Shift-Enter only selects the next cell if it is a CodeCell.

IPython/frontend/html/notebook/static/js/notebook.js

@@ -1,1048 +1,1053 b''
 var IPYTHON = {};
 
 
 //============================================================================
 // Utilities
 //============================================================================
 
 
 var uuid = function () {
     // http://www.ietf.org/rfc/rfc4122.txt
     var s = [];
     var hexDigits = "0123456789ABCDEF";
     for (var i = 0; i < 32; i++) {
         s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
     }
     s[12] = "4";  // bits 12-15 of the time_hi_and_version field to 0010
     s[16] = hexDigits.substr((s[16] & 0x3) | 0x8, 1);  // bits 6-7 of the clock_seq_hi_and_reserved to 01
 
     var uuid = s.join("");
     return uuid;
 };
 
 
 //Fix raw text to parse correctly in crazy XML
 function xmlencode(string) {
     return string.replace(/\&/g,'&'+'amp;')
         .replace(/</g,'&'+'lt;')
         .replace(/>/g,'&'+'gt;')
         .replace(/\'/g,'&'+'apos;')
         .replace(/\"/g,'&'+'quot;')
         .replace(/`/g,'&'+'#96;')
 }
 
 //Map from terminal commands to CSS classes
 attrib = {
     "30":"cblack", "31":"cred",
     "32":"cgreen", "33":"cyellow",  
     "34":"cblue", "36":"ccyan", 
     "37":"cwhite", "01":"cbold"}
 
 //Fixes escaped console commands, IE colors. Turns them into HTML
 function fixConsole(txt) {
     txt = xmlencode(txt)
     var re = /\033\[([\d;]*?)m/
     var opened = false
     var cmds = []
     var opener = ""
     var closer = ""
     
     while (re.test(txt)) {
         var cmds = txt.match(re)[1].split(";")
         closer = opened?"</span>":""
         opened = cmds.length > 1 || cmds[0] != 0
         var rep = []
         for (var i in cmds)
             if (typeof(attrib[cmds[i]]) != "undefined")
                 rep.push(attrib[cmds[i]])
         opener = rep.length > 0?"<span class=\""+rep.join(" ")+"\">":""
         txt = txt.replace(re, closer + opener)
     }
     if (opened) txt += "</span>"
     return txt.trim()
 }
 
 
 //============================================================================
 // Notebook
 //============================================================================
 
 
 var Notebook = function (selector) {
     this.element = $(selector);
     this.element.scroll();
     this.element.data("notebook", this);
     this.next_prompt_number = 1;
     this.kernel = null;
     this.msg_cell_map = {};
     this.filename = null;
     this.notebook_load_re = /%notebook load/
     this.notebook_save_re = /%notebook save/
     this.notebook_filename_re = /(\w)+.ipynb/
     this.bind_events();
     this.start_kernel();
 };
 
 
 Notebook.prototype.bind_events = function () {
     var that = this;
     $(document).keydown(function (event) {
         // console.log(event);
         if (event.which == 38 && event.shiftKey) {
             event.preventDefault();
             that.select_prev();
         } else if (event.which == 40 && event.shiftKey) {
             event.preventDefault();
             that.select_next();
         } else if (event.which == 13 && event.shiftKey) {
             // The focus is not quite working here.
             var cell = that.selected_cell();
             var cell_index = that.find_cell_index(cell);
             // TODO: the logic here needs to be moved into appropriate
             // methods of Notebook.
             if (cell instanceof CodeCell) {
                 event.preventDefault();
                 cell.clear_output();
                 var code = cell.get_code();
                 if (that.notebook_load_re.test(code)) {
                     var code_parts = code.split(' ');
                     if (code_parts.length === 3) {
                         that.load_notebook(code_parts[2]);
                     };
                 } else if (that.notebook_save_re.test(code)) {
                     var code_parts = code.split(' ');
                     if (code_parts.length === 3) {
                         that.save_notebook(code_parts[2]);
                     } else {
                         that.save_notebook()
                     };
                 } else {
                     var msg_id = that.kernel.execute(cell.get_code());
                     that.msg_cell_map[msg_id] = cell.cell_id;
                 };
                 if (cell_index === (that.ncells()-1)) {
                     that.insert_code_cell_after();
                 } else {
-                    that.select(cell_index+1);
+                    // Select the next cell if it is a CodeCell, but not
+                    // if it is a TextCell.
+                    var next_cell = that.cells()[cell_index+1];
+                    if (!(next_cell instanceof TextCell)) {
+                        that.select(cell_index+1);
+                    };
                 };
             }
         } else if (event.which == 9) {
             event.preventDefault();
             var cell = that.selected_cell();
             if (cell instanceof CodeCell) {
                 var ta = cell.element.find("textarea.input_textarea");
                 ta.val(ta.val() + "    ");
             };
         };
     });
 };
 
 
 // Cell indexing, retrieval, etc.
 
