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editor: core plugin - edumed - first take on gaps exercise
[fnpeditor.git] / src / editor / modules / documentCanvas / canvas / canvas.js
diff --git a/src/editor/modules/documentCanvas/canvas/canvas.js b/src/editor/modules/documentCanvas/canvas/canvas.js
index f8e9927..d3376e3 100644 (file)
--- a/src/editor/modules/documentCanvas/canvas/canvas.js
+++ b/src/editor/modules/documentCanvas/canvas/canvas.js
@@ -2,15 +2,25 @@ define([
 'libs/jquery',
 'libs/underscore',
 'libs/backbone',
 'libs/jquery',
 'libs/underscore',
 'libs/backbone',
+'fnpjs/logging/logging',
+'views/menu/menu',
 'modules/documentCanvas/canvas/documentElement',
 'modules/documentCanvas/canvas/keyboard',
 'modules/documentCanvas/canvas/utils',
 'modules/documentCanvas/canvas/documentElement',
 'modules/documentCanvas/canvas/keyboard',
 'modules/documentCanvas/canvas/utils',
-'modules/documentCanvas/canvas/wlxmlListener'
-], function($, _, Backbone, documentElement, keyboard, utils, wlxmlListener) {
-    
+'modules/documentCanvas/canvas/wlxmlListener',
+'modules/documentCanvas/canvas/elementsRegister',
+'modules/documentCanvas/canvas/genericElement',
+'modules/documentCanvas/canvas/nullElement',
+'modules/documentCanvas/canvas/gutter',
+'modules/documentCanvas/canvas/selection',
+'modules/documentCanvas/canvas/keyEvent',
+'libs/text!./canvas.html'
+], function($, _, Backbone, logging, Menu, documentElement, keyboard, utils, wlxmlListener, ElementsRegister, genericElement, nullElement, gutter, selection, keyEvent, canvasTemplate) {
+
 'use strict';
 'use strict';
-/* global document:false, window:false, Node:false */
+/* global document:false, window:false, Node:false, gettext */
 
 
+var logger = logging.getLogger('canvas');
 
 var TextHandler = function(canvas) {this.canvas = canvas; this.buffer = null;};
 $.extend(TextHandler.prototype, {
 
 var TextHandler = function(canvas) {this.canvas = canvas; this.buffer = null;};
 $.extend(TextHandler.prototype, {
@@ -40,24 +50,56 @@ $.extend(TextHandler.prototype, {
     },
     setText: function(text, node) {
         //this.canvas.wlxmlDocument.transform('setText', {node:node, text: text});
     },
     setText: function(text, node) {
         //this.canvas.wlxmlDocument.transform('setText', {node:node, text: text});
-        node.setText(text);
+        node.document.transaction(function() {
+            node.setText(text);
+        }, {
+            metadata:{
+                description: gettext('Changing text')
+            }
+        });
 
     }
 
 });
 
 
 
     }
 
 });
 
 
-var Canvas = function(wlxmlDocument, publisher) {
+var Canvas = function(wlxmlDocument, elements, metadata, sandbox) {
+    this.metadata = metadata || {};
+    this.sandbox = sandbox;
+    this.elementsRegister = new ElementsRegister(documentElement.DocumentNodeElement, nullElement);
+
+    elements = [
+        {tag: 'section', klass: null, prototype: genericElement},
+        {tag: 'div', klass: null, prototype: genericElement},
+        {tag: 'header', klass: null, prototype: genericElement},
+        {tag: 'span', klass: null, prototype: genericElement},
+        {tag: 'aside', klass: null, prototype: genericElement}
+    ].concat(elements || []);
+
+    (elements).forEach(function(elementDesc) {
+        this.elementsRegister.register(elementDesc);
+    }.bind(this));
     this.eventBus = _.extend({}, Backbone.Events);
     this.eventBus = _.extend({}, Backbone.Events);
-    this.wrapper = $('<div>').addClass('canvas-wrapper').attr('contenteditable', true);
+    
+    this.dom = $(canvasTemplate);
+    this.rootWrapper = this.dom.find('.root-wrapper');
+    
+
+    this.gutter = gutter.create();
+    this.gutterView = new gutter.GutterView(this.gutter);
+    this.dom.find('.view-row').append(this.gutterView.dom);
+    
     this.wlxmlListener = wlxmlListener.create(this);
     this.loadWlxmlDocument(wlxmlDocument);
     this.setupEventHandling();
     this.wlxmlListener = wlxmlListener.create(this);
     this.loadWlxmlDocument(wlxmlDocument);
     this.setupEventHandling();
-    this.publisher = publisher ? publisher : function() {};
     this.textHandler = new TextHandler(this);
 };
 
