollbars.setScrollTop(cm.doc.scrollTop);

    cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft);

  }, true);

  option("lineNumbers", false, function(cm) {

    setGuttersForLineNumbers(cm.options);

    guttersChanged(cm);

  }, true);

  option("firstLineNumber", 1, guttersChanged, true);

  option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);

  option("showCursorWhenSelecting", false, updateSelection, true);



  option("resetSelectionOnContextMenu", true);

  option("lineWiseCopyCut", true);



  option("readOnly", false, function(cm, val) {

    if (val == "nocursor") {

      onBlur(cm);

      cm.display.input.blur();

      cm.display.disabled = true;

    } else {

      cm.display.disabled = false;

    }

    cm.display.input.readOnlyChanged(val)

  });

  option("disableInput", false, function(cm, val) {if (!val) cm.display.input.reset();}, true);

  option("dragDrop", true, dragDropChanged);

  option("allowDropFileTypes", null);



  option("cursorBlinkRate", 530);

  option("cursorScrollMargin", 0);

  option("cursorHeight", 1, updateSelection, true);

  option("singleCursorHeightPerLine", true, updateSelection, true);

  option("workTime", 100);

  option("workDelay", 100);

  option("flattenSpans", true, resetModeState, true);

  option("addModeClass", false, resetModeState, true);

  option("pollInterval", 100);

  option("undoDepth", 200, function(cm, val){cm.doc.history.undoDepth = val;});

  option("historyEventDelay", 1250);

  option("viewportMargin", 10, function(cm){cm.refresh();}, true);

  option("maxHighlightLength", 10000, resetModeState, true);

  option("moveInputWithCursor", true, function(cm, val) {

    if (!val) cm.display.input.resetPosition();

  });



  option("tabindex", null, function(cm, val) {

    cm.display.input.getField().tabIndex = val || "";

  });

  option("autofocus", null);



  // MODE DEFINITION AND QUERYING



  // Known modes, by name and by MIME

  var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};



  // Extra arguments are stored as the mode's dependencies, which is

  // used by (legacy) mechanisms like loadmode.js to automatically

  // load a mode. (Preferred mechanism is the require/define calls.)

  CodeMirror.defineMode = function(name, mode) {

    if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;

    if (arguments.length > 2)

      mode.dependencies = Array.prototype.slice.call(arguments, 2);

    modes[name] = mode;

  };



  CodeMirror.defineMIME = function(mime, spec) {

    mimeModes[mime] = spec;

  };



  // Given a MIME type, a {name, ...options} config object, or a name

  // string, return a mode config object.

  CodeMirror.resolveMode = function(spec) {

    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {

      spec = mimeModes[spec];

    } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {

      var found = mimeModes[spec.name];

      if (typeof found == "string") found = {name: found};

      spec = createObj(found, spec);

      spec.name = found.name;

    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {

      return CodeMirror.resolveMode("application/xml");

    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+json$/.test(spec)) {

      return CodeMirror.resolveMode("application/json");

    }

    if (typeof spec == "string") return {name: spec};

    else return spec || {name: "null"};

  };



  // Given a mode spec (anything that resolveMode accepts), find and

  // initialize an actual mode object.

  CodeMirror.getMode = function(options, spec) {

    var spec = CodeMirror.resolveMode(spec);

    var mfactory = modes[spec.name];

    if (!mfactory) return CodeMirror.getMode(options, "text/plain");

    var modeObj = mfactory(options, spec);

    if (modeExtensions.hasOwnProperty(spec.name)) {

      var exts = modeExtensions[spec.name];

      for (var prop in exts) {

        if (!exts.hasOwnProperty(prop)) continue;

        if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];

        modeObj[prop] = exts[prop];

      }

    }

    modeObj.name = spec.name;

    if (spec.helperType) modeObj.helperType = spec.helperType;

    if (spec.modeProps) for (var prop in spec.modeProps)

      modeObj[prop] = spec.modeProps[prop];



    return modeObj;

  };



  // Minimal default mode.

  CodeMirror.defineMode("null", function() {

    return {token: function(stream) {stream.skipToEnd();}};

  });

  CodeMirror.defineMIME("text/plain", "null");



  // This can be used to attach properties to mode objects from

  // outside the actual mode definition.

  var modeExtensions = CodeMirror.modeExtensions = {};

  CodeMirror.extendMode = function(mode, properties) {

    var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});

    copyObj(properties, exts);

  };



  // EXTENSIONS



  CodeMirror.defineExtension = function(name, func) {

    CodeMirror.prototype[name] = func;

  };

  CodeMirror.defineDocExtension = function(name, func) {

    Doc.prototype[name] = func;

  };

  CodeMirror.defineOption = option;



  var initHooks = [];

  CodeMirror.defineInitHook = function(f) {initHooks.push(f);};



  var helpers = CodeMirror.helpers = {};

  CodeMirror.registerHelper = function(type, name, value) {

    if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {_global: []};

    helpers[type][name] = value;

  };

  CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {

    CodeMirror.registerHelper(type, name, value);

    helpers[type]._global.push({pred: predicate, val: value});

  };



  // MODE STATE HANDLING



  // Utility functions for working with state. Exported because nested

  // modes need to do this for their inner modes.



  var copyState = CodeMirror.copyState = function(mode, state) {

    if (state === true) return state;

    if (mode.copyState) return mode.copyState(state);

    var nstate = {};

    for (var n in state) {

      var val = state[n];

      if (val instanceof Array) val = val.concat([]);

      nstate[n] = val;

    }

    return nstate;

  };



  var startState = CodeMirror.startState = function(mode, a1, a2) {

    return mode.startState ? mode.startState(a1, a2) : true;

  };



  // Given a mode and a state (for that mode), find the inner mode and

  // state at the position that the state refers to.

  CodeMirror.innerMode = function(mode, state) {

    while (mode.innerMode) {

      var info = mode.innerMode(state);

      if (!info || info.mode == mode) break;

      state = info.state;

      mode = info.mode;

    }

    return info || {mode: mode, state: state};

  };



  // STANDARD COMMANDS



  // Commands are parameter-less actions that can be performed on an

  // editor, mostly used for keybindings.

  var commands = CodeMirror.commands = {

    selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);},

    singleSelection: function(cm) {

      cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll);

    },

    killLine: function(cm) {

      deleteNearSelection(cm, function(range) {

        if (range.empty()) {

          var len = getLine(cm.doc, range.head.line).text.length;

          if (range.head.ch == len && range.head.line < cm.lastLine())

            return {from: range.head, to: Pos(range.head.line + 1, 0)};

          else

            return {from: range.head, to: Pos(range.head.line, len)};

        } else {

          return {from: range.from(), to: range.to()};

        }

      });

    },

    deleteLine: function(cm) {

      deleteNearSelection(cm, function(range) {

        return {from: Pos(range.from().line, 0),

                to: clipPos(cm.doc, Pos(range.to().line + 1, 0))};

      });

    },

    delLineLeft: function(cm) {

      deleteNearSelection(cm, function(range) {

        return {from: Pos(range.from().line, 0), to: range.from()};

      });

    },

    delWrappedLineLeft: function(cm) {

      deleteNearSelection(cm, function(range) {

        var top = cm.charCoords(range.head, "div").top + 5;

        var leftPos = cm.coordsChar({left: 0, top: top}, "div");

        return {from: leftPos, to: range.from()};

      });

    },

    delWrappedLineRight: function(cm) {

      deleteNearSelection(cm, function(range) {

        var top = cm.charCoords(range.head, "div").top + 5;

        var rightPos = cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");

        return {from: range.from(), to: rightPos };

      });

    },

    undo: function(cm) {cm.undo();},

    redo: function(cm) {cm.redo();},

    undoSelection: function(cm) {cm.undoSelection();},

    redoSelection: function(cm) {cm.redoSelection();},

    goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},

    goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},

    goLineStart: function(cm) {

      cm.extendSelectionsBy(function(range) { return lineStart(cm, range.head.line); },

                            {origin: "+move", bias: 1});

    },

    goLineStartSmart: function(cm) {

      cm.extendSelectionsBy(function(range) {

        return lineStartSmart(cm, range.head);

      }, {origin: "+move", bias: 1});

    },

    goLineEnd: function(cm) {

      cm.extendSelectionsBy(function(range) { return lineEnd(cm, range.head.line); },

                            {origin: "+move", bias: -1});

    },

    goLineRight: function(cm) {

      cm.extendSelectionsBy(function(range) {

        var top = cm.charCoords(range.head, "div").top + 5;

        return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");

      }, sel_move);

    },

    goLineLeft: function(cm) {

      cm.extendSelectionsBy(function(range) {

        var top = cm.charCoords(range.head, "div").top + 5;

        return cm.coordsChar({left: 0, top: top}, "div");

      }, sel_move);

    },

    goLineLeftSmart: function(cm) {

      cm.extendSelectionsBy(function(range) {

        var top = cm.charCoords(range.head, "div").top + 5;

        var pos = cm.coordsChar({left: 0, top: top}, "div");

        if (pos.ch < cm.getLine(pos.line).search(/\S/)) return lineStartSmart(cm, range.head);

        return pos;

      }, sel_move);

    },

    goLineUp: function(cm) {cm.moveV(-1, "line");},

    goLineDown: function(cm) {cm.moveV(1, "line");},

    goPageUp: function(cm) {cm.moveV(-1, "page");},

    goPageDown: function(cm) {cm.moveV(1, "page");},

    goCharLeft: function(cm) {cm.moveH(-1, "char");},

    goCharRight: function(cm) {cm.moveH(1, "char");},

    goColumnLeft: function(cm) {cm.moveH(-1, "column");},

    goColumnRight: function(cm) {cm.moveH(1, "column");},

    goWordLeft: function(cm) {cm.moveH(-1, "word");},

    goGroupRight: function(cm) {cm.moveH(1, "group");},

    goGroupLeft: function(cm) {cm.moveH(-1, "group");},

    goWordRight: function(cm) {cm.moveH(1, "word");},

    delCharBefore: function(cm) {cm.deleteH(-1, "char");},

    delCharAfter: function(cm) {cm.deleteH(1, "char");},

    delWordBefore: function(cm) {cm.deleteH(-1, "word");},

    delWordAfter: function(cm) {cm.deleteH(1, "word");},

    delGroupBefore: function(cm) {cm.deleteH(-1, "group");},

    delGroupAfter: function(cm) {cm.deleteH(1, "group");},

    indentAuto: function(cm) {cm.indentSelection("smart");},

    indentMore: function(cm) {cm.indentSelection("add");},

    indentLess: function(cm) {cm.indentSelection("subtract");},

    insertTab: function(cm) {cm.replaceSelection("\t");},

    insertSoftTab: function(cm) {

      var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;

      for (var i = 0; i < ranges.length; i++) {

        var pos = ranges[i].from();

        var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);

        spaces.push(spaceStr(tabSize - col % tabSize));

      }

      cm.replaceSelections(spaces);

    },

    defaultTab: function(cm) {

      if (cm.somethingSelected()) cm.indentSelection("add");

      else cm.execCommand("insertTab");

    },

    transposeChars: function(cm) {

      runInOp(cm, function() {

        var ranges = cm.listSelections(), newSel = [];

        for (var i = 0; i < ranges.length; i++) {

          var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;

          if (line) {

            if (cur.ch == line.length) cur = new Pos(cur.line, cur.ch - 1);

            if (cur.ch > 0) {

              cur = new Pos(cur.line, cur.ch + 1);

              cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2),

                              Pos(cur.line, cur.ch - 2), cur, "+transpose");

            } else if (cur.line > cm.doc.first) {

              var prev = getLine(cm.doc, cur.line - 1).text;

              if (prev)

                cm.replaceRange(line.charAt(0) + cm.doc.lineSeparator() +

                                prev.charAt(prev.length - 1),

                                Pos(cur.line - 1, prev.length - 1), Pos(cur.line, 1), "+transpose");

            }

          }

          newSel.push(new Range(cur, cur));

        }

        cm.setSelections(newSel);

      });

    },

    newlineAndIndent: function(cm) {

      runInOp(cm, function() {

        var len = cm.listSelections().length;

        for (var i = 0; i < len; i++) {

          var range = cm.listSelections()[i];

          cm.replaceRange(cm.doc.lineSeparator(), range.anchor, range.head, "+input");

          cm.indentLine(range.from().line + 1, null, true);

        }

        ensureCursorVisible(cm);

      });

    },

    openLine: function(cm) {cm.replaceSelection("\n", "start")},

    toggleOverwrite: function(cm) {cm.toggleOverwrite();}

  };





  // STANDARD KEYMAPS



  var keyMap = CodeMirror.keyMap = {};



  keyMap.basic = {

    "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",

    "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",

    "Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",

    "Tab": "defaultTab", "Shift-Tab": "indentAuto",

    "Enter": "newlineAndIndent", "Insert": "toggleOverwrite",

    "Esc": "singleSelection"

  };

  // Note that the save and find-related commands aren't defined by

  // default. User code or addons can define them. Unknown commands

  // are simply ignored.

  keyMap.pcDefault = {

    "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",

    "Ctrl-Home": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Up": "goLineUp", "Ctrl-Down": "goLineDown",

    "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",

    "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",

    "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",

    "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",

    "Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",

    fallthrough: "basic"

  };

  // Very basic readline/emacs-style bindings, which are standard on Mac.

  keyMap.emacsy = {

    "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",

    "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",

    "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",

    "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars",

    "Ctrl-O": "openLine"

  };

  keyMap.macDefault = {

    "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",

    "Cmd-Home": "goDocStart", "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",

    "Alt-Right": "goGroupRight", "Cmd-Left": "goLineLeft", "Cmd-Right": "goLineRight", "Alt-Backspace": "delGroupBefore",

    "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",

    "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",

    "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delWrappedLineLeft", "Cmd-Delete": "delWrappedLineRight",

    "Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection", "Ctrl-Up": "goDocStart", "Ctrl-Down": "goDocEnd",

    fallthrough: ["basic", "emacsy"]

  };

  keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;



  // KEYMAP DISPATCH



  function normalizeKeyName(name) {

    var parts = name.split(/-(?!$)/), name = parts[parts.length - 1];

    var alt, ctrl, shift, cmd;

    for (var i = 0; i < parts.length - 1; i++) {

      var mod = parts[i];

      if (/^(cmd|meta|m)$/i.test(mod)) cmd = true;

      else if (/^a(lt)?$/i.test(mod)) alt = true;

      else if (/^(c|ctrl|control)$/i.test(mod)) ctrl = true;

      else if (/^s(hift)$/i.test(mod)) shift = true;

      else throw new Error("Unrecognized modifier name: " + mod);

    }

    if (alt) name = "Alt-" + name;

    if (ctrl) name = "Ctrl-" + name;

    if (cmd) name = "Cmd-" + name;

    if (shift) name = "Shift-" + name;

    return name;

  }



  // This is a kludge to keep keymaps mostly working as raw objects

  // (backwards compatibility) while at the same time support features

  // like normalization and multi-stroke key bindings. It compiles a

  // new normalized keymap, and then updates the old object to reflect

  // this.

