modules/documentCanvas/canvas/canvas.js

   1 define([
   2 'libs/jquery-1.9.1.min',
   3 'libs/underscore-min',
   4 'libs/backbone-min',
   5 'modules/documentCanvas/canvas/documentElement',
   6 'modules/documentCanvas/canvas/utils'
   7 ], function($, _, Backbone, documentElement, utils) {
   8
   9 'use strict';
  10
  11 var Canvas = function(wlxml, publisher) {
  12     this.eventBus = _.extend({}, Backbone.Events);
  13     this.loadWlxml(wlxml);
  14     this.publisher = publisher ? publisher : function() {};
  15 };
  16
  17 $.extend(Canvas.prototype, {
  18
  19     loadWlxml: function(wlxml) {
  20         var d = wlxml ? $($.trim(wlxml)) : null;
  21         if(d) {
  22             this.wrapper = $('<div>').addClass('canvas-wrapper').attr('contenteditable', true);
  23             this.wrapper.append(d);
  24             var canvas = this;
  25
  26             this.wrapper.find('*').replaceWith(function() {
  27                 var currentTag = $(this);
  28                 if(currentTag.attr('wlxml-tag'))
  29                     return;
  30
  31                 var meta = {}, others = {};
  32                 for(var i = 0; i < this.attributes.length; i++) {
  33                     var attr = this.attributes[i];
  34                     if(attr.name.substr(0, 5) === 'meta-')
  35                         meta[attr.name.substr(5)] = attr.value;
  36                     else if(attr.name !== 'class')
  37                         others[attr.name] = attr.value;
  38                 }
  39
  40                 var element = documentElement.DocumentNodeElement.create({
  41                     tag: currentTag.prop('tagName').toLowerCase(),
  42                     klass: currentTag.attr('class'),
  43                     meta: meta,
  44                     others: others,
  45                     rawChildren: currentTag.contents()
  46                 }, canvas);
  47
  48                 ['orig-before', 'orig-after', 'orig-begin', 'orig-end'].forEach(function(attr) {
  49                     element.data(attr, '');
  50                 });
  51                 return element.dom();
  52             });
  53
  54             var FIRST_CONTENT_INDEX = 0;
  55
  56             // @@ TODO - refactor!
  57             var getNode = function(element) {
  58                 return element.children('[document-element-content]');
  59             }
  60
  61             this.wrapper.find(':not(iframe)').addBack().contents()
  62                 .filter(function() {return this.nodeType === Node.TEXT_NODE})
  63                 .each(function() {
  64
  65                     // TODO: use DocumentElement API
  66
  67                     var el = $(this),
  68                         text = {original: el.text(), trimmed: $.trim(el.text())},
  69                         elParent = el.parent(),
  70                         hasSpanParent = elParent.attr('wlxml-tag') === 'span',
  71                         hasSpanBefore = el.prev().length > 0  && getNode($(el.prev()[0])).attr('wlxml-tag') === 'span',
  72                         hasSpanAfter = el.next().length > 0 && getNode($(el.next()[0])).attr('wlxml-tag') === 'span';
  73
  74                     if(el.parent().hasClass('canvas-widget'))
  75                         return true; // continue
  76
  77                     var addInfo = function(toAdd, where) {
  78                         var parentContents = elParent.contents(),
  79                             idx = parentContents.index(el[0]),
  80                             prev = idx > FIRST_CONTENT_INDEX ? parentContents[idx-1] : null,
  81                             next = idx < parentContents.length - 1 ? parentContents[idx+1] : null,
  82                             target, key;
  83
  84                         if(where === 'above') {
  85                             target = prev ? $(prev) : elParent.parent();
  86                             key = prev ? 'orig-after' : 'orig-begin';
  87                         } else if(where === 'below') {
  88                             target = next ? $(next) : elParent.parent();
  89                             key = next ? 'orig-before' : 'orig-end';
  90                         } else { throw new Object;}
  91
  92                         target.data(key, toAdd);
  93                     }
  94
  95                     text.transformed = text.trimmed;
  96
  97                     if(hasSpanParent || hasSpanBefore || hasSpanAfter) {