 
 Notebook.prototype.cell_elements = function () {
     return this.element.children("div.cell");
 }
 
 
 Notebook.prototype.ncells = function (cell) {
     return this.cell_elements().length;
 }
 
 
 // TODO: we are often calling cells as cells()[i], which we should optimize
 // to cells(i) or a new method.
 Notebook.prototype.cells = function () {
     return this.cell_elements().toArray().map(function (e) {
         return $(e).data("cell");
     });
 }
 
 
 Notebook.prototype.find_cell_index = function (cell) {
     var result = null;
     this.cell_elements().filter(function (index) {
         if ($(this).data("cell") === cell) {
             result = index;
         };
     });
     return result;
 };
 
 
 Notebook.prototype.index_or_selected = function (index) {
     return index || this.selected_index() || 0;
 }
 
 
 Notebook.prototype.select = function (index) {
     if (index !== undefined && index >= 0 && index < this.ncells()) {
         if (this.selected_index() !== null) {
             this.selected_cell().unselect();
         };
         this.cells()[index].select();
     };
     return this;
 };
 
 
 Notebook.prototype.select_next = function () {
     var index = this.selected_index();
     if (index !== null && index >= 0 && (index+1) < this.ncells()) {
         this.select(index+1);
     };
     return this;
 };
 
 
 Notebook.prototype.select_prev = function () {
     var index = this.selected_index();
     if (index !== null && index >= 0 && (index-1) < this.ncells()) {
         this.select(index-1);
     };
     return this;
 };
 
 
 Notebook.prototype.selected_index = function () {
     var result = null;
     this.cell_elements().filter(function (index) {
         if ($(this).data("cell").selected === true) {
             result = index;
         };
     });
     return result;
 };
 
 
 Notebook.prototype.cell_for_msg = function (msg_id) {
     var cell_id = this.msg_cell_map[msg_id];
     var result = null;
     this.cell_elements().filter(function (index) {
         cell = $(this).data("cell");
         if (cell.cell_id === cell_id) {
             result = cell;
         };
     });
     return result;
 };
 
 
 Notebook.prototype.selected_cell = function () {
     return this.cell_elements().eq(this.selected_index()).data("cell");
 }
 
 
 // Cell insertion, deletion and moving.
 
 
 Notebook.prototype.delete_cell = function (index) {
     var i = index || this.selected_index();
     if (i !== null && i >= 0 && i < this.ncells()) {
         this.cell_elements().eq(i).remove();
         if (i === (this.ncells())) {
             this.select(i-1);
         } else {
             this.select(i);
         };
     };
     return this;
 };
 
 
 Notebook.prototype.append_cell = function (cell) {
     this.element.append(cell.element);
     return this;
 };
 
 
 Notebook.prototype.insert_cell_after = function (cell, index) {
     var ncells = this.ncells();
     if (ncells === 0) {
         this.append_cell(cell);
         return this;
     };
     if (index >= 0 && index < ncells) {
         this.cell_elements().eq(index).after(cell.element);
     };
     return this
 };
 
 
 Notebook.prototype.insert_cell_before = function (cell, index) {
     var ncells = this.ncells();
     if (ncells === 0) {
         this.append_cell(cell);
         return this;
     };
     if (index >= 0 && index < ncells) {
         this.cell_elements().eq(index).before(cell.element);
     };
     return this;
 };
 
 
 Notebook.prototype.move_cell_up = function (index) {
     var i = index || this.selected_index();
     if (i !== null && i < this.ncells() && i > 0) {
         var pivot = this.cell_elements().eq(i-1);
         var tomove = this.cell_elements().eq(i);
         if (pivot !== null && tomove !== null) {
             tomove.detach();
             pivot.before(tomove);
             this.select(i-1);
         };
     };
     return this;
 }
 