  CodeMirror.normalizeKeyMap = function(keymap) {

    var copy = {};

    for (var keyname in keymap) if (keymap.hasOwnProperty(keyname)) {

      var value = keymap[keyname];

      if (/^(name|fallthrough|(de|at)tach)$/.test(keyname)) continue;

      if (value == "...") { delete keymap[keyname]; continue; }



      var keys = map(keyname.split(" "), normalizeKeyName);

      for (var i = 0; i < keys.length; i++) {

        var val, name;

        if (i == keys.length - 1) {

          name = keys.join(" ");

          val = value;

        } else {

          name = keys.slice(0, i + 1).join(" ");

          val = "...";

        }

        var prev = copy[name];

        if (!prev) copy[name] = val;

        else if (prev != val) throw new Error("Inconsistent bindings for " + name);

      }

      delete keymap[keyname];

    }

    for (var prop in copy) keymap[prop] = copy[prop];

    return keymap;

  };



  var lookupKey = CodeMirror.lookupKey = function(key, map, handle, context) {

    map = getKeyMap(map);

    var found = map.call ? map.call(key, context) : map[key];

    if (found === false) return "nothing";

    if (found === "...") return "multi";

    if (found != null && handle(found)) return "handled";



    if (map.fallthrough) {

      if (Object.prototype.toString.call(map.fallthrough) != "[object Array]")

        return lookupKey(key, map.fallthrough, handle, context);

      for (var i = 0; i < map.fallthrough.length; i++) {

        var result = lookupKey(key, map.fallthrough[i], handle, context);

        if (result) return result;

      }

    }

  };



  // Modifier key presses don't count as 'real' key presses for the

  // purpose of keymap fallthrough.

  var isModifierKey = CodeMirror.isModifierKey = function(value) {

    var name = typeof value == "string" ? value : keyNames[value.keyCode];

    return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";

  };



  // Look up the name of a key as indicated by an event object.

  var keyName = CodeMirror.keyName = function(event, noShift) {

    if (presto && event.keyCode == 34 && event["char"]) return false;

    var base = keyNames[event.keyCode], name = base;

    if (name == null || event.altGraphKey) return false;

    if (event.altKey && base != "Alt") name = "Alt-" + name;

    if ((flipCtrlCmd ? event.metaKey : event.ctrlKey) && base != "Ctrl") name = "Ctrl-" + name;

    if ((flipCtrlCmd ? event.ctrlKey : event.metaKey) && base != "Cmd") name = "Cmd-" + name;

    if (!noShift && event.shiftKey && base != "Shift") name = "Shift-" + name;

    return name;

  };



  function getKeyMap(val) {

    return typeof val == "string" ? keyMap[val] : val;

  }



  // FROMTEXTAREA



  CodeMirror.fromTextArea = function(textarea, options) {

    options = options ? copyObj(options) : {};

    options.value = textarea.value;

    if (!options.tabindex && textarea.tabIndex)

      options.tabindex = textarea.tabIndex;

    if (!options.placeholder && textarea.placeholder)

      options.placeholder = textarea.placeholder;

    // Set autofocus to true if this textarea is focused, or if it has

    // autofocus and no other element is focused.

    if (options.autofocus == null) {

      var hasFocus = activeElt();

      options.autofocus = hasFocus == textarea ||

        textarea.getAttribute("autofocus") != null && hasFocus == document.body;

    }



    function save() {textarea.value = cm.getValue();}

    if (textarea.form) {

      on(textarea.form, "submit", save);

      // Deplorable hack to make the submit method do the right thing.

      if (!options.leaveSubmitMethodAlone) {

        var form = textarea.form, realSubmit = form.submit;

        try {

          var wrappedSubmit = form.submit = function() {

            save();

            form.submit = realSubmit;

            form.submit();

            form.submit = wrappedSubmit;

          };

        } catch(e) {}

      }

    }



    options.finishInit = function(cm) {

      cm.save = save;

      cm.getTextArea = function() { return textarea; };

      cm.toTextArea = function() {

        cm.toTextArea = isNaN; // Prevent this from being ran twice

        save();

        textarea.parentNode.removeChild(cm.getWrapperElement());

        textarea.style.display = "";

        if (textarea.form) {

          off(textarea.form, "submit", save);

          if (typeof textarea.form.submit == "function")

            textarea.form.submit = realSubmit;

        }

      };

    };



    textarea.style.display = "none";

    var cm = CodeMirror(function(node) {

      textarea.parentNode.insertBefore(node, textarea.nextSibling);

    }, options);

    return cm;

  };



  // STRING STREAM



  // Fed to the mode parsers, provides helper functions to make

  // parsers more succinct.



  var StringStream = CodeMirror.StringStream = function(string, tabSize) {

    this.pos = this.start = 0;

    this.string = string;

    this.tabSize = tabSize || 8;

    this.lastColumnPos = this.lastColumnValue = 0;

    this.lineStart = 0;

  };



  StringStream.prototype = {

    eol: function() {return this.pos >= this.string.length;},

    sol: function() {return this.pos == this.lineStart;},

    peek: function() {return this.string.charAt(this.pos) || undefined;},

    next: function() {

      if (this.pos < this.string.length)

        return this.string.charAt(this.pos++);

    },

    eat: function(match) {

      var ch = this.string.charAt(this.pos);

      if (typeof match == "string") var ok = ch == match;

      else var ok = ch && (match.test ? match.test(ch) : match(ch));

      if (ok) {++this.pos; return ch;}

    },

    eatWhile: function(match) {

      var start = this.pos;

      while (this.eat(match)){}

      return this.pos > start;

    },

    eatSpace: function() {

      var start = this.pos;

      while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;

      return this.pos > start;

    },

    skipToEnd: function() {this.pos = this.string.length;},

    skipTo: function(ch) {

      var found = this.string.indexOf(ch, this.pos);

      if (found > -1) {this.pos = found; return true;}

    },

    backUp: function(n) {this.pos -= n;},

    column: function() {

      if (this.lastColumnPos < this.start) {

        this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);

        this.lastColumnPos = this.start;

      }

      return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);

    },

    indentation: function() {

      return countColumn(this.string, null, this.tabSize) -

        (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);

    },

    match: function(pattern, consume, caseInsensitive) {

      if (typeof pattern == "string") {

        var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};

        var substr = this.string.substr(this.pos, pattern.length);

        if (cased(substr) == cased(pattern)) {

          if (consume !== false) this.pos += pattern.length;

          return true;

        }

      } else {

        var match = this.string.slice(this.pos).match(pattern);

        if (match && match.index > 0) return null;

        if (match && consume !== false) this.pos += match[0].length;

        return match;

      }

    },

    current: function(){return this.string.slice(this.start, this.pos);},

    hideFirstChars: function(n, inner) {

      this.lineStart += n;

      try { return inner(); }

      finally { this.lineStart -= n; }

    }

  };



  // TEXTMARKERS



  // Created with markText and setBookmark methods. A TextMarker is a

  // handle that can be used to clear or find a marked position in the

  // document. Line objects hold arrays (markedSpans) containing

  // {from, to, marker} object pointing to such marker objects, and

  // indicating that such a marker is present on that line. Multiple

  // lines may point to the same marker when it spans across lines.

  // The spans will have null for their from/to properties when the

  // marker continues beyond the start/end of the line. Markers have

  // links back to the lines they currently touch.



  var nextMarkerId = 0;



  var TextMarker = CodeMirror.TextMarker = function(doc, type) {

    this.lines = [];

    this.type = type;

    this.doc = doc;

    this.id = ++nextMarkerId;

  };

  eventMixin(TextMarker);



  // Clear the marker.

  TextMarker.prototype.clear = function() {

    if (this.explicitlyCleared) return;

    var cm = this.doc.cm, withOp = cm && !cm.curOp;

    if (withOp) startOperation(cm);

    if (hasHandler(this, "clear")) {

      var found = this.find();

      if (found) signalLater(this, "clear", found.from, found.to);

    }

    var min = null, max = null;

    for (var i = 0; i < this.lines.length; ++i) {

      var line = this.lines[i];

      var span = getMarkedSpanFor(line.markedSpans, this);

      if (cm && !this.collapsed) regLineChange(cm, lineNo(line), "text");

      else if (cm) {

        if (span.to != null) max = lineNo(line);

        if (span.from != null) min = lineNo(line);

      }

      line.markedSpans = removeMarkedSpan(line.markedSpans, span);

      if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)

        updateLineHeight(line, textHeight(cm.display));

    }

    if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {

      var visual = visualLine(this.lines[i]), len = lineLength(visual);

      if (len > cm.display.maxLineLength) {

        cm.display.maxLine = visual;

        cm.display.maxLineLength = len;

        cm.display.maxLineChanged = true;

      }

    }



    if (min != null && cm && this.collapsed) regChange(cm, min, max + 1);

    this.lines.length = 0;

    this.explicitlyCleared = true;

    if (this.atomic && this.doc.cantEdit) {

      this.doc.cantEdit = false;

      if (cm) reCheckSelection(cm.doc);

    }

    if (cm) signalLater(cm, "markerCleared", cm, this);

    if (withOp) endOperation(cm);

    if (this.parent) this.parent.clear();

  };



  // Find the position of the marker in the document. Returns a {from,

  // to} object by default. Side can be passed to get a specific side

  // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the

  // Pos objects returned contain a line object, rather than a line

  // number (used to prevent looking up the same line twice).

  TextMarker.prototype.find = function(side, lineObj) {

    if (side == null && this.type == "bookmark") side = 1;

    var from, to;

    for (var i = 0; i < this.lines.length; ++i) {

      var line = this.lines[i];

      var span = getMarkedSpanFor(line.markedSpans, this);

      if (span.from != null) {

        from = Pos(lineObj ? line : lineNo(line), span.from);

        if (side == -1) return from;

      }

      if (span.to != null) {

        to = Pos(lineObj ? line : lineNo(line), span.to);

        if (side == 1) return to;

      }

    }

    return from && {from: from, to: to};

  };



  // Signals that the marker's widget changed, and surrounding layout

  // should be recomputed.

  TextMarker.prototype.changed = function() {

    var pos = this.find(-1, true), widget = this, cm = this.doc.cm;

    if (!pos || !cm) return;

    runInOp(cm, function() {

      var line = pos.line, lineN = lineNo(pos.line);

      var view = findViewForLine(cm, lineN);

      if (view) {

        clearLineMeasurementCacheFor(view);

        cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;

      }

      cm.curOp.updateMaxLine = true;

      if (!lineIsHidden(widget.doc, line) && widget.height != null) {

        var oldHeight = widget.height;

        widget.height = null;

        var dHeight = widgetHeight(widget) - oldHeight;

        if (dHeight)

          updateLineHeight(line, line.height + dHeight);

      }

    });

  };



  TextMarker.prototype.attachLine = function(line) {

    if (!this.lines.length && this.doc.cm) {

      var op = this.doc.cm.curOp;

      if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)

        (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);

    }

    this.lines.push(line);

  };

  TextMarker.prototype.detachLine = function(line) {

    this.lines.splice(indexOf(this.lines, line), 1);

    if (!this.lines.length && this.doc.cm) {

      var op = this.doc.cm.curOp;

      (op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);

    }

  };



  // Collapsed markers have unique ids, in order to be able to order

  // them, which is needed for uniquely determining an outer marker

  // when they overlap (they may nest, but not partially overlap).

  var nextMarkerId = 0;



  // Create a marker, wire it up to the right lines, and

  function markText(doc, from, to, options, type) {

    // Shared markers (across linked documents) are handled separately

    // (markTextShared will call out to this again, once per

    // document).

    if (options && options.shared) return markTextShared(doc, from, to, options, type);

    // Ensure we are in an operation.

    if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);



    var marker = new TextMarker(doc, type), diff = cmp(from, to);

    if (options) copyObj(options, marker, false);

    // Don't connect empty markers unless clearWhenEmpty is false

    if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)

      return marker;

    if (marker.replacedWith) {

      // Showing up as a widget implies collapsed (widget replaces text)

      marker.collapsed = true;

      marker.widgetNode = elt("span", [marker.replacedWith], "CodeMirror-widget");

      if (!options.handleMouseEvents) marker.widgetNode.setAttribute("cm-ignore-events", "true");

      if (options.insertLeft) marker.widgetNode.insertLeft = true;

    }

    if (marker.collapsed) {

      if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||

          from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))

        throw new Error("Inserting collapsed marker partially overlapping an existing one");

      sawCollapsedSpans = true;

    }



    if (marker.addToHistory)

      addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN);



    var curLine = from.line, cm = doc.cm, updateMaxLine;

    doc.iter(curLine, to.line + 1, function(line) {

      if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)

        updateMaxLine = true;

      if (marker.collapsed && curLine != from.line) updateLineHeight(line, 0);

      addMarkedSpan(line, new MarkedSpan(marker,

                                         curLine == from.line ? from.ch : null,

                                         curLine == to.line ? to.ch : null));

      ++curLine;

    });

    // lineIsHidden depends on the presence of the spans, so needs a second pass

    if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {

      if (lineIsHidden(doc, line)) updateLineHeight(line, 0);

    });



    if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });



    if (marker.readOnly) {

      sawReadOnlySpans = true;

      if (doc.history.done.length || doc.history.undone.length)

        doc.clearHistory();

    }

    if (marker.collapsed) {

      marker.id = ++nextMarkerId;

      marker.atomic = true;

    }

    if (cm) {

      // Sync editor state

      if (updateMaxLine) cm.curOp.updateMaxLine = true;

      if (marker.collapsed)

        regChange(cm, from.line, to.line + 1);

      else if (marker.className || marker.title || marker.startStyle || marker.endStyle || marker.css)

        for (var i = from.line; i <= to.line; i++) regLineChange(cm, i, "text");

      if (marker.atomic) reCheckSelection(cm.doc);

      signalLater(cm, "markerAdded", cm, marker);

    }

    return marker;

  }



  // SHARED TEXTMARKERS



  // A shared marker spans multiple linked documents. It is

  // implemented as a meta-marker-object controlling multiple normal

  // markers.

  var SharedTextMarker = CodeMirror.SharedTextMarker = function(markers, primary) {

    this.markers = markers;

    this.primary = primary;

    for (var i = 0; i < markers.length; ++i)

      markers[i].parent = this;

  };

  eventMixin(SharedTextMarker);



  SharedTextMarker.prototype.clear = function() {

    if (this.explicitlyCleared) return;

    this.explicitlyCleared = true;

    for (var i = 0; i < this.markers.length; ++i)

      this.markers[i].clear();

    signalLater(this, "clear");

