Special handling for CM's vim keyboard mapping.

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

@@ -1,508 +1,533 b''
 //----------------------------------------------------------------------------
 //  Copyright (C) 2008-2011  The IPython Development Team
 //
 //  Distributed under the terms of the BSD License.  The full license is in
 //  the file COPYING, distributed as part of this software.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // CodeCell
 //============================================================================
 /**
  * An extendable module that provide base functionnality to create cell for notebook.
  * @module IPython
  * @namespace IPython
  * @submodule CodeCell
  */
 
 
 /* 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 IPython = (function (IPython) {
     "use strict";
 
     var utils = IPython.utils;
     var key   = IPython.utils.keycodes;
 
     /**
      * A Cell conceived to write code.
      *
      * 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.
      * @class CodeCell
      * @extends IPython.Cell
      *
      * @constructor
      * @param {Object|null} kernel
      * @param {object|undefined} [options]
      *      @param [options.cm_config] {object} config to pass to CodeMirror
      */
     var CodeCell = function (kernel, options) {
         this.kernel = kernel || null;
         this.collapsed = false;
 
         // 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;
 
 
         var cm_overwrite_options  = {
             onKeyEvent: $.proxy(this.handle_keyevent,this)
         };
 
         options = this.mergeopt(CodeCell, options, {cm_config:cm_overwrite_options});
 
         IPython.Cell.apply(this,[options]);
 
         // 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.prototype = new IPython.Cell();
 
     /**
      * @method auto_highlight
      */
     CodeCell.prototype.auto_highlight = function () {
         this._auto_highlight(IPython.config.cell_magic_highlight);
     };
 
     /** @method create_element */
     CodeCell.prototype.create_element = function () {
         IPython.Cell.prototype.create_element.apply(this, arguments);
 
         var cell =  $('<div></div>').addClass('cell border-box-sizing 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 IPython.CellToolbar(this);
         inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('input_area');
         this.code_mirror = CodeMirror(input_area.get(0), this.cm_config);
         $(this.code_mirror.getInputField()).attr("spellcheck", "false");
         inner_cell.append(input_area);
         input.append(prompt).append(inner_cell);
         var output = $('<div></div>');
         cell.append(input).append(output);
         this.element = cell;
         this.output_area = new IPython.OutputArea(output, true);
         this.completer = new IPython.Completer(this);
     };
 
     /** @method bind_events */
     CodeCell.prototype.bind_events = function () {
         IPython.Cell.prototype.bind_events.apply(this);
         var that = this;
 
         this.element.focusout(
             function() { that.auto_highlight(); }
         );
     };
 
     CodeCell.prototype.handle_keyevent = function (editor, event) {
 
         console.log('CM', this.mode, event.which, event.type)
 
         if (this.mode === 'command') {
             return true;
         } else if (this.mode === 'edit') {
             return this.handle_codemirror_keyevent(editor, event);
         }
     };
 
     /**
      *  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 != key.TAB ) {
-            IPython.tooltip.remove_and_cancel_tooltip();
+            tooltip_closed = IPython.tooltip.remove_and_cancel_tooltip();
         }
 
         var cur = editor.getCursor();
         if (event.keyCode === key.ENTER){
             this.auto_highlight();
         }
 