 
 Notebook.prototype.move_cell_down = function (index) {
     var i = index || this.selected_index();
     if (i !== null && i < (this.ncells()-1) && i >= 0) {
         var pivot = this.cell_elements().eq(i+1)
         var tomove = this.cell_elements().eq(i)
         if (pivot !== null && tomove !== null) {
             tomove.detach();
             pivot.after(tomove);
             this.select(i+1);
         };
     };
     return this;
 }
 
 
 Notebook.prototype.sort_cells = function () {
     var ncells = this.ncells();
     var sindex = this.selected_index();
     var swapped;
     do {
         swapped = false
         for (var i=1; i<ncells; i++) {
             current = this.cell_elements().eq(i).data("cell");
             previous = this.cell_elements().eq(i-1).data("cell");
             if (previous.input_prompt_number > current.input_prompt_number) {
                 this.move_cell_up(i);
                 swapped = true;
             };
         };
     } while (swapped);
     this.select(sindex);
     return this;
 };
 
 
 Notebook.prototype.insert_code_cell_before = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var cell = new CodeCell(this);
     cell.set_input_prompt(this.next_prompt_number);
     this.next_prompt_number = this.next_prompt_number + 1;
     this.insert_cell_before(cell, i);
     this.select(this.find_cell_index(cell));
     return this;
 }
 
 
 Notebook.prototype.insert_code_cell_after = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var cell = new CodeCell(this);
     cell.set_input_prompt(this.next_prompt_number);
     this.next_prompt_number = this.next_prompt_number + 1;
     this.insert_cell_after(cell, i);
     this.select(this.find_cell_index(cell));
     return this;
 }
 
 
 Notebook.prototype.insert_text_cell_before = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var cell = new TextCell(this);
     cell.config_mathjax();
     this.insert_cell_before(cell, i);
     this.select(this.find_cell_index(cell));
     return this;
 }
 
 
 Notebook.prototype.insert_text_cell_after = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var cell = new TextCell(this);
     cell.config_mathjax();
     this.insert_cell_after(cell, i);
     this.select(this.find_cell_index(cell));
     return this;
 }
 
 
 Notebook.prototype.text_to_code = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var source_element = this.cell_elements().eq(i);
     var source_cell = source_element.data("cell");
     if (source_cell instanceof TextCell) {
         this.insert_code_cell_after(i);
         var target_cell = this.cells()[i+1];
         target_cell.set_code(source_cell.get_text());
         source_element.remove();
     };
 };
 
 
 Notebook.prototype.code_to_text = function (index) {
     // TODO: Bounds check for i
     var i = this.index_or_selected(index);
     var source_element = this.cell_elements().eq(i);
     var source_cell = source_element.data("cell");
     if (source_cell instanceof CodeCell) {
         this.insert_text_cell_after(i);
         var target_cell = this.cells()[i+1];
         var text = source_cell.get_code();
         if (text === "") {text = target_cell.placeholder;};
         target_cell.set_text(text);
         source_element.remove();
     };
 };
 
 
 // Cell collapsing
 
 Notebook.prototype.collapse = function (index) {
     var i = this.index_or_selected(index);
     this.cells()[i].collapse();
 };
 
 
 Notebook.prototype.expand = function (index) {
     var i = this.index_or_selected(index);
     this.cells()[i].expand();
 };
 
 
 // Kernel related things
 
 Notebook.prototype.start_kernel = function () {
     this.kernel = new Kernel();
     this.kernel.start_kernel(this._kernel_started, this);
 };
 
 
 Notebook.prototype._kernel_started = function () {
     console.log("Kernel started: ", this.kernel.kernel_id);
     var that = this;
 
     this.kernel.shell_channel.onmessage = function (e) {
         reply = $.parseJSON(e.data);
         console.log(reply);
         var msg_type = reply.msg_type;
         var cell = that.cell_for_msg(reply.parent_header.msg_id);
         if (msg_type === "execute_reply") {
             cell.set_input_prompt(reply.content.execution_count);
         };
     };
 
     this.kernel.iopub_channel.onmessage = function (e) {
         reply = $.parseJSON(e.data);
         var content = reply.content;
         console.log(reply);
         var msg_type = reply.msg_type;
         var cell = that.cell_for_msg(reply.parent_header.msg_id);
         if (msg_type === "stream") {
             cell.expand();
             cell.append_stream(content.data + "\n");
         } else if (msg_type === "display_data") {
             cell.expand();
             cell.append_display_data(content.data);
         } else if (msg_type === "pyout") {
             cell.expand();
             cell.append_pyout(content.data, content.execution_count)
         } else if (msg_type === "pyerr") {
             cell.expand();
             cell.append_pyerr(content.ename, content.evalue, content.traceback);
         } else if (msg_type === "status") {
             if (content.execution_state === "busy") {
                 that.kernel.status_busy();
             } else if (content.execution_state === "idle") {
                 that.kernel.status_idle();
             };
         }
     };
 };
 
