https://editorhtmlonline.com/js/codemirror/codemirror.js

1// CodeMirror, copyright (c) by Marijn Haverbeke and others
2// Distributed under an MIT license: http://codemirror.net/LICENSE
3
4// This is CodeMirror (http://codemirror.net), a code editor
5// implemented in JavaScript on top of the browser's DOM.
6//
7// You can find some technical background for some of the code below
8// at http://marijnhaverbeke.nl/blog/#cm-internals .
9
10(function(mod) {
11    if (typeof exports == "object" && typeof module == "object") // CommonJS
12        module.exports = mod();
13    else if (typeof define == "function" && define.amd) // AMD
14        return define([], mod);
15    else // Plain browser env
16        this.CodeMirror = mod();
17})(function() {
18    "use strict";
19
20    // BROWSER SNIFFING
21
22    // Kludges for bugs and behavior differences that can't be feature
23    // detected are enabled based on userAgent etc sniffing.
24
25    var gecko = /gecko\/\d/i.test(navigator.userAgent);
26    // ie_uptoN means Internet Explorer version N or lower
27    var ie_upto10 = /MSIE \d/.test(navigator.userAgent);
28    var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(navigator.userAgent);
29    var ie = ie_upto10 || ie_11up;
30    var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : ie_11up[1]);
31    var webkit = /WebKit\//.test(navigator.userAgent);
32    var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
33    var chrome = /Chrome\//.test(navigator.userAgent);
34    var presto = /Opera\//.test(navigator.userAgent);
35    var safari = /Apple Computer/.test(navigator.vendor);
36    var khtml = /KHTML\//.test(navigator.userAgent);
37    var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
38    var phantom = /PhantomJS/.test(navigator.userAgent);
39
40    var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
41    // This is woefully incomplete. Suggestions for alternative methods welcome.
42    var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(navigator.userAgent);
43    var mac = ios || /Mac/.test(navigator.platform);
44    var windows = /win/i.test(navigator.platform);
45
46    var presto_version = presto && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
47    if (presto_version) presto_version = Number(presto_version[1]);
48    if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
49    // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
50    var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
51    var captureRightClick = gecko || (ie && ie_version >= 9);
52
53    // Optimize some code when these features are not used.
54    var sawReadOnlySpans = false, sawCollapsedSpans = false;
55
56    // EDITOR CONSTRUCTOR
57
58    // A CodeMirror instance represents an editor. This is the object

59    // that user code is usually dealing with.
60
61    function CodeMirror(place, options) {
62        if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);
63
64        this.options = options = options || {};
65        // Determine effective options based on given values and defaults.
66        copyObj(defaults, options, false);
67        setGuttersForLineNumbers(options);
68
69        var doc = options.value;
70        if (typeof doc == "string") doc = new Doc(doc, options.mode);
71        this.doc = doc;
72
73        var display = this.display = new Display(place, doc);
74        display.wrapper.CodeMirror = this;
75        updateGutters(this);
76        themeChanged(this);
77        if (options.lineWrapping)
78            this.display.wrapper.className += " CodeMirror-wrap";
79        if (options.autofocus && !mobile) focusInput(this);
80
81        this.state = {
82            keyMaps: [],  // stores maps added by addKeyMap
83            overlays: [], // highlighting overlays, as added by addOverlay
84            modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
85            overwrite: false, focused: false,
86            suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
87            pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in readInput
88            draggingText: false,
89            highlight: new Delayed() // stores highlight worker timeout
90        };
91
92        // Override magic textarea content restore that IE sometimes does
93        // on our hidden textarea on reload
94        if (ie && ie_version < 11) setTimeout(bind(resetInput, this, true), 20);
95
96        registerEventHandlers(this);
97        ensureGlobalHandlers();
98
99        var cm = this;
100        runInOp(this, function() {
101            cm.curOp.forceUpdate = true;
102            attachDoc(cm, doc);
103
104            if ((options.autofocus && !mobile) || activeElt() == display.input)
105                setTimeout(bind(onFocus, cm), 20);
106            else
107                onBlur(cm);
108
109            for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))
110                optionHandlers[opt](cm, options[opt], Init);
111            maybeUpdateLineNumberWidth(cm);
112            for (var i = 0; i < initHooks.length; ++i) initHooks[i](cm);
113        });
114    }
115
116    // DISPLAY CONSTRUCTOR
117
118    // The display handles the DOM integration, both for input reading
119    // and content drawing. It holds references to DOM nodes and
120    // display-related state.
121
122    function Display(place, doc) {
123        var d = this;
124
125        // The semihidden textarea that is focused when the editor is
126        // focused, and receives input.
127        var input = d.input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none");
128        // The textarea is kept positioned near the cursor to prevent the
129        // fact that it'll be scrolled into view on input from scrolling
130        // our fake cursor out of view. On webkit, when wrap=off, paste is
131        // very slow. So make the area wide instead.
132        if (webkit) input.style.width = "1000px";
133        else input.setAttribute("wrap", "off");
134        // If border: 0; -- iOS fails to open keyboard (issue #1287)
135        if (ios) input.style.border = "1px solid black";
136        input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off"); input.setAttribute("spellcheck", "false");
137
138        // Wraps and hides input textarea
139        d.inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
140        // The fake scrollbar elements.
141        d.scrollbarH = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
142        d.scrollbarV = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
143        // Covers bottom-right square when both scrollbars are present.
144        d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
145        // Covers bottom of gutter when coverGutterNextToScrollbar is on
146        // and h scrollbar is present.
147        d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");

148        // Will contain the actual code, positioned to cover the viewport.
149        d.lineDiv = elt("div", null, "CodeMirror-code");
150        // Elements are added to these to represent selection and cursors.
151        d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
152        d.cursorDiv = elt("div", null, "CodeMirror-cursors");
153        // A visibility: hidden element used to find the size of things.
154        d.measure = elt("div", null, "CodeMirror-measure");
155        // When lines outside of the viewport are measured, they are drawn in this.
156        d.lineMeasure = elt("div", null, "CodeMirror-measure");
157        // Wraps everything that needs to exist inside the vertically-padded coordinate system
158        d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
159            null, "position: relative; outline: none");
160        // Moved around its parent to cover visible view.
161        d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
162        // Set to the height of the document, allowing scrolling.
163        d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
164        // Behavior of elts with overflow: auto and padding is
165        // inconsistent across browsers. This is used to ensure the
166        // scrollable area is big enough.
167        d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerCutOff + "px; width: 1px;");
168        // Will contain the gutters, if any.
169        d.gutters = elt("div", null, "CodeMirror-gutters");
170        d.lineGutter = null;
171        // Actual scrollable element.
172        d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
173        d.scroller.setAttribute("tabIndex", "-1");
174        // The element in which the editor lives.
175        d.wrapper = elt("div", [d.inputDiv, d.scrollbarH, d.scrollbarV,
176            d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
177
178        // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
179        if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
180        // Needed to hide big blue blinking cursor on Mobile Safari
181        if (ios) input.style.width = "0px";
182        if (!webkit) d.scroller.draggable = true;
183        // Needed to handle Tab key in KHTML
184        if (khtml) { d.inputDiv.style.height = "1px"; d.inputDiv.style.position = "absolute"; }
185        // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
186        if (ie && ie_version < 8) d.scrollbarH.style.minHeight = d.scrollbarV.style.minWidth = "18px";
187
188        if (place.appendChild) place.appendChild(d.wrapper);
189        else place(d.wrapper);
190
191        // Current rendered range (may be bigger than the view window).
192        d.viewFrom = d.viewTo = doc.first;
193        // Information about the rendered lines.
194        d.view = [];
195        // Holds info about a single rendered line when it was rendered
196        // for measurement, while not in view.
197        d.externalMeasured = null;
198        // Empty space (in pixels) above the view
199        d.viewOffset = 0;
200        d.lastSizeC = 0;
201        d.updateLineNumbers = null;
202
203        // Used to only resize the line number gutter when necessary (when
204        // the amount of lines crosses a boundary that makes its width change)
205        d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
206        // See readInput and resetInput
207        d.prevInput = "";
208        // Set to true when a non-horizontal-scrolling line widget is
209        // added. As an optimization, line widget aligning is skipped when
210        // this is false.
211        d.alignWidgets = false;
212        // Flag that indicates whether we expect input to appear real soon
213        // now (after some event like 'keypress' or 'input') and are
214        // polling intensively.
215        d.pollingFast = false;
216        // Self-resetting timeout for the poller
217        d.poll = new Delayed();
218
219        d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
220
221        // Tracks when resetInput has punted to just putting a short
222        // string into the textarea instead of the full selection.
223        d.inaccurateSelection = false;

224
225        // Tracks the maximum line length so that the horizontal scrollbar
226        // can be kept static when scrolling.
227        d.maxLine = null;
228        d.maxLineLength = 0;
229        d.maxLineChanged = false;
230
231        // Used for measuring wheel scrolling granularity
232        d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
233
234        // True when shift is held down.
235        d.shift = false;
236
237        // Used to track whether anything happened since the context menu
238        // was opened.
239        d.selForContextMenu = null;
240    }
241
242    // STATE UPDATES
243
244    // Used to get the editor into a consistent state again when options change.
245
246    function loadMode(cm) {
247        cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
248        resetModeState(cm);
249    }
250
251    function resetModeState(cm) {
252        cm.doc.iter(function(line) {
253            if (line.stateAfter) line.stateAfter = null;
254            if (line.styles) line.styles = null;
255        });
256        cm.doc.frontier = cm.doc.first;
257        startWorker(cm, 100);
258        cm.state.modeGen++;
259        if (cm.curOp) regChange(cm);
260    }
261
262    function wrappingChanged(cm) {
263        if (cm.options.lineWrapping) {
264            addClass(cm.display.wrapper, "CodeMirror-wrap");
265            cm.display.sizer.style.minWidth = "";
266        } else {
267            rmClass(cm.display.wrapper, "CodeMirror-wrap");
268            findMaxLine(cm);
269        }
270        estimateLineHeights(cm);
271        regChange(cm);
272        clearCaches(cm);
273        setTimeout(function(){updateScrollbars(cm);}, 100);
274    }
275
276    // Returns a function that estimates the height of a line, to use as
277    // first approximation until the line becomes visible (and is thus
278    // properly measurable).
279    function estimateHeight(cm) {
280        var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
281        var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
282        return function(line) {
283            if (lineIsHidden(cm.doc, line)) return 0;
284
285            var widgetsHeight = 0;
286            if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {
287                if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;
288            }
289
290            if (wrapping)
291                return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;
292            else
293                return widgetsHeight + th;
294        };
295    }
296
297    function estimateLineHeights(cm) {
298        var doc = cm.doc, est = estimateHeight(cm);
299        doc.iter(function(line) {
300            var estHeight = est(line);
301            if (estHeight != line.height) updateLineHeight(line, estHeight);
302        });
303    }
304
305    function keyMapChanged(cm) {
306        var map = keyMap[cm.options.keyMap], style = map.style;
307        cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
308            (style ? " cm-keymap-" + style : "");
309    }
310
311    function themeChanged(cm) {
312        cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
313            cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
314        clearCaches(cm);
315    }
316
317    function guttersChanged(cm) {
318        updateGutters(cm);
319        regChange(cm);
320        setTimeout(function(){alignHorizontally(cm);}, 20);
321    }
322
323    // Rebuild the gutter elements, ensure the margin to the left of the
324    // code matches their width.
325    function updateGutters(cm) {
326        var gutters = cm.display.gutters, specs = cm.options.gutters;
327        removeChildren(gutters);
328        for (var i = 0; i < specs.length; ++i) {
329            var gutterClass = specs[i];
330            var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
331            if (gutterClass == "CodeMirror-linenumbers") {
332                cm.display.lineGutter = gElt;
333                gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
334            }
335        }
336        gutters.style.display = i ? "" : "none";
337        updateGutterSpace(cm);
338    }
339
340    function updateGutterSpace(cm) {
341        var width = cm.display.gutters.offsetWidth;
342        cm.display.sizer.style.marginLeft = width + "px";
343        cm.display.scrollbarH.style.left = cm.options.fixedGutter ? width + "px" : 0;
344    }
345
346    // Compute the character length of a line, taking into account
347    // collapsed ranges (see markText) that might hide parts, and join
348    // other lines onto it.
349    function lineLength(line) {
350        if (line.height == 0) return 0;
351        var len = line.text.length, merged, cur = line;
352        while (merged = collapsedSpanAtStart(cur)) {
353            var found = merged.find(0, true);
354            cur = found.from.line;
355            len += found.from.ch - found.to.ch;
356        }
357        cur = line;
358        while (merged = collapsedSpanAtEnd(cur)) {
359            var found = merged.find(0, true);
360            len -= cur.text.length - found.from.ch;
361            cur = found.to.line;
362            len += cur.text.length - found.to.ch;
363        }
364        return len;
365    }
366
367    // Find the longest line in the document.
368    function findMaxLine(cm) {
369        var d = cm.display, doc = cm.doc;
370        d.maxLine = getLine(doc, doc.first);
371        d.maxLineLength = lineLength(d.maxLine);
372        d.maxLineChanged = true;
373        doc.iter(function(line) {
374            var len = lineLength(line);
375            if (len > d.maxLineLength) {
376                d.maxLineLength = len;
377                d.maxLine = line;
378            }
379        });
380    }
381
382    // Make sure the gutters options contains the element
383    // "CodeMirror-linenumbers" when the lineNumbers option is true.
384    function setGuttersForLineNumbers(options) {
385        var found = indexOf(options.gutters, "CodeMirror-linenumbers");
386        if (found == -1 && options.lineNumbers) {
387            options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
388        } else if (found > -1 && !options.lineNumbers) {
389            options.gutters = options.gutters.slice(0);
390            options.gutters.splice(found, 1);
391        }
392    }
393
394    // SCROLLBARS
395
396    function hScrollbarTakesSpace(cm) {
397        return cm.display.scroller.clientHeight - cm.display.wrapper.clientHeight < scrollerCutOff - 3;
398    }
399
400    // Prepare DOM reads needed to update the scrollbars. Done in one
401    // shot to minimize update/measure roundtrips.
402    function measureForScrollbars(cm) {
403        var scroll = cm.display.scroller;
404        return {
405            clientHeight: scroll.clientHeight,
406            barHeight: cm.display.scrollbarV.clientHeight,