     this.textHandler = new TextHandler(this);
 };
 
-$.extend(Canvas.prototype, {
+$.extend(Canvas.prototype, Backbone.Events, {
+
+    getElementOffset: function(element) {
+        return element.dom.offset().top - this.dom.offset().top;
+    },
 
     loadWlxmlDocument: function(wlxmlDocument) {
         if(!wlxmlDocument) {
 
     loadWlxmlDocument: function(wlxmlDocument) {
         if(!wlxmlDocument) {
@@ -69,32 +111,108 @@ $.extend(Canvas.prototype, {
         this.reloadRoot();
     },
 
         this.reloadRoot();
     },
 
+    createElement: function(wlxmlNode) {
+        var Factory;
+        if(wlxmlNode.nodeType === Node.TEXT_NODE) {
+            Factory = documentElement.DocumentTextElement;
+        } else {
+            Factory = this.elementsRegister.getElement({tag: wlxmlNode.getTagName(), klass: wlxmlNode.getClass()});
+        }
+        return new Factory(wlxmlNode, this);
+    },
+
+    getDocumentElement: function(htmlElement) {
+        /* globals HTMLElement, Text */
+        if(!htmlElement || !(htmlElement instanceof HTMLElement || htmlElement instanceof Text)) {
+            return null;
+        }
+        var $element = $(htmlElement);
+        if(htmlElement.nodeType === Node.ELEMENT_NODE && $element.attr('document-node-element') !== undefined) {
+            return $element.data('canvas-element');
+        }
+
+        if(htmlElement.nodeType === Node.TEXT_NODE && $element.parent().attr('document-text-element') !== undefined) {
+            $element = $element.parent();
+        }
+
+        if($element.attr('document-text-element') !== undefined || (htmlElement.nodeType === Node.TEXT_NODE && $element.parent().attr('document-text-element') !== undefined)) {
+            //return DocumentTextElement.fromHTMLElement(htmlElement, canvas);
+            return $element.data('canvas-element');
+        }
+    },
+
     reloadRoot: function() {
     reloadRoot: function() {
-        var canvasDOM = this.generateCanvasDOM(this.wlxmlDocument.root);
-        //var canvasDOM = this.wlxmlDocument.root.getData('canvasElement') ? this.wlxmlDocument.root.getData('canvasElement').dom() : this.generateCanvasDOM(this.wlxmlDocument.root);
+        if(this.rootElement) {
+            this.rootElement.detach();
+        }
+        this.rootElement = this.createElement(this.wlxmlDocument.root);
+        this.rootWrapper.append(this.rootElement.dom);
+    },
 
 
-        this.wrapper.empty();
-        this.wrapper.append(canvasDOM);
-        this.d = this.wrapper.children(0);
+    triggerKeyEvent: function(keyEvent, selection) {
+        selection = selection || this.getSelection();
+        if(selection && (selection.type === 'caret' || selection.type === 'textSelection') && selection.toDocumentFragment().isValid()) {
+            keyboard.handleKeyEvent(keyEvent, selection);
+        }
     },
 