 
 // Persistance and loading
 
 
 Notebook.prototype.fromJSON = function (data) {
     var ncells = this.ncells();
     for (var i=0; i<ncells; i++) {
         // Always delete cell 0 as they get renumbered as they are deleted.
         this.delete_cell(0);
     };
     var new_cells = data.cells;
     ncells = new_cells.length;
     var cell_data = null;
     for (var i=0; i<ncells; i++) {
         cell_data = new_cells[i];
         if (cell_data.cell_type == 'code') {
             this.insert_code_cell_after();
             this.selected_cell().fromJSON(cell_data);
         } else if (cell_data.cell_type === 'text') {
             this.insert_text_cell_after();
             this.selected_cell().fromJSON(cell_data);
         };
     };
 };
 
 
 Notebook.prototype.toJSON = function () {
     var cells = this.cells();
     var ncells = cells.length;
     cell_array = new Array(ncells);
     for (var i=0; i<ncells; i++) {
         cell_array[i] = cells[i].toJSON();
     };
     json = {
         cells : cell_array
     };
     return json
 };
 
 
 Notebook.prototype.test_filename = function (filename) {
     if (this.notebook_filename_re.test(filename)) {
         return true;
     } else {
         var bad_filename = $('<div/>');
         bad_filename.html(
             "The filename you entered (" + filename + ") is not valid. Notebook filenames must have the following form: foo.ipynb"
         );
         bad_filename.dialog({title: 'Invalid filename', modal: true});
         return false;
     };
 };
 
 Notebook.prototype.save_notebook = function (filename) {
     this.filename = filename || this.filename || '';
     if (this.filename === '') {
         var no_filename = $('<div/>');
         no_filename.html(
             "This notebook has no filename, please specify a filename of the form: foo.ipynb"
         );
         no_filename.dialog({title: 'Missing filename', modal: true});
         return;
     }
     if (!this.test_filename(this.filename)) {return;}
     var thedata = this.toJSON();
     var settings = {
       processData : false,
       cache : false,
       type : "PUT",
       data : JSON.stringify(thedata),
       success : function (data, status, xhr) {console.log(data);}
     };
     $.ajax("/notebooks/" + this.filename, settings);
 };
 
 
 Notebook.prototype.load_notebook = function (filename) {
     if (!this.test_filename(filename)) {return;}
     var that = this;
     $.getJSON("/notebooks/" + filename,
         function (data, status, xhr) {
             that.fromJSON(data);
             that.filename = filename;
             that.kernel.restart();
         }
     );
 }
 
 
 //============================================================================
 // Cell
 //============================================================================
 
 
 var Cell = function (notebook) {
     this.notebook = notebook;
     this.selected = false;
     this.element;
     this.create_element();
     if (this.element !== undefined) {
         this.element.data("cell", this);
         this.bind_events();
     }
     this.cell_id = uuid();
 };
 
 
 Cell.prototype.grow = function(element) {
     // Grow the cell by hand. This is used upon reloading from JSON, when the
     // autogrow handler is not called.
     var dom = element.get(0);
     var lines_count = 0;
     // modified split rule from
     // http://stackoverflow.com/questions/2035910/how-to-get-the-number-of-lines-in-a-textarea/2036424#2036424
     var lines = dom.value.split(/\r|\r\n|\n/);
     lines_count = lines.length;
     if (lines_count >= 1) {
         dom.rows = lines_count;
     } else {
         dom.rows = 1;
     }
 };
 
 
 Cell.prototype.select = function () {
     this.element.addClass('ui-widget-content ui-corner-all');
     this.selected = true;
     // TODO: we need t test across browsers to see if both of these are needed.
     // In the meantime, there should not be any harm in having them both.
     this.element.find('textarea').trigger('focusin');
     this.element.find('textarea').trigger('focus');
 };
 