407            scrollWidth: scroll.scrollWidth, clientWidth: scroll.clientWidth,
408            hScrollbarTakesSpace: hScrollbarTakesSpace(cm),
409            barWidth: cm.display.scrollbarH.clientWidth,
410            docHeight: Math.round(cm.doc.height + paddingVert(cm.display))
411        };
412    }
413
414    // Re-synchronize the fake scrollbars with the actual size of the
415    // content.
416    function updateScrollbars(cm, measure) {
417        if (!measure) measure = measureForScrollbars(cm);
418        var d = cm.display, sWidth = scrollbarWidth(d.measure);
419        var scrollHeight = measure.docHeight + scrollerCutOff;
420        var needsH = measure.scrollWidth > measure.clientWidth;
421        if (needsH && measure.scrollWidth <= measure.clientWidth + 1 &&
422            sWidth > 0 && !measure.hScrollbarTakesSpace)
423            needsH = false; // (Issue #2562)
424        var needsV = scrollHeight > measure.clientHeight;
425
426        if (needsV) {
427            d.scrollbarV.style.display = "block";
428            d.scrollbarV.style.bottom = needsH ? sWidth + "px" : "0";
429            // A bug in IE8 can cause this value to be negative, so guard it.
430            d.scrollbarV.firstChild.style.height =
431                Math.max(0, scrollHeight - measure.clientHeight + (measure.barHeight || d.scrollbarV.clientHeight)) + "px";
432        } else {
433            d.scrollbarV.style.display = "";
434            d.scrollbarV.firstChild.style.height = "0";
435        }
436        if (needsH) {
437            d.scrollbarH.style.display = "block";
438            d.scrollbarH.style.right = needsV ? sWidth + "px" : "0";
439            d.scrollbarH.firstChild.style.width =
440                (measure.scrollWidth - measure.clientWidth + (measure.barWidth || d.scrollbarH.clientWidth)) + "px";
441        } else {
442            d.scrollbarH.style.display = "";
443            d.scrollbarH.firstChild.style.width = "0";
444        }
445        if (needsH && needsV) {
446            d.scrollbarFiller.style.display = "block";
447            d.scrollbarFiller.style.height = d.scrollbarFiller.style.width = sWidth + "px";
448        } else d.scrollbarFiller.style.display = "";
449        if (needsH && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
450            d.gutterFiller.style.display = "block";
451            d.gutterFiller.style.height = sWidth + "px";
452            d.gutterFiller.style.width = d.gutters.offsetWidth + "px";
453        } else d.gutterFiller.style.display = "";
454
455        if (!cm.state.checkedOverlayScrollbar && measure.clientHeight > 0) {
456            if (sWidth === 0) {
457                var w = mac && !mac_geMountainLion ? "12px" : "18px";
458                d.scrollbarV.style.minWidth = d.scrollbarH.style.minHeight = w;
459                var barMouseDown = function(e) {
460                    if (e_target(e) != d.scrollbarV && e_target(e) != d.scrollbarH)
461                        operation(cm, onMouseDown)(e);
462                };
463                on(d.scrollbarV, "mousedown", barMouseDown);
464                on(d.scrollbarH, "mousedown", barMouseDown);
465            }
466            cm.state.checkedOverlayScrollbar = true;
467        }
468    }
469
470    // Compute the lines that are visible in a given viewport (defaults
471    // the the current scroll position). viewport may contain top,
472    // height, and ensure (see op.scrollToPos) properties.
473    function visibleLines(display, doc, viewport) {
474        var top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop;
475        top = Math.floor(top - paddingTop(display));
476        var bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight;
477
478        var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
479        // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
480        // forces those lines into the viewport (if possible).
481        if (viewport && viewport.ensure) {
482            var ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line;
483            if (ensureFrom < from)
484                return {from: ensureFrom,
485                    to: lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight)};

486            if (Math.min(ensureTo, doc.lastLine()) >= to)
487                return {from: lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight),
488                    to: ensureTo};
489        }
490        return {from: from, to: Math.max(to, from + 1)};
491    }
492
493    // LINE NUMBERS
494
495    // Re-align line numbers and gutter marks to compensate for
496    // horizontal scrolling.
497    function alignHorizontally(cm) {
498        var display = cm.display, view = display.view;
499        if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
500        var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
501        var gutterW = display.gutters.offsetWidth, left = comp + "px";
502        for (var i = 0; i < view.length; i++) if (!view[i].hidden) {
503            if (cm.options.fixedGutter && view[i].gutter)
504                view[i].gutter.style.left = left;
505            var align = view[i].alignable;
506            if (align) for (var j = 0; j < align.length; j++)
507                align[j].style.left = left;
508        }
509        if (cm.options.fixedGutter)
510            display.gutters.style.left = (comp + gutterW) + "px";
511    }
512
513    // Used to ensure that the line number gutter is still the right
514    // size for the current document size. Returns true when an update
515    // is needed.
516    function maybeUpdateLineNumberWidth(cm) {
517        if (!cm.options.lineNumbers) return false;
518        var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
519        if (last.length != display.lineNumChars) {
520            var test = display.measure.appendChild(elt("div", [elt("div", last)],
521                "CodeMirror-linenumber CodeMirror-gutter-elt"));
522            var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
523            display.lineGutter.style.width = "";
524            display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding);
525            display.lineNumWidth = display.lineNumInnerWidth + padding;
526            display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
527            display.lineGutter.style.width = display.lineNumWidth + "px";
528            updateGutterSpace(cm);
529            return true;
530        }
531        return false;
532    }
533
534    function lineNumberFor(options, i) {
535        return String(options.lineNumberFormatter(i + options.firstLineNumber));
536    }
537
538    // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
539    // but using getBoundingClientRect to get a sub-pixel-accurate
540    // result.
541    function compensateForHScroll(display) {
542        return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;
543    }
544
545    // DISPLAY DRAWING
546
547    function DisplayUpdate(cm, viewport, force) {
548        var display = cm.display;
549
550        this.viewport = viewport;
551        // Store some values that we'll need later (but don't want to force a relayout for)
552        this.visible = visibleLines(display, cm.doc, viewport);
553        this.editorIsHidden = !display.wrapper.offsetWidth;
554        this.wrapperHeight = display.wrapper.clientHeight;
555        this.oldViewFrom = display.viewFrom; this.oldViewTo = display.viewTo;
556        this.oldScrollerWidth = display.scroller.clientWidth;
557        this.force = force;
558        this.dims = getDimensions(cm);
559    }
560
561    // Does the actual updating of the line display. Bails out
562    // (returning false) when there is nothing to be done and forced is
563    // false.
564    function updateDisplayIfNeeded(cm, update) {
565        var display = cm.display, doc = cm.doc;
566        if (update.editorIsHidden) {
567            resetView(cm);
568            return false;
569        }
570
571        // Bail out if the visible area is already rendered and nothing changed.
572        if (!update.force &&
573            update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&
574            (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
575            countDirtyView(cm) == 0)
576            return false;

577
578        if (maybeUpdateLineNumberWidth(cm)) {
579            resetView(cm);
580            update.dims = getDimensions(cm);
581        }
582
583        // Compute a suitable new viewport (from & to)
584        var end = doc.first + doc.size;
585        var from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first);
586        var to = Math.min(end, update.visible.to + cm.options.viewportMargin);
587        if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);
588        if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);
589        if (sawCollapsedSpans) {
590            from = visualLineNo(cm.doc, from);
591            to = visualLineEndNo(cm.doc, to);
592        }
593
594        var different = from != display.viewFrom || to != display.viewTo ||
595            display.lastSizeC != update.wrapperHeight;
596        adjustView(cm, from, to);
597
598        display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
599        // Position the mover div to align with the current scroll position
600        cm.display.mover.style.top = display.viewOffset + "px";
601
602        var toUpdate = countDirtyView(cm);
603        if (!different && toUpdate == 0 && !update.force &&
604            (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))
605            return false;
606
607        // For big changes, we hide the enclosing element during the
608        // update, since that speeds up the operations on most browsers.
609        var focused = activeElt();
610        if (toUpdate > 4) display.lineDiv.style.display = "none";
611        patchDisplay(cm, display.updateLineNumbers, update.dims);
612        if (toUpdate > 4) display.lineDiv.style.display = "";
613        // There might have been a widget with a focused element that got
614        // hidden or updated, if so re-focus it.
615        if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();
616
617        // Prevent selection and cursors from interfering with the scroll
618        // width.
619        removeChildren(display.cursorDiv);
620        removeChildren(display.selectionDiv);
621
622        if (different) {
623            display.lastSizeC = update.wrapperHeight;
624            startWorker(cm, 400);
625        }
626
627        display.updateLineNumbers = null;
628
629        return true;
630    }
631
632    function postUpdateDisplay(cm, update) {
633        var force = update.force, viewport = update.viewport;
634        for (var first = true;; first = false) {
635            if (first && cm.options.lineWrapping && update.oldScrollerWidth != cm.display.scroller.clientWidth) {
636                force = true;
637            } else {
638                force = false;
639                // Clip forced viewport to actual scrollable area.
640                if (viewport && viewport.top != null)
641                    viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - scrollerCutOff -
642                            cm.display.scroller.clientHeight, viewport.top)};
643                // Updated line heights might result in the drawn area not
644                // actually covering the viewport. Keep looping until it does.
645                update.visible = visibleLines(cm.display, cm.doc, viewport);
646                if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)
647                    break;
648            }
649            if (!updateDisplayIfNeeded(cm, update)) break;
650            updateHeightsInViewport(cm);
651            var barMeasure = measureForScrollbars(cm);
652            updateSelection(cm);
653            setDocumentHeight(cm, barMeasure);
654            updateScrollbars(cm, barMeasure);
655        }
656
657        signalLater(cm, "update", cm);
658        if (cm.display.viewFrom != update.oldViewFrom || cm.display.viewTo != update.oldViewTo)
659            signalLater(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
660    }
661
662    function updateDisplaySimple(cm, viewport) {
663        var update = new DisplayUpdate(cm, viewport);
664        if (updateDisplayIfNeeded(cm, update)) {
665            updateHeightsInViewport(cm);
666            postUpdateDisplay(cm, update);
667            var barMeasure = measureForScrollbars(cm);
668            updateSelection(cm);
669            setDocumentHeight(cm, barMeasure);
670            updateScrollbars(cm, barMeasure);
671        }
672    }
673
674    function setDocumentHeight(cm, measure) {
675        cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = measure.docHeight + "px";
676        cm.display.gutters.style.height = Math.max(measure.docHeight, measure.clientHeight - scrollerCutOff) + "px";
677    }
678
679    function checkForWebkitWidthBug(cm, measure) {
680        // Work around Webkit bug where it sometimes reserves space for a
681        // non-existing phantom scrollbar in the scroller (Issue #2420)
682        if (cm.display.sizer.offsetWidth + cm.display.gutters.offsetWidth < cm.display.scroller.clientWidth - 1) {
683            cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = "0px";
684            cm.display.gutters.style.height = measure.docHeight + "px";
685        }
686    }
687
688    // Read the actual heights of the rendered lines, and update their
689    // stored heights to match.
690    function updateHeightsInViewport(cm) {
691        var display = cm.display;
692        var prevBottom = display.lineDiv.offsetTop;
693        for (var i = 0; i < display.view.length; i++) {
694            var cur = display.view[i], height;
695            if (cur.hidden) continue;
696            if (ie && ie_version < 8) {
697                var bot = cur.node.offsetTop + cur.node.offsetHeight;
698                height = bot - prevBottom;
699                prevBottom = bot;
700            } else {
701                var box = cur.node.getBoundingClientRect();
702                height = box.bottom - box.top;
703            }