     },
 
-    generateCanvasDOM: function(wlxmlNode) {
-        var element = documentElement.DocumentNodeElement.create(wlxmlNode, this);
-        return element.dom();
+    createAction: function(fqName, config) {
+        return this.sandbox.createAction(fqName, config);
     },
 
     setupEventHandling: function() {
         var canvas = this;
     },
 
     setupEventHandling: function() {
         var canvas = this;
-        this.wrapper.on('keyup keydown keypress', function(e) {
-            keyboard.handleKey(e, this);
-        }.bind(this));
 
 
-        this.wrapper.on('click', '[document-node-element], [document-text-element]', function(e) {
+        /* globals document */
+        $(document.body).on('keydown', function(e) {
+            canvas.triggerKeyEvent(keyEvent.fromNativeEvent(e));
+        });
+
+        this.rootWrapper.on('mouseup', function() {
+            canvas.triggerSelectionChanged();
+        });
+
+        var mouseDown;
+        this.rootWrapper.on('mousedown', '[document-node-element], [document-text-element]', function(e) {
+            mouseDown = e.target;
+            canvas.rootWrapper.find('[contenteditable]').attr('contenteditable', null);
+        });
+
+        this.rootWrapper.on('click', '[document-node-element], [document-text-element]', function(e) {
+            var position, element;
             e.stopPropagation();
             e.stopPropagation();
-            canvas.setCurrentElement(canvas.getDocumentElement(e.currentTarget), {caretTo: false});
+            if(e.originalEvent.detail === 3) {
+                e.preventDefault();
+                canvas._moveCaretToTextElement(canvas.getDocumentElement(e.currentTarget), 'whole');
+            } else {
+                if(mouseDown === e.target) {
+                    element = canvas.getDocumentElement(e.target);
+                    if(element && element.wlxmlNode.nodeType === Node.ELEMENT_NODE) {
+                        if(element.getVerticallyFirstTextElement && !element.getVerticallyFirstTextElement({considerChildren: false})) {
+                            canvas.setCurrentElement(element);
+                            return;
+                        }
+                    }
+                    if(window.getSelection().isCollapsed) {
+                        position = utils.caretPositionFromPoint(e.clientX, e.clientY);
+                        canvas.setCurrentElement(canvas.getDocumentElement(position.textNode), {caretTo: position.offset});
+                    }
+                }
+            }
         });
 
         });
 
-        this.wrapper.on('paste', function(e) {
+        this.rootWrapper.on('contextmenu', function(e) {
+            var el = canvas.getDocumentElement(e.target);
+            
+            if(!el) {
+                return;
+            }
+
+            e.preventDefault();
+            this.showContextMenu(el, {x: e.clientX, y: e.clientY});
+        }.bind(this));
+
+        this.rootWrapper.on('paste', function(e) {
             e.preventDefault();
 
             var clipboardData = e.originalEvent.clipboardData;
             e.preventDefault();
 
             var clipboardData = e.originalEvent.clipboardData;
@@ -121,7 +239,7 @@ $.extend(Canvas.prototype, {
         /* globals MutationObserver */
         var observer = new MutationObserver(function(mutations) {
             mutations.forEach(function(mutation) {
         /* globals MutationObserver */
         var observer = new MutationObserver(function(mutations) {
             mutations.forEach(function(mutation) {
-                if(documentElement.DocumentTextElement.isContentContainer(mutation.target)) {
+                if(canvas.dom[0].contains(mutation.target) && documentElement.DocumentTextElement.isContentContainer(mutation.target)) {
                     observer.disconnect();
                     if(mutation.target.data === '') {
                         mutation.target.data = utils.unicode.ZWS;
                     observer.disconnect();
                     if(mutation.target.data === '') {
                         mutation.target.data = utils.unicode.ZWS;
@@ -130,37 +248,29 @@ $.extend(Canvas.prototype, {
                         mutation.target.data = mutation.target.data.replace(utils.unicode.ZWS, '');
                         canvas._moveCaretToTextElement(canvas.getDocumentElement(mutation.target), 'end');
                     }
                         mutation.target.data = mutation.target.data.replace(utils.unicode.ZWS, '');
                         canvas._moveCaretToTextElement(canvas.getDocumentElement(mutation.target), 'end');
                     }
-                    observer.observe(canvas.wrapper[0], config);
-                    canvas.publisher('contentChanged');
+                    observer.observe(canvas.dom[0], config);
 
                     var textElement = canvas.getDocumentElement(mutation.target),
                         toSet = mutation.target.data !== utils.unicode.ZWS ? mutation.target.data : '';
 