 
 Cell.prototype.unselect = function () {
     this.element.removeClass('ui-widget-content ui-corner-all');
     this.selected = false;
 };
 
 
 Cell.prototype.bind_events = function () {
     var that = this;
     var nb = that.notebook
     that.element.click(function (event) {
         if (that.selected === false) {
             nb.select(nb.find_cell_index(that));
         };
     });
     that.element.focusin(function (event) {
         if (that.selected === false) {
             nb.select(nb.find_cell_index(that));
         };
     });
 };
 
 
 // Subclasses must implement create_element.
 Cell.prototype.create_element = function () {};
 
 
 //============================================================================
 // CodeCell
 //============================================================================
 
 
 var CodeCell = function (notebook) {
     Cell.apply(this, arguments);
     this.input_prompt_number = ' ';
 };
 
 
 CodeCell.prototype = new Cell();
 
 
 CodeCell.prototype.create_element = function () {
     var cell =  $('<div></div>').addClass('cell code_cell');
     var input = $('<div></div>').addClass('input');
     input.append($('<div/>').addClass('prompt input_prompt'));
     var input_textarea = $('<textarea/>').addClass('input_textarea').attr('rows',1).attr('wrap','hard').autogrow();
     input.append($('<div/>').addClass('input_area').append(input_textarea));
     var output = $('<div></div>').addClass('output');
     cell.append(input).append(output);
     this.element = cell;
     this.collapse()
 };
 
 
 CodeCell.prototype.append_pyout = function (data, n) {
     var toinsert = $("<div/>").addClass("output_area output_pyout");
     toinsert.append($('<div/>').
         addClass('prompt output_prompt').
         html('Out[' + n + ']:')
     );
     this.append_display_data(data, toinsert);
     toinsert.children().last().addClass("box_flex1");
     this.element.find("div.output").append(toinsert);
     // If we just output latex, typeset it.
     if (data["text/latex"] !== undefined) {
         MathJax.Hub.Queue(["Typeset",MathJax.Hub]);
     };
 };
 
 
 CodeCell.prototype.append_pyerr = function (ename, evalue, tb) {
     var s = '';
     var len = tb.length;
     for (var i=0; i<len; i++) {
         s = s + tb[i] + '\n';
     }
     s = s + '\n';
     this.append_stream(s);
 };
 
 
 CodeCell.prototype.append_display_data = function (data, element) {
     if (data["text/latex"] !== undefined) {
         this.append_latex(data["text/latex"], element);
         // If it is undefined, then we just appended to div.output, which
         // makes the latex visible and we can typeset it. The typesetting
         // has to be done after the latex is on the page.
         if (element === undefined) {
             MathJax.Hub.Queue(["Typeset",MathJax.Hub]);
         };
     } else if (data["image/svg+xml"] !== undefined) {
         this.append_svg(data["image/svg+xml"], element);
     } else if (data["text/plain"] !== undefined) {
         this.append_stream(data["text/plain"], element);
     };
     return element;
 };
 
 
 CodeCell.prototype.append_stream = function (data, element) {
     element = element || this.element.find("div.output");
     var toinsert = $("<div/>").addClass("output_area output_stream");
     toinsert.append($("<pre/>").html(fixConsole(data)));
     element.append(toinsert);
     return element;
 };
 
 
 CodeCell.prototype.append_svg = function (svg, element) {
     element = element || this.element.find("div.output");
     var toinsert = $("<div/>").addClass("output_area output_svg");
     toinsert.append(svg);
     element.append(toinsert);
     return element;
 };
 
 
 CodeCell.prototype.append_latex = function (latex, element) {
     // This method cannot do the typesetting because the latex first has to
     // be on the page.
     element = element || this.element.find("div.output");
     var toinsert = $("<div/>").addClass("output_area output_latex");
     toinsert.append(latex);
     element.append(toinsert);
     return element;
 }
 
 
 CodeCell.prototype.clear_output = function () {
     this.element.find("div.output").html("");
 };
 
 
 CodeCell.prototype.collapse = function () {
     this.element.find('div.output').hide();
 };
 
 
 CodeCell.prototype.expand = function () {
     this.element.find('div.output').show();
 };
 
