+                var selectsWholeTextElement = function() {
+                    if(cursor.isSelecting() && cursor.getSelectionStart().offsetAtBeginning && cursor.getSelectionEnd().offsetAtEnd)
+                        return true;
+                    return false;
+                }
+
+                if(e.which === KEYS.X && e.ctrlKey && selectsWholeTextElement()) {
+                    e.preventDefault();
+                }
+
+                if(e.which === KEYS.BACKSPACE || e.which === KEYS.DELETE) {
+                    if(cursor.isSelecting() && !cursor.isSelectingWithinElement()) {
+                        e.preventDefault();
+                        return;
+                    }
+                        
+                    var cursorAtOperationEdge = position.offsetAtBeginning;
+                    if(e.which === KEYS.DELETE) {
+                        cursorAtOperationEdge = position.offsetAtEnd;
+                    }
+
+                    if(element.getText().length === 1 || selectsWholeTextElement()) {
+                        e.preventDefault();
+                        element.setText('');
+                    }
+                    else if(element.isEmpty()) {
+
+                        var direction = 'above',
+                            caretTo = 'end';
+                            
+                        if(e.which === KEYS.DELETE) {
+                            direction = 'below';
+                            caretTo = 'start';
+                        }
+
+                        e.preventDefault();
+
+                        var parent = element.parent(),
+                            grandParent = parent ? parent.parent() : null,
+                            goto;
+                        if(parent.children().length === 1) {
+                            if(grandParent && grandParent.children().length === 1) {
+                                goto = grandParent.append({text: ''});
+                            } else {
+                                goto = canvas.getDocumentElement(utils.nearestInDocumentOrder('[document-text-element]', direction, element.dom()[0]));
+                            }
+                            parent.detach();
+                        } else {
+                            goto = canvas.getDocumentElement(utils.nearestInDocumentOrder('[document-text-element]', direction, element.dom()[0]));
+                            element.detach();
+                        }
+                        canvas.setCurrentElement(goto, {caretTo: caretTo});
+                    }
+                    else if(cursorAtOperationEdge) {
+                        // todo
+                        e.preventDefault();
+                    }
+                }
+            });
+
+            this.wrapper.on('click', '[document-node-element], [document-text-element]', function(e) {
+                e.stopPropagation();
+                canvas.setCurrentElement(canvas.getDocumentElement(e.currentTarget), {caretTo: false});
+            });
+
+            var observer = new MutationObserver(function(mutations) {
+                mutations.forEach(function(mutation) {
+                    if(documentElement.DocumentTextElement.isContentContainer(mutation.target) && mutation.target.data === '')
+                        mutation.target.data = utils.unicode.ZWS;
+                });
+            });
+            var config = { attributes: false, childList: false, characterData: true, subtree: true, characterDataOldValue: true};
+            observer.observe(this.d[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);
+                if(!el)
+                    return;