                     //textElement.data('wlxmlNode').setText(toSet);
                     //textElement.data('wlxmlNode').document.transform('setText', {node: textElement.data('wlxmlNode'), text: toSet});
 
                     var textElement = canvas.getDocumentElement(mutation.target),
                         toSet = mutation.target.data !== utils.unicode.ZWS ? mutation.target.data : '';
 
                     //textElement.data('wlxmlNode').setText(toSet);
                     //textElement.data('wlxmlNode').document.transform('setText', {node: textElement.data('wlxmlNode'), text: toSet});
-                    if(textElement.data('wlxmlNode').getText() !== toSet) {
-                        canvas.textHandler.handle(textElement.data('wlxmlNode'), toSet);
+                    if(textElement.wlxmlNode.getText() !== toSet) {
+                        canvas.textHandler.handle(textElement.wlxmlNode, toSet);
                     }
                 }
             });
         });
         var config = { attributes: false, childList: false, characterData: true, subtree: true, characterDataOldValue: true};
                     }
                 }
             });
         });
         var config = { attributes: false, childList: false, characterData: true, subtree: true, characterDataOldValue: true};
-        observer.observe(this.wrapper[0], config);
+        observer.observe(this.rootWrapper[0], config);
 
 
 
 
-        this.wrapper.on('mouseover', '[document-node-element], [document-text-element]', function(e) {
-            var el = canvas.getDocumentElement(e.currentTarget);
-            if(!el) {
-                return;
-            }
-            e.stopPropagation();
-            if(el instanceof documentElement.DocumentTextElement) {
-                el = el.parent();
-            }
-            el.toggleLabel(true);
-        });
-        this.wrapper.on('mouseout', '[document-node-element], [document-text-element]', function(e) {
-            var el = canvas.getDocumentElement(e.currentTarget);
+        var hoverHandler = function(e) {
+            var el = canvas.getDocumentElement(e.currentTarget),
+                expose = {
+                    mouseover: true,
+                    mouseout: false
+                };
             if(!el) {
                 return;
             }
             if(!el) {
                 return;
             }
@@ -168,60 +278,120 @@ $.extend(Canvas.prototype, {
             if(el instanceof documentElement.DocumentTextElement) {
                 el = el.parent();
             }
             if(el instanceof documentElement.DocumentTextElement) {
                 el = el.parent();
             }
-            el.toggleLabel(false);
-        });
+            el.updateState({exposed:expose[e.type]});
+        };
+
+        this.rootWrapper.on('mouseover', '[document-node-element], [document-text-element]', hoverHandler);
+        this.rootWrapper.on('mouseout', '[document-node-element], [document-text-element]', hoverHandler);
 
         this.eventBus.on('elementToggled', function(toggle, element) {
             if(!toggle) {
 
         this.eventBus.on('elementToggled', function(toggle, element) {
             if(!toggle) {
-                canvas.setCurrentElement(element.getPreviousTextElement());
+                canvas.setCurrentElement(canvas.getPreviousTextElement(element));
             }
         });
     },
 
     view: function() {
             }
         });
     },
 
     view: function() {
-        return this.wrapper;
+        return this.dom;
     },
 
     doc: function() {
     },
 
     doc: function() {
-        if(this.d === null) {
-            return null;
-        }
-        return documentElement.DocumentNodeElement.fromHTMLElement(this.d.get(0), this); //{wlxmlTag: this.d.prop('tagName')};
+        return this.rootElement;
     },
 
     toggleElementHighlight: function(node, toggle) {
     },
 
     toggleElementHighlight: function(node, toggle) {
-        var element = utils.findCanvasElement(node);
-        element.toggleHighlight(toggle);
-    },
-
-    createNodeElement: function(params) {
-        return documentElement.DocumentNodeElement.create(params, this);
+        var element = utils.getElementForNode(node);
+        element.updateState({exposed: toggle});
     },
 