  98                         var startSpace = /\s/g.test(text.original.substr(0,1)),
  99                             endSpace = /\s/g.test(text.original.substr(-1)) && text.original.length > 1;
 100                         text.transformed = (startSpace && (hasSpanParent || hasSpanBefore) ? ' ' : '')
 101                                     + text.trimmed
 102                                     + (endSpace && (hasSpanParent || hasSpanAfter) ? ' ' : '');
 103                     } else {
 104                         if(text.trimmed.length === 0 && text.original.length > 0 && elParent.contents().length === 1)
 105                             text.transformed = ' ';
 106                     }
 107
 108                     if(!text.transformed) {
 109                         addInfo(text.original, 'below');
 110                         el.remove();
 111                         return true; // continue
 112                     }
 113
 114                     if(text.transformed !== text.original) {
 115                         if(!text.trimmed) {
 116                             addInfo(text.original, 'below');
 117                         } else {
 118                             var startingMatch = text.original.match(/^\s+/g),
 119                                 endingMatch = text.original.match(/\s+$/g),
 120                                 startingWhiteSpace = startingMatch ? startingMatch[0] : null,
 121                                 endingWhiteSpace = endingMatch ? endingMatch[0] : null;
 122
 123                             if(endingWhiteSpace) {
 124                                 if(text.transformed[text.transformed.length - 1] === ' ' && endingWhiteSpace[0] === ' ')
 125                                     endingWhiteSpace = endingWhiteSpace.substr(1);
 126                                 addInfo(endingWhiteSpace, 'below');
 127                             }
 128
 129                             if(startingWhiteSpace) {
 130                                 if(text.transformed[0] === ' ' && startingWhiteSpace[startingWhiteSpace.length-1] === ' ')
 131                                     startingWhiteSpace = startingWhiteSpace.substr(0, startingWhiteSpace.length -1);
 132                                 addInfo(startingWhiteSpace, 'above');
 133                             }
 134                         }
 135                     }
 136
 137                     var element = documentElement.DocumentTextElement.create({text: text.transformed});
 138                     el.replaceWith(element.dom());
 139                 });
 140
 141             this.d = this.wrapper.children(0);
 142
 143             this.wrapper.on('keydown', function(e) {
 144                 if(e.which === 13) {
 145                     e.preventDefault();
 146                     var cursor = canvas.getCursor();
 147                     if(!cursor.isSelecting()) {
 148                         var position = cursor.getPosition(),
 149                             element = position.element;
 150
 151                         if(!(element.parent().parent())) {
 152                             return false; // top level element is unsplittable
 153                         }
 154
 155                         var elements = position.element.split({offset: position.offset}),
 156                             newEmpty,
 157                             goto;
 158
 159                         if(position.offsetAtBeginning)
 160                             newEmpty = elements.first;
 161                         else if(position.offsetAtEnd)
 162                             newEmpty = elements.second;
 163                         if(newEmpty) {
 164                             goto = newEmpty.append(documentElement.DocumentTextElement.create({text: ''}, this));
 165                             canvas.setCurrentElement(goto);
 166                         }
 167                     }
 168                 }
 169             });
 170
 171
 172             var KEYS = {
 173                 ARROW_LEFT: 37,
 174                 ARROW_UP: 38,
 175                 ARROW_RIGHT: 39,
 176                 ARROW_DOWN: 40
 177             }
 178
 179             this.wrapper.on('keyup', function(e) {
 180                 if(e.which >= 37 && e.which <= 40) {
 181                     var element = canvas.getCursor().getPosition().element,
 182                         caretTo = false;
 183                     if(!element) {
 184                         // Chrome hack
 185                         var direction;