         if (event.keyCode === key.ENTER && (event.shiftKey || event.ctrlKey)) {
             // Always ignore shift-enter in CodeMirror as we handle it.
             return true;
         } else if (event.which === 40 && event.type === 'keypress' && IPython.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
             IPython.tooltip.pending(that, true);
         } else if (event.which === key.UPARROW && event.type === 'keydown') {
             // If we are not at the top, let CM handle the up arrow and
             // prevent the global keydown handler from handling it.
             if (!that.at_top()) {
                 event.stop();
                 return false;
             } else {
                 return true;
             }
-        } else if (event.which === key.ESC) {
-            return IPython.tooltip.remove_and_cancel_tooltip(true);
+        } else if (event.which === key.ESC && event.type === 'keydown') {
+            // First see if the tooltip is active and if so cancel it.
+            if (tooltip_closed) {
+                // The call to remove_and_cancel_tooltip above in L177 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 (!IPython.tooltip._hidden) {
+                    IPython.tooltip.remove_and_cancel_tooltip(true);
+                }
+                // If we closed the tooltip, don't let CM or the global handlers
+                // handle this event.
+                event.stop();
+                return true;
+            }
+            if (that.code_mirror.options.keyMap === "vim-insert") {
+                // vim keyMap is active and in insert mode. In this case we leave vim
+                // insert mode, but remain in notebook edit mode.
+                // Let' CM handle this event and prevent global handling.
+                event.stop();
+                return false;
+            } else {
+                // vim keyMap is not active. Leave notebook edit mode.
+                // Don't let CM handle the event, defer to global handling.
+                return true;
+            }
         } else if (event.which === key.DOWNARROW && event.type === 'keydown') {
             // If we are not at the bottom, let CM handle the down arrow and
             // prevent the global keydown handler from handling it.
             if (!that.at_bottom()) {
                 event.stop();
                 return false;
             } else {
                 return true;
             }
-        } else if (event.keyCode === key.TAB && event.type == 'keydown' && event.shiftKey) {
+        } else if (event.keyCode === key.TAB && event.type === 'keydown' && event.shiftKey) {
                 if (editor.somethingSelected()){
                     var anchor = editor.getCursor("anchor");
                     var head = editor.getCursor("head");
                     if( anchor.line != head.line){
                         return false;
                     }
                 }
                 IPython.tooltip.request(that);
                 event.stop();
                 return true;
         } else if (event.keyCode === key.TAB && event.type == 'keydown') {
             // Tab completion.
             IPython.tooltip.remove_and_cancel_tooltip();
             if (editor.somethingSelected()) {
                 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.stop();
                 this.completer.startCompletion();
                 return true;
             }
         } else {
             // keypress/keyup also trigger on TAB press, and we don't want to
             // use those to disable tab completion.
             return false;
         }
         return false;
     };
 
     // 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 () {
         this.output_area.clear_output();
         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();
         
         this.last_msg_id = this.kernel.execute(this.get_text(), callbacks, {silent: false, store_history: true});
     };
     
     /**
      * Construct the default callbacks for
      * @method get_callbacks
      */
     CodeCell.prototype.get_callbacks = function () {
         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 : $.proxy(this.output_area.handle_output, this.output_area),
                 clear_output : $.proxy(this.output_area.handle_clear_output, this.output_area),
             },
             input : $.proxy(this._handle_input_request, this)
         };
     };
     
     CodeCell.prototype._open_with_pager = function (payload) {
         $([IPython.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");
         $([IPython.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};
         $([IPython.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 = IPython.Cell.prototype.select.apply(this);
         if (cont) {
             this.code_mirror.refresh();
             this.auto_highlight();
         };
         return cont;
     };
 
     CodeCell.prototype.render = function () {
         var cont = IPython.Cell.prototype.render.apply(this);
         // Always execute, even if we are already in the rendered state
         return cont;
     };
     
     CodeCell.prototype.unrender = function () {
         // CodeCell is always rendered
         return false;
     };
 
     CodeCell.prototype.command_mode = function () {
         var cont = IPython.Cell.prototype.command_mode.apply(this);
         if (cont) {
             this.focus_cell();
         };
         return cont;
     }
 
     CodeCell.prototype.edit_mode = function () {
         var cont = IPython.Cell.prototype.edit_mode.apply(this);
         if (cont) {
             this.focus_editor();
         };
         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 = function () {
         this.collapsed = true;
         this.output_area.collapse();
     };
 
 
     CodeCell.prototype.expand = function () {
         this.collapsed = false;
         this.output_area.expand();
     };
 
 
     CodeCell.prototype.toggle_output = function () {
         this.collapsed = Boolean(1 - this.collapsed);
         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 = prompt_value || "&nbsp;";
         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.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.at_top = function () {
         var cursor = this.code_mirror.getCursor();
         if (cursor.line === 0 && cursor.ch === 0) {
             return true;
         } else {
             return false;
         }
     };
 
