third batch
[fnpeditor.git] / src / editor / modules / documentCanvas / canvas / canvas.js
index cf63c47..0ec22a1 100644 (file)
@@ -2,23 +2,84 @@ define([
 'libs/jquery',
 'libs/underscore',
 'libs/backbone',
+'fnpjs/logging/logging',
 'modules/documentCanvas/canvas/documentElement',
 'modules/documentCanvas/canvas/keyboard',
 'modules/documentCanvas/canvas/utils',
-'modules/documentCanvas/canvas/wlxmlListener'
-], function($, _, Backbone, documentElement, keyboard, utils, wlxmlListener) {
+'modules/documentCanvas/canvas/wlxmlListener',
+'modules/documentCanvas/canvas/elementsRegister',
+'modules/documentCanvas/canvas/genericElement',
+], function($, _, Backbone, logging, documentElement, keyboard, utils, wlxmlListener, ElementsRegister, genericElement) {
     
 'use strict';
+/* 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, {
+    handle: function(node, text) {
+        this.setText(text, node);
+        // return;
+        // if(!this.node) {
+        //     this.node = node;
+        // }
+        // if(this.node.sameNode(node)) {
+        //     this._ping(text);
+        // } else {
+        //     this.flush();
+        //     this.node = node;
+        //     this._ping(text);
+        // }
+    },
+    _ping: _.throttle(function(text) {
+        this.buffer = text;
+        this.flush();
+    }, 1000),
+    flush: function() {
+        if(this.buffer !== null) {
+            this.setText(this.buffer, this.node);
+            this.buffer = null;
+        }
+    },
+    setText: function(text, node) {
+        //this.canvas.wlxmlDocument.transform('setText', {node:node, text: text});
+        node.document.transaction(function() {
+            node.setText(text);
+        }, {
+            metadata:{
+                description: gettext('Changing text')
+            }
+        });
+
+    }
+
+});
 
-var Canvas = function(wlxmlDocument, publisher) {
+
+var Canvas = function(wlxmlDocument, elements) {
+    this.elementsRegister = new ElementsRegister(documentElement.DocumentNodeElement, genericElement);
+
+    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.wrapper = $('<div>').addClass('canvas-wrapper').attr('contenteditable', true);
     this.wlxmlListener = wlxmlListener.create(this);
     this.loadWlxmlDocument(wlxmlDocument);
-    this.publisher = publisher ? publisher : function() {};
+    this.setupEventHandling();
+    this.textHandler = new TextHandler(this);
 };
 
-$.extend(Canvas.prototype, {
+$.extend(Canvas.prototype, Backbone.Events, {
 
     loadWlxmlDocument: function(wlxmlDocument) {
         if(!wlxmlDocument) {
@@ -28,72 +89,145 @@ $.extend(Canvas.prototype, {
         this.wlxmlListener.listenTo(wlxmlDocument);
         this.wlxmlDocument = wlxmlDocument;
         this.reloadRoot();
-        this.setupEventHandling();
     },
 
-    reloadRoot: function() {
-        var canvasDOM = this.generateCanvasDOM(this.wlxmlDocument.root);
-        this.wrapper.empty();
-        this.wrapper.append(canvasDOM);
-        this.d = this.wrapper.children(0);
+    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');
+        }
     },
 
-    generateCanvasDOM: function(wlxmlNode) {
-        var element = documentElement.DocumentNodeElement.create(wlxmlNode, this);
-        return element.dom();
+    reloadRoot: function() {
+        this.rootElement = this.createElement(this.wlxmlDocument.root);
+        this.wrapper.empty();
+        this.wrapper.append(this.rootElement.dom());
     },
 
     setupEventHandling: function() {
         var canvas = this;
+
         this.wrapper.on('keyup keydown keypress', function(e) {
-            keyboard.handleKey(e, this);
-        }.bind(this));
+            keyboard.handleKey(e, canvas);
+        });
+
+        this.wrapper.on('mouseup', function() {
+            canvas.triggerSelectionChanged();
+        });
+
+        var mouseDown;
+        this.wrapper.on('mousedown', '[document-node-element], [document-text-element]', function(e) {
+            mouseDown = e.target;
+        });
 
         this.wrapper.on('click', '[document-node-element], [document-text-element]', function(e) {
             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) {
+                    canvas.setCurrentElement(canvas.getDocumentElement(e.currentTarget), {caretTo: false});
+                }
+            }
         });
 