 186                         if(e.which === KEYS.ARROW_LEFT  || e.which === KEYS.ARROW_UP) {
 187                             direction = 'above';
 188                             caretTo = 'end';
 189                         } else {
 190                             direction = 'below';
 191                             caretTo = 'start';
 192                         }
 193                         element = canvas.getDocumentElement(utils.nearestInDocumentOrder('[document-text-element]:visible', direction, window.getSelection().focusNode));
 194                     }
 195                     canvas.setCurrentElement(element, {caretTo: caretTo});
 196                 }
 197             });
 198
 199             this.wrapper.on('keydown', function(e) {
 200                 if(e.which >= 37 && e.which <= 40) {
 201                     var position = canvas.getCursor().getPosition(),
 202                         element = position.element;
 203                     if(element && (element instanceof documentElement.DocumentTextElement)) {
 204                         if(element.isEmpty()) {
 205                             var direction, caretTo;
 206                             if(e.which === KEYS.ARROW_LEFT  || e.which === KEYS.ARROW_UP) {
 207                                 direction = 'above';
 208                                 caretTo = 'end';
 209                             } else {
 210                                 direction = 'below';
 211                                 caretTo = 'start';
 212                             }
 213                             var el = canvas.getDocumentElement(utils.nearestInDocumentOrder('[document-text-element]', direction, window.getSelection().focusNode))
 214                             canvas.setCurrentElement(element, {caretTo: caretTo});
 215                         } else {
 216                             var txt = element.dom().contents()[0].data;
 217                             if(e.which === KEYS.ARROW_LEFT && position.offset > 1 && txt.charAt(position.offset-2) === utils.unicode.ZWS) {
 218                                 e.preventDefault();
 219                                 canvas._moveCaretToTextElement(element, position.offset-2);
 220                             }
 221                             if(e.which === KEYS.ARROW_RIGHT && position.offset < txt.length - 1 && txt.charAt(position.offset+1) === utils.unicode.ZWS) {
 222                                 e.preventDefault();
 223                                 canvas._moveCaretToTextElement(element, position.offset+2);
 224                             }
 225                         }
 226                     }
 227
 228
 229                 }
 230             });
 231
 232             this.wrapper.on('click', '[document-node-element], [document-text-element]', function(e) {
 233                 e.stopPropagation();
 234                 canvas.setCurrentElement(canvas.getDocumentElement(e.currentTarget), {caretTo: false});
 235             });
 236
 237             var observer = new MutationObserver(function(mutations) {
 238                 mutations.forEach(function(mutation) {
 239                     if(documentElement.DocumentTextElement.isContentContainer(mutation.target) && mutation.target.data === '')
 240                         mutation.target.data = utils.unicode.ZWS;
 241                 });
 242             });
 243             var config = { attributes: false, childList: false, characterData: true, subtree: true, characterDataOldValue: true};
 244             observer.observe(this.d[0], config);
 245
 246
 247             this.wrapper.on('mouseover', '[document-node-element], [document-text-element]', function(e) {
 248                 var el = canvas.getDocumentElement(e.currentTarget);
 249                 if(!el)
 250                     return;
 251                 e.stopPropagation();
 252                 if(el instanceof documentElement.DocumentTextElement)
 253                     el = el.parent();
 254                 el.toggleLabel(true);
 255             });
 256             this.wrapper.on('mouseout', '[document-node-element], [document-text-element]', function(e) {
 257                 var el = canvas.getDocumentElement(e.currentTarget);
 258                 if(!el)
 259                     return;
 260                 e.stopPropagation();
 261                 if(el instanceof documentElement.DocumentTextElement)
 262                     el = el.parent();
