enable keyboard manager when codemirror is focused

This should always be true, and mitigate focus-related keyboard bugs, such as  #7555.

IPython/html/static/notebook/js/codecell.js

@@ -1,645 +1,653 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 /**
  *
  *
  * @module codecell
  * @namespace codecell
  * @class CodeCell
  */
 
 
 define([
     'base/js/namespace',
     'jquery',
     'base/js/utils',
     'base/js/keyboard',
     'services/config',
     'notebook/js/cell',
     'notebook/js/outputarea',
     'notebook/js/completer',
     'notebook/js/celltoolbar',
     'codemirror/lib/codemirror',
     'codemirror/mode/python/python',
     'notebook/js/codemirror-ipython'
 ], function(IPython,
     $,
     utils,
     keyboard,
     configmod,
     cell,
     outputarea,
     completer,
     celltoolbar,
     CodeMirror,
     cmpython,
     cmip
     ) {
     "use strict";
     
     var Cell = cell.Cell;
 
     /* local util for codemirror */
     var posEq = function(a, b) {return a.line === b.line && a.ch === b.ch;};
 
     /**
      *
      * function to delete until previous non blanking space character
      * or first multiple of 4 tabstop.
      * @private
      */
     CodeMirror.commands.delSpaceToPrevTabStop = function(cm){
         var from = cm.getCursor(true), to = cm.getCursor(false), sel = !posEq(from, to);
         if (!posEq(from, to)) { cm.replaceRange("", from, to); return; }
         var cur = cm.getCursor(), line = cm.getLine(cur.line);
         var tabsize = cm.getOption('tabSize');
         var chToPrevTabStop = cur.ch-(Math.ceil(cur.ch/tabsize)-1)*tabsize;
         from = {ch:cur.ch-chToPrevTabStop,line:cur.line};
         var select = cm.getRange(from,cur);
         if( select.match(/^\ +$/) !== null){
             cm.replaceRange("",from,cur);
         } else {
             cm.deleteH(-1,"char");
         }
     };
 
     var keycodes = keyboard.keycodes;
 
     var CodeCell = function (kernel, options) {
         /**
          * Constructor
          *
          * A Cell conceived to write code.
          *
          * Parameters:
          *  kernel: Kernel instance
          *      The kernel doesn't have to be set at creation time, in that case
          *      it will be null and set_kernel has to be called later.
          *  options: dictionary
          *      Dictionary of keyword arguments.
          *          events: $(Events) instance 
          *          config: dictionary
          *          keyboard_manager: KeyboardManager instance 
          *          notebook: Notebook instance
          *          tooltip: Tooltip instance
          */
         this.kernel = kernel || null;
         this.notebook = options.notebook;
         this.collapsed = false;
         this.events = options.events;
         this.tooltip = options.tooltip;
         this.config = options.config;
         this.class_config = new configmod.ConfigWithDefaults(this.config,
                                         CodeCell.config_defaults, 'CodeCell');
 
         // create all attributed in constructor function
         // even if null for V8 VM optimisation
         this.input_prompt_number = null;
         this.celltoolbar = null;
         this.output_area = null;
 
         this.last_msg_id = null;
         this.completer = null;
         this.widget_views = [];
         this._widgets_live = true;
 
         Cell.apply(this,[{
             config: $.extend({}, CodeCell.options_default), 
             keyboard_manager: options.keyboard_manager, 
             events: this.events}]);
 
         // Attributes we want to override in this subclass.
         this.cell_type = "code";
         var that  = this;
         this.element.focusout(
             function() { that.auto_highlight(); }
         );
     };
 
     CodeCell.options_default = {
         cm_config : {
             extraKeys: {
                 "Tab" :  "indentMore",
                 "Shift-Tab" : "indentLess",
                 "Backspace" : "delSpaceToPrevTabStop",
                 "Cmd-/" : "toggleComment",
                 "Ctrl-/" : "toggleComment"
             },
             mode: 'ipython',
             theme: 'ipython',
             matchBrackets: true
         }
     };
 