 
 CodeCell.prototype.set_input_prompt = function (number) {
     var n = number || ' ';
     this.input_prompt_number = n
     this.element.find('div.input_prompt').html('In&nbsp;[' + n + ']:');
 };
 
 
 CodeCell.prototype.get_code = function () {
     return this.element.find("textarea.input_textarea").val();
 };
 
 
 CodeCell.prototype.set_code = function (code) {
     return this.element.find("textarea.input_textarea").val(code);
 };
 
 
 CodeCell.prototype.fromJSON = function (data) {
     if (data.cell_type === 'code') {
         this.set_code(data.code);
         this.set_input_prompt(data.prompt_number);
         this.grow(this.element.find("textarea.input_textarea"));
     };
 };
 
 
 CodeCell.prototype.toJSON = function () {
     return {
         code : this.get_code(),
         cell_type : 'code',
         prompt_number : this.input_prompt_number
     };
 };
 
 //============================================================================
 // TextCell
 //============================================================================
 
 
 var TextCell = function (notebook) {
     Cell.apply(this, arguments);
     this.placeholder = "Type <strong>HTML</strong> and LaTeX: $\\alpha^2$"
 };
 
 
 TextCell.prototype = new Cell();
 
 
 TextCell.prototype.create_element = function () {
     var cell = $("<div>").addClass('cell text_cell').
                append(
                    $("<textarea>" + this.placeholder + "</textarea>").
                    addClass('text_cell_input').
                    attr('rows',1).
                    attr('cols',80).
                    autogrow()
                ).append(
                    $('<div></div>').addClass('text_cell_render')
                )
     this.element = cell;
 };
 
 
 TextCell.prototype.select = function () {
     this.edit();
     Cell.prototype.select.apply(this);
 };
 
 
 TextCell.prototype.edit = function () {
     var text_cell = this.element;
     var input = text_cell.find("textarea.text_cell_input");
     var output = text_cell.find("div.text_cell_render");  
     output.hide();
     input.show().trigger('focus');
 };
 
 
 TextCell.prototype.render = function () {
     var text_cell = this.element;
     var input = text_cell.find("textarea.text_cell_input");
     var output = text_cell.find("div.text_cell_render");    
     var text = input.val();
     if (text === "") {
         text = this.placeholder;
         input.val(text);
     };
     output.html(text)
     input.html(text);
     MathJax.Hub.Queue(["Typeset",MathJax.Hub]);
     input.hide();
     output.show();
 };
 
 
 TextCell.prototype.config_mathjax = function () {
     var text_cell = this.element;
     var that = this;
     text_cell.click(function () {
         that.edit();
     }).focusout(function () {
         that.render();
     });
     
     text_cell.trigger("focusout");
 };
 
 
 TextCell.prototype.get_text = function() {
     return this.element.find("textarea.text_cell_input").val();
 };
 
 
 TextCell.prototype.set_text = function(text) {
     this.element.find("textarea.text_cell_input").val(text);
     this.element.find("textarea.text_cell_input").html(text);
     this.element.find("div.text_cell_render").html(text);
 };
 
 
 TextCell.prototype.fromJSON = function (data) {
     if (data.cell_type === 'text') {
         this.set_text(data.text);
         this.grow(this.element.find("textarea.text_cell_input"));
     };
 }
 
 
 TextCell.prototype.toJSON = function () {
     return {
         cell_type : 'text',
         text : this.get_text(),
     };
 };
 
 //============================================================================
 // On document ready
 //============================================================================
 
 
 var Kernel = function () {
     this.kernel_id = null;
     this.base_url = "/kernels";
     this.kernel_url = null;
 };
 
 
 Kernel.prototype.get_msg = function (msg_type, content) {
     var msg = {
         header : {
             msg_id : uuid(),
             username : "bgranger",
             session: this.session_id
         },
         msg_type : msg_type,
         content : content,
         parent_header : {}
     };
     return msg;
 }
 
 Kernel.prototype.start_kernel = function (callback, context) {
     var that = this;
     $.post(this.base_url,
         function (kernel_id) {
             that._handle_start_kernel(kernel_id, callback, context);
         }, 
         'json'
     );
 };
 
 
 Kernel.prototype._handle_start_kernel = function (kernel_id, callback, context) {
     this.kernel_id = kernel_id;
     this.kernel_url = this.base_url + "/" + this.kernel_id;
     this._start_channels();
     callback.call(context);
 };
 