  };

  SharedTextMarker.prototype.find = function(side, lineObj) {

    return this.primary.find(side, lineObj);

  };



  function markTextShared(doc, from, to, options, type) {

    options = copyObj(options);

    options.shared = false;

    var markers = [markText(doc, from, to, options, type)], primary = markers[0];

    var widget = options.widgetNode;

    linkedDocs(doc, function(doc) {

      if (widget) options.widgetNode = widget.cloneNode(true);

      markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));

      for (var i = 0; i < doc.linked.length; ++i)

        if (doc.linked[i].isParent) return;

      primary = lst(markers);

    });

    return new SharedTextMarker(markers, primary);

  }



  function findSharedMarkers(doc) {

    return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())),

                         function(m) { return m.parent; });

  }



  function copySharedMarkers(doc, markers) {

    for (var i = 0; i < markers.length; i++) {

      var marker = markers[i], pos = marker.find();

      var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);

      if (cmp(mFrom, mTo)) {

        var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);

        marker.markers.push(subMark);

        subMark.parent = marker;

      }

    }

  }



  function detachSharedMarkers(markers) {

    for (var i = 0; i < markers.length; i++) {

      var marker = markers[i], linked = [marker.primary.doc];;

      linkedDocs(marker.primary.doc, function(d) { linked.push(d); });

      for (var j = 0; j < marker.markers.length; j++) {

        var subMarker = marker.markers[j];

        if (indexOf(linked, subMarker.doc) == -1) {

          subMarker.parent = null;

          marker.markers.splice(j--, 1);

        }

      }

    }

  }



  // TEXTMARKER SPANS



  function MarkedSpan(marker, from, to) {

    this.marker = marker;

    this.from = from; this.to = to;

  }



  // Search an array of spans for a span matching the given marker.

  function getMarkedSpanFor(spans, marker) {

    if (spans) for (var i = 0; i < spans.length; ++i) {

      var span = spans[i];

      if (span.marker == marker) return span;

    }

  }

  // Remove a span from an array, returning undefined if no spans are

  // left (we don't store arrays for lines without spans).

  function removeMarkedSpan(spans, span) {

    for (var r, i = 0; i < spans.length; ++i)

      if (spans[i] != span) (r || (r = [])).push(spans[i]);

    return r;

  }

  // Add a span to a line.

  function addMarkedSpan(line, span) {

    line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];

    span.marker.attachLine(line);

  }



  // Used for the algorithm that adjusts markers for a change in the

  // document. These functions cut an array of spans at a given

  // character position, returning an array of remaining chunks (or

  // undefined if nothing remains).

  function markedSpansBefore(old, startCh, isInsert) {

    if (old) for (var i = 0, nw; i < old.length; ++i) {

      var span = old[i], marker = span.marker;

      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);

      if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {

        var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);

        (nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));

      }

    }

    return nw;

  }

  function markedSpansAfter(old, endCh, isInsert) {

    if (old) for (var i = 0, nw; i < old.length; ++i) {

      var span = old[i], marker = span.marker;

      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);

      if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {

        var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);

        (nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,

                                              span.to == null ? null : span.to - endCh));

      }

    }

    return nw;

  }



  // Given a change object, compute the new set of marker spans that

  // cover the line in which the change took place. Removes spans

  // entirely within the change, reconnects spans belonging to the

  // same marker that appear on both sides of the change, and cuts off

  // spans partially within the change. Returns an array of span

  // arrays with one element for each line in (after) the change.

  function stretchSpansOverChange(doc, change) {

    if (change.full) return null;

    var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;

    var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;

    if (!oldFirst && !oldLast) return null;



    var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;

    // Get the spans that 'stick out' on both sides

    var first = markedSpansBefore(oldFirst, startCh, isInsert);

    var last = markedSpansAfter(oldLast, endCh, isInsert);



    // Next, merge those two ends

    var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);

    if (first) {

      // Fix up .to properties of first

      for (var i = 0; i < first.length; ++i) {

        var span = first[i];

        if (span.to == null) {

          var found = getMarkedSpanFor(last, span.marker);

          if (!found) span.to = startCh;

          else if (sameLine) span.to = found.to == null ? null : found.to + offset;

        }

      }

    }

    if (last) {

      // Fix up .from in last (or move them into first in case of sameLine)

      for (var i = 0; i < last.length; ++i) {

        var span = last[i];

        if (span.to != null) span.to += offset;

        if (span.from == null) {

          var found = getMarkedSpanFor(first, span.marker);

          if (!found) {

            span.from = offset;

            if (sameLine) (first || (first = [])).push(span);

          }

        } else {

          span.from += offset;

          if (sameLine) (first || (first = [])).push(span);

        }

      }

    }

    // Make sure we didn't create any zero-length spans

    if (first) first = clearEmptySpans(first);

    if (last && last != first) last = clearEmptySpans(last);



    var newMarkers = [first];

    if (!sameLine) {

      // Fill gap with whole-line-spans

      var gap = change.text.length - 2, gapMarkers;

      if (gap > 0 && first)

        for (var i = 0; i < first.length; ++i)

          if (first[i].to == null)

            (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i].marker, null, null));

      for (var i = 0; i < gap; ++i)

        newMarkers.push(gapMarkers);

      newMarkers.push(last);

    }

    return newMarkers;

  }



  // Remove spans that are empty and don't have a clearWhenEmpty

  // option of false.

  function clearEmptySpans(spans) {

    for (var i = 0; i < spans.length; ++i) {

      var span = spans[i];

      if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)

        spans.splice(i--, 1);

    }

    if (!spans.length) return null;

    return spans;

  }



  // Used for un/re-doing changes from the history. Combines the

  // result of computing the existing spans with the set of spans that

  // existed in the history (so that deleting around a span and then

  // undoing brings back the span).

  function mergeOldSpans(doc, change) {

    var old = getOldSpans(doc, change);

    var stretched = stretchSpansOverChange(doc, change);

    if (!old) return stretched;

    if (!stretched) return old;



    for (var i = 0; i < old.length; ++i) {

      var oldCur = old[i], stretchCur = stretched[i];

      if (oldCur && stretchCur) {

        spans: for (var j = 0; j < stretchCur.length; ++j) {

          var span = stretchCur[j];

          for (var k = 0; k < oldCur.length; ++k)

            if (oldCur[k].marker == span.marker) continue spans;

          oldCur.push(span);

        }

      } else if (stretchCur) {

        old[i] = stretchCur;

      }

    }

    return old;

  }



  // Used to 'clip' out readOnly ranges when making a change.

  function removeReadOnlyRanges(doc, from, to) {

    var markers = null;

    doc.iter(from.line, to.line + 1, function(line) {

      if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {

        var mark = line.markedSpans[i].marker;

        if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))

          (markers || (markers = [])).push(mark);

      }

    });

    if (!markers) return null;

    var parts = [{from: from, to: to}];

    for (var i = 0; i < markers.length; ++i) {

      var mk = markers[i], m = mk.find(0);

      for (var j = 0; j < parts.length; ++j) {

        var p = parts[j];

        if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) continue;

        var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);

        if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)

          newParts.push({from: p.from, to: m.from});

        if (dto > 0 || !mk.inclusiveRight && !dto)

          newParts.push({from: m.to, to: p.to});

        parts.splice.apply(parts, newParts);

        j += newParts.length - 1;

      }

    }

    return parts;

  }



  // Connect or disconnect spans from a line.

  function detachMarkedSpans(line) {

    var spans = line.markedSpans;

    if (!spans) return;

    for (var i = 0; i < spans.length; ++i)

      spans[i].marker.detachLine(line);

    line.markedSpans = null;

  }

  function attachMarkedSpans(line, spans) {

    if (!spans) return;

    for (var i = 0; i < spans.length; ++i)

      spans[i].marker.attachLine(line);

    line.markedSpans = spans;

  }



  // Helpers used when computing which overlapping collapsed span

  // counts as the larger one.

  function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0; }

  function extraRight(marker) { return marker.inclusiveRight ? 1 : 0; }



  // Returns a number indicating which of two overlapping collapsed

  // spans is larger (and thus includes the other). Falls back to

  // comparing ids when the spans cover exactly the same range.

  function compareCollapsedMarkers(a, b) {

    var lenDiff = a.lines.length - b.lines.length;

    if (lenDiff != 0) return lenDiff;

    var aPos = a.find(), bPos = b.find();

    var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);

    if (fromCmp) return -fromCmp;

    var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);

    if (toCmp) return toCmp;

    return b.id - a.id;

  }



  // Find out whether a line ends or starts in a collapsed span. If

  // so, return the marker for that span.

  function collapsedSpanAtSide(line, start) {

    var sps = sawCollapsedSpans && line.markedSpans, found;

    if (sps) for (var sp, i = 0; i < sps.length; ++i) {

      sp = sps[i];

      if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&

          (!found || compareCollapsedMarkers(found, sp.marker) < 0))

        found = sp.marker;

    }

    return found;

  }

  function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true); }

  function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false); }



  // Test whether there exists a collapsed span that partially

  // overlaps (covers the start or end, but not both) of a new span.

  // Such overlap is not allowed.

  function conflictingCollapsedRange(doc, lineNo, from, to, marker) {

    var line = getLine(doc, lineNo);

    var sps = sawCollapsedSpans && line.markedSpans;

    if (sps) for (var i = 0; i < sps.length; ++i) {

      var sp = sps[i];

      if (!sp.marker.collapsed) continue;

      var found = sp.marker.find(0);

      var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);

      var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);

      if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) continue;

      if (fromCmp <= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.to, from) >= 0 : cmp(found.to, from) > 0) ||

          fromCmp >= 0 && (sp.marker.inclusiveRight && marker.inclusiveLeft ? cmp(found.from, to) <= 0 : cmp(found.from, to) < 0))

        return true;

    }

  }



  // A visual line is a line as drawn on the screen. Folding, for

  // example, can cause multiple logical lines to appear on the same

  // visual line. This finds the start of the visual line that the

  // given line is part of (usually that is the line itself).

  function visualLine(line) {

    var merged;

    while (merged = collapsedSpanAtStart(line))

      line = merged.find(-1, true).line;

    return line;

  }



  // Returns an array of logical lines that continue the visual line

  // started by the argument, or undefined if there are no such lines.

  function visualLineContinued(line) {

    var merged, lines;

    while (merged = collapsedSpanAtEnd(line)) {

      line = merged.find(1, true).line;

      (lines || (lines = [])).push(line);

    }

    return lines;

  }



  // Get the line number of the start of the visual line that the

  // given line number is part of.

  function visualLineNo(doc, lineN) {

    var line = getLine(doc, lineN), vis = visualLine(line);

    if (line == vis) return lineN;

    return lineNo(vis);

  }

  // Get the line number of the start of the next visual line after

  // the given line.

  function visualLineEndNo(doc, lineN) {

    if (lineN > doc.lastLine()) return lineN;

    var line = getLine(doc, lineN), merged;

    if (!lineIsHidden(doc, line)) return lineN;

    while (merged = collapsedSpanAtEnd(line))

      line = merged.find(1, true).line;

    return lineNo(line) + 1;

  }



  // Compute whether a line is hidden. Lines count as hidden when they

  // are part of a visual line that starts with another line, or when

  // they are entirely covered by collapsed, non-widget span.

  function lineIsHidden(doc, line) {

    var sps = sawCollapsedSpans && line.markedSpans;

    if (sps) for (var sp, i = 0; i < sps.length; ++i) {

      sp = sps[i];

      if (!sp.marker.collapsed) continue;

      if (sp.from == null) return true;

      if (sp.marker.widgetNode) continue;

      if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))

        return true;

    }

  }

  function lineIsHiddenInner(doc, line, span) {

    if (span.to == null) {

      var end = span.marker.find(1, true);

      return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker));

    }

    if (span.marker.inclusiveRight && span.to == line.text.length)

      return true;

    for (var sp, i = 0; i < line.markedSpans.length; ++i) {

      sp = line.markedSpans[i];

      if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&

          (sp.to == null || sp.to != span.from) &&

          (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&

          lineIsHiddenInner(doc, line, sp)) return true;

    }

  }



  // LINE WIDGETS



  // Line widgets are block elements displayed above or below a line.



  var LineWidget = CodeMirror.LineWidget = function(doc, node, options) {

    if (options) for (var opt in options) if (options.hasOwnProperty(opt))

      this[opt] = options[opt];

    this.doc = doc;

    this.node = node;

  };

  eventMixin(LineWidget);



  function adjustScrollWhenAboveVisible(cm, line, diff) {

    if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))

      addToScrollPos(cm, null, diff);

  }



  LineWidget.prototype.clear = function() {

    var cm = this.doc.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);

    if (no == null || !ws) return;

    for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);

    if (!ws.length) line.widgets = null;

    var height = widgetHeight(this);

    updateLineHeight(line, Math.max(0, line.height - height));

    if (cm) runInOp(cm, function() {

      adjustScrollWhenAboveVisible(cm, line, -height);

      regLineChange(cm, no, "widget");

    });

  };

  LineWidget.prototype.changed = function() {

    var oldH = this.height, cm = this.doc.cm, line = this.line;

    this.height = null;

    var diff = widgetHeight(this) - oldH;

    if (!diff) return;

    updateLineHeight(line, line.height + diff);

    if (cm) runInOp(cm, function() {

      cm.curOp.forceUpdate = true;

      adjustScrollWhenAboveVisible(cm, line, diff);

    });

  };



  function widgetHeight(widget) {

    if (widget.height != null) return widget.height;

    var cm = widget.doc.cm;

    if (!cm) return 0;

    if (!contains(document.body, widget.node)) {

      var parentStyle = "position: relative;";

      if (widget.coverGutter)

        parentStyle += "margin-left: -" + cm.display.gutters.offsetWidth + "px;";

      if (widget.noHScroll)

        parentStyle += "width: " + cm.display.wrapper.clientWidth + "px;";

      removeChildrenAndAdd(cm.display.measure, elt("div", [widget.node], null, parentStyle));

    }

    return widget.height = widget.node.parentNode.offsetHeight;

  }



  function addLineWidget(doc, handle, node, options) {

    var widget = new LineWidget(doc, node, options);

    var cm = doc.cm;

    if (cm && widget.noHScroll) cm.display.alignWidgets = true;

    changeLine(doc, handle, "widget", function(line) {

      var widgets = line.widgets || (line.widgets = []);

      if (widget.insertAt == null) widgets.push(widget);

      else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);

      widget.line = line;

      if (cm && !lineIsHidden(doc, line)) {

        var aboveVisible = heightAtLine(line) < doc.scrollTop;

        updateLineHeight(line, line.height + widgetHeight(widget));

        if (aboveVisible) addToScrollPos(cm, null, widget.height);

        cm.curOp.forceUpdate = true;