+        this.wrapper.on('paste', function(e) {
+            e.preventDefault();
+
+            var clipboardData = e.originalEvent.clipboardData;
+            if(!clipboardData || !clipboardData.getData) {
+                return; // TODO: alert
+            }
+
+            var text = clipboardData.getData('text/plain').replace(/\r?\n|\r/g, ' '),
+                cursor = canvas.getCursor(),
+                element = cursor.getPosition().element,
+                lhs, rhs;
+            
+            if(element && cursor.isWithinElement()) {
+                lhs = element.getText().substr(0, cursor.getSelectionStart().offset);
+                rhs = element.getText().substr(cursor.getSelectionEnd().offset);
+                element.setText(lhs+text+rhs);
+                canvas.setCurrentElement(element, {caretTo: lhs.length + text.length});
+            } else {
+                /* jshint noempty:false */
+                // TODO: alert
+            }
+        });
+
+        /* globals MutationObserver */
         var observer = new MutationObserver(function(mutations) {
             mutations.forEach(function(mutation) {
                 if(documentElement.DocumentTextElement.isContentContainer(mutation.target)) {
                     observer.disconnect();
-                    if(mutation.target.data === '')
+                    if(mutation.target.data === '') {
                         mutation.target.data = utils.unicode.ZWS;
+                    }
                     else if(mutation.oldValue === utils.unicode.ZWS) {
                         mutation.target.data = mutation.target.data.replace(utils.unicode.ZWS, '');
                         canvas._moveCaretToTextElement(canvas.getDocumentElement(mutation.target), 'end');
                     }
-                    observer.observe(canvas.d[0], config);
-                    canvas.publisher('contentChanged');
+                    observer.observe(canvas.wrapper[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').setText(toSet);
+                    //textElement.data('wlxmlNode').document.transform('setText', {node: textElement.data('wlxmlNode'), text: toSet});
+                    if(textElement.wlxmlNode.getText() !== toSet) {
+                        canvas.textHandler.handle(textElement.wlxmlNode, toSet);
+                    }
                 }
             });
         });
         var config = { attributes: false, childList: false, characterData: true, subtree: true, characterDataOldValue: true};
-        observer.observe(this.d[0], config);
+        observer.observe(this.wrapper[0], config);
 
 
         this.wrapper.on('mouseover', '[document-node-element], [document-text-element]', function(e) {
             var el = canvas.getDocumentElement(e.currentTarget);
-            if(!el)
+            if(!el) {
                 return;
+            }
             e.stopPropagation();
-            if(el instanceof documentElement.DocumentTextElement)
+            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);
-            if(!el)
+            if(!el) {
                 return;
+            }
             e.stopPropagation();
-            if(el instanceof documentElement.DocumentTextElement)
+            if(el instanceof documentElement.DocumentTextElement) {
                 el = el.parent();
+            }
             el.toggleLabel(false);
         });
 
@@ -109,9 +243,7 @@ $.extend(Canvas.prototype, {
     },
 
     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) {
@@ -119,46 +251,63 @@ $.extend(Canvas.prototype, {
         element.toggleHighlight(toggle);
     },
 
-    createNodeElement: function(params) {
-        return documentElement.DocumentNodeElement.create(params, this);
-    },
-
-    getDocumentElement: function(from) {
-        if(from instanceof HTMLElement || from instanceof Text) {
-           return documentElement.DocumentElement.fromHTMLElement(from, this);
-        }
-    },
     getCursor: function() {
         return new Cursor(this);
     },
 