 
     CodeCell.prototype.at_bottom = function () {
         var cursor = this.code_mirror.getCursor();
         if (cursor.line === (this.code_mirror.lineCount()-1) && cursor.ch === this.code_mirror.getLine(cursor.line).length) {
             return true;
         } else {
             return false;
         }
     };
 
 
     CodeCell.prototype.clear_output = function (wait) {
         this.output_area.clear_output(wait);
     };
 
 
     // JSON serialization
 
     CodeCell.prototype.fromJSON = function (data) {
         IPython.Cell.prototype.fromJSON.apply(this, arguments);
         if (data.cell_type === 'code') {
             if (data.input !== undefined) {
                 this.set_text(data.input);
                 // 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();
             }
             if (data.prompt_number !== undefined) {
                 this.set_input_prompt(data.prompt_number);
             } else {
                 this.set_input_prompt();
             }
             this.output_area.fromJSON(data.outputs);
             if (data.collapsed !== undefined) {
                 if (data.collapsed) {
                     this.collapse();
                 } else {
                     this.expand();
                 }
             }
         }
     };
 
 
     CodeCell.prototype.toJSON = function () {
         var data = IPython.Cell.prototype.toJSON.apply(this);
         data.input = this.get_text();
         // is finite protect against undefined and '*' value
         if (isFinite(this.input_prompt_number)) {
             data.prompt_number = this.input_prompt_number;
         }
         var outputs = this.output_area.toJSON();
         data.outputs = outputs;
         data.language = 'python';
         data.collapsed = this.collapsed;
         return data;
     };
 
 
     IPython.CodeCell = CodeCell;
 
     return IPython;
 }(IPython));

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

@@ -1,589 +1,601 b''
 //----------------------------------------------------------------------------
 //  Copyright (C) 2008-2012  The IPython Development Team
 //
 //  Distributed under the terms of the BSD License.  The full license is in
 //  the file COPYING, distributed as part of this software.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // TextCell
 //============================================================================
 
 
 
 /**
     A module that allow to create different type of Text Cell
     @module IPython
     @namespace IPython
  */
 var IPython = (function (IPython) {
     "use strict";
 
     // TextCell base class
     var key = IPython.utils.keycodes;
 
     /**
      * Construct a new TextCell, codemirror mode is by default 'htmlmixed', and cell type is 'text'
      * cell start as not redered.
      *
      * @class TextCell
      * @constructor TextCell
      * @extend IPython.Cell
      * @param {object|undefined} [options]
      *      @param [options.cm_config] {object} config to pass to CodeMirror, will extend/overwrite default config
      *      @param [options.placeholder] {string} default string to use when souce in empty for rendering (only use in some TextCell subclass)
      */
     var TextCell = function (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.
 
         // we cannot put this as a class key as it has handle to "this".
         var cm_overwrite_options  = {
             onKeyEvent: $.proxy(this.handle_keyevent,this)
         };
 
         options = this.mergeopt(TextCell,options,{cm_config:cm_overwrite_options});
 
         this.cell_type = this.cell_type || 'text';
 
         IPython.Cell.apply(this, [options]);
 
         this.rendered = false;
     };
 
     TextCell.prototype = new IPython.Cell();
 
     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 () {
         IPython.Cell.prototype.create_element.apply(this, arguments);
 
         var cell = $("<div>").addClass('cell text_cell border-box-sizing');
         cell.attr('tabindex','2');
 
         var prompt = $('<div/>').addClass('prompt input_prompt');
         cell.append(prompt);
         var inner_cell = $('<div/>').addClass('inner_cell');
         this.celltoolbar = new IPython.CellToolbar(this);
         inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('text_cell_input border-box-sizing');
         this.code_mirror = CodeMirror(input_area.get(0), this.cm_config);
         // The tabindex=-1 makes this div focusable.
         var render_area = $('<div/>').addClass('text_cell_render border-box-sizing').
             addClass('rendered_html').attr('tabindex','-1');
         inner_cell.append(input_area).append(render_area);
         cell.append(inner_cell);
         this.element = cell;
     };
 