      }

      return true;

    });

    return widget;

  }



  // LINE DATA STRUCTURE



  // Line objects. These hold state related to a line, including

  // highlighting info (the styles array).

  var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {

    this.text = text;

    attachMarkedSpans(this, markedSpans);

    this.height = estimateHeight ? estimateHeight(this) : 1;

  };

  eventMixin(Line);

  Line.prototype.lineNo = function() { return lineNo(this); };



  // Change the content (text, markers) of a line. Automatically

  // invalidates cached information and tries to re-estimate the

  // line's height.

  function updateLine(line, text, markedSpans, estimateHeight) {

    line.text = text;

    if (line.stateAfter) line.stateAfter = null;

    if (line.styles) line.styles = null;

    if (line.order != null) line.order = null;

    detachMarkedSpans(line);

    attachMarkedSpans(line, markedSpans);

    var estHeight = estimateHeight ? estimateHeight(line) : 1;

    if (estHeight != line.height) updateLineHeight(line, estHeight);

  }



  // Detach a line from the document tree and its markers.

  function cleanUpLine(line) {

    line.parent = null;

    detachMarkedSpans(line);

  }



  function extractLineClasses(type, output) {

    if (type) for (;;) {

      var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);

      if (!lineClass) break;

      type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);

      var prop = lineClass[1] ? "bgClass" : "textClass";

      if (output[prop] == null)

        output[prop] = lineClass[2];

      else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))

        output[prop] += " " + lineClass[2];

    }

    return type;

  }



  function callBlankLine(mode, state) {

    if (mode.blankLine) return mode.blankLine(state);

    if (!mode.innerMode) return;

    var inner = CodeMirror.innerMode(mode, state);

    if (inner.mode.blankLine) return inner.mode.blankLine(inner.state);

  }



  function readToken(mode, stream, state, inner) {

    for (var i = 0; i < 10; i++) {

      if (inner) inner[0] = CodeMirror.innerMode(mode, state).mode;

      var style = mode.token(stream, state);

      if (stream.pos > stream.start) return style;

    }

    throw new Error("Mode " + mode.name + " failed to advance stream.");

  }



  // Utility for getTokenAt and getLineTokens

  function takeToken(cm, pos, precise, asArray) {

    function getObj(copy) {

      return {start: stream.start, end: stream.pos,

              string: stream.current(),

              type: style || null,

              state: copy ? copyState(doc.mode, state) : state};

    }



    var doc = cm.doc, mode = doc.mode, style;

    pos = clipPos(doc, pos);

    var line = getLine(doc, pos.line), state = getStateBefore(cm, pos.line, precise);

    var stream = new StringStream(line.text, cm.options.tabSize), tokens;

    if (asArray) tokens = [];

    while ((asArray || stream.pos < pos.ch) && !stream.eol()) {

      stream.start = stream.pos;

      style = readToken(mode, stream, state);

      if (asArray) tokens.push(getObj(true));

    }

    return asArray ? tokens : getObj();

  }



  // Run the given mode's parser over a line, calling f for each token.

  function runMode(cm, text, mode, state, f, lineClasses, forceToEnd) {

    var flattenSpans = mode.flattenSpans;

    if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;

    var curStart = 0, curStyle = null;

    var stream = new StringStream(text, cm.options.tabSize), style;

    var inner = cm.options.addModeClass && [null];

    if (text == "") extractLineClasses(callBlankLine(mode, state), lineClasses);

    while (!stream.eol()) {

      if (stream.pos > cm.options.maxHighlightLength) {

        flattenSpans = false;

        if (forceToEnd) processLine(cm, text, state, stream.pos);

        stream.pos = text.length;

        style = null;

      } else {

        style = extractLineClasses(readToken(mode, stream, state, inner), lineClasses);

      }

      if (inner) {

        var mName = inner[0].name;

        if (mName) style = "m-" + (style ? mName + " " + style : mName);

      }

      if (!flattenSpans || curStyle != style) {

        while (curStart < stream.start) {

          curStart = Math.min(stream.start, curStart + 5000);

          f(curStart, curStyle);

        }

        curStyle = style;

      }

      stream.start = stream.pos;

    }

    while (curStart < stream.pos) {

      // Webkit seems to refuse to render text nodes longer than 57444

      // characters, and returns inaccurate measurements in nodes

      // starting around 5000 chars.

      var pos = Math.min(stream.pos, curStart + 5000);

      f(pos, curStyle);

      curStart = pos;

    }

  }



  // Compute a style array (an array starting with a mode generation

  // -- for invalidation -- followed by pairs of end positions and

  // style strings), which is used to highlight the tokens on the

  // line.

  function highlightLine(cm, line, state, forceToEnd) {

    // A styles array always starts with a number identifying the

    // mode/overlays that it is based on (for easy invalidation).

    var st = [cm.state.modeGen], lineClasses = {};

    // Compute the base array of styles

    runMode(cm, line.text, cm.doc.mode, state, function(end, style) {

      st.push(end, style);

    }, lineClasses, forceToEnd);



    // Run overlays, adjust style array.

    for (var o = 0; o < cm.state.overlays.length; ++o) {

      var overlay = cm.state.overlays[o], i = 1, at = 0;

      runMode(cm, line.text, overlay.mode, true, function(end, style) {

        var start = i;

        // Ensure there's a token end at the current position, and that i points at it

        while (at < end) {

          var i_end = st[i];

          if (i_end > end)

            st.splice(i, 1, end, st[i+1], i_end);

          i += 2;

          at = Math.min(end, i_end);

        }

        if (!style) return;

        if (overlay.opaque) {

          st.splice(start, i - start, end, "cm-overlay " + style);

          i = start + 2;

        } else {

          for (; start < i; start += 2) {

            var cur = st[start+1];

            st[start+1] = (cur ? cur + " " : "") + "cm-overlay " + style;

          }

        }

      }, lineClasses);

    }



    return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null};

  }



  function getLineStyles(cm, line, updateFrontier) {

    if (!line.styles || line.styles[0] != cm.state.modeGen) {

      var state = getStateBefore(cm, lineNo(line));

      var result = highlightLine(cm, line, line.text.length > cm.options.maxHighlightLength ? copyState(cm.doc.mode, state) : state);

      line.stateAfter = state;

      line.styles = result.styles;

      if (result.classes) line.styleClasses = result.classes;

      else if (line.styleClasses) line.styleClasses = null;

      if (updateFrontier === cm.doc.frontier) cm.doc.frontier++;

    }

    return line.styles;

  }



  // Lightweight form of highlight -- proceed over this line and

  // update state, but don't save a style array. Used for lines that

  // aren't currently visible.

  function processLine(cm, text, state, startAt) {

    var mode = cm.doc.mode;

    var stream = new StringStream(text, cm.options.tabSize);

    stream.start = stream.pos = startAt || 0;

    if (text == "") callBlankLine(mode, state);

    while (!stream.eol()) {

      readToken(mode, stream, state);

      stream.start = stream.pos;

    }

  }



  // Convert a style as returned by a mode (either null, or a string

  // containing one or more styles) to a CSS style. This is cached,

  // and also looks for line-wide styles.

  var styleToClassCache = {}, styleToClassCacheWithMode = {};

  function interpretTokenStyle(style, options) {

    if (!style || /^\s*$/.test(style)) return null;

    var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;

    return cache[style] ||

      (cache[style] = style.replace(/\S+/g, "cm-$&"));

  }



  // Render the DOM representation of the text of a line. Also builds

  // up a 'line map', which points at the DOM nodes that represent

  // specific stretches of text, and is used by the measuring code.

  // The returned object contains the DOM node, this map, and

  // information about line-wide styles that were set by the mode.

  function buildLineContent(cm, lineView) {

    // The padding-right forces the element to have a 'border', which

    // is needed on Webkit to be able to get line-level bounding

    // rectangles for it (in measureChar).

    var content = elt("span", null, null, webkit ? "padding-right: .1px" : null);

    var builder = {pre: elt("pre", [content], "CodeMirror-line"), content: content,

                   col: 0, pos: 0, cm: cm,

                   trailingSpace: false,

                   splitSpaces: (ie || webkit) && cm.getOption("lineWrapping")};

    lineView.measure = {};



    // Iterate over the logical lines that make up this visual line.

    for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {

      var line = i ? lineView.rest[i - 1] : lineView.line, order;

      builder.pos = 0;

      builder.addToken = buildToken;

      // Optionally wire in some hacks into the token-rendering

      // algorithm, to deal with browser quirks.

      if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line)))

        builder.addToken = buildTokenBadBidi(builder.addToken, order);

      builder.map = [];

      var allowFrontierUpdate = lineView != cm.display.externalMeasured && lineNo(line);

      insertLineContent(line, builder, getLineStyles(cm, line, allowFrontierUpdate));

      if (line.styleClasses) {

        if (line.styleClasses.bgClass)

          builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || "");

        if (line.styleClasses.textClass)

          builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || "");

      }



      // Ensure at least a single node is present, for measuring.

      if (builder.map.length == 0)

        builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)));



      // Store the map and a cache object for the current logical line

      if (i == 0) {

        lineView.measure.map = builder.map;

        lineView.measure.cache = {};

      } else {

        (lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map);

        (lineView.measure.caches || (lineView.measure.caches = [])).push({});

      }

    }



    // See issue #2901

    if (webkit) {

      var last = builder.content.lastChild

      if (/\bcm-tab\b/.test(last.className) || (last.querySelector && last.querySelector(".cm-tab")))

        builder.content.className = "cm-tab-wrap-hack";

    }



    signal(cm, "renderLine", cm, lineView.line, builder.pre);

    if (builder.pre.className)

      builder.textClass = joinClasses(builder.pre.className, builder.textClass || "");



    return builder;

  }



  function defaultSpecialCharPlaceholder(ch) {

    var token = elt("span", "\u2022", "cm-invalidchar");

    token.title = "\\u" + ch.charCodeAt(0).toString(16);

    token.setAttribute("aria-label", token.title);

    return token;

  }



  // Build up the DOM representation for a single token, and add it to

  // the line map. Takes care to render special characters separately.

  function buildToken(builder, text, style, startStyle, endStyle, title, css) {

    if (!text) return;

    var displayText = builder.splitSpaces ? splitSpaces(text, builder.trailingSpace) : text

    var special = builder.cm.state.specialChars, mustWrap = false;

    if (!special.test(text)) {

      builder.col += text.length;

      var content = document.createTextNode(displayText);

      builder.map.push(builder.pos, builder.pos + text.length, content);

      if (ie && ie_version < 9) mustWrap = true;

      builder.pos += text.length;

    } else {

      var content = document.createDocumentFragment(), pos = 0;

      while (true) {

        special.lastIndex = pos;

        var m = special.exec(text);

        var skipped = m ? m.index - pos : text.length - pos;

        if (skipped) {

          var txt = document.createTextNode(displayText.slice(pos, pos + skipped));

          if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));

          else content.appendChild(txt);

          builder.map.push(builder.pos, builder.pos + skipped, txt);

          builder.col += skipped;

          builder.pos += skipped;

        }

        if (!m) break;

        pos += skipped + 1;

        if (m[0] == "\t") {

          var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;

          var txt = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));

          txt.setAttribute("role", "presentation");

          txt.setAttribute("cm-text", "\t");

          builder.col += tabWidth;

        } else if (m[0] == "\r" || m[0] == "\n") {

          var txt = content.appendChild(elt("span", m[0] == "\r" ? "\u240d" : "\u2424", "cm-invalidchar"));

          txt.setAttribute("cm-text", m[0]);

          builder.col += 1;

        } else {

          var txt = builder.cm.options.specialCharPlaceholder(m[0]);

          txt.setAttribute("cm-text", m[0]);

          if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));

          else content.appendChild(txt);

          builder.col += 1;

        }

        builder.map.push(builder.pos, builder.pos + 1, txt);

        builder.pos++;

      }

    }

    builder.trailingSpace = displayText.charCodeAt(text.length - 1) == 32

    if (style || startStyle || endStyle || mustWrap || css) {

      var fullStyle = style || "";

      if (startStyle) fullStyle += startStyle;

      if (endStyle) fullStyle += endStyle;

      var token = elt("span", [content], fullStyle, css);

      if (title) token.title = title;

      return builder.content.appendChild(token);

    }

    builder.content.appendChild(content);

  }



  function splitSpaces(text, trailingBefore) {

    if (text.length > 1 && !/  /.test(text)) return text

    var spaceBefore = trailingBefore, result = ""

    for (var i = 0; i < text.length; i++) {

      var ch = text.charAt(i)

      if (ch == " " && spaceBefore && (i == text.length - 1 || text.charCodeAt(i + 1) == 32))

        ch = "\u00a0"

      result += ch

      spaceBefore = ch == " "

    }

    return result

  }



  // Work around nonsense dimensions being reported for stretches of

  // right-to-left text.

  function buildTokenBadBidi(inner, order) {

    return function(builder, text, style, startStyle, endStyle, title, css) {

      style = style ? style + " cm-force-border" : "cm-force-border";

      var start = builder.pos, end = start + text.length;

      for (;;) {

        // Find the part that overlaps with the start of this text

        for (var i = 0; i < order.length; i++) {

          var part = order[i];

          if (part.to > start && part.from <= start) break;

        }

        if (part.to >= end) return inner(builder, text, style, startStyle, endStyle, title, css);

        inner(builder, text.slice(0, part.to - start), style, startStyle, null, title, css);

        startStyle = null;

        text = text.slice(part.to - start);

        start = part.to;

      }

    };

  }



  function buildCollapsedSpan(builder, size, marker, ignoreWidget) {

    var widget = !ignoreWidget && marker.widgetNode;

    if (widget) builder.map.push(builder.pos, builder.pos + size, widget);

    if (!ignoreWidget && builder.cm.display.input.needsContentAttribute) {

      if (!widget)

        widget = builder.content.appendChild(document.createElement("span"));

      widget.setAttribute("cm-marker", marker.id);

    }

    if (widget) {

      builder.cm.display.input.setUneditable(widget);

      builder.content.appendChild(widget);

    }

    builder.pos += size;

    builder.trailingSpace = false

  }



  // Outputs a number of spans to make up a line, taking highlighting

  // and marked text into account.

  function insertLineContent(line, builder, styles) {

    var spans = line.markedSpans, allText = line.text, at = 0;

    if (!spans) {

      for (var i = 1; i < styles.length; i+=2)

        builder.addToken(builder, allText.slice(at, at = styles[i]), interpretTokenStyle(styles[i+1], builder.cm.options));

      return;

    }



    var len = allText.length, pos = 0, i = 1, text = "", style, css;

    var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;

    for (;;) {

      if (nextChange == pos) { // Update current marker set

        spanStyle = spanEndStyle = spanStartStyle = title = css = "";

        collapsed = null; nextChange = Infinity;

        var foundBookmarks = [], endStyles

        for (var j = 0; j < spans.length; ++j) {

          var sp = spans[j], m = sp.marker;

          if (m.type == "bookmark" && sp.from == pos && m.widgetNode) {

            foundBookmarks.push(m);