704            var diff = cur.line.height - height;
705            if (height < 2) height = textHeight(display);
706            if (diff > .001 || diff < -.001) {
707                updateLineHeight(cur.line, height);
708                updateWidgetHeight(cur.line);
709                if (cur.rest) for (var j = 0; j < cur.rest.length; j++)
710                    updateWidgetHeight(cur.rest[j]);
711            }
712        }
713    }
714
715    // Read and store the height of line widgets associated with the
716    // given line.
717    function updateWidgetHeight(line) {
718        if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)
719            line.widgets[i].height = line.widgets[i].node.offsetHeight;
720    }
721
722    // Do a bulk-read of the DOM positions and sizes needed to draw the
723    // view, so that we don't interleave reading and writing to the DOM.
724    function getDimensions(cm) {
725        var d = cm.display, left = {}, width = {};
726        for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
727            left[cm.options.gutters[i]] = n.offsetLeft;
728            width[cm.options.gutters[i]] = n.offsetWidth;
729        }
730        return {fixedPos: compensateForHScroll(d),
731            gutterTotalWidth: d.gutters.offsetWidth,
732            gutterLeft: left,
733            gutterWidth: width,
734            wrapperWidth: d.wrapper.clientWidth};
735    }
736
737    // Sync the actual display DOM structure with display.view, removing
738    // nodes for lines that are no longer in view, and creating the ones
739    // that are not there yet, and updating the ones that are out of
740    // date.
741    function patchDisplay(cm, updateNumbersFrom, dims) {
742        var display = cm.display, lineNumbers = cm.options.lineNumbers;
743        var container = display.lineDiv, cur = container.firstChild;
744
745        function rm(node) {
746            var next = node.nextSibling;
747            // Works around a throw-scroll bug in OS X Webkit
748            if (webkit && mac && cm.display.currentWheelTarget == node)
749                node.style.display = "none";
750            else
751                node.parentNode.removeChild(node);
752            return next;
753        }
754
755        var view = display.view, lineN = display.viewFrom;
756        // Loop over the elements in the view, syncing cur (the DOM nodes
757        // in display.lineDiv) with the view as we go.
758        for (var i = 0; i < view.length; i++) {
759            var lineView = view[i];
760            if (lineView.hidden) {
761            } else if (!lineView.node) { // Not drawn yet
762                var node = buildLineElement(cm, lineView, lineN, dims);
763                container.insertBefore(node, cur);
764            } else { // Already drawn
765                while (cur != lineView.node) cur = rm(cur);
766                var updateNumber = lineNumbers && updateNumbersFrom != null &&
767                    updateNumbersFrom <= lineN && lineView.lineNumber;
768                if (lineView.changes) {
769                    if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;
770                    updateLineForChanges(cm, lineView, lineN, dims);
771                }
772                if (updateNumber) {
773                    removeChildren(lineView.lineNumber);
774                    lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
775                }
776                cur = lineView.node.nextSibling;
777            }
778            lineN += lineView.size;
779        }
780        while (cur) cur = rm(cur);
781    }
782
783    // When an aspect of a line changes, a string is added to
784    // lineView.changes. This updates the relevant part of the line's
785    // DOM structure.
786    function updateLineForChanges(cm, lineView, lineN, dims) {
787        for (var j = 0; j < lineView.changes.length; j++) {
788            var type = lineView.changes[j];
789            if (type == "text") updateLineText(cm, lineView);
790            else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);
791            else if (type == "class") updateLineClasses(lineView);
792            else if (type == "widget") updateLineWidgets(lineView, dims);
793        }
794        lineView.changes = null;
795    }
796
797    // Lines with gutter elements, widgets or a background class 

797need to
798    // be wrapped, and have the extra elements added to the wrapper div
799    function ensureLineWrapped(lineView) {
800        if (lineView.node == lineView.text) {
801            lineView.node = elt("div", null, null, "position: relative");
802            if (lineView.text.parentNode)
803                lineView.text.parentNode.replaceChild(lineView.node, lineView.text);
804            lineView.node.appendChild(lineView.text);
805            if (ie && ie_version < 8) lineView.node.style.zIndex = 2;
806        }
807        return lineView.node;
808    }
809
810    function updateLineBackground(lineView) {
811        var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
812        if (cls) cls += " CodeMirror-linebackground";
813        if (lineView.background) {
814            if (cls) lineView.background.className = cls;
815            else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
816        } else if (cls) {
817            var wrap = ensureLineWrapped(lineView);
818            lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
819        }
820    }
821
822    // Wrapper around buildLineContent which will reuse the structure
823    // in display.externalMeasured when possible.
824    function getLineContent(cm, lineView) {
825        var ext = cm.display.externalMeasured;
826        if (ext && ext.line == lineView.line) {
827            cm.display.externalMeasured = null;
828            lineView.measure = ext.measure;
829            return ext.built;
830        }
831        return buildLineContent(cm, lineView);
832    }
833
834    // Redraw the line's text. Interacts with the background and text
835    // classes because the mode may output tokens that influence these
836    // classes.
837    function updateLineText(cm, lineView) {
838        var cls = lineView.text.className;
839        var built = getLineContent(cm, lineView);
840        if (lineView.text == lineView.node) lineView.node = built.pre;
841        lineView.text.parentNode.replaceChild(built.pre, lineView.text);
842        lineView.text = built.pre;
843        if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
844            lineView.bgClass = built.bgClass;
845            lineView.textClass = built.textClass;
846            updateLineClasses(lineView);
847        } else if (cls) {
848            lineView.text.className = cls;
849        }
850    }
851
852    function updateLineClasses(lineView) {
853        updateLineBackground(lineView);
854        if (lineView.line.wrapClass)
855            ensureLineWrapped(lineView).className = lineView.line.wrapClass;
856        else if (lineView.node != lineView.text)
857            lineView.node.className = "";
858        var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
859        lineView.text.className = textClass || "";
860    }
861
862    function updateLineGutter(cm, lineView, lineN, dims) {
863        if (lineView.gutter) {
864            lineView.node.removeChild(lineView.gutter);
865            lineView.gutter = null;
866        }
867        var markers = lineView.line.gutterMarkers;
868        if (cm.options.lineNumbers || markers) {
869            var wrap = ensureLineWrapped(lineView);
870            var gutterWrap = lineView.gutter =
871                wrap.insertBefore(elt("div", null, "CodeMirror-gutter-wrapper", "position: absolute; left: " +
872                        (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"),
873                    lineView.text);
874            if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
875                lineView.lineNumber = gutterWrap.appendChild(
876                    elt("div", lineNumberFor(cm.options, lineN),
877                        "CodeMirror-linenumber CodeMirror-gutter-elt",
878                        "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
879                        + cm.display.lineNumInnerWidth + "px"));
880            if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {
881                var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
882                if (found)
883                    gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
884                        dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
885            }
886        }
887    }
888
889    function updateLineWidgets(lineView, dims) {
890        if (lineView.alignable) lineView.alignable = null;
891        for (var node = lineView.node.firstChild, next; node; node = next) {
892            var next = node.nextSibling;
893            if (node.className == "CodeMirror-linewidget")
894                lineView.node.removeChild(node);
895        }
896        insertLineWidgets(lineView, dims);
897    }
898
899    // Build a line's DOM representation from scratch
900    function buildLineElement(cm, lineView, lineN, dims) {
901        var built = getLineContent(cm, lineView);
902        lineView.text = lineView.node = built.pre;
903        if (built.bgClass) lineView.bgClass = built.bgClass;
904        if (built.textClass) lineView.textClass = built.textClass;
905
906        updateLineClasses(lineView);
907        updateLineGutter(cm, lineView, lineN, dims);
908        insertLineWidgets(lineView, dims);
909        return lineView.node;
910    }
911
912    // A lineView may contain multiple logical lines (when merged by
913    // collapsed spans). The widgets for all of them need to be drawn.
914    function insertLineWidgets(lineView, dims) {
915        insertLineWidgetsFor(lineView.line, lineView, dims, true);
916        if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
917            insertLineWidgetsFor(lineView.rest[i], lineView, dims, false);
918    }
919
920    function insertLineWidgetsFor(line, lineView, dims, allowAbove) {
921        if (!line.widgets) return;
922        var wrap = ensureLineWrapped(lineView);
923        for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
924            var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
925            if (!widget.handleMouseEvents) node.ignoreEvents = true;
926            positionLineWidget(widget, node, lineView, dims);
927            if (allowAbove && widget.above)
928                wrap.insertBefore(node, lineView.gutter || lineView.text);
929            else
930                wrap.appendChild(node);
931            signalLater(widget, "redraw");
932        }
933    }
934
935    function positionLineWidget(widget, node, lineView, dims) {
936        if (widget.noHScroll) {
937            (lineView.alignable || (lineView.alignable = [])).push(node);
938            var width = dims.wrapperWidth;
939            node.style.left = dims.fixedPos + "px";
940            if (!widget.coverGutter) {
941                width -= dims.gutterTotalWidth;
942                node.style.paddingLeft = dims.gutterTotalWidth + "px";
943            }
944            node.style.width = width + "px";
945        }
946        if (widget.coverGutter) {
947            node.style.zIndex = 5;
948            node.style.position = "relative";
949            if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
950        }
951    }
952
953    // POSITION OBJECT
954
955    // A Pos instance represents a position within the text.
956    var Pos = CodeMirror.Pos = function(line, ch) {
957        if (!(this instanceof Pos)) return new Pos(line, ch);
958        this.line = line; this.ch = ch;
959    };
960
961    // Compare two positions, return 0 if they are the same, a negative
962    // number when a is less, and a positive number otherwise.
963    var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };
964
965    function copyPos(x) {return Pos(x.line, x.ch);}
966    function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }
967    function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }
968
969    // SELECTION / CURSOR
970
971    // Selection objects are immutable. A new one is created every time
972    // the selection changes. A selection is one or more non-overlapping
973    // (and non-touching) ranges, sorted, and an integer that indicates
974    // which one is the primary selection (the one that's scrolled into
975    // view, that getCursor returns, etc).
976    function Selection(ranges, primIndex) {
977        this.ranges = ranges;
978        this.primIndex = primIndex;
979    }
980
981    Selection.prototype = {
982        primary: function() { return this.ranges[this.primIndex]; },
983        equals: function(other) {
984            if (other == this) return true;
985            if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;
986            for (var i = 0; i < this.ranges.length; i++) {
987                var here = this.ranges[i], there = other.ranges[i];
988                if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;
989            }
990            return true;
991        },
992        deepCopy: function() {
993            for (var out = [], i = 0; i < this.ranges.length; i++)
994                out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));
995            return new Selection(out, this.primIndex);
996        },
997        somethingSelected: function() {
998            for (var i = 0; i < this.ranges.length; i++)
999                if (!this.ranges[i].empty()) return true;
1000            return false;
1001        },
1002        contains: function(pos, end) {
1003            if (!end) end = pos;
1004            for (var i = 0; i < this.ranges.length; i++) {
1005                var range = this.ranges[i];
1006                if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
1007                    return i;
1008            }
1009            return -1;
1010        }
1011    };
1012
1013    function Range(anchor, head) {
1014        this.anchor = anchor; this.head = head;
1015    }
1016
1017    Range.prototype = {
1018        from: function() { return minPos(this.anchor, this.head); },
1019        to: function() { return maxPos(this.anchor, this.head); },
1020        empty: function() {
1021            return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;
1022        }
1023    };
1024
1025    // Take an unsorted, potentially overlapping set of ranges, and
1026    // build a selection out of it. 'Consumes' ranges array (modifying
1027    // it).
1028    function normalizeSelection(ranges, primIndex) {
1029        var prim = ranges[primIndex];
1030        ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });
1031        primIndex = indexOf(ranges, prim);
1032        for (var i = 1; i < ranges.length; i++) {
1033            var cur = ranges[i], prev = ranges[i - 1];
1034            if (cmp(prev.to(), cur.from()) >= 0) {
1035                var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
1036                var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
1037                if (i <= primIndex) --primIndex;
1038                ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
1039            }
1040        }
1041        return new Selection(ranges, primIndex);
1042    }
1043
1044    function simpleSelection(anchor, head) {
1045        return new Selection([new Range(anchor, head || anchor)], 0);
1046    }
1047
1048    // Most of the external API clips given positions to make sure they
1049    // actually exist within the document.
1050    function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
1051    function clipPos(doc, pos) {
1052        if (pos.line < doc.first) return Pos(doc.first, 0);
1053        var last = doc.first + doc.size - 1;
1054        if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
1055        return clipToLen(pos, getLine(doc, pos.line).text.length);
1056    }
1057    function clipToLen(pos, linelen) {
1058        var ch = pos.ch;
1059        if (ch == null || ch > linelen) return Pos(pos.line, linelen);
1060        else if (ch < 0) return Pos(pos.line, 0);
1061        else return pos;
1062    }
1063    function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}
1064    function clipPosArray(doc, array) {
1065        for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);
1066        return out;
1067    }
1068
1069    // SELECTION UPDATES
1070
1071    // The 'scroll' parameter given to many of these indicated whether
1072    // the new cursor position should be scrolled into view after
1073    // modifying the selection.
1074
1075    // If shift is held or the extend flag is set, extends a range to
1076    // include a given position (and optionally a second position).
1077    // Otherwise, simply returns the range between the given positions.
1078    // Used for cursor motion and such.
1079    function extendRange(doc, range, head, other) {
1080        if (doc.cm && doc.cm.display.shift || doc.extend) {
1081            var anchor = range.anchor;
1082            if (other) {
1083                var posBefore = cmp(head, anchor) < 0;
1084                if (posBefore != (cmp(other, anchor) < 0)) {
1085                    anchor = head;
1086                    head = other;
1087                } else if (posBefore != (cmp(head, other) < 0)) {
1088                    head = other;
1089                }
1090            }
1091            return new Range(anchor, head);
1092        } else {
1093            return new Range(other || head, head);
1094        }
1095    }
1096
1097    // Extend the primary selection range, discard the rest.
1098    function extendSelection(doc, head, other, options) {
1099        setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);
1100    }
1101
1102    // Extend all selections (pos is an array of selections with length
1103    // equal the number of selections)
1104    function extendSelections(doc, heads, options) {
1105        for (var out = [], i = 0; i < doc.sel.ranges.length; i++)
1106            out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);
1107        var newSel = normalizeSelection(out, doc.sel.primIndex);
1108        setSelection(doc, newSel, options);
1109    }
1110
1111    // Updates a single range in the selection.
1112    function replaceOneSelection(doc, i, range, options) {
1113        var ranges = doc.sel.ranges.slice(0);
1114        ranges[i] = range;
1115        setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);
1116    }
1117
1118    // Reset the selection to a single range.
1119    function setSimpleSelection(doc, anchor, head, options) {
1120        setSelection(doc, simpleSelection(anchor, head), options);
1121    }
1122
1123    // Give beforeSelectionChange handlers a change to influence a
1124    // selection update.
1125    function filterSelectionChange(doc, sel) {
1126        var obj = {
1127            ranges: sel.ranges,
1128            update: function(ranges) {
1129                this.ranges = [];
1130                for (var i = 0; i < ranges.length; i++)
1131                    this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
1132                        clipPos(doc, ranges[i].head));
1133            }
1134        };
1135        signal(doc, "beforeSelectionChange", doc, obj);
1136        if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
1137        if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);
1138        else return sel;
1139    }
1140
1141    function setSelectionReplaceHistory(doc, sel, options) {
1142        var done = doc.history.done, last = lst(done);
1143        if (last && last.ranges) {
1144            done[done.length - 1] = sel;
1145            setSelectionNoUndo(doc, sel, options);
1146        } else {
1147            setSelection(doc, sel, options);
1148        }
1149    }
1150
1151    // Set a new selection.
1152    function setSelection(doc, sel, options) {
1153        setSelectionNoUndo(doc, sel, options);
1154        addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
1155    }
1156
1157    function setSelectionNoUndo(doc, sel, options) {
1158        if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
1159            sel = filterSelectionChange(doc, sel);
1160
1161        var bias = options && options.bias ||
1162            (cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);
1163        setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));
1164
1165        if (!(options && options.scroll === false) && doc.cm)
1166            ensureCursorVisible(doc.cm);
1167    }
1168
1169    function setSelectionInner(doc, sel) {
1170        if (sel.equals(doc.sel)) return;
1171
1172        doc.sel = sel;
1173
1174        if (doc.cm) {
1175            doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;
1176            signalCursorActivity(doc.cm);
1177        }
1178        signalLater(doc, "cursorActivity", doc);
1179    }
1180
1181    // Verify that the selection does not partially select any atomic
1182    // marked ranges.
1183    function reCheckSelection(doc) {
1184        setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);
1185    }
1186
1187    // Return a selection that does not partially select any atomic
1188    // ranges.
1189    function skipAtomicInSelection(doc, sel, bias, mayClear) {
1190        var out;
1191        for (var i = 0; i < sel.ranges.length; i++) {
1192            var range = sel.ranges[i];
1193            var newAnchor = skipAtomic(doc, range.anchor, bias, mayClear);
1194            var newHead = skipAtomic(doc, range.head, bias, mayClear);
1195            if (out || newAnchor != range.anchor || newHead != range.head) {
1196                if (!out) out = sel.ranges.slice(0, i);
1197                out[i] = new Range(newAnchor, newHead);
1198            }
1199        }
1200        return out ? normalizeSelection(out, sel.primIndex) : sel;
1201    }
1202
1203    // Ensure a given position is not inside an atomic range.
1204    function skipAtomic(doc, pos, bias, mayClear) {
1205        var flipped = false, curPos = pos;
1206        var dir = bias || 1;
1207        doc.cantEdit = false;