-    list: {},
-
     
     getCurrentNodeElement: function() {
-        return this.getDocumentElement(this.wrapper.find('.current-node-element').parent()[0]);
+        var htmlElement = this.wrapper.find('.current-node-element').parent()[0];
+        if(htmlElement) {
+            return this.getDocumentElement(htmlElement);
+        }
     },
 
     getCurrentTextElement: function() {
-        return this.getDocumentElement(this.wrapper.find('.current-text-element')[0]);
+        var htmlElement = this.wrapper.find('.current-text-element')[0];
+        if(htmlElement) {
+            return this.getDocumentElement(htmlElement);
+        }
     },
 
+    contains: function(element) {
+        return element.dom().parents().index(this.wrapper) !== -1;
+    },
 
+    triggerSelectionChanged: function() {
+        this.trigger('selectionChanged', this.getSelection());
+    },
+
+    getSelection: function() {
+        return new Selection(this);
+    },
 
     setCurrentElement: function(element, params) {
+        if(!element) {
+            logger.debug('Invalid element passed to setCurrentElement: ' + element);
+            return;
+        }
+
         if(!(element instanceof documentElement.DocumentElement)) {
             element = utils.findCanvasElement(element);
         }
 
+        if(!element || !this.contains(element)) {
+            logger.warning('Cannot set current element: element doesn\'t exist on canvas');
+            return;
+        }
+
         params = _.extend({caretTo: 'end'}, params);
         var findFirstDirectTextChild = function(e, nodeToLand) {
             var byBrowser = this.getCursor().getPosition().element;
-            if(byBrowser && byBrowser.parent().sameNode(nodeToLand))
+            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)
+                if(children[i] instanceof documentElement.DocumentTextElement) {
                     return children[i];
+                }
             }
             return null;
         }.bind(this);
@@ -167,9 +316,8 @@ $.extend(Canvas.prototype, {
                 this.wrapper.find('.current-text-element').removeClass('current-text-element');
                 element.dom().addClass('current-text-element');
             } else {
-                this.wrapper.find('.current-node-element').removeClass('current-node-element')
+                this.wrapper.find('.current-node-element').removeClass('current-node-element');
                 element._container().addClass('current-node-element');
-                this.publisher('currentElementChanged', element);
             }
         }.bind(this);
 
@@ -180,24 +328,23 @@ $.extend(Canvas.prototype, {
             currentTextElement = this.getCurrentTextElement(),
             currentNodeElement = this.getCurrentNodeElement();
 
-        if(currentTextElement && !(currentTextElement.sameNode(textElementToLand)))
+        if(currentTextElement && !(currentTextElement.sameNode(textElementToLand))) {
             this.wrapper.find('.current-text-element').removeClass('current-text-element');
+        }
 
         if(textElementToLand) {
             _markAsCurrent(textElementToLand);
-            if(params.caretTo || !textElementToLand.sameNode(this.getCursor().getPosition().element))
+            if(params.caretTo || !textElementToLand.sameNode(this.getCursor().getPosition().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);
-
-            this.publisher('currentNodeElementSet', nodeElementToLand.data('wlxmlNode'));
         }
+        this.triggerSelectionChanged();
     },
 
     _moveCaretToTextElement: function(element, where) {
@@ -207,14 +354,16 @@ $.extend(Canvas.prototype, {
         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;
-        range.collapse(collapseArg);
-        
+        if(where !== 'whole') {
+            var collapseArg = true;
+            if(where === 'end') {
+                collapseArg = false;
+            }
+            range.collapse(collapseArg);
+        }
         var selection = document.getSelection();
 
         selection.removeAllRanges();
@@ -223,148 +372,106 @@ $.extend(Canvas.prototype, {
     },
 
     setCursorPosition: function(position) {
-        if(position.element)
+        if(position.element) {
             this._moveCaretToTextElement(position.element, position.offset);
+        }
+    },
+
+    findCanvasElement: function(node) {
+        return utils.findCanvasElement(node);
+    },
+
+    toggleGrid: function() {
+        this.wrapper.toggleClass('grid-on');
+        this.trigger('changed');
+    },
+    isGridToggled: function() {
+        return this.wrapper.hasClass('grid-on');
     }
 });
 