 263                 el.toggleLabel(false);
 264             });
 265
 266             this.eventBus.on('elementToggled', function(toggle, element) {
 267                 if(!toggle) {
 268                     element = canvas.getDocumentElement(utils.nearestInDocumentOrder('[document-text-element]:visible', 'above', element.dom()[0]));
 269                     canvas.setCurrentElement(element);
 270                 }
 271             })
 272
 273         } else {
 274             this.d = null;
 275         }
 276     },
 277
 278     view: function() {
 279         return this.wrapper;
 280     },
 281
 282     doc: function() {
 283         if(this.d === null)
 284             return null;
 285         return documentElement.DocumentNodeElement.fromHTMLElement(this.d.get(0), this); //{wlxmlTag: this.d.prop('tagName')};
 286     },
 287
 288     wrapText: function(params) {
 289         params = _.extend({textNodeIdx: 0}, params);
 290         if(typeof params.textNodeIdx === 'number')
 291             params.textNodeIdx = [params.textNodeIdx];
 292
 293         var childrenInside = params.inside.children(),
 294             idx1 = Math.min.apply(Math, params.textNodeIdx),
 295             idx2 = Math.max.apply(Math, params.textNodeIdx),
 296             textNode1 = childrenInside[idx1],
 297             textNode2 = childrenInside[idx2],
 298             sameNode = textNode1.sameNode(textNode2),
 299             prefixOutside = textNode1.getText().substr(0, params.offsetStart),
 300             prefixInside = textNode1.getText().substr(params.offsetStart),
 301             suffixInside = textNode2.getText().substr(0, params.offsetEnd),
 302             suffixOutside = textNode2.getText().substr(params.offsetEnd)
 303         ;
 304
 305         var wrapperElement = documentElement.DocumentNodeElement.create({tag: params._with.tag, klass: params._with.klass});
 306         textNode1.after(wrapperElement);
 307         textNode1.detach();
 308
 309         if(prefixOutside.length > 0)
 310             wrapperElement.before({text:prefixOutside});
 311         if(sameNode) {
 312             var core = textNode1.getText().substr(params.offsetStart, params.offsetEnd - params.offsetStart);
 313             wrapperElement.append({text: core});
 314         } else {
 315             textNode2.detach();
 316             if(prefixInside.length > 0)
 317                 wrapperElement.append({text: prefixInside});
 318             for(var i = idx1 + 1; i < idx2; i++) {
 319                 wrapperElement.append(childrenInside[i]);
 320             }
 321             if(suffixInside.length > 0)
 322                 wrapperElement.append({text: suffixInside});
 323         }
 324         if(suffixOutside.length > 0)
 325             wrapperElement.after({text: suffixOutside});
 326         return wrapperElement;
 327     },
 328
 329     wrapElements: function(params) {
 330         if(!(params.element1.parent().sameNode(params.element2.parent())))
 331             return;
 332
 333         var parent = params.element1.parent(),
 334             parentChildren = parent.children(),
 335             wrapper = documentElement.DocumentNodeElement.create({
 336                 tag: params._with.tag,
 337                 klass: params._with.klass}),
 338             idx1 = parent.childIndex(params.element1),
 339             idx2 = parent.childIndex(params.element2);
 340
 341         if(idx1 > idx2) {
 342             var tmp = idx1;
 343             idx1 = idx2;
 344             idx2 = tmp;
 345         }
 346
 347         var insertingMethod, insertingTarget;
 348         if(idx1 === 0) {
 349             insertingMethod = 'prepend';
 350             insertingTarget = parent;
 351         } else {
 352             insertingMethod = 'after';
 353             insertingTarget = parentChildren[idx1-1];
 354         }
 355
 356         for(var i = idx1; i <= idx2; i++) {
 357             wrapper.append(parentChildren[i].detach());
 358         }
 359
 360         insertingTarget[insertingMethod](wrapper);
 361         return wrapper;
 362     },
 363
 364     getSiblingParents: function(params) {
 365         var parents1 = [params.element1].concat(params.element1.parents()).reverse(),
 366             parents2 = [params.element2].concat(params.element2.parents()).reverse(),
 367             noSiblingParents = null;
 368
 369         if(parents1.length === 0 || parents2.length === 0 || !(parents1[0].sameNode(parents2[0])))
 370             return noSiblingParents;