1208        search: for (;;) {
1209            var line = getLine(doc, curPos.line);
1210            if (line.markedSpans) {
1211                for (var i = 0; i < line.markedSpans.length; ++i) {
1212                    var sp = line.markedSpans[i], m = sp.marker;
1213                    if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
1214                        (sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
1215                        if (mayClear) {
1216                            signal(m, "beforeCursorEnter");
1217                            if (m.explicitlyCleared) {
1218                                if (!line.markedSpans) break;
1219                                else {--i; continue;}
1220                            }
1221                        }
1222                        if (!m.atomic) continue;
1223                        var newPos = m.find(dir < 0 ? -1 : 1);
1224                        if (cmp(newPos, curPos) == 0) {
1225                            newPos.ch += dir;
1226                            if (newPos.ch < 0) {
1227                                if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
1228                                else newPos = null;
1229                            } else if (newPos.ch > line.text.length) {
1230                                if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
1231                                else newPos = null;
1232                            }
1233                            if (!newPos) {
1234                                if (flipped) {
1235                                    // Driven in a corner -- no valid cursor position found at all
1236                                    // -- try again *with* clearing, if we didn't already
1237                                    if (!mayClear) return skipAtomic(doc, pos, bias, true);
1238                                    // Otherwise, turn off editing until further notice, and return the start of the doc
1239                                    doc.cantEdit = true;
1240                                    return Pos(doc.first, 0);
1241                                }
1242                                flipped = true; newPos = pos; dir = -dir;
1243                            }
1244                        }
1245                        curPos = newPos;
1246                        continue search;
1247                    }
1248                }
1249            }
1250            return curPos;
1251        }
1252    }
1253
1254    // SELECTION DRAWING
1255
1256    // Redraw the selection and/or cursor
1257    function drawSelection(cm) {
1258        var display = cm.display, doc = cm.doc, result = {};
1259        var curFragment = result.cursors = document.createDocumentFragment();
1260        var selFragment = result.selection = document.createDocumentFragment();
1261
1262        for (var i = 0; i < doc.sel.ranges.length; i++) {
1263            var range = doc.sel.ranges[i];
1264            var collapsed = range.empty();
1265            if (collapsed || cm.options.showCursorWhenSelecting)
1266                drawSelectionCursor(cm, range, curFragment);
1267            if (!collapsed)
1268                drawSelectionRange(cm, range, selFragment);
1269        }
1270
1271        // Move the hidden textarea near the cursor to prevent scrolling artifacts
1272        if (cm.options.moveInputWithCursor) {
1273            var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
1274            var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
1275            result.teTop = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
1276                headPos.top + lineOff.top - wrapOff.top));
1277            result.teLeft = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
1278                headPos.left + lineOff.left - wrapOff.left));
1279        }
1280
1281        return result;
1282    }
1283
1284    function showSelection(cm, drawn) {
1285        removeChildrenAndAdd(cm.display.cursorDiv, drawn.cursors);
1286        removeChildrenAndAdd(cm.display.selectionDiv, drawn.selection);
1287        if (drawn.teTop != null) {
1288            cm.display.inputDiv.style.top = drawn.teTop + "px";
1289            cm.display.inputDiv.style.left = drawn.teLeft + "px";
1290        }
1291    }
1292
1293    function updateSelection(cm) {
1294        showSelection(cm, drawSelection(cm));
1295    }
1296
1297    // Draws a cursor for the given range
1298    function drawSelectionCursor(cm, range, output) {
1299        var pos = cursorCoords(cm, range.head, "div", null, null, !cm.options.singleCursorHeightPerLine);
1300
1301        var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
1302        cursor.style.left = pos.left + "px";
1303        cursor.style.top = pos.top + "px";
1304        cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
1305
1306        if (pos.other) {
1307            // Secondary cursor, shown when on a 'jump' in bi-directional text
1308            var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
1309            otherCursor.style.display = "";
1310            otherCursor.style.left = pos.other.left + "px";
1311            otherCursor.style.top = pos.other.top + "px";
1312            otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
1313        }
1314    }
1315
1316    // Draws the given range as a highlighted selection
1317    function drawSelectionRange(cm, range, output) {
1318        var display = cm.display, doc = cm.doc;
1319        var fragment = document.createDocumentFragment();
1320        var padding = paddingH(cm.display), leftSide = padding.left, rightSide = display.lineSpace.offsetWidth - padding.right;
1321
1322        function add(left, top, width, bottom) {
1323            if (top < 0) top = 0;
1324            top = Math.round(top);
1325            bottom = Math.round(bottom);
1326            fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
1327                "px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +
1328                "px; height: " + (bottom - top) + "px"));
1329        }
1330
1331        function drawForLine(line, fromArg, toArg) {
1332            var lineObj = getLine(doc, line);
1333            var lineLen = lineObj.text.length;
1334            var start, end;
1335            function coords(ch, bias) {
1336                return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
1337            }
1338
1339            iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
1340                var leftPos = coords(from, "left"), rightPos, left, right;
1341                if (from == to) {

1342                    rightPos = leftPos;
1343                    left = right = leftPos.left;
1344                } else {
1345                    rightPos = coords(to - 1, "right");
1346                    if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
1347                    left = leftPos.left;
1348                    right = rightPos.right;
1349                }
1350                if (fromArg == null && from == 0) left = leftSide;
1351                if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
1352                    add(left, leftPos.top, null, leftPos.bottom);
1353                    left = leftSide;
1354                    if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
1355                }
1356                if (toArg == null && to == lineLen) right = rightSide;
1357                if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
1358                    start = leftPos;
1359                if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
1360                    end = rightPos;
1361                if (left < leftSide + 1) left = leftSide;
1362                add(left, rightPos.top, right - left, rightPos.bottom);
1363            });
1364            return {start: start, end: end};
1365        }
1366
1367        var sFrom = range.from(), sTo = range.to();
1368        if (sFrom.line == sTo.line) {
1369            drawForLine(sFrom.line, sFrom.ch, sTo.ch);
1370        } else {
1371            var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
1372            var singleVLine = visualLine(fromLine) == visualLine(toLine);
1373            var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
1374            var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
1375            if (singleVLine) {
1376                if (leftEnd.top < rightStart.top - 2) {
1377                    add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
1378                    add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
1379                } else {
1380                    add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
1381                }
1382            }
1383            if (leftEnd.bottom < rightStart.top)
1384                add(leftSide, leftEnd.bottom, null, rightStart.top);
1385        }
1386
1387        output.appendChild(fragment);
1388    }
1389
1390    // Cursor-blinking
1391    function restartBlink(cm) {
1392        if (!cm.state.focused) return;
1393        var display = cm.display;
1394        clearInterval(display.blinker);
1395        var on = true;
1396        display.cursorDiv.style.visibility = "";
1397        if (cm.options.cursorBlinkRate > 0)
1398            display.blinker = setInterval(function() {
1399                display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
1400            }, cm.options.cursorBlinkRate);
1401        else if (cm.options.cursorBlinkRate < 0)
1402            display.cursorDiv.style.visibility = "hidden";
1403    }
1404
1405    // HIGHLIGHT WORKER
1406
1407    function startWorker(cm, time) {
1408        if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)
1409            cm.state.highlight.set(time, bind(highlightWorker, cm));
1410    }
1411
1412    function highlightWorker(cm) {
1413        var doc = cm.doc;
1414        if (doc.frontier < doc.first) doc.frontier = doc.first;
1415        if (doc.frontier >= cm.display.viewTo) return;
1416        var end = +new Date + cm.options.workTime;