     CodeCell.config_defaults = {
         highlight_modes : {
             'magic_javascript'    :{'reg':[/^%%javascript/]},
             'magic_perl'          :{'reg':[/^%%perl/]},
             'magic_ruby'          :{'reg':[/^%%ruby/]},
             'magic_python'        :{'reg':[/^%%python3?/]},
             'magic_shell'         :{'reg':[/^%%bash/]},
             'magic_r'             :{'reg':[/^%%R/]},
             'magic_text/x-cython' :{'reg':[/^%%cython/]},
         },
     };
 
     CodeCell.msg_cells = {};
 
     CodeCell.prototype = Object.create(Cell.prototype);
 
     /** @method create_element */
     CodeCell.prototype.create_element = function () {
         Cell.prototype.create_element.apply(this, arguments);
+        var that = this;
 
         var cell =  $('<div></div>').addClass('cell code_cell');
         cell.attr('tabindex','2');
 
         var input = $('<div></div>').addClass('input');
         var prompt = $('<div/>').addClass('prompt input_prompt');
         var inner_cell = $('<div/>').addClass('inner_cell');
         this.celltoolbar = new celltoolbar.CellToolbar({
             cell: this, 
             notebook: this.notebook});
         inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('input_area');
         this.code_mirror = new CodeMirror(input_area.get(0), this.cm_config);
+        // In case of bugs that put the keyboard manager into an inconsistent state,
+        // ensure KM is enabled when CodeMirror is focused:
+        this.code_mirror.on('focus', function () {
+            if (that.keyboard_manager) {
+                that.keyboard_manager.enable();
+            }
+        });
         this.code_mirror.on('keydown', $.proxy(this.handle_keyevent,this));
         $(this.code_mirror.getInputField()).attr("spellcheck", "false");
         inner_cell.append(input_area);
         input.append(prompt).append(inner_cell);
 
         var widget_area = $('<div/>')
             .addClass('widget-area')
             .hide();
         this.widget_area = widget_area;
         var widget_prompt = $('<div/>')
             .addClass('prompt')
             .appendTo(widget_area);
         var widget_subarea = $('<div/>')
             .addClass('widget-subarea')
             .appendTo(widget_area);
         this.widget_subarea = widget_subarea;
         var that = this;
         var widget_clear_buton = $('<button />')
             .addClass('close')
             .html('&times;')
             .click(function() {
                 widget_area.slideUp('', function(){ 
                     for (var i = 0; i < that.widget_views.length; i++) {
                         var view = that.widget_views[i];
                         view.remove();
 
                         // Remove widget live events.
                         view.off('comm:live', that._widget_live);
                         view.off('comm:dead', that._widget_dead);
                     }
                     that.widget_views = [];
                     widget_subarea.html(''); 
                 });
             })
             .appendTo(widget_prompt);
 
         var output = $('<div></div>');
         cell.append(input).append(widget_area).append(output);
         this.element = cell;
         this.output_area = new outputarea.OutputArea({
             selector: output, 
             prompt_area: true, 
             events: this.events, 
             keyboard_manager: this.keyboard_manager});
         this.completer = new completer.Completer(this, this.events);
     };
 
     /**
     *  Display a widget view in the cell.
     */
     CodeCell.prototype.display_widget_view = function(view_promise) {
 
         // Display a dummy element
         var dummy = $('<div/>');
         this.widget_subarea.append(dummy);
 
         // Display the view.
         var that = this;
         return view_promise.then(function(view) {
             that.widget_area.show();
             dummy.replaceWith(view.$el);
             that.widget_views.push(view);
 
             // Check the live state of the view's model.
             if (view.model.comm_live) {
                 that._widget_live(view);
             } else {
                 that._widget_dead(view);
             }
 