          } else if (sp.from <= pos && (sp.to == null || sp.to > pos || m.collapsed && sp.to == pos && sp.from == pos)) {

            if (sp.to != null && sp.to != pos && nextChange > sp.to) {

              nextChange = sp.to;

              spanEndStyle = "";

            }

            if (m.className) spanStyle += " " + m.className;

            if (m.css) css = (css ? css + ";" : "") + m.css;

            if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;

            if (m.endStyle && sp.to == nextChange) (endStyles || (endStyles = [])).push(m.endStyle, sp.to)

            if (m.title && !title) title = m.title;

            if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))

              collapsed = sp;

          } else if (sp.from > pos && nextChange > sp.from) {

            nextChange = sp.from;

          }

        }

        if (endStyles) for (var j = 0; j < endStyles.length; j += 2)

          if (endStyles[j + 1] == nextChange) spanEndStyle += " " + endStyles[j]



        if (!collapsed || collapsed.from == pos) for (var j = 0; j < foundBookmarks.length; ++j)

          buildCollapsedSpan(builder, 0, foundBookmarks[j]);

        if (collapsed && (collapsed.from || 0) == pos) {

          buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,

                             collapsed.marker, collapsed.from == null);

          if (collapsed.to == null) return;

          if (collapsed.to == pos) collapsed = false;

        }

      }

      if (pos >= len) break;



      var upto = Math.min(len, nextChange);

      while (true) {

        if (text) {

          var end = pos + text.length;

          if (!collapsed) {

            var tokenText = end > upto ? text.slice(0, upto - pos) : text;

            builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,

                             spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title, css);

          }

          if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}

          pos = end;

          spanStartStyle = "";

        }

        text = allText.slice(at, at = styles[i++]);

        style = interpretTokenStyle(styles[i++], builder.cm.options);

      }

    }

  }



  // DOCUMENT DATA STRUCTURE



  // By default, updates that start and end at the beginning of a line

  // are treated specially, in order to make the association of line

  // widgets and marker elements with the text behave more intuitive.

  function isWholeLineUpdate(doc, change) {

    return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&

      (!doc.cm || doc.cm.options.wholeLineUpdateBefore);

  }



  // Perform a change on the document data structure.

  function updateDoc(doc, change, markedSpans, estimateHeight) {

    function spansFor(n) {return markedSpans ? markedSpans[n] : null;}

    function update(line, text, spans) {

      updateLine(line, text, spans, estimateHeight);

      signalLater(line, "change", line, change);

    }

    function linesFor(start, end) {

      for (var i = start, result = []; i < end; ++i)

        result.push(new Line(text[i], spansFor(i), estimateHeight));

      return result;

    }



    var from = change.from, to = change.to, text = change.text;

    var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);

    var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;



    // Adjust the line structure

    if (change.full) {

      doc.insert(0, linesFor(0, text.length));

      doc.remove(text.length, doc.size - text.length);

    } else if (isWholeLineUpdate(doc, change)) {

      // This is a whole-line replace. Treated specially to make

      // sure line objects move the way they are supposed to.

      var added = linesFor(0, text.length - 1);

      update(lastLine, lastLine.text, lastSpans);

      if (nlines) doc.remove(from.line, nlines);

      if (added.length) doc.insert(from.line, added);

    } else if (firstLine == lastLine) {

      if (text.length == 1) {

        update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);

      } else {

        var added = linesFor(1, text.length - 1);

        added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));

        update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));

        doc.insert(from.line + 1, added);

      }

    } else if (text.length == 1) {

      update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));

      doc.remove(from.line + 1, nlines);

    } else {

      update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));

      update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);

      var added = linesFor(1, text.length - 1);

      if (nlines > 1) doc.remove(from.line + 1, nlines - 1);

      doc.insert(from.line + 1, added);

    }



    signalLater(doc, "change", doc, change);

  }



  // The document is represented as a BTree consisting of leaves, with

  // chunk of lines in them, and branches, with up to ten leaves or

  // other branch nodes below them. The top node is always a branch

  // node, and is the document object itself (meaning it has

  // additional methods and properties).

  //

  // All nodes have parent links. The tree is used both to go from

  // line numbers to line objects, and to go from objects to numbers.

  // It also indexes by height, and is used to convert between height

  // and line object, and to find the total height of the document.

  //

  // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html



  function LeafChunk(lines) {

    this.lines = lines;

    this.parent = null;

    for (var i = 0, height = 0; i < lines.length; ++i) {

      lines[i].parent = this;

      height += lines[i].height;

    }

    this.height = height;

  }



  LeafChunk.prototype = {

    chunkSize: function() { return this.lines.length; },

    // Remove the n lines at offset 'at'.

    removeInner: function(at, n) {

      for (var i = at, e = at + n; i < e; ++i) {

        var line = this.lines[i];

        this.height -= line.height;

        cleanUpLine(line);

        signalLater(line, "delete");

      }

      this.lines.splice(at, n);

    },

    // Helper used to collapse a small branch into a single leaf.

    collapse: function(lines) {

      lines.push.apply(lines, this.lines);

    },

    // Insert the given array of lines at offset 'at', count them as

    // having the given height.

    insertInner: function(at, lines, height) {

      this.height += height;

      this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));

      for (var i = 0; i < lines.length; ++i) lines[i].parent = this;

    },

    // Used to iterate over a part of the tree.

    iterN: function(at, n, op) {

      for (var e = at + n; at < e; ++at)

        if (op(this.lines[at])) return true;

    }

  };



  function BranchChunk(children) {

    this.children = children;

    var size = 0, height = 0;

    for (var i = 0; i < children.length; ++i) {

      var ch = children[i];

      size += ch.chunkSize(); height += ch.height;

      ch.parent = this;

    }

    this.size = size;

    this.height = height;

    this.parent = null;

  }



  BranchChunk.prototype = {

    chunkSize: function() { return this.size; },

    removeInner: function(at, n) {

      this.size -= n;

      for (var i = 0; i < this.children.length; ++i) {

        var child = this.children[i], sz = child.chunkSize();

        if (at < sz) {

          var rm = Math.min(n, sz - at), oldHeight = child.height;

          child.removeInner(at, rm);

          this.height -= oldHeight - child.height;

          if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }

          if ((n -= rm) == 0) break;

          at = 0;

        } else at -= sz;

      }

      // If the result is smaller than 25 lines, ensure that it is a

      // single leaf node.

      if (this.size - n < 25 &&

          (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {

        var lines = [];

        this.collapse(lines);

        this.children = [new LeafChunk(lines)];

        this.children[0].parent = this;

      }

    },

    collapse: function(lines) {

      for (var i = 0; i < this.children.length; ++i) this.children[i].collapse(lines);

    },

    insertInner: function(at, lines, height) {

      this.size += lines.length;

      this.height += height;

      for (var i = 0; i < this.children.length; ++i) {

        var child = this.children[i], sz = child.chunkSize();

        if (at <= sz) {

          child.insertInner(at, lines, height);

          if (child.lines && child.lines.length > 50) {

            // To avoid memory thrashing when child.lines is huge (e.g. first view of a large file), it's never spliced.

            // Instead, small slices are taken. They're taken in order because sequential memory accesses are fastest.

            var remaining = child.lines.length % 25 + 25

            for (var pos = remaining; pos < child.lines.length;) {

              var leaf = new LeafChunk(child.lines.slice(pos, pos += 25));

              child.height -= leaf.height;

              this.children.splice(++i, 0, leaf);

              leaf.parent = this;

            }

            child.lines = child.lines.slice(0, remaining);

            this.maybeSpill();

          }

          break;

        }

        at -= sz;

      }

    },

    // When a node has grown, check whether it should be split.

    maybeSpill: function() {

      if (this.children.length <= 10) return;

      var me = this;

      do {

        var spilled = me.children.splice(me.children.length - 5, 5);

        var sibling = new BranchChunk(spilled);

        if (!me.parent) { // Become the parent node

          var copy = new BranchChunk(me.children);

          copy.parent = me;

          me.children = [copy, sibling];

          me = copy;

       } else {

          me.size -= sibling.size;

          me.height -= sibling.height;

          var myIndex = indexOf(me.parent.children, me);

          me.parent.children.splice(myIndex + 1, 0, sibling);

        }

        sibling.parent = me.parent;

      } while (me.children.length > 10);

      me.parent.maybeSpill();

    },

    iterN: function(at, n, op) {

      for (var i = 0; i < this.children.length; ++i) {

        var child = this.children[i], sz = child.chunkSize();

        if (at < sz) {

          var used = Math.min(n, sz - at);

          if (child.iterN(at, used, op)) return true;

          if ((n -= used) == 0) break;

          at = 0;

        } else at -= sz;

      }

    }

  };



  var nextDocId = 0;

  var Doc = CodeMirror.Doc = function(text, mode, firstLine, lineSep) {

    if (!(this instanceof Doc)) return new Doc(text, mode, firstLine, lineSep);

    if (firstLine == null) firstLine = 0;



    BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);

    this.first = firstLine;

    this.scrollTop = this.scrollLeft = 0;

    this.cantEdit = false;

    this.cleanGeneration = 1;

    this.frontier = firstLine;

    var start = Pos(firstLine, 0);

    this.sel = simpleSelection(start);

    this.history = new History(null);

    this.id = ++nextDocId;

    this.modeOption = mode;

    this.lineSep = lineSep;

    this.extend = false;



    if (typeof text == "string") text = this.splitLines(text);

    updateDoc(this, {from: start, to: start, text: text});

    setSelection(this, simpleSelection(start), sel_dontScroll);

  };



  Doc.prototype = createObj(BranchChunk.prototype, {

    constructor: Doc,

    // Iterate over the document. Supports two forms -- with only one

    // argument, it calls that for each line in the document. With

    // three, it iterates over the range given by the first two (with

    // the second being non-inclusive).

    iter: function(from, to, op) {

      if (op) this.iterN(from - this.first, to - from, op);

      else this.iterN(this.first, this.first + this.size, from);

    },



    // Non-public interface for adding and removing lines.

    insert: function(at, lines) {

      var height = 0;

      for (var i = 0; i < lines.length; ++i) height += lines[i].height;

      this.insertInner(at - this.first, lines, height);

    },

    remove: function(at, n) { this.removeInner(at - this.first, n); },



    // From here, the methods are part of the public interface. Most

    // are also available from CodeMirror (editor) instances.



    getValue: function(lineSep) {

      var lines = getLines(this, this.first, this.first + this.size);

      if (lineSep === false) return lines;

      return lines.join(lineSep || this.lineSeparator());

    },

    setValue: docMethodOp(function(code) {

      var top = Pos(this.first, 0), last = this.first + this.size - 1;

      makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),

                        text: this.splitLines(code), origin: "setValue", full: true}, true);

      setSelection(this, simpleSelection(top));

    }),

    replaceRange: function(code, from, to, origin) {

      from = clipPos(this, from);

      to = to ? clipPos(this, to) : from;

      replaceRange(this, code, from, to, origin);

    },

    getRange: function(from, to, lineSep) {

      var lines = getBetween(this, clipPos(this, from), clipPos(this, to));

      if (lineSep === false) return lines;

      return lines.join(lineSep || this.lineSeparator());

    },



    getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},



    getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},

    getLineNumber: function(line) {return lineNo(line);},



    getLineHandleVisualStart: function(line) {

      if (typeof line == "number") line = getLine(this, line);

      return visualLine(line);

    },



    lineCount: function() {return this.size;},

    firstLine: function() {return this.first;},

    lastLine: function() {return this.first + this.size - 1;},



    clipPos: function(pos) {return clipPos(this, pos);},



    getCursor: function(start) {

      var range = this.sel.primary(), pos;

      if (start == null || start == "head") pos = range.head;

      else if (start == "anchor") pos = range.anchor;

      else if (start == "end" || start == "to" || start === false) pos = range.to();

      else pos = range.from();

      return pos;

    },

    listSelections: function() { return this.sel.ranges; },

    somethingSelected: function() {return this.sel.somethingSelected();},



    setCursor: docMethodOp(function(line, ch, options) {

      setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);

    }),

    setSelection: docMethodOp(function(anchor, head, options) {

      setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);

    }),

    extendSelection: docMethodOp(function(head, other, options) {

      extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);

    }),

    extendSelections: docMethodOp(function(heads, options) {

      extendSelections(this, clipPosArray(this, heads), options);

    }),

    extendSelectionsBy: docMethodOp(function(f, options) {

      var heads = map(this.sel.ranges, f);

      extendSelections(this, clipPosArray(this, heads), options);

    }),

    setSelections: docMethodOp(function(ranges, primary, options) {

      if (!ranges.length) return;

      for (var i = 0, out = []; i < ranges.length; i++)

        out[i] = new Range(clipPos(this, ranges[i].anchor),

                           clipPos(this, ranges[i].head));

      if (primary == null) primary = Math.min(ranges.length - 1, this.sel.primIndex);

      setSelection(this, normalizeSelection(out, primary), options);

    }),

    addSelection: docMethodOp(function(anchor, head, options) {

      var ranges = this.sel.ranges.slice(0);

      ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));

      setSelection(this, normalizeSelection(ranges, ranges.length - 1), options);

    }),



    getSelection: function(lineSep) {

      var ranges = this.sel.ranges, lines;

      for (var i = 0; i < ranges.length; i++) {

        var sel = getBetween(this, ranges[i].from(), ranges[i].to());

        lines = lines ? lines.concat(sel) : sel;

      }

      if (lineSep === false) return lines;

      else return lines.join(lineSep || this.lineSeparator());

    },

    getSelections: function(lineSep) {

      var parts = [], ranges = this.sel.ranges;

      for (var i = 0; i < ranges.length; i++) {

        var sel = getBetween(this, ranges[i].from(), ranges[i].to());

        if (lineSep !== false) sel = sel.join(lineSep || this.lineSeparator());

        parts[i] = sel;

      }

      return parts;

    },

    replaceSelection: function(code, collapse, origin) {

      var dup = [];

      for (var i = 0; i < this.sel.ranges.length; i++)

        dup[i] = code;

      this.replaceSelections(dup, collapse, origin || "+input");

    },

    replaceSelections: docMethodOp(function(code, collapse, origin) {

      var changes = [], sel = this.sel;

      for (var i = 0; i < sel.ranges.length; i++) {

        var range = sel.ranges[i];

        changes[i] = {from: range.from(), to: range.to(), text: this.splitLines(code[i]), origin: origin};

      }

      var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);

      for (var i = changes.length - 1; i >= 0; i--)

        makeChange(this, changes[i]);

      if (newSel) setSelectionReplaceHistory(this, newSel);

      else if (this.cm) ensureCursorVisible(this.cm);

