monkey patch codemirror with new functionality

use marijnh recommended way:
https://github.com/marijnh/CodeMirror/pull/661

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

@@ -1,384 +1,410 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;
+    var 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;
     CodeMirror.modeURL = "/static/codemirror/mode/%N/%N.js";
 
     /**
      * 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
      */
     var CodeCell = function (kernel) {
         this.kernel = kernel || null;
         this.code_mirror = null;
         this.input_prompt_number = null;
         this.collapsed = false;
         this.default_mode = 'python';
         IPython.Cell.apply(this, arguments);
 
         var that = this;
         this.element.focusout(
             function() { that.auto_highlight(); }
         );
     };
 
     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 vbox');
         cell.attr('tabindex','2');
 
         this.celltoolbar = new IPython.CellToolbar(this);
         cell.append(this.celltoolbar.element);
 
         var input = $('<div></div>').addClass('input hbox');
         input.append($('<div/>').addClass('prompt input_prompt'));
         var input_area = $('<div/>').addClass('input_area box-flex1');
         this.code_mirror = CodeMirror(input_area.get(0), {
             indentUnit : 4,
             mode: 'python',
             theme: 'ipython',
             readOnly: this.read_only,
             extraKeys: {"Tab": "indentMore","Shift-Tab" : "indentLess",'Backspace':"delSpaceToPrevTabStop"},
             onKeyEvent: $.proxy(this.handle_codemirror_keyevent,this),
             matchBrackets: true
         });
         input.append(input_area);
         var output = $('<div></div>');
         cell.append(input).append(output);
         this.element = cell;
         this.output_area = new IPython.OutputArea(output, true);
 
         // construct a completer only if class exist
         // otherwise no print view
         if (IPython.Completer !== undefined)
         {
             this.completer = new IPython.Completer(this);
         }
     };
 
     /**
      *  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) {
 
         if (this.read_only){
             return false;
         }
 
         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
         if (event.type === 'keydown' && event.which != key.TAB ) {
             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
             IPython.tooltip.pending(that);
         } 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) {
             IPython.tooltip.remove_and_cancel_tooltip(true);
             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) {
                 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.
             //Do not trim here because of 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 if ((pre_cursor.substr(-1) === "("|| pre_cursor.substr(-1) === " ") && IPython.config.tooltip_on_tab ) {
                 IPython.tooltip.request(that);
                 // Prevent the event from bubbling up.
                 event.stop();
                 // Prevent CodeMirror from handling the tab.
                 return true;
             } 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(true, true, true);
         this.set_input_prompt('*');
         this.element.addClass("running");
         var callbacks = {
             'execute_reply': $.proxy(this._handle_execute_reply, this),
             'output': $.proxy(this.output_area.handle_output, this.output_area),
             'clear_output': $.proxy(this.output_area.handle_clear_output, this.output_area),
             'set_next_input': $.proxy(this._handle_set_next_input, this)
         };
         var msg_id = this.kernel.execute(this.get_text(), callbacks, {silent: false});
     };
 
     /**
      * @method _handle_execute_reply
      * @private
      */
     CodeCell.prototype._handle_execute_reply = function (content) {
         this.set_input_prompt(content.execution_count);
         this.element.removeClass("running");
         $([IPython.events]).trigger('set_dirty.Notebook', {'value': true});
     }
 
     CodeCell.prototype._handle_set_next_input = function (text) {
         var data = {'cell': this, 'text': text}
         $([IPython.events]).trigger('set_next_input.Notebook', data);
     }
 
     // Basic cell manipulation.
 
     CodeCell.prototype.select = function () {
         IPython.Cell.prototype.select.apply(this);
         this.code_mirror.refresh();
         this.code_mirror.focus();
         this.auto_highlight();
         // We used to need an additional refresh() after the focus, but
         // it appears that this has been fixed in CM. This bug would show
         // up on FF when a newly loaded markdown cell was edited.
     };
 
 
     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 (stdout, stderr, other) {
         this.output_area.clear_output(stdout, stderr, other);
     };
 
 
     // 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();
         data.cell_type = 'code';
         if (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));