             // Listen to comm live events for the view.
             view.on('comm:live', that._widget_live, that);
             view.on('comm:dead', that._widget_dead, that);
             return view;
         });
     };
 
     /**
      * Handles when a widget loses it's comm connection.
      * @param  {WidgetView} view
      */
     CodeCell.prototype._widget_dead = function(view) {
         if (this._widgets_live) {
             this._widgets_live = false;
             this.widget_area.addClass('connection-problems');
         }
 
     };
 
     /**
      * Handles when a widget is connected to a live comm.
      * @param  {WidgetView} view
      */
     CodeCell.prototype._widget_live = function(view) {
         if (!this._widgets_live) {
             // Check that the other widgets are live too.  O(N) operation.
             // Abort the function at the first dead widget found.
             for (var i = 0; i < this.widget_views.length; i++) {
                 if (!this.widget_views[i].model.comm_live) return;
             }
             this._widgets_live = true;
             this.widget_area.removeClass('connection-problems');
         }
     };
 
     /** @method bind_events */
     CodeCell.prototype.bind_events = function () {
         Cell.prototype.bind_events.apply(this);
         var that = this;
 
         this.element.focusout(
             function() { that.auto_highlight(); }
         );
     };
 
 
     /**
      *  This method gets called in CodeMirror's onKeyDown/onKeyPress
      *  handlers and is used to provide custom key handling. Its return
      *  value is used to determine if CodeMirror should ignore the event:
      *  true = ignore, false = don't ignore.
      *  @method handle_codemirror_keyevent
      */
 
     CodeCell.prototype.handle_codemirror_keyevent = function (editor, event) {
 
         var that = this;
         // whatever key is pressed, first, cancel the tooltip request before
         // they are sent, and remove tooltip if any, except for tab again
         var tooltip_closed = null;
         if (event.type === 'keydown' && event.which !== keycodes.tab ) {
             tooltip_closed = this.tooltip.remove_and_cancel_tooltip();
         }
 
         var cur = editor.getCursor();
         if (event.keyCode === keycodes.enter){
             this.auto_highlight();
         }
 
         if (event.which === keycodes.down && event.type === 'keypress' && this.tooltip.time_before_tooltip >= 0) {
             // triger on keypress (!) otherwise inconsistent event.which depending on plateform
             // browser and keyboard layout !
             // Pressing '(' , request tooltip, don't forget to reappend it
             // The second argument says to hide the tooltip if the docstring
             // is actually empty
             this.tooltip.pending(that, true);
         } else if ( tooltip_closed && event.which === keycodes.esc && event.type === 'keydown') {
             // If tooltip is active, cancel it.  The call to
             // remove_and_cancel_tooltip above doesn't pass, force=true.
             // Because of this it won't actually close the tooltip
             // if it is in sticky mode. Thus, we have to check again if it is open
             // and close it with force=true.
             if (!this.tooltip._hidden) {
                 this.tooltip.remove_and_cancel_tooltip(true);
             }
             // If we closed the tooltip, don't let CM or the global handlers
             // handle this event.
             event.codemirrorIgnore = true;
             event.preventDefault();
             return true;
         } else if (event.keyCode === keycodes.tab && event.type === 'keydown' && event.shiftKey) {
                 if (editor.somethingSelected() || editor.getSelections().length !== 1){
                     var anchor = editor.getCursor("anchor");
                     var head = editor.getCursor("head");
                     if( anchor.line !== head.line){
                         return false;
                     }
                 }
                 this.tooltip.request(that);
                 event.codemirrorIgnore = true;
                 event.preventDefault();
                 return true;
         } else if (event.keyCode === keycodes.tab && event.type === 'keydown') {
             // Tab completion.
             this.tooltip.remove_and_cancel_tooltip();
 