-$.extend(Canvas.prototype.list, {
-    create: function(params) {
-        if(!(params.element1.parent().sameNode(params.element2.parent())))
-            return false;
-            
-        var parent = params.element1.parent(),
-            canvas = params.element1.canvas;
-        
-        if(parent.childIndex(params.element1) > parent.childIndex(params.element2)) {
-            var tmp = params.element1;
-            params.element1 = params.element2;
-            params.element2 = tmp;
-        }
-        
-        var elementsToWrap = [];
-        
-        var place = 'before';
-        parent.children().some(function(element) {
-            var _e = element;
-            if(element.sameNode(params.element1))
-                place = 'inside';
-            if(place === 'inside') {
-                if(element instanceof documentElement.DocumentTextElement) {
-                    element = element.wrapWithNodeElement({tag: 'div', klass: 'list.item'});
-                    if(element.children()[0].sameNode(params.element1))
-                        params.element1 = element;
+
+var isText = function(node) {
+    return node && node.nodeType === Node.TEXT_NODE && $(node.parentNode).is('[document-text-element]');
+};
+
+var Selection = function(canvas) {
+    this.canvas = canvas;
+    var nativeSelection = this.nativeSelection = window.getSelection();
+    Object.defineProperty(this, 'type', {
+        get: function() {
+            if(nativeSelection.focusNode) {
+                if(nativeSelection.isCollapsed && isText(nativeSelection.focusNode)) {
+                    return 'caret';
+                }
+                if(isText(nativeSelection.focusNode) && isText(nativeSelection.anchorNode)) {
+                    return 'textSelection';
                 }
-                element.setWlxmlClass('item');
-                elementsToWrap.push(element);
             }
-            if(_e.sameNode(params.element2))
-                return true;
-        });
-        
-        var listElement = canvas.createNodeElement({tag: 'div', klass: 'list-items' + (params.type === 'enum' ? '-enum' : '')});
-        var toret;
-        if(parent.is('list')) {
-            var item = listElement.wrapWithNodeElement({tag: 'div', klass: 'item'});
-            item.exec('toggleBullet', false);
-            toret = listElement.parent();
-        } else {
-            toret = listElement;
-        }  
-        
-        params.element1.before(toret);
-        
-        elementsToWrap.forEach(function(element) {
-            element.detach();
-            listElement.append(element);
-        });
-    },
-    extractItems: function(params) {
-        params = _.extend({merge: true}, params);
-        var list = params.element1.parent();
-        if(!list.is('list') || !(list.sameNode(params.element2.parent())))
-            return false;
-
-        var idx1 = list.childIndex(params.element1),
-            idx2 = list.childIndex(params.element2),
-            precedingItems = [],
-            extractedItems = [],
-            succeedingItems = [],
-            items = list.children(),
-            listIsNested = list.parent().getWlxmlClass() === 'item',
-            canvas = params.element1.canvas,
-            i;
-
-        if(idx1 > idx2) {
-            var tmp = idx1; idx1 = idx2; idx2 = tmp;
+            if(canvas.getCurrentNodeElement()) {
+                return 'node';
+            }
         }
+    });
+};
 