 
     /**
      * Bind the DOM evet to cell actions
      * Need to be called after TextCell.create_element
      * @private
      * @method bind_event
      */
     TextCell.prototype.bind_events = function () {
         IPython.Cell.prototype.bind_events.apply(this);
         var that = this;
 
         this.element.dblclick(function () {
             if (that.selected === false) {
                 $([IPython.events]).trigger('select.Cell', {'cell':that});
             };
             $([IPython.events]).trigger('edit_mode.Cell', {cell: that});
         });
     };
 
     TextCell.prototype.handle_keyevent = function (editor, event) {
 
         console.log('CM', this.mode, event.which, event.type)
 
         if (this.mode === 'command') {
             return true;
         } else if (this.mode === 'edit') {
             return this.handle_codemirror_keyevent(editor, event);
         }
     };
 
     /**
      * This method gets called in CodeMirror's onKeyDown/onKeyPress
      * handlers and is used to provide custom key handling.
      *
      * Subclass should override this method to have custom handeling
      *
      * @method handle_codemirror_keyevent
      * @param {CodeMirror} editor - The codemirror instance bound to the cell
      * @param {event} event -
      * @return {Boolean} `true` if CodeMirror should ignore the event, `false` Otherwise
      */
     TextCell.prototype.handle_codemirror_keyevent = function (editor, event) {
         var that = this;
 
         if (event.keyCode === 13 && (event.shiftKey || event.ctrlKey || event.altKey)) {
             // Always ignore shift-enter in CodeMirror as we handle it.
             return true;
         } else if (event.which === key.UPARROW && event.type === 'keydown') {
             // If we are not at the top, let CM handle the up arrow and
             // prevent the global keydown handler from handling it.
             if (!that.at_top()) {
                 event.stop();
                 return false;
             } else {
                 return true;
             };
         } else if (event.which === key.DOWNARROW && event.type === 'keydown') {
             // If we are not at the bottom, let CM handle the down arrow and
             // prevent the global keydown handler from handling it.
             if (!that.at_bottom()) {
                 event.stop();
                 return false;
             } else {
                 return true;
             };
+        } else if (event.which === key.ESC && event.type === 'keydown') {
+            if (that.code_mirror.options.keyMap === "vim-insert") {
+                // vim keyMap is active and in insert mode. In this case we leave vim
+                // insert mode, but remain in notebook edit mode.
+                // Let' CM handle this event and prevent global handling.
+                event.stop();
+                return false;
+            } else {
+                // vim keyMap is not active. Leave notebook edit mode.
+                // Don't let CM handle the event, defer to global handling.
+                return true;
+            }
         }
         return false;
     };
 
     // Cell level actions
     
     TextCell.prototype.select = function () {
         var cont = IPython.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 = IPython.Cell.prototype.unrender.apply(this);
         if (cont) {
             var text_cell = this.element;
             var output = text_cell.find("div.text_cell_render");
             output.hide();
             text_cell.find('div.text_cell_input').show();
             if (this.get_text() === this.placeholder) {
                 this.set_text('');
                 this.refresh();
             }
 
         };
         return cont;
     };
 
     TextCell.prototype.execute = function () {
         this.render();
     };
 
     TextCell.prototype.command_mode = function () {
         var cont = IPython.Cell.prototype.command_mode.apply(this);
         if (cont) {
             this.focus_cell();
         };
         return cont;
     }
 
     TextCell.prototype.edit_mode = function () {
         var cont = IPython.Cell.prototype.edit_mode.apply(this);
         if (cont) {
             this.unrender();
             this.focus_editor();
         };
         return cont;
     }
 
     /**
      * 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.code_mirror.refresh();
     };
 
     /**
      * setter :{{#crossLink "TextCell/set_rendered"}}{{/crossLink}}
      * @method get_rendered
      * @return {html} html of rendered element
      * */
     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);
     };
 
     /**
      * @method at_top
      * @return {Boolean}
      */
     TextCell.prototype.at_top = function () {
         if (this.rendered) {
             return true;
         } else {
             var cursor = this.code_mirror.getCursor();
             if (cursor.line === 0 && cursor.ch === 0) {
                 return true;
             } else {
                 return false;
             };
         };
     };
 