 371
 372         var i;
 373         for(i = 0; i < Math.min(parents1.length, parents2.length); i++) {
 374             if(parents1[i].sameNode(parents2[i]))
 375                 continue;
 376             break;
 377         }
 378         return {element1: parents1[i], element2: parents2[i]};
 379     },
 380
 381     getDocumentElement: function(from) {
 382         if(from instanceof HTMLElement || from instanceof Text) {
 383            return documentElement.DocumentElement.fromHTMLElement(from, this);
 384         }
 385     },
 386     getCursor: function() {
 387         return new Cursor(this);
 388     },
 389
 390     list: {},
 391
 392
 393     getCurrentNodeElement: function() {
 394         return this.getDocumentElement(this.wrapper.find('.current-node-element').parent()[0]);
 395     },
 396
 397     getCurrentTextElement: function() {
 398         return this.getDocumentElement(this.wrapper.find('.current-text-element')[0]);
 399     },
 400
 401
 402
 403     setCurrentElement: function(element, params) {
 404         params = _.extend({caretTo: 'end'}, params);
 405         var findFirstDirectTextChild = function(e, nodeToLand) {
 406             var byBrowser = this.getCursor().getPosition().element;
 407             if(byBrowser && byBrowser.parent().sameNode(nodeToLand))
 408                 return byBrowser;
 409             var children = e.children();
 410             for(var i = 0; i < children.length; i++) {
 411                 if(children[i] instanceof documentElement.DocumentTextElement)
 412                     return children[i];
 413             }
 414             return null;
 415         }.bind(this);
 416         var _markAsCurrent = function(element) {
 417             if(element instanceof documentElement.DocumentTextElement) {
 418                 this.wrapper.find('.current-text-element').removeClass('current-text-element');
 419                 element.dom().addClass('current-text-element');
 420             } else {
 421                 this.wrapper.find('.current-node-element').removeClass('current-node-element')
 422                 element._container().addClass('current-node-element');
 423                 this.publisher('currentElementChanged', element);
 424             }
 425         }.bind(this);
 426
 427
 428         var isTextElement = element instanceof documentElement.DocumentTextElement,
 429             nodeElementToLand = isTextElement ? element.parent() : element,
 430             textElementToLand = isTextElement ? element : findFirstDirectTextChild(element, nodeElementToLand),
 431             currentTextElement = this.getCurrentTextElement(),
 432             currentNodeElement = this.getCurrentNodeElement();
 433
 434         if(currentTextElement && !(currentTextElement.sameNode(textElementToLand)))
 435             this.wrapper.find('.current-text-element').removeClass('current-text-element');
 436
 437         if(textElementToLand) {
 438             _markAsCurrent(textElementToLand);
 439             if(params.caretTo || !textElementToLand.sameNode(this.getCursor().getPosition().element))
 440                 this._moveCaretToTextElement(textElementToLand, params.caretTo); // as method on element?
 441             if(!(textElementToLand.sameNode(currentTextElement)))
 442                 this.publisher('currentTextElementSet', textElementToLand);
 443         } else {
 444             document.getSelection().removeAllRanges();
 445         }
 446
 447         if(!(currentNodeElement && currentNodeElement.sameNode(nodeElementToLand))) {
 448             _markAsCurrent(nodeElementToLand);
 449
 450             this.publisher('currentNodeElementSet', nodeElementToLand);
 451         }
 452     },
 453
 454     _moveCaretToTextElement: function(element, where) {
 455         var range = document.createRange(),
 456             node = element.dom().contents()[0];
 457
 458         if(typeof where !== 'number') {
 459             range.selectNodeContents(node);
 460         } else {
 461             range.setStart(node, where);
 462         }
 463
 464         var collapseArg = true;
 465         if(where === 'end')
 466             collapseArg = false;
 467         range.collapse(collapseArg);
 468
 469         var selection = document.getSelection();
 470
 471         selection.removeAllRanges();
 472         selection.addRange(range);
 473         this.wrapper.focus(); // FF requires this for caret to be put where range colllapses, Chrome doesn't.