1417        var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
1418        var changedLines = [];
1419
1420        doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {
1421            if (doc.frontier >= cm.display.viewFrom) { // Visible
1422                var oldStyles = line.styles;
1423                var highlighted = highlightLine(cm, line, state, true);
1424                line.styles = highlighted.styles;
1425                var oldCls = line.styleClasses, newCls = highlighted.classes;
1426                if (newCls) line.styleClasses = newCls;
1427                else if (oldCls) line.styleClasses = null;
1428                var ischange = !oldStyles || oldStyles.length != line.styles.length ||
1429                    oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);
1430                for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
1431                if (ischange) changedLines.push(doc.frontier);
1432                line.stateAfter = copyState(doc.mode, state);
1433            } else {
1434                processLine(cm, line.text, state);
1435                line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
1436            }
1437            ++doc.frontier;
1438            if (+new Date >

1438 end) {
1439                startWorker(cm, cm.options.workDelay);
1440                return true;
1441            }
1442        });
1443        if (changedLines.length) runInOp(cm, function() {
1444            for (var i = 0; i < changedLines.length; i++)
1445                regLineChange(cm, changedLines[i], "text");
1446        });
1447    }
1448
1449    // Finds the line to start with when starting a parse. Tries to
1450    // find a line with a stateAfter, so that it can start with a
1451    // valid state. If that fails, it returns the line with the
1452    // smallest indentation, which tends to need the least context to
1453    // parse correctly.
1454    function findStartLine(cm, n, precise) {
1455        var minindent, minline, doc = cm.doc;
1456        var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
1457        for (var search = n; search > lim; --search) {
1458            if (search <= doc.first) return doc.first;
1459            var line = getLine(doc, search - 1);
1460            if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
1461            var indented = countColumn(line.text, null, cm.options.tabSize);
1462            if (minline == null || minindent > indented) {
1463                minline = search - 1;
1464                minindent = indented;
1465            }
1466        }
1467        return minline;
1468    }
1469
1470    function getStateBefore(cm, n, precise) {
1471        var doc = cm.doc, display = cm.display;
1472        if (!doc.mode.startState) return true;
1473        var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
1474        if (!state) state = startState(doc.mode);
1475        else state = copyState(doc.mode, state);
1476        doc.iter(pos, n, function(line) {
1477            processLine(cm, line.text, state);
1478            var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;
1479            line.stateAfter = save ? copyState(doc.mode, state) : null;
1480            ++pos;
1481        });
1482        if (precise) doc.frontier = pos;
1483        return state;
1484    }
1485
1486    // POSITION MEASUREMENT
1487
1488    function paddingTop(display) {return display.lineSpace.offsetTop;}
1489    function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
1490    function paddingH(display) {
1491        if (display.cachedPaddingH) return display.cachedPaddingH;
1492        var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));
1493        var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
1494        var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
1495        if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;
1496        return data;
1497    }
1498
1499    // Ensure the lineView.wrapping.heights array is populated. This is
1500    // an array of bottom offsets for the lines that make up a drawn
1501    // line. When lineWrapping is on, there might be more than one
1502    // height.
1503    function ensureLineHeights(cm, lineView, rect) {
1504        var wrapping = cm.options.lineWrapping;
1505        var curWidth = wrapping && cm.display.scroller.clientWidth;
1506        if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
1507            var heights = lineView.measure.heights = [];
1508            if (wrapping) {
1509                lineView.measure.width = curWidth;
1510                var rects = lineView.text.firstChild.getClientRects();
1511                for (var i = 0; i < rects.length - 1; i++) {
1512                    var cur = rects[i], next = rects[i + 1];
1513                    if (Math.abs(cur.bottom - next.bottom) > 2)
1514                        heights.push((cur.bottom + next.top) / 2 - rect.top);
1515                }
1516            }
1517            heights.push(rect.bottom - rect.top);
1518        }
1519    }
1520
1521    // Find a line map (mapping character offsets to text nodes) and a
1522    // measurement cache for the given line number. (A line view might
1523    // contain multiple lines when collapsed ranges are present.)
1524    function mapFromLineView(lineView, line, lineN) {
1525        if (lineView.line == line)
1526            return {map: lineView.measure.map, cache: lineView.measure.cache};
1527        for (var i = 0; i < lineView.rest.length; i++)
1528            if (lineView.rest[i] == line)
1529                return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};
1530        for (var i = 0; i < lineView.rest.length; i++)
1531            if (lineNo(lineView.rest[i]) > lineN)
1532                return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};
1533    }
1534
1535    // Render a line into the hidden node display.externalMeasured. Used
1536    // when measurement is needed for a line that's not in the viewport.
1537    function updateExternalMeasurement(cm, line) {
1538        line = visualLine(line);
1539        var lineN = lineNo(line);
1540        var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
1541        view.lineN = lineN;
1542        var built = view.built = buildLineContent(cm, view);
1543        view.text = built.pre;
1544        removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
1545        return view;
1546    }
1547
1548    // Get a {top, bottom, left, right} box (in line-local coordinates)
1549    // for a given character.
1550    function measureChar(cm, line, ch, bias) {
1551        return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);
1552    }
1553
1554    // Find a line view that corresponds to the given line number.
1555    function findViewForLine(cm, lineN) {
1556        if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
1557            return cm.display.view[findViewIndex(cm, lineN)];
1558        var ext = cm.display.externalMeasured;
1559        if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
1560            return ext;
1561    }
1562
1563    // Measurement can be split in two steps, the set-up work that
1564    // applies to the whole line, and the measurement of the actual
1565    // character. Functions like coordsChar, that need to do a lot of
1566    // measurements in a row, can thus ensure that the set-up work is
1567    // only done once.
1568    function prepareMeasureForLine(cm, line) {
1569        var lineN = lineNo(line);
1570        var view = findViewForLine(cm, lineN);
1571        if (view && !view.text)
1572            view = null;
1573        else if (view && view.changes)
1574            updateLineForChanges(cm, view, lineN, getDimensions(cm));
1575        if (!view)
1576            view = updateExternalMeasurement(cm, line);
1577
1578        var info = mapFromLineView(view, line, lineN);
1579        return {
1580            line: line, view: view, rect: null,
1581            map: info.map, cache: info.cache, before: info.before,
1582            hasHeights: false
1583        };
1584    }
1585
1586    // Given a prepared measurement object, measures the position of an
1587    // actual character (or fetches it from the cache).
1588    function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
1589        if (prepared.before) ch = -1;
1590        var key = ch + (bias || ""), found;
1591        if (prepared.cache.hasOwnProperty(key)) {
1592            found = prepared.cache[key];
1593        } else {
1594            if (!prepared.rect)
1595                prepared.rect = prepared.view.text.getBoundingClientRect();
1596            if (!prepared.hasHeights) {
1597                ensureLineHeights(cm, prepared.view, prepared.rect);
1598                prepared.hasHeights = true;
1599            }
1600            found = measureCharInner(cm, prepared, ch, bias);
1601            if (!found.bogus) prepared.cache[key] = found;
1602        }
1603        return {left: found.left, right: found.right,
1604            top: varHeight ? found.rtop : found.top,
1605            bottom: varHeight ? found.rbottom : found.bottom};
1606    }
1607
1608    var nullRect = {left: 0, right: 0, top: 0, bottom: 0};
1609
1610    function measureCharInner(cm, prepared, ch, bias) {
1611        var map = prepared.map;
1612
1613        var node, start, end, collapse;
1614        // First, search the line map for the text node corresponding to,
1615        // or closest to, the target character.
1616        for (var i = 0; i < map.length; i += 3) {
1617            var mStart = map[i], mEnd = map[i + 1];
1618            if (ch < mStart) {
1619                start = 0; end = 1;
1620                collapse = "left";
1621            } else if (ch < mEnd) {
1622                start = ch - mStart;
1623                end = start + 1;
1624            } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
1625                end = mEnd - mStart;
1626                start = end - 1;
1627                if (ch >= mEnd) collapse = "right";
1628            }
1629            if (start != null) {
1630                node = map[i + 2];
1631                if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
1632                    collapse = bias;
1633                if (bias == "left" && start == 0)
1634                    while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
1635                        node = map[(i -= 3) + 2];
1636                        collapse = "left";
1637                    }
1638                if (bias == "right" && start == mEnd - mStart)
1639                    while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
1640                        node = map[(i += 3) + 2];
1641                        collapse = "right";
1642                    }
1643                break;
1644            }
1645        }
1646
1647        var rect;
1648        if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
1649            for (var i = 0; i < 4; i++) { // Retry a maximum of 4 times when nonsense rectangles are returned
1650                while (start && isExtendingChar(prepared.line.text.charAt(mStart + start))) --start;
1651                while (mStart + end < mEnd && isExtendingChar(prepared.line.text.charAt(mStart + end))) ++end;
1652                if (ie && ie_version < 9 && start == 0 && end == mEnd - mStart) {
1653                    rect = node.parentNode.getBoundingClientRect();
1654                } else if (ie && cm.options.lineWrapping) {
1655                    var rects = range(node, start, end).getClientRects();
1656                    if (rects.length)
1657                        rect = rects[bias == "right" ? rects.length - 1 : 0];
1658                    else
1659                        rect = nullRect;
1660                } else {
1661                    rect = range(node, start, end).getBoundingClientRect() || nullRect;
1662                }
1663                if (rect.left || rect.right || start == 0) break;
1664                end = start;
1665                start = start - 1;
1666                collapse = "right";
1667            }
1668            if (ie && ie_version < 11) rect = maybeUpdateRectForZooming(cm.display.measure, rect);
1669        } else { // If it is a widget, simply get the box for the whole widget.
1670            if (start > 0) collapse = bias = "right";
1671            var rects;
1672            if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
1673                rect = rects[bias == "right" ? rects.length - 1 : 0];
1674            else
1675                rect = node.getBoundingClientRect();
1676        }
1677        if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {
1678            var rSpan = node.parentNode.getClientRects()[0];
1679            if (rSpan)
1680                rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};
1681            else
1682                rect = nullRect;
1683        }
1684
1685        var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;
1686        var mid = (rtop + rbot) / 2;
1687        var heights = prepared.view.measure.heights;
1688        for (var i = 0; i < heights.length - 1; i++)
1689            if (mid < heights[i]) break;
1690        var top = i ? heights[i - 1] : 0, bot = heights[i];
1691        var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
1692            right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
1693            top: top, bottom: bot};
1694        if (!rect.left && !rect.right) result.bogus = true;
1695        if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }
1696
1697        return result;
1698    }
1699
1700    // Work around problem with bounding client rects on ranges being
1701    // returned incorrectly when zoomed on IE10 and below.
1702    function maybeUpdateRectForZooming(measure, rect) {
1703        if (!window.screen || screen.logicalXDPI == null ||
1704            screen.logicalXDPI == screen.deviceXDPI || !hasBadZoomedRects(measure))
1705            return rect;
1706        var scaleX = screen.logicalXDPI / screen.deviceXDPI;
1707        var scaleY = screen.logicalYDPI / screen.deviceYDPI;
1708        return {left: rect.left * scaleX, right: rect.right * scaleX,
1709            top: rect.top * scaleY, bottom: rect.bottom * scaleY};
1710    }
1711
1712    function clearLineMeasurementCacheFor(lineView) {
1713        if (lineView.measure) {
1714            lineView.measure.cache = {};
1715            lineView.measure.heights = null;
1716            if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
1717                lineView.measure.caches[i] = {};
1718        }
1719    }
1720
1721    function clearLineMeasurementCache(cm) {
1722        cm.display.externalMeasure = null;
1723        removeChildren(cm.display.lineMeasure);
1724        for (var i = 0; i < cm.display.view.length; i++)
1725            clearLineMeasurementCacheFor(cm.display.view[i]);
1726    }
1727
1728    function clearCaches(cm) {
1729        clearLineMeasurementCache(cm);
1730        cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
1731        if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
1732        cm.display.lineNumChars = null;
1733    }
1734
1735    function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
1736    function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }
1737
1738    // Converts a {top, bottom, left, right} box from line-local
1739    // coordinates into another coordinate system. Context may be one of
1740    // "line", "div" (display.lineDiv), "local"/null (editor), or "page".
1741    function intoCoordSystem(cm, lineObj, rect, context) {
1742        if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
1743            var size = widgetHeight(lineObj.widgets[i]);
1744            rect.top += size; rect.bottom += size;
1745        }
1746        if (context == "line") return rect;
1747        if (!context) context = "local";
1748        var yOff = heightAtLine(lineObj);
1749        if (context == "local") yOff += paddingTop(cm.display);
1750        else yOff -= cm.display.viewOffset;
1751        if (context == "page" || context == "window") {
1752            var lOff = cm.display.lineSpace.getBoundingClientRect();
1753            yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
1754            var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
1755            rect.left += xOff; rect.right += xOff;
1756        }
1757        rect.top += yOff; rect.bottom += yOff;
1758        return rect;
1759    }
1760
1761    // Coverts a box from "div" coords to another coordinate system.
1762    // Context may be "window", "page", "div", or "local"/null.
1763    function fromCoordSystem(cm, coords, context) {
1764        if (context == "div") return coords;
1765        var left = coords.left, top = coords.top;
1766        // First move into "page" coordinate system
1767        if (context == "page") {
1768            left -= pageScrollX();
1769            top -= pageScrollY();
1770        } else if (context == "local" || !context) {
1771            var localBox = cm.display.sizer.getBoundingClientRect();
1772            left += localBox.left;
1773            top += localBox.top;
1774        }
1775
1776        var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
1777        return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
1778    }
1779
1780    function charCoords(cm, pos, context, lineObj, bias) {
1781        if (!lineObj) lineObj = getLine(cm.doc, pos.line);
1782        return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);
1783    }
1784
1785    // Returns a box for a given cursor position, which may have an
1786    // 'other' property containing the position of the secondary cursor
1787    // on a bidi boundary.
1788    function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
1789        lineObj = lineObj || getLine(cm.doc, pos.line);
1790        if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);
1791        function get(ch, right) {
1792            var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);
1793            if (right) m.left = m.right; else m.right = m.left;
1794            return intoCoordSystem(cm, lineObj, m, context);
1795        }
1796        function getBidi(ch, partPos) {
1797            var part = order[partPos], right = part.level % 2;
1798            if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
1799                part = order[--partPos];
1800                ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
1801                right = true;
1802            } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
1803                part = order[++partPos];
1804                ch = bidiLeft(part) - part.level % 2;
1805                right = false;
1806            }
1807            if (right && ch == part.to && ch > part.from) return get(ch - 1);
1808            return get(ch, right);
1809        }
1810        var order = getOrder(lineObj), ch = pos.ch;
1811        if (!order) return get(ch);
1812        var partPos = getBidiPartAt(order, ch);
1813        var val = getBidi(ch, partPos);
1814        if (bidiOther != null) val.other = getBidi(ch, bidiOther);
1815        return val;
1816    }
1817
1818    // Used to cheaply estimate the coordinates for a position. Used for
1819    // intermediate scroll updates.
1820    function estimateCoords(cm, pos) {
1821        var left = 0, pos = clipPos(cm.doc, pos);
1822        if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;
1823        var lineObj = getLine(cm.doc, pos.line);
1824        var top = heightAtLine(lineObj) + paddingTop(cm.display);
1825        return {left: left, right: left, top: top, bottom: top + lineObj.height};
1826    }
1827
1828    // Positions returned by coordsChar contain some extra information.
1829    // xRel is the relative x position of the input coordinates compared
1830    // to the found position (so xRel > 0 means the coordinates are to
1831    // the right of the character position, for example). When outside
1832    // is true, that means the coordinates lie outside the line's
1833    // vertical range.
1834    function PosWithInfo(line, ch, outside, xRel) {
1835        var pos = Pos(line, ch);
1836        pos.xRel = xRel;
1837        if (outside) pos.outside = true;
1838        return pos;
1839    }
1840
1841    // Compute the character position closest to the given coordinates.
1842    // Input must be lineSpace-local ("div" coordinate system).
1843    function coordsChar(cm, x, y) {
1844        var doc = cm.doc;
1845        y += cm.display.viewOffset;
1846        if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
1847        var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
1848        if (lineN > last)
1849            return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
1850        if (x < 0) x = 0;
1851
1852        var lineObj = getLine(doc, lineN);
1853        for (;;) {
1854            var found = coordsCharInner(cm, lineObj, lineN, x, y);
1855            var merged = collapsedSpanAtEnd(lineObj);
1856            var mergedPos = merged && merged.find(0, true);
1857            if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
1858                lineN = lineNo(lineObj = mergedPos.to.line);
1859            else
1860                return found;
1861        }
1862    }
1863
1864    function coordsCharInner(cm, lineObj, lineNo, x, y) {
1865        var innerOff = y - heightAtLine(lineObj);
1866        var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
1867        var preparedMeasure = prepareMeasureForLine(cm, lineObj);
1868
1869        function getX(ch) {
1870            var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);
1871            wrongLine = true;
1872            if (innerOff > sp.bottom) return sp.left - adjust;
1873            else if (innerOff < sp.top) return sp.left + adjust;
1874            else wrongLine = false;
1875            return sp.left;
1876        }
1877
1878        var bidi = getOrder(lineObj), dist = lineObj.text.length;
1879        var from = lineLeft(lineObj), to = lineRight(lineObj);
1880        var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;
1881
1882        if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
1883        // Do a binary search between these bounds.
1884        for (;;) {
1885            if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
1886                var ch = x < fromX || x - fromX <= toX - x ? from : to;
1887                var xDiff = x - (ch == from ? fromX : toX);
1888                while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
1889                var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
1890                    xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
1891                return pos;
1892            }
1893            var step = Math.ceil(dist / 2), middle = from + step;
1894            if (bidi) {
1895                middle = from;
1896                for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
1897            }
1898            var middleX = getX(middle);
1899            if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
1900            else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
1901        }
1902    }
1903
1904    var measureText;
1905    // Compute the default text height.
1906    function textHeight(display) {
1907        if (display.cachedTextHeight != null) return display.cachedTextHeight;
1908        if (measureText == null) {
1909            measureText = elt("pre");
1910            // Measure a bunch of lines, for browsers that compute
1911            // fractional heights.
1912            for (var i = 0; i < 49; ++i) {
1913                measureText.appendChild(document.createTextNode("x"));
1914                measureText.appendChild(elt("br"));
1915            }
1916            measureText.appendChild(document.createTextNode("x"));
1917        }
1918        removeChildrenAndAdd(display.measure, measureText);
1919        var height = measureText.offsetHeight / 50;
1920        if (height > 3) display.cachedTextHeight = height;
1921        removeChildren(display.measure);
1922        return height || 1;
1923    }
1924
1925    // Compute the default character width.
1926    function charWidth(display) {
1927        if (display.cachedCharWidth != null) return display.cachedCharWidth;
1928        var anchor = elt("span", "xxxxxxxxxx");
1929        var pre = elt("pre", [anchor]);
1930        removeChildrenAndAdd(display.measure, pre);
1931        var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
1932        if (width > 2) display.cachedCharWidth = width;
1933        return width || 10;
1934    }
1935
1936    // OPERATIONS
1937
1938    // Operations are used to wrap a series of changes to the editor