     /**
      * @method at_bottom
      * @return {Boolean}
      * */
     TextCell.prototype.at_bottom = function () {
         if (this.rendered) {
             return true;
         } else {
             var cursor = this.code_mirror.getCursor();
             if (cursor.line === (this.code_mirror.lineCount()-1) && cursor.ch === this.code_mirror.getLine(cursor.line).length) {
                 return true;
             } else {
                 return false;
             };
         };
     };
 
     /**
      * Create Text cell from JSON
      * @param {json} data - JSON serialized text-cell
      * @method fromJSON
      */
     TextCell.prototype.fromJSON = function (data) {
         IPython.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();
                 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 = IPython.Cell.prototype.toJSON.apply(this);
         data.source = this.get_text();
         if (data.source == this.placeholder) {
             data.source = "";
         }
         return data;
     };
 
 
     /**
      * @class MarkdownCell
      * @constructor MarkdownCell
      * @extends IPython.HTMLCell
      */
     var MarkdownCell = function (options) {
         options = this.mergeopt(MarkdownCell, options);
 
         this.cell_type = 'markdown';
         TextCell.apply(this, [options]);
     };
 
     MarkdownCell.options_default = {
         cm_config: {
             mode: 'gfm'
         },
         placeholder: "Type *Markdown* and LaTeX: $\\alpha^2$"
     }
 
     MarkdownCell.prototype = new TextCell();
 
     /**
      * @method render
      */
     MarkdownCell.prototype.render = function () {
         var cont = IPython.TextCell.prototype.render.apply(this);
         if (cont) {
             var text = this.get_text();
             var math = null;
             if (text === "") { text = this.placeholder; }
             var text_and_math = IPython.mathjaxutils.remove_math(text);
             text = text_and_math[0];
             math = text_and_math[1];
             var html = marked.parser(marked.lexer(text));
             html = $(IPython.mathjaxutils.replace_math(html, math));
             // links in markdown cells should open in new tabs
             html.find("a[href]").not('[href^="#"]').attr("target", "_blank");
             try {
                 this.set_rendered(html);
             } catch (e) {
                 console.log("Error running Javascript in Markdown:");
                 console.log(e);
                 this.set_rendered($("<div/>").addClass("js-error").html(
                     "Error rendering Markdown!<br/>" + e.toString())
                 );
             }
             this.element.find('div.text_cell_input').hide();
             this.element.find("div.text_cell_render").show();
             this.typeset()
         };
         return cont;
     };
 
 
     // RawCell
 
     /**
      * @class RawCell
      * @constructor RawCell
      * @extends IPython.TextCell
      */
     var RawCell = function (options) {
 
         options = this.mergeopt(RawCell,options)
         TextCell.apply(this, [options]);
         this.cell_type = 'raw';
         // RawCell should always hide its rendered div
         this.element.find('div.text_cell_render').hide();
     };
 
     RawCell.options_default = {
         placeholder : "Write raw LaTeX or other formats here, for use with nbconvert.\n" +
             "It will not be rendered in the notebook.\n" + 
             "When passing through nbconvert, a Raw Cell's content is added to the output unmodified."
     };
 
     RawCell.prototype = new TextCell();
 
     /** @method bind_events **/
     RawCell.prototype.bind_events = function () {
         TextCell.prototype.bind_events.apply(this);
         var that = this
         this.element.focusout(function() {
             that.auto_highlight();
         });
     };
 
     /**
      * Trigger autodetection of highlight scheme for current cell
      * @method auto_highlight
      */
     RawCell.prototype.auto_highlight = function () {
         this._auto_highlight(IPython.config.raw_cell_highlight);
     };
 
     /** @method render **/
     RawCell.prototype.render = function () {
         // Make sure that this cell type can never be rendered
         if (this.rendered) {
             this.unrender();
         }
         var text = this.get_text();
         if (text === "") { text = this.placeholder; }
         this.set_text(text);
     };
 