    }),

    undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),

    redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),

    undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),

    redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),



    setExtending: function(val) {this.extend = val;},

    getExtending: function() {return this.extend;},



    historySize: function() {

      var hist = this.history, done = 0, undone = 0;

      for (var i = 0; i < hist.done.length; i++) if (!hist.done[i].ranges) ++done;

      for (var i = 0; i < hist.undone.length; i++) if (!hist.undone[i].ranges) ++undone;

      return {undo: done, redo: undone};

    },

    clearHistory: function() {this.history = new History(this.history.maxGeneration);},



    markClean: function() {

      this.cleanGeneration = this.changeGeneration(true);

    },

    changeGeneration: function(forceSplit) {

      if (forceSplit)

        this.history.lastOp = this.history.lastSelOp = this.history.lastOrigin = null;

      return this.history.generation;

    },

    isClean: function (gen) {

      return this.history.generation == (gen || this.cleanGeneration);

    },



    getHistory: function() {

      return {done: copyHistoryArray(this.history.done),

              undone: copyHistoryArray(this.history.undone)};

    },

    setHistory: function(histData) {

      var hist = this.history = new History(this.history.maxGeneration);

      hist.done = copyHistoryArray(histData.done.slice(0), null, true);

      hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);

    },



    addLineClass: docMethodOp(function(handle, where, cls) {

      return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {

        var prop = where == "text" ? "textClass"

                 : where == "background" ? "bgClass"

                 : where == "gutter" ? "gutterClass" : "wrapClass";

        if (!line[prop]) line[prop] = cls;

        else if (classTest(cls).test(line[prop])) return false;

        else line[prop] += " " + cls;

        return true;

      });

    }),

    removeLineClass: docMethodOp(function(handle, where, cls) {

      return changeLine(this, handle, where == "gutter" ? "gutter" : "class", function(line) {

        var prop = where == "text" ? "textClass"

                 : where == "background" ? "bgClass"

                 : where == "gutter" ? "gutterClass" : "wrapClass";

        var cur = line[prop];

        if (!cur) return false;

        else if (cls == null) line[prop] = null;

        else {

          var found = cur.match(classTest(cls));

          if (!found) return false;

          var end = found.index + found[0].length;

          line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;

        }

        return true;

      });

    }),



    addLineWidget: docMethodOp(function(handle, node, options) {

      return addLineWidget(this, handle, node, options);

    }),

    removeLineWidget: function(widget) { widget.clear(); },



    markText: function(from, to, options) {

      return markText(this, clipPos(this, from), clipPos(this, to), options, options && options.type || "range");

    },

    setBookmark: function(pos, options) {

      var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),

                      insertLeft: options && options.insertLeft,

                      clearWhenEmpty: false, shared: options && options.shared,

                      handleMouseEvents: options && options.handleMouseEvents};

      pos = clipPos(this, pos);

      return markText(this, pos, pos, realOpts, "bookmark");

    },

    findMarksAt: function(pos) {

      pos = clipPos(this, pos);

      var markers = [], spans = getLine(this, pos.line).markedSpans;

      if (spans) for (var i = 0; i < spans.length; ++i) {

        var span = spans[i];

        if ((span.from == null || span.from <= pos.ch) &&

            (span.to == null || span.to >= pos.ch))

          markers.push(span.marker.parent || span.marker);

      }

      return markers;

    },

    findMarks: function(from, to, filter) {

      from = clipPos(this, from); to = clipPos(this, to);

      var found = [], lineNo = from.line;

      this.iter(from.line, to.line + 1, function(line) {

        var spans = line.markedSpans;

        if (spans) for (var i = 0; i < spans.length; i++) {

          var span = spans[i];

          if (!(span.to != null && lineNo == from.line && from.ch >= span.to ||

                span.from == null && lineNo != from.line ||

                span.from != null && lineNo == to.line && span.from >= to.ch) &&

              (!filter || filter(span.marker)))

            found.push(span.marker.parent || span.marker);

        }

        ++lineNo;

      });

      return found;

    },

    getAllMarks: function() {

      var markers = [];

      this.iter(function(line) {

        var sps = line.markedSpans;

        if (sps) for (var i = 0; i < sps.length; ++i)

          if (sps[i].from != null) markers.push(sps[i].marker);

      });

      return markers;

    },



    posFromIndex: function(off) {

      var ch, lineNo = this.first, sepSize = this.lineSeparator().length;

      this.iter(function(line) {

        var sz = line.text.length + sepSize;

        if (sz > off) { ch = off; return true; }

        off -= sz;

        ++lineNo;

      });

      return clipPos(this, Pos(lineNo, ch));

    },

    indexFromPos: function (coords) {

      coords = clipPos(this, coords);

      var index = coords.ch;

      if (coords.line < this.first || coords.ch < 0) return 0;

      var sepSize = this.lineSeparator().length;

      this.iter(this.first, coords.line, function (line) {

        index += line.text.length + sepSize;

      });

      return index;

    },



    copy: function(copyHistory) {

      var doc = new Doc(getLines(this, this.first, this.first + this.size),

                        this.modeOption, this.first, this.lineSep);

      doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;

      doc.sel = this.sel;

      doc.extend = false;

      if (copyHistory) {

        doc.history.undoDepth = this.history.undoDepth;

        doc.setHistory(this.getHistory());

      }

      return doc;

    },



    linkedDoc: function(options) {

      if (!options) options = {};

      var from = this.first, to = this.first + this.size;

      if (options.from != null && options.from > from) from = options.from;

      if (options.to != null && options.to < to) to = options.to;

      var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from, this.lineSep);

      if (options.sharedHist) copy.history = this.history;

      (this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});

      copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];

      copySharedMarkers(copy, findSharedMarkers(this));

      return copy;

    },

    unlinkDoc: function(other) {

      if (other instanceof CodeMirror) other = other.doc;

      if (this.linked) for (var i = 0; i < this.linked.length; ++i) {

        var link = this.linked[i];

        if (link.doc != other) continue;

        this.linked.splice(i, 1);

        other.unlinkDoc(this);

        detachSharedMarkers(findSharedMarkers(this));

        break;

      }

      // If the histories were shared, split them again

      if (other.history == this.history) {

        var splitIds = [other.id];

        linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);

        other.history = new History(null);

        other.history.done = copyHistoryArray(this.history.done, splitIds);

        other.history.undone = copyHistoryArray(this.history.undone, splitIds);

      }

    },

    iterLinkedDocs: function(f) {linkedDocs(this, f);},



    getMode: function() {return this.mode;},

    getEditor: function() {return this.cm;},



    splitLines: function(str) {

      if (this.lineSep) return str.split(this.lineSep);

      return splitLinesAuto(str);

    },

    lineSeparator: function() { return this.lineSep || "\n"; }

  });



  // Public alias.

  Doc.prototype.eachLine = Doc.prototype.iter;



  // Set up methods on CodeMirror's prototype to redirect to the editor's document.

  var dontDelegate = "iter insert remove copy getEditor constructor".split(" ");

  for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)

    CodeMirror.prototype[prop] = (function(method) {

      return function() {return method.apply(this.doc, arguments);};

    })(Doc.prototype[prop]);



  eventMixin(Doc);



  // Call f for all linked documents.

  function linkedDocs(doc, f, sharedHistOnly) {

    function propagate(doc, skip, sharedHist) {

      if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {

        var rel = doc.linked[i];

        if (rel.doc == skip) continue;

        var shared = sharedHist && rel.sharedHist;

        if (sharedHistOnly && !shared) continue;

        f(rel.doc, shared);

        propagate(rel.doc, doc, shared);

      }

    }

    propagate(doc, null, true);

  }



  // Attach a document to an editor.

  function attachDoc(cm, doc) {

    if (doc.cm) throw new Error("This document is already in use.");

    cm.doc = doc;

    doc.cm = cm;

    estimateLineHeights(cm);

    loadMode(cm);

    if (!cm.options.lineWrapping) findMaxLine(cm);

    cm.options.mode = doc.modeOption;

    regChange(cm);

  }



  // LINE UTILITIES



  // Find the line object corresponding to the given line number.

  function getLine(doc, n) {

    n -= doc.first;

    if (n < 0 || n >= doc.size) throw new Error("There is no line " + (n + doc.first) + " in the document.");

    for (var chunk = doc; !chunk.lines;) {

      for (var i = 0;; ++i) {

        var child = chunk.children[i], sz = child.chunkSize();

        if (n < sz) { chunk = child; break; }

        n -= sz;

      }

    }

    return chunk.lines[n];

  }



  // Get the part of a document between two positions, as an array of

  // strings.

  function getBetween(doc, start, end) {

    var out = [], n = start.line;

    doc.iter(start.line, end.line + 1, function(line) {

      var text = line.text;

      if (n == end.line) text = text.slice(0, end.ch);

      if (n == start.line) text = text.slice(start.ch);

      out.push(text);

      ++n;

    });

    return out;

  }

  // Get the lines between from and to, as array of strings.

  function getLines(doc, from, to) {

    var out = [];

    doc.iter(from, to, function(line) { out.push(line.text); });

    return out;

  }



  // Update the height of a line, propagating the height change

  // upwards to parent nodes.

  function updateLineHeight(line, height) {

    var diff = height - line.height;

    if (diff) for (var n = line; n; n = n.parent) n.height += diff;

  }



  // Given a line object, find its line number by walking up through

  // its parent links.

  function lineNo(line) {

    if (line.parent == null) return null;

    var cur = line.parent, no = indexOf(cur.lines, line);

    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {

      for (var i = 0;; ++i) {

        if (chunk.children[i] == cur) break;

        no += chunk.children[i].chunkSize();

      }

    }

    return no + cur.first;

  }



  // Find the line at the given vertical position, using the height

  // information in the document tree.

  function lineAtHeight(chunk, h) {

    var n = chunk.first;

    outer: do {

      for (var i = 0; i < chunk.children.length; ++i) {

        var child = chunk.children[i], ch = child.height;

        if (h < ch) { chunk = child; continue outer; }

        h -= ch;

        n += child.chunkSize();

      }

      return n;

    } while (!chunk.lines);

    for (var i = 0; i < chunk.lines.length; ++i) {

      var line = chunk.lines[i], lh = line.height;

      if (h < lh) break;

      h -= lh;

    }

    return n + i;

  }





  // Find the height above the given line.

  function heightAtLine(lineObj) {

    lineObj = visualLine(lineObj);



    var h = 0, chunk = lineObj.parent;

    for (var i = 0; i < chunk.lines.length; ++i) {

      var line = chunk.lines[i];

      if (line == lineObj) break;

      else h += line.height;

    }

    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {

      for (var i = 0; i < p.children.length; ++i) {

        var cur = p.children[i];

        if (cur == chunk) break;

        else h += cur.height;

      }

    }

    return h;

  }



  // Get the bidi ordering for the given line (and cache it). Returns

  // false for lines that are fully left-to-right, and an array of

  // BidiSpan objects otherwise.

  function getOrder(line) {

    var order = line.order;

    if (order == null) order = line.order = bidiOrdering(line.text);

    return order;

  }



  // HISTORY



  function History(startGen) {

    // Arrays of change events and selections. Doing something adds an

    // event to done and clears undo. Undoing moves events from done

    // to undone, redoing moves them in the other direction.

    this.done = []; this.undone = [];

    this.undoDepth = Infinity;

    // Used to track when changes can be merged into a single undo

    // event

    this.lastModTime = this.lastSelTime = 0;

    this.lastOp = this.lastSelOp = null;

    this.lastOrigin = this.lastSelOrigin = null;

    // Used by the isClean() method

    this.generation = this.maxGeneration = startGen || 1;

  }



  // Create a history change event from an updateDoc-style change

  // object.

  function historyChangeFromChange(doc, change) {

    var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};

    attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);

    linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);

    return histChange;

  }



  // Pop all selection events off the end of a history array. Stop at

  // a change event.

  function clearSelectionEvents(array) {

    while (array.length) {

      var last = lst(array);

      if (last.ranges) array.pop();

      else break;

    }

  }



  // Find the top change event in the history. Pop off selection

  // events that are in the way.

  function lastChangeEvent(hist, force) {

    if (force) {

      clearSelectionEvents(hist.done);

      return lst(hist.done);

    } else if (hist.done.length && !lst(hist.done).ranges) {

      return lst(hist.done);

    } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {

      hist.done.pop();

      return lst(hist.done);

    }

  }



  // Register a change in the history. Merges changes that are within

  // a single operation, or are close together with an origin that

  // allows merging (starting with "+") into a single event.

  function addChangeToHistory(doc, change, selAfter, opId) {

    var hist = doc.history;

    hist.undone.length = 0;

    var time = +new Date, cur;



    if ((hist.lastOp == opId ||

         hist.lastOrigin == change.origin && change.origin &&

         ((change.origin.charAt(0) == "+" && doc.cm && hist.lastModTime > time - doc.cm.options.historyEventDelay) ||

          change.origin.charAt(0) == "*")) &&

        (cur = lastChangeEvent(hist, hist.lastOp == opId))) {

      // Merge this change into the last event

      var last = lst(cur.changes);

      if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {

        // Optimized case for simple insertion -- don't want to add

        // new changesets for every character typed

        last.to = changeEnd(change);

      } else {

        // Add new sub-event

        cur.changes.push(historyChangeFromChange(doc, change));

      }

    } else {

      // Can not be merged, start a new event.

      var before = lst(hist.done);

      if (!before || !before.ranges)

        pushSelectionToHistory(doc.sel, hist.done);

      cur = {changes: [historyChangeFromChange(doc, change)],

             generation: hist.generation};

      hist.done.push(cur);

      while (hist.done.length > hist.undoDepth) {

        hist.done.shift();

        if (!hist.done[0].ranges) hist.done.shift();

      }

    }

    hist.done.push(selAfter);

    hist.generation = ++hist.maxGeneration;

    hist.lastModTime = hist.lastSelTime = time;

    hist.lastOp = hist.lastSelOp = opId;

    hist.lastOrigin = hist.lastSelOrigin = change.origin;



    if (!last) signal(doc, "historyAdded");

  }



  function selectionEventCanBeMerged(doc, origin, prev, sel) {

    var ch = origin.charAt(0);

    return ch == "*" ||

      ch == "+" &&

      prev.ranges.length == sel.ranges.length &&

      prev.somethingSelected() == sel.somethingSelected() &&

      new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500);

  }



  // Called whenever the selection changes, sets the new selection as

  // the pending selection in the history, and pushes the old pending

  // selection into the 'done' array when it was significantly

  // different (in number of selected ranges, emptiness, or time).

  function addSelectionToHistory(doc, sel, opId, options) {

    var hist = doc.history, origin = options && options.origin;