             // completion does not work on multicursor, it might be possible though in some cases
             if (editor.somethingSelected() || editor.getSelections().length > 1) {
                 return false;
             }
             var pre_cursor = editor.getRange({line:cur.line,ch:0},cur);
             if (pre_cursor.trim() === "") {
                 // Don't autocomplete if the part of the line before the cursor
                 // is empty.  In this case, let CodeMirror handle indentation.
                 return false;
             } else {
                 event.codemirrorIgnore = true;
                 event.preventDefault();
                 this.completer.startCompletion();
                 return true;
             }
         } 
         
         // keyboard event wasn't one of those unique to code cells, let's see
         // if it's one of the generic ones (i.e. check edit mode shortcuts)
         return Cell.prototype.handle_codemirror_keyevent.apply(this, [editor, event]);
     };
 
     // Kernel related calls.
 
     CodeCell.prototype.set_kernel = function (kernel) {
         this.kernel = kernel;
     };
 
     /**
      * Execute current code cell to the kernel
      * @method execute
      */
     CodeCell.prototype.execute = function (stop_on_error) {
         if (!this.kernel || !this.kernel.is_connected()) {
             console.log("Can't execute, kernel is not connected.");
             return;
         }
 
         this.output_area.clear_output(false, true);
 
         if (stop_on_error === undefined) {
             stop_on_error = true;
         }
 
         // Clear widget area
         for (var i = 0; i < this.widget_views.length; i++) {
             var view = this.widget_views[i];
             view.remove();
 
             // Remove widget live events.
             view.off('comm:live', this._widget_live);
             view.off('comm:dead', this._widget_dead);
         }
         this.widget_views = [];
         this.widget_subarea.html('');
         this.widget_subarea.height('');
         this.widget_area.height('');
         this.widget_area.hide();
 
         this.set_input_prompt('*');
         this.element.addClass("running");
         if (this.last_msg_id) {
             this.kernel.clear_callbacks_for_msg(this.last_msg_id);
         }
         var callbacks = this.get_callbacks();
         
         var old_msg_id = this.last_msg_id;
         this.last_msg_id = this.kernel.execute(this.get_text(), callbacks, {silent: false, store_history: true,
             stop_on_error : stop_on_error});
         if (old_msg_id) {
             delete CodeCell.msg_cells[old_msg_id];
         }
         CodeCell.msg_cells[this.last_msg_id] = this;
         this.render();
         this.events.trigger('execute.CodeCell', {cell: this});
     };
     
     /**
      * Construct the default callbacks for
      * @method get_callbacks
      */
     CodeCell.prototype.get_callbacks = function () {
         var that = this;
         return {
             shell : {
                 reply : $.proxy(this._handle_execute_reply, this),
                 payload : {
                     set_next_input : $.proxy(this._handle_set_next_input, this),
                     page : $.proxy(this._open_with_pager, this)
                 }
             },
             iopub : {
                 output : function() { 
                     that.output_area.handle_output.apply(that.output_area, arguments);
                 }, 
                 clear_output : function() { 
                     that.output_area.handle_clear_output.apply(that.output_area, arguments);
                 }, 
             },
             input : $.proxy(this._handle_input_request, this)
         };
     };
     
     CodeCell.prototype._open_with_pager = function (payload) {
         this.events.trigger('open_with_text.Pager', payload);
     };
 
     /**
      * @method _handle_execute_reply
      * @private
      */
     CodeCell.prototype._handle_execute_reply = function (msg) {
         this.set_input_prompt(msg.content.execution_count);
         this.element.removeClass("running");
         this.events.trigger('set_dirty.Notebook', {value: true});
     };
 
     /**
      * @method _handle_set_next_input
      * @private
      */
     CodeCell.prototype._handle_set_next_input = function (payload) {
         var data = {'cell': this, 'text': payload.text, replace: payload.replace};
         this.events.trigger('set_next_input.Notebook', data);
     };
 
     /**
      * @method _handle_input_request
      * @private
      */
     CodeCell.prototype._handle_input_request = function (msg) {
         this.output_area.append_raw_input(msg);
     };
 
 
     // Basic cell manipulation.
 