 
     /** @method handle_codemirror_keyevent **/
     RawCell.prototype.handle_codemirror_keyevent = function (editor, event) {
 
         var that = this;
         if (this.mode === 'command') {
             return false
         } else if (this.mode === 'edit') {
             // TODO: review these handlers...
             if (event.which === key.UPARROW && event.type === 'keydown') {
                 // If we are not at the top, let CM handle the up arrow and
                 // prevent the global keydown handler from handling it.
                 if (!that.at_top()) {
                     event.stop();
                     return false;
                 } else {
                     return true;
                 };
             } else if (event.which === key.DOWNARROW && event.type === 'keydown') {
                 // If we are not at the bottom, let CM handle the down arrow and
                 // prevent the global keydown handler from handling it.
                 if (!that.at_bottom()) {
                     event.stop();
                     return false;
                 } else {
                     return true;
                 };
             };
             return false;
         };
         return false;
     };
 
 
     /**
      * @class HeadingCell
      * @extends IPython.TextCell
      */
 
     /**
      * @constructor HeadingCell
      * @extends IPython.TextCell
      */
     var HeadingCell = function (options) {
         options = this.mergeopt(HeadingCell, options);
 
         this.level = 1;
         this.cell_type = 'heading';
         TextCell.apply(this, [options]);
 
         /**
          * heading level of the cell, use getter and setter to access
          * @property level
          */
     };
 
     HeadingCell.options_default = {
         placeholder: "Type Heading Here"
     };
 
     HeadingCell.prototype = new TextCell();
 
     /** @method fromJSON */
     HeadingCell.prototype.fromJSON = function (data) {
         if (data.level != undefined){
             this.level = data.level;
         }
         TextCell.prototype.fromJSON.apply(this, arguments);
     };
 
 
     /** @method toJSON */
     HeadingCell.prototype.toJSON = function () {
         var data = TextCell.prototype.toJSON.apply(this);
         data.level = this.get_level();
         return data;
     };
 
     /**
      * can the cell be split into two cells
      * @method is_splittable
      **/
     HeadingCell.prototype.is_splittable = function () {
         return false;
     };
 
 
     /**
      * can the cell be merged with other cells
      * @method is_mergeable
      **/
     HeadingCell.prototype.is_mergeable = function () {
         return false;
     };
 
     /**
      * Change heading level of cell, and re-render
      * @method set_level
      */
     HeadingCell.prototype.set_level = function (level) {
         this.level = level;
         if (this.rendered) {
             this.rendered = false;
             this.render();
         };
     };
 
     /** The depth of header cell, based on html (h1 to h6)
      * @method get_level
      * @return {integer} level - for 1 to 6
      */
     HeadingCell.prototype.get_level = function () {
         return this.level;
     };
 
 
     HeadingCell.prototype.set_rendered = function (html) {
         this.element.find("div.text_cell_render").html(html);
     };
 
 
     HeadingCell.prototype.get_rendered = function () {
         var r = this.element.find("div.text_cell_render");
         return r.children().first().html();
     };
 
 
     HeadingCell.prototype.render = function () {
         var cont = IPython.TextCell.prototype.render.apply(this);
         if (cont) {
             var text = this.get_text();
             var math = null;
             // Markdown headings must be a single line
             text = text.replace(/\n/g, ' ');
             if (text === "") { text = this.placeholder; }
             text = Array(this.level + 1).join("#") + " " + text;
             var text_and_math = IPython.mathjaxutils.remove_math(text);
             text = text_and_math[0];
             math = text_and_math[1];
             var html = marked.parser(marked.lexer(text));
             var h = $(IPython.mathjaxutils.replace_math(html, math));
             // add id and linkback anchor
             var hash = h.text().replace(/ /g, '-');
             h.attr('id', hash);
             h.append(
                 $('<a/>')
                     .addClass('anchor-link')
                     .attr('href', '#' + hash)
                     .text('¶')
             );
             
             this.set_rendered(h);
             this.typeset();
             this.element.find('div.text_cell_input').hide();
             this.element.find("div.text_cell_render").show();
 
         };
         return cont;
     };
 
     IPython.TextCell = TextCell;
     IPython.MarkdownCell = MarkdownCell;
     IPython.RawCell = RawCell;
     IPython.HeadingCell = HeadingCell;
 
 
     return IPython;
 
 }(IPython));