1939    // state in such a way that each change won't have to update the
1940    // cursor and display (which would be awkward, slow, and
1941    // error-prone). Instead, display updates are batched and then all
1942    // combined and executed at once.
1943
1944    var operationGroup = null;
1945
1946    var nextOpId = 0;
1947    // Start a new operation.
1948    function startOperation(cm) {
1949        cm.curOp = {
1950            cm: cm,
1951            viewChanged: false,      // Flag that indicates that lines might need to be redrawn
1952            startHeight: cm.doc.height, // Used to detect need to update scrollbar
1953            forceUpdate: false,      // Used to force a redraw
1954            updateInput: null,       // Whether to reset the input textarea
1955            typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
1956            changeObjs: null,        // Accumulated changes, for firing change events
1957            cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
1958            cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
1959            selectionChanged: false, // Whether the selection needs to be redrawn
1960            updateMaxLine: false,    // Set when the widest line needs to be determined anew
1961            scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
1962            scrollToPos: null,       // Used to scroll to a specific position
1963            id: ++nextOpId           // Unique ID
1964        };
1965        if (operationGroup) {
1966            operationGroup.ops.push(cm.curOp);
1967        } else {
1968            cm.curOp.ownsGroup = operationGroup = {
1969                ops: [cm.curOp],
1970                delayedCallbacks: []
1971            };
1972        }
1973    }
1974
1975    function fireCallbacksForOps(group) {
1976        // Calls delayed callbacks and cursorActivity handlers until no
1977        // new ones appear
1978        var callbacks = group.delayedCallbacks, i = 0;
1979        do {
1980            for (; i < callbacks.length; i++)
1981                callbacks[i]();
1982            for (var j = 0; j < group.ops.length; j++) {
1983                var op = group.ops[j];
1984                if (op.cursorActivityHandlers)
1985                    while (op.cursorActivityCalled < op.cursorActivityHandlers.length)
1986                        op.cursorActivityHandlers[op.cursorActivityCalled++](op.cm);
1987            }
1988        } while (i < callbacks.length);
1989    }
1990
1991    // Finish an operation, updating the display and signalling delayed events
1992    function endOperation(cm) {
1993        var op = cm.curOp, group = op.ownsGroup;
1994        if (!group) return;
1995
1996        try { fireCallbacksForOps(group); }
1997        finally {
1998            operationGroup = null;
1999            for (var i = 0; i < group.ops.length; i++)
2000                group.ops[i].cm.curOp = null;
2001            endOperations(group);
2002        }
2003    }
2004
2005    // The DOM updates done when an operation finishes are batched so
2006    // that the minimum number of relayouts are required.
2007    function endOperations(group) {
2008        var ops = group.ops;
2009        for (var i = 0; i < ops.length; i++) // Read DOM
2010            endOperation_R1(ops[i]);
2011        for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
2012            endOperation_W1(ops[i]);
2013        for (var i = 0; i < ops.length; i++) // Read DOM
2014            endOperation_R2(ops[i]);
2015        for (var i = 0; i < ops.length; i++) // Write DOM (maybe)
2016            endOperation_W2(ops[i]);
2017        for (var i = 0; i < ops.length; i++) // Read DOM
2018            endOperation_finish(ops[i]);
2019    }
2020
2021    function endOperation_R1(op) {
2022        var cm = op.cm, display = cm.display;
2023        if (op.updateMaxLine) findMaxLine(cm);
2024
2025        op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||
2026            op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
2027                op.scrollToPos.to.line >= display.viewTo) ||
2028            display.maxLineChanged && cm.options.lineWrapping;
2029        op.update = op.mustUpdate &&
2030            new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}