    // A new event is started when the previous origin does not match

    // the current, or the origins don't allow matching. Origins

    // starting with * are always merged, those starting with + are

    // merged when similar and close together in time.

    if (opId == hist.lastSelOp ||

        (origin && hist.lastSelOrigin == origin &&

         (hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||

          selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))

      hist.done[hist.done.length - 1] = sel;

    else

      pushSelectionToHistory(sel, hist.done);



    hist.lastSelTime = +new Date;

    hist.lastSelOrigin = origin;

    hist.lastSelOp = opId;

    if (options && options.clearRedo !== false)

      clearSelectionEvents(hist.undone);

  }



  function pushSelectionToHistory(sel, dest) {

    var top = lst(dest);

    if (!(top && top.ranges && top.equals(sel)))

      dest.push(sel);

  }



  // Used to store marked span information in the history.

  function attachLocalSpans(doc, change, from, to) {

    var existing = change["spans_" + doc.id], n = 0;

    doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {

      if (line.markedSpans)

        (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;

      ++n;

    });

  }



  // When un/re-doing restores text containing marked spans, those

  // that have been explicitly cleared should not be restored.

  function removeClearedSpans(spans) {

    if (!spans) return null;

    for (var i = 0, out; i < spans.length; ++i) {

      if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }

      else if (out) out.push(spans[i]);

    }

    return !out ? spans : out.length ? out : null;

  }



  // Retrieve and filter the old marked spans stored in a change event.

  function getOldSpans(doc, change) {

    var found = change["spans_" + doc.id];

    if (!found) return null;

    for (var i = 0, nw = []; i < change.text.length; ++i)

      nw.push(removeClearedSpans(found[i]));

    return nw;

  }



  // Used both to provide a JSON-safe object in .getHistory, and, when

  // detaching a document, to split the history in two

  function copyHistoryArray(events, newGroup, instantiateSel) {

    for (var i = 0, copy = []; i < events.length; ++i) {

      var event = events[i];

      if (event.ranges) {

        copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);

        continue;

      }

      var changes = event.changes, newChanges = [];

      copy.push({changes: newChanges});

      for (var j = 0; j < changes.length; ++j) {

        var change = changes[j], m;

        newChanges.push({from: change.from, to: change.to, text: change.text});

        if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {

          if (indexOf(newGroup, Number(m[1])) > -1) {

            lst(newChanges)[prop] = change[prop];

            delete change[prop];

          }

        }

      }

    }

    return copy;

  }



  // Rebasing/resetting history to deal with externally-sourced changes



  function rebaseHistSelSingle(pos, from, to, diff) {

    if (to < pos.line) {

      pos.line += diff;

    } else if (from < pos.line) {

      pos.line = from;

      pos.ch = 0;

    }

  }



  // Tries to rebase an array of history events given a change in the

  // document. If the change touches the same lines as the event, the

  // event, and everything 'behind' it, is discarded. If the change is

  // before the event, the event's positions are updated. Uses a

  // copy-on-write scheme for the positions, to avoid having to

  // reallocate them all on every rebase, but also avoid problems with

  // shared position objects being unsafely updated.

  function rebaseHistArray(array, from, to, diff) {

    for (var i = 0; i < array.length; ++i) {

      var sub = array[i], ok = true;

      if (sub.ranges) {

        if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }

        for (var j = 0; j < sub.ranges.length; j++) {

          rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);

          rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);

        }

        continue;

      }

      for (var j = 0; j < sub.changes.length; ++j) {

        var cur = sub.changes[j];

        if (to < cur.from.line) {

          cur.from = Pos(cur.from.line + diff, cur.from.ch);

          cur.to = Pos(cur.to.line + diff, cur.to.ch);

        } else if (from <= cur.to.line) {

          ok = false;

          break;

        }

      }

      if (!ok) {

        array.splice(0, i + 1);

        i = 0;

      }

    }

  }



  function rebaseHist(hist, change) {

    var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;

    rebaseHistArray(hist.done, from, to, diff);

    rebaseHistArray(hist.undone, from, to, diff);

  }



  // EVENT UTILITIES



  // Due to the fact that we still support jurassic IE versions, some

  // compatibility wrappers are needed.



  var e_preventDefault = CodeMirror.e_preventDefault = function(e) {

    if (e.preventDefault) e.preventDefault();

    else e.returnValue = false;

  };

  var e_stopPropagation = CodeMirror.e_stopPropagation = function(e) {

    if (e.stopPropagation) e.stopPropagation();

    else e.cancelBubble = true;

  };

  function e_defaultPrevented(e) {

    return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;

  }

  var e_stop = CodeMirror.e_stop = function(e) {e_preventDefault(e); e_stopPropagation(e);};



  function e_target(e) {return e.target || e.srcElement;}

  function e_button(e) {

    var b = e.which;

    if (b == null) {

      if (e.button & 1) b = 1;

      else if (e.button & 2) b = 3;

      else if (e.button & 4) b = 2;

    }

    if (mac && e.ctrlKey && b == 1) b = 3;

    return b;

  }



  // EVENT HANDLING



  // Lightweight event framework. on/off also work on DOM nodes,

  // registering native DOM handlers.



  var on = CodeMirror.on = function(emitter, type, f) {

    if (emitter.addEventListener)

      emitter.addEventListener(type, f, false);

    else if (emitter.attachEvent)

      emitter.attachEvent("on" + type, f);

    else {

      var map = emitter._handlers || (emitter._handlers = {});

      var arr = map[type] || (map[type] = []);

      arr.push(f);

    }

  };



  var noHandlers = []

  function getHandlers(emitter, type, copy) {

    var arr = emitter._handlers && emitter._handlers[type]

    if (copy) return arr && arr.length > 0 ? arr.slice() : noHandlers

    else return arr || noHandlers

  }



  var off = CodeMirror.off = function(emitter, type, f) {

    if (emitter.removeEventListener)

      emitter.removeEventListener(type, f, false);

    else if (emitter.detachEvent)

      emitter.detachEvent("on" + type, f);

    else {

      var handlers = getHandlers(emitter, type, false)

      for (var i = 0; i < handlers.length; ++i)

        if (handlers[i] == f) { handlers.splice(i, 1); break; }

    }

  };



  var signal = CodeMirror.signal = function(emitter, type /*, values...*/) {

    var handlers = getHandlers(emitter, type, true)

    if (!handlers.length) return;

    var args = Array.prototype.slice.call(arguments, 2);

    for (var i = 0; i < handlers.length; ++i) handlers[i].apply(null, args);

  };



  var orphanDelayedCallbacks = null;



  // Often, we want to signal events at a point where we are in the

  // middle of some work, but don't want the handler to start calling

  // other methods on the editor, which might be in an inconsistent

  // state or simply not expect any other events to happen.

  // signalLater looks whether there are any handlers, and schedules

  // them to be executed when the last operation ends, or, if no

  // operation is active, when a timeout fires.

  function signalLater(emitter, type /*, values...*/) {

    var arr = getHandlers(emitter, type, false)

    if (!arr.length) return;

    var args = Array.prototype.slice.call(arguments, 2), list;

    if (operationGroup) {

      list = operationGroup.delayedCallbacks;

    } else if (orphanDelayedCallbacks) {

      list = orphanDelayedCallbacks;

    } else {

      list = orphanDelayedCallbacks = [];

      setTimeout(fireOrphanDelayed, 0);

    }

    function bnd(f) {return function(){f.apply(null, args);};};

    for (var i = 0; i < arr.length; ++i)

      list.push(bnd(arr[i]));

  }



  function fireOrphanDelayed() {

    var delayed = orphanDelayedCallbacks;

    orphanDelayedCallbacks = null;

    for (var i = 0; i < delayed.length; ++i) delayed[i]();

  }



  // The DOM events that CodeMirror handles can be overridden by

  // registering a (non-DOM) handler on the editor for the event name,

  // and preventDefault-ing the event in that handler.

  function signalDOMEvent(cm, e, override) {

    if (typeof e == "string")

      e = {type: e, preventDefault: function() { this.defaultPrevented = true; }};

    signal(cm, override || e.type, cm, e);

    return e_defaultPrevented(e) || e.codemirrorIgnore;

  }



  function signalCursorActivity(cm) {

    var arr = cm._handlers && cm._handlers.cursorActivity;

    if (!arr) return;

    var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);

    for (var i = 0; i < arr.length; ++i) if (indexOf(set, arr[i]) == -1)

      set.push(arr[i]);

  }



  function hasHandler(emitter, type) {

    return getHandlers(emitter, type).length > 0

  }



  // Add on and off methods to a constructor's prototype, to make

  // registering events on such objects more convenient.

  function eventMixin(ctor) {

    ctor.prototype.on = function(type, f) {on(this, type, f);};

    ctor.prototype.off = function(type, f) {off(this, type, f);};

  }



  // MISC UTILITIES



  // Number of pixels added to scroller and sizer to hide scrollbar

  var scrollerGap = 30;



  // Returned or thrown by various protocols to signal 'I'm not

  // handling this'.

  var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};



  // Reused option objects for setSelection & friends

  var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};



  function Delayed() {this.id = null;}

  Delayed.prototype.set = function(ms, f) {

    clearTimeout(this.id);

    this.id = setTimeout(f, ms);

  };



  // Counts the column offset in a string, taking tabs into account.

  // Used mostly to find indentation.

  var countColumn = CodeMirror.countColumn = function(string, end, tabSize, startIndex, startValue) {

    if (end == null) {

      end = string.search(/[^\s\u00a0]/);

      if (end == -1) end = string.length;

    }

    for (var i = startIndex || 0, n = startValue || 0;;) {

      var nextTab = string.indexOf("\t", i);

      if (nextTab < 0 || nextTab >= end)

        return n + (end - i);

      n += nextTab - i;

      n += tabSize - (n % tabSize);

      i = nextTab + 1;

    }

  };



  // The inverse of countColumn -- find the offset that corresponds to

  // a particular column.

  var findColumn = CodeMirror.findColumn = function(string, goal, tabSize) {

    for (var pos = 0, col = 0;;) {

      var nextTab = string.indexOf("\t", pos);

      if (nextTab == -1) nextTab = string.length;

      var skipped = nextTab - pos;

      if (nextTab == string.length || col + skipped >= goal)

        return pos + Math.min(skipped, goal - col);

      col += nextTab - pos;

      col += tabSize - (col % tabSize);

      pos = nextTab + 1;

      if (col >= goal) return pos;

    }

  }



  var spaceStrs = [""];

  function spaceStr(n) {

    while (spaceStrs.length <= n)

      spaceStrs.push(lst(spaceStrs) + " ");

    return spaceStrs[n];

  }



  function lst(arr) { return arr[arr.length-1]; }



  var selectInput = function(node) { node.select(); };

  if (ios) // Mobile Safari apparently has a bug where select() is broken.

    selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; };

  else if (ie) // Suppress mysterious IE10 errors

    selectInput = function(node) { try { node.select(); } catch(_e) {} };



  function indexOf(array, elt) {

    for (var i = 0; i < array.length; ++i)

      if (array[i] == elt) return i;

    return -1;

  }

  function map(array, f) {

    var out = [];

    for (var i = 0; i < array.length; i++) out[i] = f(array[i], i);

    return out;

  }



  function insertSorted(array, value, score) {

    var pos = 0, priority = score(value)

    while (pos < array.length && score(array[pos]) <= priority) pos++

    array.splice(pos, 0, value)

  }



  function nothing() {}



  function createObj(base, props) {

    var inst;

    if (Object.create) {

      inst = Object.create(base);

    } else {

      nothing.prototype = base;

      inst = new nothing();

    }

    if (props) copyObj(props, inst);

    return inst;

  };



  function copyObj(obj, target, overwrite) {

    if (!target) target = {};

    for (var prop in obj)

      if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))

        target[prop] = obj[prop];

    return target;

  }



  function bind(f) {

    var args = Array.prototype.slice.call(arguments, 1);

    return function(){return f.apply(null, args);};

  }



  var nonASCIISingleCaseWordChar = /[\u00df\u0587\u0590-\u05f4\u0600-\u06ff\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;

  var isWordCharBasic = CodeMirror.isWordChar = function(ch) {

    return /\w/.test(ch) || ch > "\x80" &&

      (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));

  };

  function isWordChar(ch, helper) {

    if (!helper) return isWordCharBasic(ch);

    if (helper.source.indexOf("\\w") > -1 && isWordCharBasic(ch)) return true;

    return helper.test(ch);

  }



  function isEmpty(obj) {

    for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;

    return true;

  }



  // Extending unicode characters. A series of a non-extending char +

  // any number of extending chars is treated as a single unit as far

  // as editing and measuring is concerned. This is not fully correct,

  // since some scripts/fonts/browsers also treat other configurations

  // of code points as a group.

  var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;

  function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch); }



  // DOM UTILITIES



  function elt(tag, content, className, style) {

    var e = document.createElement(tag);

    if (className) e.className = className;

    if (style) e.style.cssText = style;

    if (typeof content == "string") e.appendChild(document.createTextNode(content));

    else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);

    return e;

  }



  var range;

  if (document.createRange) range = function(node, start, end, endNode) {

    var r = document.createRange();

    r.setEnd(endNode || node, end);

    r.setStart(node, start);

    return r;

  };

  else range = function(node, start, end) {

    var r = document.body.createTextRange();

    try { r.moveToElementText(node.parentNode); }

    catch(e) { return r; }

    r.collapse(true);

    r.moveEnd("character", end);

    r.moveStart("character", start);

    return r;

  };



  function removeChildren(e) {

    for (var count = e.childNodes.length; count > 0; --count)

      e.removeChild(e.firstChild);

    return e;

  }



  function removeChildrenAndAdd(parent, e) {

    return removeChildren(parent).appendChild(e);

  }



  var contains = CodeMirror.contains = function(parent, child) {

    if (child.nodeType == 3) // Android browser always returns false when child is a textnode

      child = child.parentNode;

    if (parent.contains)

      return parent.contains(child);

    do {

      if (child.nodeType == 11) child = child.host;

      if (child == parent) return true;

    } while (child = child.parentNode);

  };



  function activeElt() {

    var activeElement = document.activeElement;

    while (activeElement && activeElement.root && activeElement.root.activeElement)

      activeElement = activeElement.root.activeElement;

    return activeElement;

  }

  // Older versions of IE throws unspecified error when touching

  // document.activeElement in some cases (during loading, in iframe)

  if (ie && ie_version < 11) activeElt = function() {

    try { return document.activeElement; }

    catch(e) { return document.body; }

  };



  function classTest(cls) { return new RegExp("(^|\\s)" + cls + "(?:$|\\s)\\s*"); }

  var rmClass = CodeMirror.rmClass = function(node, cls) {

    var current = node.className;

    var match = classTest(cls).exec(current);

    if (match) {

      var after = current.slice(match.index + match[0].length);

      node.className = current.slice(0, match.index) + (after ? match[1] + after : "");