 
 Kernel.prototype._start_channels = function () {
     var ws_url = "ws://127.0.0.1:8888" + this.kernel_url;
     this.shell_channel = new WebSocket(ws_url + "/shell");
     this.iopub_channel = new WebSocket(ws_url + "/iopub");
 }
 
 
 Kernel.prototype.execute = function (code) {
     var content = {
         code : code,
         silent : false,
         user_variables : [],
         user_expressions : {}
     };
     var msg = this.get_msg("execute_request", content);
     this.shell_channel.send(JSON.stringify(msg));
     return msg.header.msg_id;
 }
 
 
 Kernel.prototype.interrupt = function () {
     $.post(this.kernel_url + "/interrupt");
 };
 
 
 Kernel.prototype.restart = function () {
     this.status_restarting();
     url = this.kernel_url + "/restart"
     var that = this;
     $.post(url, function (kernel_id) {
         console.log("Kernel restarted: " + kernel_id);
         that.kernel_id = kernel_id;
         that.kernel_url = that.base_url + "/" + that.kernel_id;
         that.status_idle();
     }, 'json');
 };
 
 
 Kernel.prototype.status_busy = function () {
     $("#kernel_status").removeClass("status_idle");
     $("#kernel_status").removeClass("status_restarting");
     $("#kernel_status").addClass("status_busy");
     $("#kernel_status").text("Busy");
 };
 
 
 Kernel.prototype.status_idle = function () {
     $("#kernel_status").removeClass("status_busy");
     $("#kernel_status").removeClass("status_restarting");
     $("#kernel_status").addClass("status_idle");
     $("#kernel_status").text("Idle");
 };
 
 Kernel.prototype.status_restarting = function () {
     $("#kernel_status").removeClass("status_busy");
     $("#kernel_status").removeClass("status_idle");
     $("#kernel_status").addClass("status_restarting");
     $("#kernel_status").text("Restarting");
 };
 
 //============================================================================
 // On document ready
 //============================================================================
 
 
 $(document).ready(function () {
 
     MathJax.Hub.Config({
         tex2jax: {
             inlineMath: [ ['$','$'], ["\\(","\\)"] ],
             displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
         },
         displayAlign: 'left', // Change this to 'center' to center equations.
         "HTML-CSS": {
             styles: {'.MathJax_Display': {"margin": 0}}
         }
     });
 
     IPYTHON.notebook = new Notebook('div.notebook');
     IPYTHON.notebook.insert_code_cell_after();
 
     $("#menu_tabs").tabs();
 
     $("#help_toolbar").buttonset();
 
     $("#kernel_toolbar").buttonset();
     $("#interrupt_kernel").click(function () {IPYTHON.notebook.kernel.interrupt();});
     $("#restart_kernel").click(function () {IPYTHON.notebook.kernel.restart();});
     $("#kernel_status").addClass("status_idle");
 
     $("#move_cell").buttonset();
     $("#move_up").button("option", "icons", {primary:"ui-icon-arrowthick-1-n"});
     $("#move_up").button("option", "text", false);
     $("#move_up").click(function () {IPYTHON.notebook.move_cell_up();});
     $("#move_down").button("option", "icons", {primary:"ui-icon-arrowthick-1-s"});
     $("#move_down").button("option", "text", false);
     $("#move_down").click(function () {IPYTHON.notebook.move_cell_down();});
 
     $("#insert_delete").buttonset();
     $("#insert_cell_before").click(function () {IPYTHON.notebook.insert_code_cell_before();});
     $("#insert_cell_after").click(function () {IPYTHON.notebook.insert_code_cell_after();});
     $("#delete_cell").button("option", "icons", {primary:"ui-icon-closethick"});
     $("#delete_cell").button("option", "text", false);
     $("#delete_cell").click(function () {IPYTHON.notebook.delete_cell();});
 
     $("#cell_type").buttonset();
     $("#to_code").click(function () {IPYTHON.notebook.text_to_code();});
     $("#to_text").click(function () {IPYTHON.notebook.code_to_text();});
 
     $("#sort").buttonset();
     $("#sort_cells").click(function () {IPYTHON.notebook.sort_cells();});
 
     $("#toggle").buttonset();
     $("#collapse").click(function () {IPYTHON.notebook.collapse();});
     $("#expand").click(function () {IPYTHON.notebook.expand();});
 
 });
  No newline at end of file