     },
 
-    getDocumentElement: function(from) {
-        /* globals HTMLElement, Text */
-        if(from instanceof HTMLElement || from instanceof Text) {
-           return documentElement.DocumentElement.fromHTMLElement(from, this);
-        }
-    },
     getCursor: function() {
         return new Cursor(this);
     },
 
     
     getCurrentNodeElement: function() {
     getCursor: function() {
         return new Cursor(this);
     },
 
     
     getCurrentNodeElement: function() {
-        return this.getDocumentElement(this.wrapper.find('.current-node-element').parent()[0]);
+        return this.currentNodeElement;
     },
 
     getCurrentTextElement: function() {
     },
 
     getCurrentTextElement: function() {
-        return this.getDocumentElement(this.wrapper.find('.current-text-element')[0]);
+        var htmlElement = this.rootWrapper.find('.current-text-element')[0];
+        if(htmlElement) {
+            return this.getDocumentElement(htmlElement);
+        }
+    },
+
+    getPreviousTextElement: function(relativeToElement, includeInvisible) {
+        return this.getNearestTextElement('above', relativeToElement, includeInvisible);
+    },
+
+    getNextTextElement: function(relativeToElement, includeInvisible) {
+        return this.getNearestTextElement('below', relativeToElement, includeInvisible);
+    },
+
+    getNearestTextElement: function(direction, relativeToElement, includeInvisible) {
+        includeInvisible = includeInvisible !== undefined ? includeInvisible : false;
+        var selector = '[document-text-element]' + (includeInvisible ? '' : ':visible');
+        return this.getDocumentElement(utils.nearestInDocumentOrder(selector, direction, relativeToElement.dom[0]));
+    },
+
+    contains: function(element) {
+        return element && element.dom && element.dom.parents().index(this.rootWrapper) !== -1;
+    },
+
+    triggerSelectionChanged: function() {
+        var s = this.getSelection(),
+            f;
+        if(!s) {
+            return;
+        }
+        this.trigger('selectionChanged', s);
+        f = s.toDocumentFragment();
+
+        if(f && f instanceof f.RangeFragment) {
+            if(this.currentNodeElement) {
+                this.currentNodeElement.updateState({active: false});
+                this.currentNodeElement = null;
+            }
+        }
     },
 
     },
 
+    getSelection: function() {
+        return selection.fromNativeSelection(this);
+    },
+
+    select: function(fragment) {
+        if(fragment instanceof this.wlxmlDocument.RangeFragment) {
+            this.setCurrentElement(fragment.endNode, {caretTo: fragment.endOffset});
+        } else if(fragment instanceof this.wlxmlDocument.NodeFragment) {
+            var params = {
+                caretTo: fragment instanceof this.wlxmlDocument.CaretFragment ? fragment.offset : 'start'
+            };
+            this.setCurrentElement(fragment.node, params);
+        } else {
+            logger.debug('Fragment not supported');
+        }
+    },
 
 
+    setSelection: function(selection) {
+        this.select(this, selection.toDocumentFragment());
+    },
 