    }

  };

  var addClass = CodeMirror.addClass = function(node, cls) {

    var current = node.className;

    if (!classTest(cls).test(current)) node.className += (current ? " " : "") + cls;

  };

  function joinClasses(a, b) {

    var as = a.split(" ");

    for (var i = 0; i < as.length; i++)

      if (as[i] && !classTest(as[i]).test(b)) b += " " + as[i];

    return b;

  }



  // WINDOW-WIDE EVENTS



  // These must be handled carefully, because naively registering a

  // handler for each editor will cause the editors to never be

  // garbage collected.



  function forEachCodeMirror(f) {

    if (!document.body.getElementsByClassName) return;

    var byClass = document.body.getElementsByClassName("CodeMirror");

    for (var i = 0; i < byClass.length; i++) {

      var cm = byClass[i].CodeMirror;

      if (cm) f(cm);

    }

  }



  var globalsRegistered = false;

  function ensureGlobalHandlers() {

    if (globalsRegistered) return;

    registerGlobalHandlers();

    globalsRegistered = true;

  }

  function registerGlobalHandlers() {

    // When the window resizes, we need to refresh active editors.

    var resizeTimer;

    on(window, "resize", function() {

      if (resizeTimer == null) resizeTimer = setTimeout(function() {

        resizeTimer = null;

        forEachCodeMirror(onResize);

      }, 100);

    });

    // When the window loses focus, we want to show the editor as blurred

    on(window, "blur", function() {

      forEachCodeMirror(onBlur);

    });

  }



  // FEATURE DETECTION



  // Detect drag-and-drop

  var dragAndDrop = function() {

    // There is *some* kind of drag-and-drop support in IE6-8, but I

    // couldn't get it to work yet.

    if (ie && ie_version < 9) return false;

    var div = elt('div');

    return "draggable" in div || "dragDrop" in div;

  }();



  var zwspSupported;

  function zeroWidthElement(measure) {

    if (zwspSupported == null) {

      var test = elt("span", "\u200b");

      removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));

      if (measure.firstChild.offsetHeight != 0)

        zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8);

    }

    var node = zwspSupported ? elt("span", "\u200b") :

      elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");

    node.setAttribute("cm-text", "");

    return node;

  }



  // Feature-detect IE's crummy client rect reporting for bidi text

  var badBidiRects;

  function hasBadBidiRects(measure) {

    if (badBidiRects != null) return badBidiRects;

    var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));

    var r0 = range(txt, 0, 1).getBoundingClientRect();

    var r1 = range(txt, 1, 2).getBoundingClientRect();

    removeChildren(measure);

    if (!r0 || r0.left == r0.right) return false; // Safari returns null in some cases (#2780)

    return badBidiRects = (r1.right - r0.right < 3);

  }



  // See if "".split is the broken IE version, if so, provide an

  // alternative way to split lines.

  var splitLinesAuto = CodeMirror.splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {

    var pos = 0, result = [], l = string.length;

    while (pos <= l) {

      var nl = string.indexOf("\n", pos);

      if (nl == -1) nl = string.length;

      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);

      var rt = line.indexOf("\r");

      if (rt != -1) {

        result.push(line.slice(0, rt));

        pos += rt + 1;

      } else {

        result.push(line);

        pos = nl + 1;

      }

    }

    return result;

  } : function(string){return string.split(/\r\n?|\n/);};



  var hasSelection = window.getSelection ? function(te) {

    try { return te.selectionStart != te.selectionEnd; }

    catch(e) { return false; }

  } : function(te) {

    try {var range = te.ownerDocument.selection.createRange();}

    catch(e) {}

    if (!range || range.parentElement() != te) return false;

    return range.compareEndPoints("StartToEnd", range) != 0;

  };



  var hasCopyEvent = (function() {

    var e = elt("div");

    if ("oncopy" in e) return true;

    e.setAttribute("oncopy", "return;");

    return typeof e.oncopy == "function";

  })();



  var badZoomedRects = null;

  function hasBadZoomedRects(measure) {

    if (badZoomedRects != null) return badZoomedRects;

    var node = removeChildrenAndAdd(measure, elt("span", "x"));

    var normal = node.getBoundingClientRect();

    var fromRange = range(node, 0, 1).getBoundingClientRect();

    return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1;

  }



  // KEY NAMES



  var keyNames = CodeMirror.keyNames = {

    3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",

    19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",

    36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",

    46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod",

    106: "*", 107: "=", 109: "-", 110: ".", 111: "/", 127: "Delete",

    173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",

    221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",

    63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"

  };

  (function() {

    // Number keys

    for (var i = 0; i < 10; i++) keyNames[i + 48] = keyNames[i + 96] = String(i);

    // Alphabetic keys

    for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);

    // Function keys

    for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;

  })();



  // BIDI HELPERS



  function iterateBidiSections(order, from, to, f) {

    if (!order) return f(from, to, "ltr");

    var found = false;

    for (var i = 0; i < order.length; ++i) {

      var part = order[i];

      if (part.from < to && part.to > from || from == to && part.to == from) {

        f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");

        found = true;

      }

    }

    if (!found) f(from, to, "ltr");

  }



  function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }

  function bidiRight(part) { return part.level % 2 ? part.from : part.to; }



  function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }

  function lineRight(line) {

    var order = getOrder(line);

    if (!order) return line.text.length;

    return bidiRight(lst(order));

  }



  function lineStart(cm, lineN) {

    var line = getLine(cm.doc, lineN);

    var visual = visualLine(line);

    if (visual != line) lineN = lineNo(visual);

    var order = getOrder(visual);

    var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);

    return Pos(lineN, ch);

  }

  function lineEnd(cm, lineN) {

    var merged, line = getLine(cm.doc, lineN);

    while (merged = collapsedSpanAtEnd(line)) {

      line = merged.find(1, true).line;

      lineN = null;

    }

    var order = getOrder(line);

    var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);

    return Pos(lineN == null ? lineNo(line) : lineN, ch);

  }

  function lineStartSmart(cm, pos) {

    var start = lineStart(cm, pos.line);

    var line = getLine(cm.doc, start.line);

    var order = getOrder(line);

    if (!order || order[0].level == 0) {

      var firstNonWS = Math.max(0, line.text.search(/\S/));

      var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch;

      return Pos(start.line, inWS ? 0 : firstNonWS);

    }

    return start;

  }



  function compareBidiLevel(order, a, b) {

    var linedir = order[0].level;

    if (a == linedir) return true;

    if (b == linedir) return false;

    return a < b;

  }

  var bidiOther;

  function getBidiPartAt(order, pos) {

    bidiOther = null;

    for (var i = 0, found; i < order.length; ++i) {

      var cur = order[i];

      if (cur.from < pos && cur.to > pos) return i;

      if ((cur.from == pos || cur.to == pos)) {

        if (found == null) {

          found = i;

        } else if (compareBidiLevel(order, cur.level, order[found].level)) {

          if (cur.from != cur.to) bidiOther = found;

          return i;

        } else {

          if (cur.from != cur.to) bidiOther = i;

          return found;

        }

      }

    }

    return found;

  }



  function moveInLine(line, pos, dir, byUnit) {

    if (!byUnit) return pos + dir;

    do pos += dir;

    while (pos > 0 && isExtendingChar(line.text.charAt(pos)));

    return pos;

  }



  // This is needed in order to move 'visually' through bi-directional

  // text -- i.e., pressing left should make the cursor go left, even

  // when in RTL text. The tricky part is the 'jumps', where RTL and

  // LTR text touch each other. This often requires the cursor offset

  // to move more than one unit, in order to visually move one unit.

  function moveVisually(line, start, dir, byUnit) {

    var bidi = getOrder(line);

    if (!bidi) return moveLogically(line, start, dir, byUnit);

    var pos = getBidiPartAt(bidi, start), part = bidi[pos];

    var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);



    for (;;) {

      if (target > part.from && target < part.to) return target;

      if (target == part.from || target == part.to) {

        if (getBidiPartAt(bidi, target) == pos) return target;

        part = bidi[pos += dir];

        return (dir > 0) == part.level % 2 ? part.to : part.from;

      } else {

        part = bidi[pos += dir];

        if (!part) return null;

        if ((dir > 0) == part.level % 2)

          target = moveInLine(line, part.to, -1, byUnit);

        else

          target = moveInLine(line, part.from, 1, byUnit);

      }

    }

  }



  function moveLogically(line, start, dir, byUnit) {

    var target = start + dir;

    if (byUnit) while (target > 0 && isExtendingChar(line.text.charAt(target))) target += dir;

    return target < 0 || target > line.text.length ? null : target;

  }



  // Bidirectional ordering algorithm

  // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm

  // that this (partially) implements.



  // One-char codes used for character types:

  // L (L):   Left-to-Right

  // R (R):   Right-to-Left

  // r (AL):  Right-to-Left Arabic

  // 1 (EN):  European Number

  // + (ES):  European Number Separator

  // % (ET):  European Number Terminator

  // n (AN):  Arabic Number

  // , (CS):  Common Number Separator

  // m (NSM): Non-Spacing Mark

  // b (BN):  Boundary Neutral

  // s (B):   Paragraph Separator

  // t (S):   Segment Separator

  // w (WS):  Whitespace

  // N (ON):  Other Neutrals



  // Returns null if characters are ordered as they appear

  // (left-to-right), or an array of sections ({from, to, level}

  // objects) in the order in which they occur visually.

  var bidiOrdering = (function() {

    // Character types for codepoints 0 to 0xff

    var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";

    // Character types for codepoints 0x600 to 0x6ff

    var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmm";

    function charType(code) {

      if (code <= 0xf7) return lowTypes.charAt(code);

      else if (0x590 <= code && code <= 0x5f4) return "R";

      else if (0x600 <= code && code <= 0x6ed) return arabicTypes.charAt(code - 0x600);

      else if (0x6ee <= code && code <= 0x8ac) return "r";

      else if (0x2000 <= code && code <= 0x200b) return "w";

      else if (code == 0x200c) return "b";

      else return "L";

    }



    var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;

    var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;

    // Browsers seem to always treat the boundaries of block elements as being L.

    var outerType = "L";



    function BidiSpan(level, from, to) {

      this.level = level;

      this.from = from; this.to = to;

    }



    return function(str) {

      if (!bidiRE.test(str)) return false;

      var len = str.length, types = [];

      for (var i = 0, type; i < len; ++i)

        types.push(type = charType(str.charCodeAt(i)));



      // W1. Examine each non-spacing mark (NSM) in the level run, and

      // change the type of the NSM to the type of the previous

      // character. If the NSM is at the start of the level run, it will

      // get the type of sor.

      for (var i = 0, prev = outerType; i < len; ++i) {

        var type = types[i];

        if (type == "m") types[i] = prev;

        else prev = type;

      }



      // W2. Search backwards from each instance of a European number

      // until the first strong type (R, L, AL, or sor) is found. If an

      // AL is found, change the type of the European number to Arabic

      // number.

      // W3. Change all ALs to R.

      for (var i = 0, cur = outerType; i < len; ++i) {

        var type = types[i];

        if (type == "1" && cur == "r") types[i] = "n";

        else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }

      }



      // W4. A single European separator between two European numbers

      // changes to a European number. A single common separator between

      // two numbers of the same type changes to that type.

      for (var i = 1, prev = types[0]; i < len - 1; ++i) {

        var type = types[i];

        if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";

        else if (type == "," && prev == types[i+1] &&

                 (prev == "1" || prev == "n")) types[i] = prev;

        prev = type;

      }



      // W5. A sequence of European terminators adjacent to European

      // numbers changes to all European numbers.

      // W6. Otherwise, separators and terminators change to Other

      // Neutral.

      for (var i = 0; i < len; ++i) {

        var type = types[i];

        if (type == ",") types[i] = "N";

        else if (type == "%") {

          for (var end = i + 1; end < len && types[end] == "%"; ++end) {}

          var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";

          for (var j = i; j < end; ++j) types[j] = replace;

          i = end - 1;

        }

      }



      // W7. Search backwards from each instance of a European number

      // until the first strong type (R, L, or sor) is found. If an L is

      // found, then change the type of the European number to L.

      for (var i = 0, cur = outerType; i < len; ++i) {

        var type = types[i];

        if (cur == "L" && type == "1") types[i] = "L";

        else if (isStrong.test(type)) cur = type;

      }



      // N1. A sequence of neutrals takes the direction of the

      // surrounding strong text if the text on both sides has the same

      // direction. European and Arabic numbers act as if they were R in

      // terms of their influence on neutrals. Start-of-level-run (sor)

      // and end-of-level-run (eor) are used at level run boundaries.

      // N2. Any remaining neutrals take the embedding direction.

      for (var i = 0; i < len; ++i) {

        if (isNeutral.test(types[i])) {

          for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}

          var before = (i ? types[i-1] : outerType) == "L";

          var after = (end < len ? types[end] : outerType) == "L";

          var replace = before || after ? "L" : "R";

          for (var j = i; j < end; ++j) types[j] = replace;

          i = end - 1;

        }

      }



      // Here we depart from the documented algorithm, in order to avoid

      // building up an actual levels array. Since there are only three

      // levels (0, 1, 2) in an implementation that doesn't take

      // explicit embedding into account, we can build up the order on

      // the fly, without following the level-based algorithm.

      var order = [], m;

      for (var i = 0; i < len;) {

        if (countsAsLeft.test(types[i])) {

          var start = i;

          for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}

          order.push(new BidiSpan(0, start, i));

        } else {

          var pos = i, at = order.length;

          for (++i; i < len && types[i] != "L"; ++i) {}

          for (var j = pos; j < i;) {

            if (countsAsNum.test(types[j])) {

              if (pos < j) order.splice(at, 0, new BidiSpan(1, pos, j));

              var nstart = j;

              for (++j; j < i && countsAsNum.test(types[j]); ++j) {}

              order.splice(at, 0, new BidiSpan(2, nstart, j));

              pos = j;

            } else ++j;

          }

          if (pos < i) order.splice(at, 0, new BidiSpan(1, pos, i));

        }

      }

      if (order[0].level == 1 && (m = str.match(/^\s+/))) {

        order[0].from = m[0].length;

        order.unshift(new BidiSpan(0, 0, m[0].length));

      }

      if (lst(order).level == 1 && (m = str.match(/\s+$/))) {

        lst(order).to -= m[0].length;

        order.push(new BidiSpan(0, len - m[0].length, len));

      }

      if (order[0].level == 2)

        order.unshift(new BidiSpan(1, order[0].to, order[0].to));

      if (order[0].level != lst(order).level)

        order.push(new BidiSpan(order[0].level, len, len));



      return order;

    };

  })();



  // THE END



  CodeMirror.version = "5.19.0";



  return CodeMirror;

});