-        items.forEach(function(item, idx) {
-            if(idx < idx1)
-                precedingItems.push(item);
-            else if(idx >= idx1 && idx <= idx2) {
-                extractedItems.push(item);
+$.extend(Selection.prototype, {
+    toDocumentFragment: function() {
+        var doc = this.canvas.wlxmlDocument,
+            anchorElement = this.canvas.getDocumentElement(this.nativeSelection.anchorNode),
+            focusElement = this.canvas.getDocumentElement(this.nativeSelection.focusNode),
+            anchorNode = anchorElement ? anchorElement.wlxmlNode : null,
+            focusNode = focusElement ? focusElement.wlxmlNode : null;
+        if(this.type === 'caret') {
+            return doc.createFragment(doc.CaretFragment, {node: anchorNode, offset: this.nativeSelection.anchorOffset});
+        }
+        if(this.type === 'textSelection') {
+            if(anchorNode.isSiblingOf(focusNode)) {
+                return doc.createFragment(doc.TextRangeFragment, {
+                    node1: anchorNode,
+                    offset1: this.nativeSelection.anchorOffset,
+                    node2: focusNode,
+                    offset2: this.nativeSelection.focusOffset,
+                });
             }
             else {
-                succeedingItems.push(item);
+                var siblingParents = doc.getSiblingParents({node1: anchorNode, node2: focusNode});
+                return doc.createFragment(doc.RangeFragment, {
+                    node1: siblingParents.node1,
+                    node2: siblingParents.node2
+                });
             }
-        });
-
-        var reference = listIsNested ? list.parent() : list;
-        if(succeedingItems.length === 0) {
-            var reference_orig = reference;
-            extractedItems.forEach(function(item) {
-                reference.after(item);
-                reference = item;
-                if(!listIsNested)
-                    item.setWlxmlClass(null);
-            });
-            if(precedingItems.length === 0)
-                reference_orig.detach();
-        } else if(precedingItems.length === 0) {
-            extractedItems.forEach(function(item) {
-                reference.before(item);
-                if(!listIsNested)
-                    item.setWlxmlClass(null);
-            });
-        } else {
-            extractedItems.forEach(function(item) {
-                reference.after(item);
-                if(!listIsNested)
-                    item.setWlxmlClass(null);
-                reference = item;
-            });
-            var secondList = canvas.createNodeElement({tag: 'div', klass:'list-items'}),
-                toAdd = secondList;
-            
-            if(listIsNested) {
-                toAdd = secondList.wrapWithNodeElement({tag: 'div', klass:'item'});
-            }
-            succeedingItems.forEach(function(item) {
-                secondList.append(item);
-            });
-
-            reference.after(toAdd);
         }
-        if(!params.merge && listIsNested) {
-            return this.extractItems({element1: extractedItems[0], element2: extractedItems[extractedItems.length-1]});
+        if(this.type === 'node') {
+            return doc.createFragment(doc.NodeFragment, {node: this.canvas.getCurrentNodeElement().wlxmlNode});
         }
-        return true;
     },
-    areItemsOfTheSameList: function(params) {
-        var e1 = params.element1,
-            e2 = params.element2;
-        return e1.parent().sameNode(e2.parent())
-            && e1.parent().is('list');
+    sameAs: function(other) {
+        void(other);
     }
 });
 
-
 var Cursor = function(canvas) {
     this.canvas = canvas;
+    this.selection = window.getSelection();
 };
 
 $.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;
@@ -372,6 +479,9 @@ $.extend(Cursor.prototype, {
     isSelectingWithinElement: function() {
         return this.isSelecting() && this.getSelectionStart().element.sameNode(this.getSelectionEnd().element);
     },
+    isWithinElement: function() {
+        return !this.isSelecting() || this.isSelectingWithinElement();
+    },
     isSelectingSiblings: function() {
         return this.isSelecting() && this.getSelectionStart().element.parent().sameNode(this.getSelectionEnd().element.parent());
     },
@@ -391,79 +501,85 @@ $.extend(Cursor.prototype, {
         return this.getSelectionBoundry('focus');
     },
     getSelectionBoundry: function(which) {
+        /* globals window */
         var selection = window.getSelection(),
             anchorElement = this.canvas.getDocumentElement(selection.anchorNode),
             focusElement = this.canvas.getDocumentElement(selection.focusNode);
         