     CodeCell.prototype.select = function () {
         var cont = Cell.prototype.select.apply(this);
         if (cont) {
             this.code_mirror.refresh();
             this.auto_highlight();
         }
         return cont;
     };
 
     CodeCell.prototype.render = function () {
         var cont = Cell.prototype.render.apply(this);
         // Always execute, even if we are already in the rendered state
         return cont;
     };
     
     CodeCell.prototype.select_all = function () {
         var start = {line: 0, ch: 0};
         var nlines = this.code_mirror.lineCount();
         var last_line = this.code_mirror.getLine(nlines-1);
         var end = {line: nlines-1, ch: last_line.length};
         this.code_mirror.setSelection(start, end);
     };
 
 
     CodeCell.prototype.collapse_output = function () {
         this.output_area.collapse();
     };
 
 
     CodeCell.prototype.expand_output = function () {
         this.output_area.expand();
         this.output_area.unscroll_area();
     };
 
     CodeCell.prototype.scroll_output = function () {
         this.output_area.expand();
         this.output_area.scroll_if_long();
     };
 
     CodeCell.prototype.toggle_output = function () {
         this.output_area.toggle_output();
     };
 
     CodeCell.prototype.toggle_output_scroll = function () {
         this.output_area.toggle_scroll();
     };
 
 
     CodeCell.input_prompt_classical = function (prompt_value, lines_number) {
         var ns;
         if (prompt_value === undefined || prompt_value === null) {
             ns = "&nbsp;";
         } else {
             ns = encodeURIComponent(prompt_value);
         }
         return 'In&nbsp;[' + ns + ']:';
     };
 
     CodeCell.input_prompt_continuation = function (prompt_value, lines_number) {
         var html = [CodeCell.input_prompt_classical(prompt_value, lines_number)];
         for(var i=1; i < lines_number; i++) {
             html.push(['...:']);
         }
         return html.join('<br/>');
     };
 
     CodeCell.input_prompt_function = CodeCell.input_prompt_classical;
 
 
     CodeCell.prototype.set_input_prompt = function (number) {
         var nline = 1;
         if (this.code_mirror !== undefined) {
            nline = this.code_mirror.lineCount();
         }
         this.input_prompt_number = number;
         var prompt_html = CodeCell.input_prompt_function(this.input_prompt_number, nline);
         // This HTML call is okay because the user contents are escaped.
         this.element.find('div.input_prompt').html(prompt_html);
     };
 
 
     CodeCell.prototype.clear_input = function () {
         this.code_mirror.setValue('');
     };
 
 
     CodeCell.prototype.get_text = function () {
         return this.code_mirror.getValue();
     };
 
 
     CodeCell.prototype.set_text = function (code) {
         return this.code_mirror.setValue(code);
     };
 
 
     CodeCell.prototype.clear_output = function (wait) {
         this.output_area.clear_output(wait);
         this.set_input_prompt();
     };
 
 
     // JSON serialization
 
     CodeCell.prototype.fromJSON = function (data) {
         Cell.prototype.fromJSON.apply(this, arguments);
         if (data.cell_type === 'code') {
             if (data.source !== undefined) {
                 this.set_text(data.source);
                 // make this value the starting point, so that we can only undo
                 // to this state, instead of a blank cell
                 this.code_mirror.clearHistory();
                 this.auto_highlight();
             }
             this.set_input_prompt(data.execution_count);
             this.output_area.trusted = data.metadata.trusted || false;
             this.output_area.fromJSON(data.outputs);
             if (data.metadata.collapsed !== undefined) {
                 if (data.metadata.collapsed) {
                     this.collapse_output();
                 } else {
                     this.expand_output();
                 }
             }
         }
     };
 