2030, op.forceUpdate);
2031    }
2032
2033    function endOperation_W1(op) {
2034        op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update);
2035    }
2036
2037    function endOperation_R2(op) {
2038        var cm = op.cm, display = cm.display;
2039        if (op.updatedDisplay) updateHeightsInViewport(cm);
2040
2041        op.barMeasure = measureForScrollbars(cm);
2042
2043        // If the max line changed since it was last measured, measure it,
2044        // and ensure the document's width matches it.
2045        // updateDisplay_W2 will use these properties to do the actual resizing
2046        if (display.maxLineChanged && !cm.options.lineWrapping) {
2047            op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3;
2048            op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo +
2049                scrollerCutOff - display.scroller.clientWidth);
2050        }
2051
2052        if (op.updatedDisplay || op.selectionChanged)
2053            op.newSelectionNodes = drawSelection(cm);
2054    }
2055
2056    function endOperation_W2(op) {
2057        var cm = op.cm;
2058
2059        if (op.adjustWidthTo != null) {
2060            cm.display.sizer.style.minWidth = op.adjustWidthTo + "px";
2061            if (op.maxScrollLeft < cm.doc.scrollLeft)
2062                setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true);
2063            cm.display.maxLineChanged = false;
2064        }
2065
2066        if (op.newSelectionNodes)
2067            showSelection(cm, op.newSelectionNodes);
2068        if (op.updatedDisplay)
2069            setDocumentHeight(cm, op.barMeasure);
2070        if (op.updatedDisplay || op.startHeight != cm.doc.height)
2071            updateScrollbars(cm, op.barMeasure);
2072
2073        if (op.selectionChanged) restartBlink(cm);
2074
2075        if (cm.state.focused && op.updateInput)
2076            resetInput(cm, op.typing);
2077    }
2078
2079    function endOperation_finish(op) {
2080        var cm = op.cm, display = cm.display, doc = cm.doc;
2081
2082        if (op.adjustWidthTo != null && Math.abs(op.barMeasure.scrollWidth - cm.display.scroller.scrollWidth) > 1)
2083            updateScrollbars(cm);
2084
2085        if (op.updatedDisplay) postUpdateDisplay(cm, op.update);
2086
2087        // Abort mouse wheel delta measurement, when scrolling explicitly
2088        if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
2089            display.wheelStartX = display.wheelStartY = null;
2090
2091        // Propagate the scroll position to the actual DOM scroller
2092        if (op.scrollTop != null && (display.scroller.scrollTop != op.scrollTop || op.forceScroll)) {
2093            var top = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));
2094            display.scroller.scrollTop = display.scrollbarV.scrollTop = doc.scrollTop = top;
2095        }
2096        if (op.scrollLeft != null && (display.scroller.scrollLeft != op.scrollLeft || op.forceScroll)) {
2097            var left = Math.max(0, Math.min(display.scroller.scrollWidth - display.scroller.clientWidth, op.scrollLeft));
2098            display.scroller.scrollLeft = display.scrollbarH.scrollLeft = doc.scrollLeft = left;
2099            alignHorizontally(cm);
2100        }
2101        // If we need to scroll a specific position into view, do so.
2102        if (op.scrollToPos) {
2103            var coords = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),
2104                clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin);
2105            if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);
2106        }
2107
2108        // Fire events for markers that are hidden/unidden by editing or
2109        // undoing
2110        var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
2111        if (hidden) for (var i = 0; i < hidden.length; ++i)
2112            if (!hidden[i].lines.length) signal(hidden[i], "hide");
2113        if (unhidden) for (var i = 0; i < unhidden.length; ++i)
2114            if (unhidden[i].lines.length) signal(unhidden[i], "unhide");
2115
2116        if (display.wrapper.offsetHeight)
2117            doc.scrollTop = cm.display.scroller.scrollTop;
2118
2119        // Apply workaround for two webkit bugs
2120        if (op.updatedDisplay && webkit) {
2121            if (cm.options.lineWrapping)
2122                checkForWebkitWidthBug(cm, op.barMeasure); // (Issue #2420)
2123            if (op.barMeasure.scrollWidth > op.barMeasure.clientWidth &&
2124                op.barMeasure.scrollWidth < op.barMeasure.clientWidth + 1 &&
2125                !hScrollbarTakesSpace(cm))
2126                updateScrollbars(cm); // (Issue #2562)
2127        }
2128
2129        // Fire change events, and delayed event handlers

2130        if (op.changeObjs)
2131            signal(cm, "changes", cm, op.changeObjs);
2132    }
2133
2134    // Run the given function in an operation
2135    function runInOp(cm, f) {
2136        if (cm.curOp) return f();
2137        startOperation(cm);
2138        try { return f(); }
2139        finally { endOperation(cm); }
2140    }
2141    // Wraps a function in an operation. Returns the wrapped function.
2142    function operation(cm, f) {
2143        return function() {
2144            if (cm.curOp) return f.apply(cm, arguments);
2145            startOperation(cm);
2146            try { return f.apply(cm, arguments); }
2147            finally { endOperation(cm); }
2148        };
2149    }
2150    // Used to add methods to editor and doc instances, wrapping them in
2151    // operations.
2152    function methodOp(f) {
2153        return function() {
2154            if (this.curOp) return f.apply(this, arguments);
2155            startOperation(this);
2156            try { return f.apply(this, arguments); }
2157            finally { endOperation(this); }
2158        };
2159    }
2160    function docMethodOp(f) {
2161        return function() {
2162            var cm = this.cm;
2163            if (!cm || cm.curOp) return f.apply(this, arguments);
2164            startOperation(cm);
2165            try { return f.apply(this, arguments); }
2166            finally { endOperation(cm); }
2167        };
2168    }
2169
2170    // VIEW TRACKING
2171
2172    // These objects are used to represent the visible (currently drawn)
2173    // part of the document. A LineView may correspond to multiple
2174    // logical lines, if those are connected by collapsed ranges.
2175    function LineView(doc, line, lineN) {
2176        // The starting line
2177        this.line = line;
2178        // Continuing lines, if any
2179        this.rest = visualLineContinued(line);
2180        // Number of logical lines in this visual line
2181        this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
2182        this.node = this.text = null;
2183        this.hidden = lineIsHidden(doc, line);
2184    }
2185
2186    // Create a range of LineView objects for the given lines.
2187    function buildViewArray(cm, from, to) {
2188        var array = [], nextPos;
2189        for (var pos = from; pos < to; pos = nextPos) {
2190            var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
2191            nextPos = pos + view.size;
2192            array.push(view);
2193        }
2194        return array;
2195    }
2196
2197    // Updates the display.view data structure for a given change to the
2198    // document. From and to are in pre-change coordinates. Lendiff is
2199    // the amount of lines added or subtracted by the change. This is
2200    // used for changes that span multiple lines, or change the way
2201    // lines are divided into visual lines. regLineChange (below)
2202    // registers single-line changes.
2203    function regChange(cm, from, to, lendiff) {
2204        if (from == null) from = cm.doc.first;
2205        if (to == null) to = cm.doc.first + cm.doc.size;
2206        if (!lendiff) lendiff = 0;
2207
2208        var display = cm.display;
2209        if (lendiff && to < display.viewTo &&
2210            (display.updateLineNumbers == null || display.updateLineNumbers > from))
2211            display.updateLineNumbers = from;
2212
2213        cm.curOp.viewChanged = true;
2214
2215        if (from >= display.viewTo) { // Change after
2216            if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
2217                resetView(cm);
2218        } else if (to <= display.viewFrom) { // Change before
2219            if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
2220                resetView(cm);
2221            } else {
2222                display.viewFrom += lendiff;
2223                display.viewTo += lendiff;
2224            }
2225        } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
2226            resetView(cm);
2227        } else if (from <= display.viewFrom) { // Top overlap
2228            var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
2229            if (cut) {
2230                display.view = display.view.slice(cut.index);
2231                display.viewFrom = cut.lineN;
2232                display.viewTo += lendiff;
2233            } else {
2234                resetView(cm);
2235            }
2236        } else if (to >= display.viewTo) { // Bottom overlap
2237            var cut = viewCuttingPoint(cm, from, from, -1);
2238            if (cut) {
2239                display.view = display.view.slice(0, cut.index);
2240                display.viewTo = cut.lineN;
2241            } else {
2242                resetView(cm);
2243            }
2244        } else { // Gap in the middle
2245            var cutTop = viewCuttingPoint(cm, from, from, -1);
2246            var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
2247            if (cutTop && cutBot) {
2248                display.view = display.view.slice(0, cutTop.index)
2249                    .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
2250                    .concat(display.view.slice(cutBot.index));
2251                display.viewTo += lendiff;
2252            } else {
2253                resetView(cm);
2254            }
2255        }
2256
2257        var ext = display.externalMeasured;
2258        if (ext) {
2259            if (to < ext.lineN)
2260                ext.lineN += lendiff;
2261            else if (from < ext.lineN + ext.size)
2262                display.externalMeasured = null;
2263        }
2264    }
2265
2266    // Register a change to a single line. Type must be one of "text",
2267    // "gutter", "class", "widget"
2268    function regLineChange(cm, line, type) {
2269        cm.curOp.viewChanged = true;
2270        var display = cm.display, ext = cm.display.externalMeasured;
2271        if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
2272            display.externalMeasured = null;
2273
2274        if (line < display.viewFrom || line >= display.viewTo) return;
2275        var lineView = display.view[findViewIndex(cm, line)];
2276        if (lineView.node == null) return;
2277        var arr = lineView.changes || (lineView.changes = []);
2278        if (indexOf(arr, type) == -1) arr.push(type);
2279    }
2280
2281    // Clear the view.
2282    function resetView(cm) {
2283        cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
2284        cm.display.view = [];
2285        cm.display.viewOffset = 0;
2286    }
2287
2288    // Find the view element corresponding to a given line. Return null
2289    // when the line isn't visible.
2290    function findViewIndex(cm, n) {
2291        if (n >= cm.display.viewTo) return null;
2292        n -= cm.display.viewFrom;
2293        if (n < 0) return null;
2294        var view = cm.display.view;
2295        for (var i = 0; i < view.length; i++) {
2296            n -= view[i].size;
2297            if (n < 0) return i;
2298        }
2299    }
2300
2301    function viewCuttingPoint(cm, oldN, newN, dir) {
2302        var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
2303        if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
2304            return {index: index, lineN: newN};
2305        for (var i = 0, n = cm.display.viewFrom; i < index; i++)
2306            n += view[i].size;
2307        if (n != oldN) {
2308            if (dir > 0) {
2309                if (index == view.length - 1) return null;
2310                diff = (n + view[index].size) - oldN;
2311                index++;
2312            } else {
2313                diff = n - oldN;
2314            }
2315            oldN += diff; newN += diff;
2316        }
2317        while (visualLineNo(cm.doc, newN) != newN) {
2318            if (index == (dir < 0 ? 0 : view.length - 1)) return null;
2319            newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
2320            index += dir;
2321        }
2322        return {index: index, lineN: newN};
2323    }
2324
2325    // Force the view to cover a given range, adding empty view element
2326    // or clipping off existing ones as needed.
2327    function adjustView(cm, from, to) {
2328        var display = cm.display, view = display.view;
2329        if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
2330            display.view = buildViewArray(cm, from, to);
2331            display.viewFrom = from;
2332        } else {
2333            if (display.viewFrom > from)
2334                display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);
2335            else if (display.viewFrom < from)
2336                display.view = display.view.slice(findViewIndex(cm, from));
2337            display.viewFrom = from;
2338            if (display.viewTo < to)
2339                display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));
2340            else if (display.viewTo > to)
2341                display.view = display.view.slice(0, findViewIndex(cm, to));
2342        }
2343        display.viewTo = to;
2344    }
2345
2346    // Count the number of lines in the view whose DOM representation is
2347    // out of date (or nonexistent).
2348    function countDirtyView(cm) {
2349        var view = cm.display.view, dirty = 0;
2350        for (var i = 0; i < view.length; i++) {
2351            var lineView = view[i];
2352            if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
2353        }
2354        return dirty;
2355    }
2356
2357    // INPUT HANDLING
2358
2359    // Poll for input changes, using the normal rate of polling. This
2360    // runs as long as the editor is focused.
2361    function slowPoll(cm) {
2362        if (cm.display.pollingFast) return;
2363        cm.display.poll.set(cm.options.pollInterval, function() {
2364            readInput(cm);
2365            if (cm.state.focused) slowPoll(cm);
2366        });
2367    }
2368
2369    // When an event has just come in that is likely to add or change
2370    // something in the input textarea, we poll faster, to ensure that
2371    // the change appears on the screen quickly.
2372    function fastPoll(cm) {
2373        var missed = false;
2374        cm.display.pollingFast = true;
2375        function p() {
2376            var changed = readInput(cm);
2377            if (!changed && !missed) {missed = true; cm.display.poll.set(60, p);}
2378            else {cm.display.pollingFast = false; slowPoll(cm);}
2379        }
2380        cm.display.poll.set(20, p);
2381    }
2382