-        if((!anchorElement) || (anchorElement instanceof documentElement.DocumentNodeElement) || (!focusElement) || focusElement instanceof documentElement.DocumentNodeElement)
+        if((!anchorElement) || (anchorElement instanceof documentElement.DocumentNodeElement) || (!focusElement) || focusElement instanceof documentElement.DocumentNodeElement) {
             return {};
+        }
 
         if(which === 'anchor') {
             return {
                 element: anchorElement,
                 offset: selection.anchorOffset,
-                offsetAtBeginning: selection.anchorOffset === 0,
-                offsetAtEnd: selection.anchorNode.data.length === selection.anchorOffset
+                offsetAtBeginning: selection.anchorOffset === 0 || anchorElement.getText() === '',
+                offsetAtEnd: selection.anchorNode.data.length === selection.anchorOffset || anchorElement.getText() === ''
             };
         }
         if(which === 'focus') {
             return {
                 element: focusElement,
                 offset: selection.focusOffset,
-                offsetAtBeginning: selection.focusOffset === 0,
-                offsetAtEnd: selection.focusNode.data.length === selection.focusOffset
+                offsetAtBeginning: selection.focusOffset === 0 || focusElement.getText() === '',
+                offsetAtEnd: selection.focusNode.data.length === selection.focusOffset || focusElement.getText() === '',
             };
         }
         
-        var element,
-            offset;
-
-        if(anchorElement.parent().sameNode(focusElement.parent())) {
-            var parent = anchorElement.parent(),
-                anchorFirst = parent.childIndex(anchorElement) < parent.childIndex(focusElement);
+        var getPlaceData = function(anchorFirst) {
+            var element, offset;
             if(anchorFirst) {
                 if(which === 'start') {
                     element = anchorElement;
-                    offset = selection.anchorOffset
+                    offset = selection.anchorOffset;
                 }
                 else if(which === 'end') {
-                    element = focusElement,
-                    offset = selection.focusOffset
+                    element = focusElement;
+                    offset = selection.focusOffset;
                 }
             } else {
                 if(which === 'start') {
-                    element = focusElement,
-                    offset = selection.focusOffset
+                    element = focusElement;
+                    offset = selection.focusOffset;
                 }
                 else if(which === 'end') {
                     element = anchorElement;
-                    offset = selection.anchorOffset
+                    offset = selection.anchorOffset;
                 }
             }
-        } else {
-            // TODO: Handle order via https://developer.mozilla.org/en-US/docs/Web/API/Node.compareDocumentPosition
-            if(which === 'start') {
-                element = anchorElement;
-                offset = selection.anchorOffset
+            return {element: element, offset: offset};
+        };
+
+        var anchorFirst, placeData, parent;
+
+        if(anchorElement.parent().sameNode(focusElement.parent())) {
+            parent = anchorElement.parent();
+            if(selection.anchorNode === selection.focusNode) {
+                anchorFirst = selection.anchorOffset <= selection.focusOffset;
             } else {
-                element = focusElement;
-                offset = selection.focusOffset
+                anchorFirst = parent.childIndex(anchorElement) < parent.childIndex(focusElement);
             }
+            placeData = getPlaceData(anchorFirst);
+        } else {
+            /*jshint bitwise: false*/
+            anchorFirst = selection.anchorNode.compareDocumentPosition(selection.focusNode) & Node.DOCUMENT_POSITION_FOLLOWING;
+            placeData = getPlaceData(anchorFirst);
         }
 
-        var nodeLen = (element.sameNode(focusElement) ? selection.focusNode : selection.anchorNode).length;
+        var nodeLen = (placeData.element.sameNode(focusElement) ? selection.focusNode : selection.anchorNode).length;
         return {
-            element: element,
-            offset: offset,
-            offsetAtBeginning: offset === 0,
-            offsetAtEnd: nodeLen === offset
-        }
+            element: placeData.element,
+            offset: placeData.offset,
+            offsetAtBeginning: placeData.offset === 0 || focusElement.getText() === '',
+            offsetAtEnd: nodeLen === placeData.offset || focusElement.getText() === ''
+        };
     }
-})
+});
 
 return {
-    fromXMLDocument: function(wlxmlDocument, publisher) {
-        return new Canvas(wlxmlDocument, publisher);
+    fromXMLDocument: function(wlxmlDocument, elements) {
+        return new Canvas(wlxmlDocument, elements);
     }
 };