 
     CodeCell.prototype.toJSON = function () {
         var data = Cell.prototype.toJSON.apply(this);
         data.source = this.get_text();
         // is finite protect against undefined and '*' value
         if (isFinite(this.input_prompt_number)) {
             data.execution_count = this.input_prompt_number;
         } else {
             data.execution_count = null;
         }
         var outputs = this.output_area.toJSON();
         data.outputs = outputs;
         data.metadata.trusted = this.output_area.trusted;
         data.metadata.collapsed = this.output_area.collapsed;
         return data;
     };
 
     /**
      * handle cell level logic when a cell is unselected
      * @method unselect
      * @return is the action being taken
      */
     CodeCell.prototype.unselect = function () {
         var cont = Cell.prototype.unselect.apply(this);
         if (cont) {
             // When a code cell is usnelected, make sure that the corresponding
             // tooltip and completer to that cell is closed.
             this.tooltip.remove_and_cancel_tooltip(true);
             if (this.completer !== null) {
                 this.completer.close();
             }
         }
         return cont;
     };
 
     // Backwards compatability.
     IPython.CodeCell = CodeCell;
 
     return {'CodeCell': CodeCell};
 });

IPython/html/static/notebook/js/textcell.js

@@ -1,367 +1,375 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     'base/js/namespace',
     'base/js/utils',
     'jquery',
     'notebook/js/cell',
     'base/js/security',
     'services/config',
     'notebook/js/mathjaxutils',
     'notebook/js/celltoolbar',
     'components/marked/lib/marked',
     'codemirror/lib/codemirror',
     'codemirror/mode/gfm/gfm',
     'notebook/js/codemirror-ipythongfm'
 ], function(IPython,
     utils,
     $,
     cell,
     security,
     configmod,
     mathjaxutils,
     celltoolbar,
     marked,
     CodeMirror,
     gfm,
     ipgfm
     ) {
     "use strict";
     var Cell = cell.Cell;
 
     var TextCell = function (options) {
         /**
          * Constructor
          *
          * Construct a new TextCell, codemirror mode is by default 'htmlmixed', 
          * and cell type is 'text' cell start as not redered.
          *
          * Parameters:
          *  options: dictionary
          *      Dictionary of keyword arguments.
          *          events: $(Events) instance 
          *          config: dictionary
          *          keyboard_manager: KeyboardManager instance 
          *          notebook: Notebook instance
          */
         options = options || {};
 
         // in all TextCell/Cell subclasses
         // do not assign most of members here, just pass it down
         // in the options dict potentially overwriting what you wish.
         // they will be assigned in the base class.
         this.notebook = options.notebook;
         this.events = options.events;
         this.config = options.config;
         
         // we cannot put this as a class key as it has handle to "this".
         var config = utils.mergeopt(TextCell, this.config);
         Cell.apply(this, [{
                     config: config, 
                     keyboard_manager: options.keyboard_manager, 
                     events: this.events}]);
 
         this.cell_type = this.cell_type || 'text';
         mathjaxutils = mathjaxutils;
         this.rendered = false;
     };
 
     TextCell.prototype = Object.create(Cell.prototype);
 
     TextCell.options_default = {
         cm_config : {
             extraKeys: {"Tab": "indentMore","Shift-Tab" : "indentLess"},
             mode: 'htmlmixed',
             lineWrapping : true,
         }
     };
 
 
     /**
      * Create the DOM element of the TextCell
      * @method create_element
      * @private
      */
     TextCell.prototype.create_element = function () {
         Cell.prototype.create_element.apply(this, arguments);
+        var that = this;
 
         var cell = $("<div>").addClass('cell text_cell');
         cell.attr('tabindex','2');
 
         var prompt = $('<div/>').addClass('prompt input_prompt');
         cell.append(prompt);
         var inner_cell = $('<div/>').addClass('inner_cell');
         this.celltoolbar = new celltoolbar.CellToolbar({
             cell: this, 
             notebook: this.notebook});
         inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('input_area');
         this.code_mirror = new CodeMirror(input_area.get(0), this.cm_config);
+        // In case of bugs that put the keyboard manager into an inconsistent state,
+        // ensure KM is enabled when CodeMirror is focused:
+        this.code_mirror.on('focus', function () {
+            if (that.keyboard_manager) {
+                that.keyboard_manager.enable();
+            }
+        });
         this.code_mirror.on('keydown', $.proxy(this.handle_keyevent,this))
         // The tabindex=-1 makes this div focusable.
         var render_area = $('<div/>').addClass('text_cell_render rendered_html')
             .attr('tabindex','-1');
         inner_cell.append(input_area).append(render_area);
         cell.append(inner_cell);
         this.element = cell;
     };
 