2383    // This will be set to an array of strings when copying, so that,
2384    // when pasting, we know what kind of selections the copied text
2385    // was made out of.
2386    var lastCopied = null;
2387
2388    // Read input from the textarea, and update the document to match.
2389    // When something is selected, it is present in the textarea, and
2390    // selected (unless it is huge, in which case a placeholder is
2391    // used). When nothing is selected, the cursor sits after previously
2392    // seen text (can be empty), which is stored in prevInput (we must
2393    // not reset the textarea when typing, because that breaks IME).
2394    function readInput(cm) {
2395        var input = cm.display.input, prevInput = cm.display.prevInput, doc = cm.doc;
2396        // Since this is called a *lot*, try to bail out as cheaply as
2397        // possible when it is clear that nothing happened. hasSelection
2398        // will be the case when there is a lot of text in the textarea,
2399        // in which case reading its value would be expensive.
2400        if (!cm.state.focused || (hasSelection(input) && !prevInput) || isReadOnly(cm) || cm.options.disableInput)
2401            return false;
2402        // See paste handler for more on the fakedLastChar kludge
2403        if (cm.state.pasteIncoming && cm.state.fakedLastChar) {
2404            input.value = input.value.substring(0, input.value.length - 1);
2405            cm.state.fakedLastChar = false;
2406        }
2407        var text = input.value;
2408        // If nothing changed, bail.
2409        if (text == prevInput && !cm.somethingSelected()) return false;
2410        // Work around nonsensical selection resetting in IE9/10, and
2411        // inexplicable appearance of private area unicode characters on
2412        // some key combos in Mac (#2689).
2413        if (ie && ie_version >= 9 && cm.display.inputHasSelection === text ||
2414            mac && /[\uf700-\uf7ff]/.test(text)) {
2415            resetInput(cm);
2416            return false;
2417        }
2418
2419        var withOp = !cm.curOp;
2420        if (withOp) startOperation(cm);
2421        cm.display.shift = false;
2422
2423        if (text.charCodeAt(0) == 0x200b && doc.sel == cm.display.selForContextMenu && !prevInput)
2424            prevInput = "\u200b";
2425        // Find the part of the input that is actually new
2426        var same = 0, l = Math.min(prevInput.length, text.length);
2427        while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
2428        var inserted = text.slice(same), textLines = splitLines(inserted);
2429
2430        // When pasing N lines into N selections, insert one line per selection
2431        var multiPaste = null;
2432        if (cm.state.pasteIncoming && doc.sel.ranges.length > 1) {
2433            if (lastCopied && lastCopied.join("\n") == inserted)
2434                multiPaste = doc.sel.ranges.length % lastCopied.length == 0 && map(lastCopied, splitLines);
2435            else if (textLines.length == doc.sel.ranges.length)
2436                multiPaste = map(textLines, function(l) { return [l]; });
2437        }
2438
2439        // Normal behavior is to insert the new text into every selection
2440        for (var i = doc.sel.ranges.length - 1; i >= 0; i--) {
2441            var range = doc.sel.ranges[i];
2442            var from = range.from(), to = range.to();
2443            // Handle deletion
2444            if (same < prevInput.length)
2445                from = Pos(from.line, from.ch - (prevInput.length - same));
2446            // Handle overwrite
2447            else if (cm.state.overwrite && range.empty() && !cm.state.pasteIncoming)
2448                to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));
2449            var updateInput = cm.curOp.updateInput;
2450            var changeEvent = {from: from, to: to, text: multiPaste ? multiPaste[i % multiPaste.length] : textLines,
2451                origin: cm.state.pasteIncoming ? "paste" : cm.state.cutIncoming ? "cut" : "+input"};
2452            makeChange(cm.doc, changeEvent);
2453            signalLater(cm, "inputRead", cm, changeEvent);
2454            // When an 'electric' character is inserted, immediately trigger a reindent
2455            if (inserted && !cm.state.pasteIncoming && cm.options.electricChars &&
2456                cm.options.smartIndent && range.head.ch < 100 &&
2457                (!i || doc.sel.ranges[i - 1].head.line != range.head.line)) {
2458                var mode = cm.getModeAt(range.head);
2459                var end = changeEnd(changeEvent);
2460                if (mode.electricChars) {
2461                    for (var j = 0; j < mode.electricChars.length; j++)
2462                        if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
2463                            indentLine(cm, end.line, "smart");
2464                            break;
2465                        }
2466                } else if (mode.electricInput) {
2467                    if (mode.electricInput.test(getLine(doc, end.line).text.slice(0, end.ch)))
2468                        indentLine(cm, end.line, "smart");
2469                }
2470            }
2471        }
2472        ensureCursorVisible(cm);
2473        cm.curOp.updateInput = updateInput;
2474        cm.curOp.typing = true;
2475
2476        // Don't leave long text in the textarea, since it makes further polling slow
2477        if (text.length > 1000 || text.indexOf("\n") > -1) input.value = cm.display.prevInput = "";
2478        else cm.display.prevInput = text;
2479        if (withOp) endOperation(cm);
2480        cm.state.pasteIncoming = cm.state.cutIncoming = false;

2481        return true;
2482    }
2483
2484    // Reset the input to correspond to the selection (or to be empty,
2485    // when not typing and nothing is selected)
2486    function resetInput(cm, typing) {
2487        var minimal, selected, doc = cm.doc;
2488        if (cm.somethingSelected()) {
2489            cm.display.prevInput = "";
2490            var range = doc.sel.primary();
2491            minimal = hasCopyEvent &&
2492                (range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);
2493            var content = minimal ? "-" : selected || cm.getSelection();
2494            cm.display.input.value = content;
2495            if (cm.state.focused) selectInput(cm.display.input);
2496            if (ie && ie_version >= 9) cm.display.inputHasSelection = content;
2497        } else if (!typing) {
2498            cm.display.prevInput = cm.display.input.value = "";
2499            if (ie && ie_version >= 9) cm.display.inputHasSelection = null;
2500        }
2501        cm.display.inaccurateSelection = minimal;
2502    }
2503
2504    function focusInput(cm) {
2505        if (cm.options.readOnly != "nocursor" && (!mobile || activeElt() != cm.display.input))
2506            cm.display.input.focus();
2507    }
2508
2509    function ensureFocus(cm) {
2510        if (!cm.state.focused) { focusInput(cm); onFocus(cm); }
2511    }
2512
2513    function isReadOnly(cm) {
2514        return cm.options.readOnly || cm.doc.cantEdit;
2515    }
2516
2517    // EVENT HANDLERS
2518
2519    // Attach the necessary event handlers when initializing the editor
2520    function registerEventHandlers(cm) {
2521        var d = cm.display;
2522        on(d.scroller, "mousedown", operation(cm, onMouseDown));
2523        // Older IE's will not fire a second mousedown for a double click
2524        if (ie && ie_version < 11)
2525            on(d.scroller, "dblclick", operation(cm, function(e) {
2526                if (signalDOMEvent(cm, e)) return;
2527                var pos = posFromMouse(cm, e);
2528                if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
2529                e_preventDefault(e);
2530                var word = cm.findWordAt(pos);
2531                extendSelection(cm.doc, word.anchor, word.head);
2532            }));
2533        else
2534            on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
2535        // Prevent normal selection in the editor (we handle our own)
2536        on(d.lineSpace, "selectstart", function(e) {
2537            if (!eventInWidget(d, e)) e_preventDefault(e);
2538        });
2539        // Some browsers fire contextmenu *after* opening the menu, at
2540        // which point we can't mess with it anymore. Context menu is
2541        // handled in onMouseDown for these browsers.
2542        if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});
2543
2544        // Sync scrolling between fake scrollbars and real scrollable
2545        // area, ensure viewport is updated when scrolling.
2546        on(d.scroller, "scroll", function() {
2547            if (d.scroller.clientHeight) {
2548                setScrollTop(cm, d.scroller.scrollTop);
2549                setScrollLeft(cm, d.scroller.scrollLeft, true);
2550                signal(cm, "scroll", cm);
2551            }
2552        });
2553        on(d.scrollbarV, "scroll", function() {
2554            if (d.scroller.clientHeight) setScrollTop(cm, d.scrollbarV.scrollTop);
2555        });
2556        on(d.scrollbarH, "scroll", function() {
2557            if (d.scroller.clientHeight) setScrollLeft(cm, d.scrollbarH.scrollLeft);
2558        });
2559
2560        // Listen to wheel events in order to try and update the viewport on time.
2561        on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
2562        on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});
2563
2564        // Prevent clicks in the scrollbars from killing focus
2565        function reFocus() { if (cm.state.focused) setTimeout(bind(focusInput, cm), 0); }
2566        on(d.scrollbarH, "mousedown", reFocus);
2567        on(d.scrollbarV, "mousedown", reFocus);
2568        // Prevent wrapper from ever scrolling
2569        on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });
2570
2571        on(d.input, "keyup", function(e) { onKeyUp.call(cm, e); });
2572        on(d.input, "input", function() {
2573            if (ie && ie_version >= 9 && cm.display.inputHasSelection) cm.display.inputHasSelection = null;
2574            fastPoll(cm);
2575        });
2576        on(d.input, "keydown", operation(cm, onKeyDown));
2577        on(d.input, "keypress", operation(cm, onKeyPress));

2578        on(d.input, "focus", bind(onFocus, cm));
2579        on(d.input, "blur", bind(onBlur, cm));
2580
2581        function drag_(e) {
2582            if (!signalDOMEvent(cm, e)) e_stop(e);
2583        }
2584        if (cm.options.dragDrop) {
2585            on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
2586            on(d.scroller, "dragenter", drag_);
2587            on(d.scroller, "dragover", drag_);
2588            on(d.scroller, "drop", operation(cm, onDrop));
2589        }
2590        on(d.scroller, "paste", function(e) {
2591            if (eventInWidget(d, e)) return;
2592            cm.state.pasteIncoming = true;
2593            focusInput(cm);
2594            fastPoll(cm);
2595        });
2596        on(d.input, "paste", function() {
2597            // Workaround for webkit bug https://bugs.webkit.org/show_bug.cgi?id=90206
2598            // Add a char to the end of textarea before paste occur so that
2599            // selection doesn't span to the end of textarea.
2600            if (webkit && !cm.state.fakedLastChar && !(new Date - cm.state.lastMiddleDown < 200)) {
2601                var start = d.input.selectionStart, end = d.input.selectionEnd;
2602                d.input.value += "$";
2603                // The selection end needs to be set before the start, otherwise there
2604                // can be an intermediate non-empty selection between the two, which
2605                // can override the middle-click paste buffer on linux and cause the
2606                // wrong thing to get pasted.
2607                d.input.selectionEnd = end;
2608                d.input.selectionStart = start;
2609                cm.state.fakedLastChar = true;
2610            }
2611            cm.state.pasteIncoming = true;
2612            fastPoll(cm);
2613        });
2614
2615        function prepareCopyCut(e) {
2616            if (cm.somethingSelected()) {
2617                lastCopied = cm.getSelections();
2618                if (d.inaccurateSelection) {
2619                    d.prevInput = "";
2620                    d.inaccurateSelection = false;
2621                    d.input.value = lastCopied.join("\n");
2622                    selectInput(d.input);
2623                }
2624            } else {
2625                var text = [], ranges = [];
2626                for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
2627                    var line = cm.doc.sel.ranges[i].head.line;
2628                    var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
2629                    ranges.push(lineRange);
2630                    text.push(cm.getRange(lineRange.anchor, lineRange.head));
2631                }
2632                if (e.type == "cut") {
2633                    cm.setSelections(ranges, null, sel_dontScroll);
2634                } else {
2635                    d.prevInput = "";
2636                    d.input.value = text.join("\n");
2637                    selectInput(d.input);
2638                }
2639                lastCopied = text;
2640            }
2641            if (e.type == "cut") cm.state.cutIncoming = true;
2642        }
2643        on(d.input, "cut", prepareCopyCut);
2644        on(d.input, "copy", prepareCopyCut);
2645
2646        // Needed to handle Tab key in KHTML
2647        if (khtml) on(d.sizer, "mouseup", function() {
2648            if (activeElt() == d.input) d.input.blur();
2649            focusInput(cm);
2650        });
2651    }
2652
2653    // Called when the window resizes
2654    function onResize(cm) {
2655        // Might be a text scaling operation, clear size caches.
2656        var d = cm.display;
2657        d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
2658        cm.setSize();
2659    }
2660
2661    // MOUSE EVENTS
2662
2663    // Return true when the given mouse event happened in a widget
2664    function eventInWidget(display, e) {
2665        for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
2666            if (!n || n.ignoreEvents || n.parentNode == display.sizer && n != display.mover) return true;
2667        }
2668    }
2669
2670    // Given a mouse event, find the corresponding position. If liberal
2671    // is false, it checks whether a gutter or scrollbar was clicked,
2672    // and returns null if it was. forRect is used by rectangular
2673    // selections, and tries to estimate a character position even for
2674    // coordinates beyond the right of the text.
2675    function posFromMouse(cm, e, liberal, forRect) {
2676        var display = cm.display;
2677        if (!liberal) {
2678            var target = e_target(e);
2679            if (target == display.scrollbarH || target == display.scrollbarV ||
2680                target == display.scrollbarFiller || target == display.gutterFiller) return null;
2681        }
2682        var x, y, space = display.lineSpace.getBoundingClientRect();
2683        // Fails unpredictably on IE[67] when mouse is dragged around quickly.
2684        try { x = e.clientX - space.left; y = e.clientY - space.top; }
2685        catch (e) { return null; }
2686        var coords = coordsChar(cm, x, y), line;
2687        if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
2688            var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
2689            coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
2690        }
2691        return coords;
2692    }
2693
2694    // A mouse down can be a single click, double click, triple click,
2695    // start of selection drag, start of text drag, new cursor
2696    // (ctrl-click), rectangle drag (alt-drag), or xwin
2697    // middle-click-paste. Or it might be a click on something we should
2698    // not interfere with, such as a scrollbar or widget.
2699    function onMouseDown(e) {
2700        if (signalDOMEvent(this, e)) return;
2701        var cm = this, display = cm.display;
2702        display.shift = e.shiftKey;
2703
2704        if (eventInWidget(display, e)) {
2705            if (!webkit) {
2706                // Briefly turn off draggability, to allow widgets to do
2707                // normal dragging things.
2708                display.scroller.draggable = false;