 
+    createSelection: function(params) {
+        return selection.fromParams(this, params);
+    },
     setCurrentElement: function(element, params) {
     setCurrentElement: function(element, params) {
+        if(!element) {
+            logger.debug('Invalid element passed to setCurrentElement: ' + element);
+            return;
+        }
+
         if(!(element instanceof documentElement.DocumentElement)) {
         if(!(element instanceof documentElement.DocumentElement)) {
-            element = utils.findCanvasElement(element);
+            element = utils.getElementForNode(element);
+        }
+
+        if(!element || !this.contains(element)) {
+            logger.warning('Cannot set current element: element doesn\'t exist on canvas');
+            return;
         }
 
         params = _.extend({caretTo: 'end'}, params);
         }
 
         params = _.extend({caretTo: 'end'}, params);
@@ -230,22 +400,18 @@ $.extend(Canvas.prototype, {
             if(byBrowser && byBrowser.parent().sameNode(nodeToLand)) {
                 return byBrowser;
             }
             if(byBrowser && byBrowser.parent().sameNode(nodeToLand)) {
                 return byBrowser;
             }
-            var children = e.children();
-            for(var i = 0; i < children.length; i++) {
-                if(children[i] instanceof documentElement.DocumentTextElement) {
-                    return children[i];
-                }
-            }
-            return null;
+            return _.isFunction(e.getVerticallyFirstTextElement) ? e.getVerticallyFirstTextElement({considerChildren: false}) : null;
         }.bind(this);
         var _markAsCurrent = function(element) {
             if(element instanceof documentElement.DocumentTextElement) {
         }.bind(this);
         var _markAsCurrent = function(element) {
             if(element instanceof documentElement.DocumentTextElement) {
-                this.wrapper.find('.current-text-element').removeClass('current-text-element');
-                element.dom().addClass('current-text-element');
+                this.rootWrapper.find('.current-text-element').removeClass('current-text-element');
+                element.dom.addClass('current-text-element');
             } else {
             } else {
-                this.wrapper.find('.current-node-element').removeClass('current-node-element');
-                element._container().addClass('current-node-element');
-                this.publisher('currentElementChanged', element);
+                if(this.currentNodeElement) {
+                    this.currentNodeElement.updateState({active: false});
+                }
+                element.updateState({active: true});
+                this.currentNodeElement = element;
             }
         }.bind(this);
 
             }
         }.bind(this);
 
@@ -257,64 +423,90 @@ $.extend(Canvas.prototype, {
             currentNodeElement = this.getCurrentNodeElement();
 
         if(currentTextElement && !(currentTextElement.sameNode(textElementToLand))) {
             currentNodeElement = this.getCurrentNodeElement();
 
         if(currentTextElement && !(currentTextElement.sameNode(textElementToLand))) {
-            this.wrapper.find('.current-text-element').removeClass('current-text-element');
+            this.rootWrapper.find('.current-text-element').removeClass('current-text-element');
         }
 
         if(textElementToLand) {
             _markAsCurrent(textElementToLand);
         }
 
         if(textElementToLand) {
             _markAsCurrent(textElementToLand);
-            if(params.caretTo || !textElementToLand.sameNode(this.getCursor().getPosition().element)) {
+            if((params.caretTo || params.caretTo === 0) || !textElementToLand.sameNode(this.getCursor().getPosition().element)) {
                 this._moveCaretToTextElement(textElementToLand, params.caretTo); // as method on element?
             }
                 this._moveCaretToTextElement(textElementToLand, params.caretTo); // as method on element?
             }
-            if(!(textElementToLand.sameNode(currentTextElement))) {
-                this.publisher('currentTextElementSet', textElementToLand.data('wlxmlNode'));
-            }
         } else {
             document.getSelection().removeAllRanges();
         }
 
         if(!(currentNodeElement && currentNodeElement.sameNode(nodeElementToLand))) {
             _markAsCurrent(nodeElementToLand);
         } else {
             document.getSelection().removeAllRanges();
         }
 
         if(!(currentNodeElement && currentNodeElement.sameNode(nodeElementToLand))) {
             _markAsCurrent(nodeElementToLand);
-
-            this.publisher('currentNodeElementSet', nodeElementToLand.data('wlxmlNode'));
         }
         }
+        this.triggerSelectionChanged();
     },
 
     _moveCaretToTextElement: function(element, where) {
         var range = document.createRange(),
     },
 