 
     // Cell level actions
     
     TextCell.prototype.select = function () {
         var cont = Cell.prototype.select.apply(this);
         if (cont) {
             if (this.mode === 'edit') {
                 this.code_mirror.refresh();
             }
         }
         return cont;
     };
 
     TextCell.prototype.unrender = function () {
         if (this.read_only) return;
         var cont = Cell.prototype.unrender.apply(this);
         if (cont) {
             var text_cell = this.element;
             if (this.get_text() === this.placeholder) {
                 this.set_text('');
             }
             this.refresh();
         }
         return cont;
     };
 
     TextCell.prototype.execute = function () {
         this.render();
     };
 
     /**
      * setter: {{#crossLink "TextCell/set_text"}}{{/crossLink}}
      * @method get_text
      * @retrun {string} CodeMirror current text value
      */
     TextCell.prototype.get_text = function() {
         return this.code_mirror.getValue();
     };
 
     /**
      * @param {string} text - Codemiror text value
      * @see TextCell#get_text
      * @method set_text
      * */
     TextCell.prototype.set_text = function(text) {
         this.code_mirror.setValue(text);
         this.unrender();
         this.code_mirror.refresh();
     };
 
     /**
      * setter :{{#crossLink "TextCell/set_rendered"}}{{/crossLink}}
      * @method get_rendered
      * */
     TextCell.prototype.get_rendered = function() {
         return this.element.find('div.text_cell_render').html();
     };
 
     /**
      * @method set_rendered
      */
     TextCell.prototype.set_rendered = function(text) {
         this.element.find('div.text_cell_render').html(text);
     };
 
 
     /**
      * Create Text cell from JSON
      * @param {json} data - JSON serialized text-cell
      * @method fromJSON
      */
     TextCell.prototype.fromJSON = function (data) {
         Cell.prototype.fromJSON.apply(this, arguments);
         if (data.cell_type === this.cell_type) {
             if (data.source !== undefined) {
                 this.set_text(data.source);
                 // make this value the starting point, so that we can only undo
                 // to this state, instead of a blank cell
                 this.code_mirror.clearHistory();
                 // TODO: This HTML needs to be treated as potentially dangerous
                 // user input and should be handled before set_rendered.         
                 this.set_rendered(data.rendered || '');
                 this.rendered = false;
                 this.render();
             }
         }
     };
 
     /** Generate JSON from cell
      * @return {object} cell data serialised to json
      */
     TextCell.prototype.toJSON = function () {
         var data = Cell.prototype.toJSON.apply(this);
         data.source = this.get_text();
         if (data.source == this.placeholder) {
             data.source = "";
         }
         return data;
     };
 
 
     var MarkdownCell = function (options) {
         /**
          * Constructor
          *
          * Parameters:
          *  options: dictionary
          *      Dictionary of keyword arguments.
          *          events: $(Events) instance 
          *          config: ConfigSection instance
          *          keyboard_manager: KeyboardManager instance 
          *          notebook: Notebook instance
          */
         options = options || {};
         var config = utils.mergeopt(MarkdownCell, {});
         TextCell.apply(this, [$.extend({}, options, {config: config})]);
 
         this.class_config = new configmod.ConfigWithDefaults(options.config,
                                             {}, 'MarkdownCell');
         this.cell_type = 'markdown';
     };
 