 474     },
 475
 476     setCursorPosition: function(position) {
 477         if(position.element)
 478             this._moveCaretToTextElement(position.element, position.offset);
 479     },
 480
 481     toXML: function() {
 482         var parent = $('<div>'),
 483             parts = this.doc().toXML(0);
 484         parent.append(parts);
 485         return parent.html();
 486     }
 487 });
 488
 489 $.extend(Canvas.prototype.list, {
 490     create: function(params) {
 491         if(!(params.element1.parent().sameNode(params.element2.parent())))
 492             return false;
 493
 494         var parent = params.element1.parent();
 495
 496         if(parent.childIndex(params.element1) > parent.childIndex(params.element2)) {
 497             var tmp = params.element1;
 498             params.element1 = params.element2;
 499             params.element2 = tmp;
 500         }
 501
 502         var elementsToWrap = [];
 503
 504         var place = 'before';
 505         var canvas = this;
 506         parent.children().some(function(element) {
 507             var _e = element;
 508             if(element.sameNode(params.element1))
 509                 place = 'inside';
 510             if(place === 'inside') {
 511                 if(element instanceof documentElement.DocumentTextElement) {
 512                     element = element.wrapWithNodeElement({tag: 'div', klass: 'list.item'});
 513                     if(element.children()[0].sameNode(params.element1))
 514                         params.element1 = element;
 515                 }
 516                 element.setWlxmlClass('item');
 517                 elementsToWrap.push(element);
 518             }
 519             if(_e.sameNode(params.element2))
 520                 return true;
 521         });
 522
 523         var listElement = documentElement.DocumentNodeElement.create({tag: 'div', klass: 'list-items' + (params.type === 'enum' ? '-enum' : '')});
 524
 525         var toret;
 526         if(parent.is('list')) {
 527             listElement.wrapWithNodeElement({tag: 'div', klass: 'item'});
 528             toret = listElement.parent();
 529         } else {
 530             toret = listElement;
 531         }
 532
 533         params.element1.before(toret);
 534
 535         elementsToWrap.forEach(function(element) {
 536             element.detach();
 537             listElement.append(element);
 538         });
 539     },
 540     extractItems: function(params) {
 541         params = _.extend({merge: true}, params);
 542         var list = params.element1.parent();
 543         if(!list.is('list') || !(list.sameNode(params.element2.parent())))
 544             return false;
 545
 546         var idx1 = list.childIndex(params.element1),
 547             idx2 = list.childIndex(params.element2),
 548             precedingItems = [],
 549             extractedItems = [],
 550             succeedingItems = [],
 551             items = list.children(),
 552             listIsNested = list.parent().getWlxmlClass() === 'item',
 553             i;
 554
 555         if(idx1 > idx2) {
 556             var tmp = idx1; idx1 = idx2; idx2 = tmp;
 557         }
 558
 559         items.forEach(function(item, idx) {
 560             if(idx < idx1)
 561                 precedingItems.push(item);
 562             else if(idx >= idx1 && idx <= idx2) {
 563                 extractedItems.push(item);
 564             }
 565             else {
 566                 succeedingItems.push(item);
 567             }
 568         });
 569
 570         var reference = listIsNested ? list.parent() : list;
 571         if(succeedingItems.length === 0) {
 572             var reference_orig = reference;
 573             extractedItems.forEach(function(item) {
 574                 reference.after(item);
 575                 reference = item;
 576                 if(!listIsNested)
 577                     item.setWlxmlClass(null);
 578             });
 579             if(precedingItems.length === 0)
 580                 reference_orig.detach();
 581         } else if(precedingItems.length === 0) {
 582             extractedItems.forEach(function(item) {
 583                 reference.before(item);
 584                 if(!listIsNested)
 585                     item.setWlxmlClass(null);
 586             });
 587         } else {
 588             extractedItems.forEach(function(item) {
 589                 reference.after(item);
 590                 if(!listIsNested)
 591                     item.setWlxmlClass(null);
 592                 reference = item;
 593             });
 594             var secondList = documentElement.DocumentNodeElement.create({tag: 'div', klass:'list-items'}, this),
 595                 toAdd = secondList;
 596
 597             if(listIsNested) {
 598                 toAdd = secondList.wrapWithNodeElement({tag: 'div', klass:'item'});
 599             }
 600             succeedingItems.forEach(function(item) {
 601                 secondList.append(item);
 602             });
 603
 604             reference.after(toAdd);
 605         }
 606         if(!params.merge && listIsNested) {
 607             return this.extractItems({element1: extractedItems[0], element2: extractedItems[extractedItems.length-1]});
 608         }