     _moveCaretToTextElement: function(element, where) {
         var range = document.createRange(),
-            node = element.dom().contents()[0];
+            node = element.dom.contents()[0];
 
         if(typeof where !== 'number') {
             range.selectNodeContents(node);
         } else {
 
         if(typeof where !== 'number') {
             range.selectNodeContents(node);
         } else {
-            range.setStart(node, where);
+            range.setStart(node, Math.min(node.data.length, where));
         }
         
         }
         
-        var collapseArg = true;
-        if(where === 'end') {
-            collapseArg = false;
+        if(where !== 'whole') {
+            var collapseArg = true;
+            if(where === 'end') {
+                collapseArg = false;
+            }
+            range.collapse(collapseArg);
         }
         }
-        range.collapse(collapseArg);
-        
         var selection = document.getSelection();
 
         var selection = document.getSelection();
 
+        $(node).parent().attr('contenteditable', true);
         selection.removeAllRanges();
         selection.addRange(range);
         selection.removeAllRanges();
         selection.addRange(range);
-        this.wrapper.focus(); // FF requires this for caret to be put where range colllapses, Chrome doesn't.
+        $(node).parent().focus(); // FF requires this for caret to be put where range colllapses, Chrome doesn't.
     },
 
     setCursorPosition: function(position) {
         if(position.element) {
             this._moveCaretToTextElement(position.element, position.offset);
         }
     },
 
     setCursorPosition: function(position) {
         if(position.element) {
             this._moveCaretToTextElement(position.element, position.offset);
         }
+    },
+    showContextMenu: function(element, coors) {
+        var menu = new Menu();
+
+        while(element) {
+            (element.contextMenuActions || []).forEach(menu.addAction.bind(menu));
+            element = element.parent();
+        }
+        if(menu.actions.length) {
+            menu.updateContextParam('fragment', this.getSelection().toDocumentFragment());
+            this.sandbox.showContextMenu(menu, {x: coors.x, y: coors.y});
+        }
     }
 });
 
 
 var Cursor = function(canvas) {
     this.canvas = canvas;
     }
 });
 
 
 var Cursor = function(canvas) {
     this.canvas = canvas;
+    this.selection = window.getSelection();
 };
 
 $.extend(Cursor.prototype, {
 };
 
 $.extend(Cursor.prototype, {
+    sameAs: function(other) {
+        var same = true;
+        if(!other) {
+            return false;
+        }
+
+        ['focusNode', 'focusOffset', 'anchorNode', 'anchorOffset'].some(function(prop) {
+            same = same && this.selection[prop] === other.selection[prop];
+            if(!same) {
+                return true; // break
+            }
+        }.bind(this));
+
+        return same;
+    },
     isSelecting: function() {
         var selection = window.getSelection();
         return !selection.isCollapsed;
     isSelecting: function() {
         var selection = window.getSelection();
         return !selection.isCollapsed;
@@ -401,7 +593,7 @@ $.extend(Cursor.prototype, {
             if(selection.anchorNode === selection.focusNode) {
                 anchorFirst = selection.anchorOffset <= selection.focusOffset;
             } else {
             if(selection.anchorNode === selection.focusNode) {
                 anchorFirst = selection.anchorOffset <= selection.focusOffset;
             } else {
-                anchorFirst = parent.childIndex(anchorElement) < parent.childIndex(focusElement);
+                anchorFirst = (parent.getFirst(anchorElement, focusElement) === anchorElement);
             }
             placeData = getPlaceData(anchorFirst);
         } else {
             }
             placeData = getPlaceData(anchorFirst);
         } else {
@@ -421,8 +613,8 @@ $.extend(Cursor.prototype, {
 });
 
 return {
 });
 
 return {
-    fromXMLDocument: function(wlxmlDocument, publisher) {
-        return new Canvas(wlxmlDocument, publisher);
+    fromXMLDocument: function(wlxmlDocument, elements, metadata, sandbox) {
+        return new Canvas(wlxmlDocument, elements, metadata, sandbox);
     }
 };
 
     }
 };