     MarkdownCell.options_default = {
         cm_config: {
             mode: 'ipythongfm'
         },
         placeholder: "Type *Markdown* and LaTeX: $\\alpha^2$"
     };
 
     MarkdownCell.prototype = Object.create(TextCell.prototype);
 
     MarkdownCell.prototype.set_heading_level = function (level) {
         /**
          * make a markdown cell a heading
          */
         level = level || 1;
         var source = this.get_text();
         source = source.replace(/^(#*)\s?/,
             new Array(level + 1).join('#') + ' ');
         this.set_text(source);
         this.refresh();
         if (this.rendered) {
             this.render();
         }
     };
 
     /**
      * @method render
      */
     MarkdownCell.prototype.render = function () {
         var cont = TextCell.prototype.render.apply(this);
         if (cont) {
             var that = this;
             var text = this.get_text();
             var math = null;
             if (text === "") { text = this.placeholder; }
             var text_and_math = mathjaxutils.remove_math(text);
             text = text_and_math[0];
             math = text_and_math[1];
             marked(text, function (err, html) {
                 html = mathjaxutils.replace_math(html, math);
                 html = security.sanitize_html(html);
                 html = $($.parseHTML(html));
                 // add anchors to headings
                 html.find(":header").addBack(":header").each(function (i, h) {
                     h = $(h);
                     var hash = h.text().replace(/ /g, '-');
                     h.attr('id', hash);
                     h.append(
                         $('<a/>')
                             .addClass('anchor-link')
                             .attr('href', '#' + hash)
                             .text('¶')
                     );
                 });
                 // links in markdown cells should open in new tabs
                 html.find("a[href]").not('[href^="#"]').attr("target", "_blank");
                 that.set_rendered(html);
                 that.typeset();
                 that.events.trigger("rendered.MarkdownCell", {cell: that});
             });
         }
         return cont;
     };
 
 
     var RawCell = function (options) {
         /**
          * Constructor
          *
          * Parameters:
          *  options: dictionary
          *      Dictionary of keyword arguments.
          *          events: $(Events) instance 
          *          config: ConfigSection instance
          *          keyboard_manager: KeyboardManager instance 
          *          notebook: Notebook instance
          */
         options = options || {};
         var config = utils.mergeopt(RawCell, {});
         TextCell.apply(this, [$.extend({}, options, {config: config})]);
 
         this.class_config = new configmod.ConfigWithDefaults(options.config,
                                             RawCell.config_defaults, 'RawCell');
         this.cell_type = 'raw';
     };
 
     RawCell.options_default = {
         placeholder : "Write raw LaTeX or other formats here, for use with nbconvert. " +
             "It will not be rendered in the notebook. " + 
             "When passing through nbconvert, a Raw Cell's content is added to the output unmodified."
     };
     
     RawCell.config_defaults =  {
         highlight_modes : {
             'diff'         :{'reg':[/^diff/]}
         },
     };
 
     RawCell.prototype = Object.create(TextCell.prototype);
 
     /** @method bind_events **/
     RawCell.prototype.bind_events = function () {
         TextCell.prototype.bind_events.apply(this);
         var that = this;
         this.element.focusout(function() {
             that.auto_highlight();
             that.render();
         });
 
         this.code_mirror.on('focus', function() { that.unrender(); });
     };
 
     /** @method render **/
     RawCell.prototype.render = function () {
         var cont = TextCell.prototype.render.apply(this);
         if (cont){
             var text = this.get_text();
             if (text === "") { text = this.placeholder; }
             this.set_text(text);
             this.element.removeClass('rendered');
             this.auto_highlight();
         }
         return cont;
     };
 
     // Backwards compatability.
     IPython.TextCell = TextCell;
     IPython.MarkdownCell = MarkdownCell;
     IPython.RawCell = RawCell;
 
     var textcell = {
         TextCell: TextCell,
         MarkdownCell: MarkdownCell,
         RawCell: RawCell
     };
     return textcell;
 });