 609         return true;
 610     },
 611     areItemsOfTheSameList: function(params) {
 612         var e1 = params.element1,
 613             e2 = params.element2;
 614         return e1.parent().sameNode(e2.parent())
 615             && e1.parent().is('list');
 616     }
 617 });
 618
 619
 620 var Cursor = function(canvas) {
 621     this.canvas = canvas;
 622 };
 623
 624 $.extend(Cursor.prototype, {
 625     isSelecting: function() {
 626         var selection = window.getSelection();
 627         return !selection.isCollapsed;
 628     },
 629     isSelectingWithinElement: function() {
 630         return this.isSelecting() && this.getSelectionStart().element.sameNode(this.getSelectionEnd().element);
 631     },
 632     isSelectingSiblings: function() {
 633         return this.isSelecting() && this.getSelectionStart().element.parent().sameNode(this.getSelectionEnd().element.parent());
 634     },
 635     getPosition: function() {
 636         return this.getSelectionAnchor();
 637     },
 638     getSelectionStart: function() {
 639         return this.getSelectionBoundry('start');
 640     },
 641     getSelectionEnd: function() {
 642         return this.getSelectionBoundry('end');
 643     },
 644     getSelectionAnchor: function() {
 645         return this.getSelectionBoundry('anchor');
 646     },
 647     getSelectionFocus: function() {
 648         return this.getSelectionBoundry('focus');
 649     },
 650     getSelectionBoundry: function(which) {
 651         var selection = window.getSelection(),
 652             anchorElement = this.canvas.getDocumentElement(selection.anchorNode),
 653             focusElement = this.canvas.getDocumentElement(selection.focusNode);
 654
 655         var getOffset = function(where) {
 656             var toret, node;
 657             if(where === 'anchor') {
 658                 node = selection.anchorNode;
 659                 toret = selection.anchorOffset;
 660             } else {
 661                 node = selection.focusNode;
 662                 toret = selection.focusOffset;
 663             }
 664
 665             if(toret === 1 && node.data.charAt(0) === utils.unicode.ZWS)
 666                 toret = 0;
 667             else if((toret === node.data.length - 1) && (node.data.charAt(node.data.length - 1) === utils.unicode.ZWS))
 668                 toret++;
 669             return toret;
 670         }
 671
 672         if((!anchorElement) || (anchorElement instanceof documentElement.DocumentNodeElement) || (!focusElement) || focusElement instanceof documentElement.DocumentNodeElement)
 673             return {};
 674
 675         if(which === 'anchor') {
 676             return {
 677                 element: anchorElement,
 678                 offset: getOffset('anchor'),
 679                 offsetAtBeginning: getOffset('anchor') === 0,
 680                 offsetAtEnd: selection.anchorNode.data.length === getOffset('anchor')
 681             };
 682         }
 683         if(which === 'focus') {
 684             return {
 685                 element: focusElement,
 686                 offset: getOffset('focus'),
 687                 offsetAtBeginning: getOffset('focus') === 0,
 688                 offsetAtEnd: selection.focusNode.data.length === getOffset('focus')
 689             };
 690         }
 691
 692         var element,
 693             offset;
 694
 695         if(anchorElement.parent().sameNode(focusElement.parent())) {
 696             var parent = anchorElement.parent(),
 697                 anchorFirst = parent.childIndex(anchorElement) < parent.childIndex(focusElement);
 698             if(anchorFirst) {
 699                 if(which === 'start') {
 700                     element = anchorElement;
 701                     offset = getOffset('anchor')
 702                 }
 703                 else if(which === 'end') {
 704                     element = focusElement,
 705                     offset = getOffset('focus')
 706                 }
 707             } else {
 708                 if(which === 'start') {
 709                     element = focusElement,
 710                     offset = getOffset('focus')
 711                 }
 712                 else if(which === 'end') {
 713                     element = anchorElement;
 714                     offset = getOffset('anchor')
 715                 }
 716             }
 717         } else {
 718             // TODO: Handle order via https://developer.mozilla.org/en-US/docs/Web/API/Node.compareDocumentPosition
 719             if(which === 'start') {
 720                 element = anchorElement;
 721                 offset = getOffset('anchor')
 722             } else {
 723                 element = focusElement;
 724                 offset = getOffset('focus')
 725             }
 726         }
 727
 728         var nodeLen = (element.sameNode(focusElement) ? selection.focusNode : selection.anchorNode).length;
 729         return {
 730             element: element,
 731             offset: offset,
 732             offsetAtBeginning: offset === 0,
 733             offsetAtEnd: nodeLen === offset
 734         }
 735     }
 736 })
 737
 738 return {
 739     fromXML: function(xml, publisher) {
 740         return new Canvas(xml, publisher);
 741     }
 742 };
 743
 744 });