Make cell be undeletable ONLY when metadata is explicitly false

IPython/html/static/notebook/js/cell.js

@@ -1,568 +1,571 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     'base/js/namespace',
     'jquery',
     'base/js/utils',
 ], function(IPython, $, utils) {
     // TODO: remove IPython dependency here 
     "use strict";
 
     // monkey patch CM to be able to syntax highlight cell magics
     // bug reported upstream,
     // see https://github.com/codemirror/CodeMirror/issues/670
     if(CodeMirror.getMode(1,'text/plain').indent === undefined ){
         CodeMirror.modes.null = function() {
             return {token: function(stream) {stream.skipToEnd();},indent : function(){return 0;}};
         };
     }
 
     CodeMirror.patchedGetMode = function(config, mode){
             var cmmode = CodeMirror.getMode(config, mode);
             if(cmmode.indent === null) {
                 console.log('patch mode "' , mode, '" on the fly');
                 cmmode.indent = function(){return 0;};
             }
             return cmmode;
         };
     // end monkey patching CodeMirror
 
     var Cell = function (options) {
         // Constructor
         //
         // The Base `Cell` class from which to inherit.
         //
         // Parameters:
         //  options: dictionary
         //      Dictionary of keyword arguments.
         //          events: $(Events) instance 
         //          config: dictionary
         //          keyboard_manager: KeyboardManager instance 
         options = options || {};
         this.keyboard_manager = options.keyboard_manager;
         this.events = options.events;
         var config = utils.mergeopt(Cell, options.config);
         // superclass default overwrite our default
         
         this.placeholder = config.placeholder || '';
         this.read_only = config.cm_config.readOnly;
         this.selected = false;
         this.rendered = false;
         this.mode = 'command';
         this.metadata = {};
         // load this from metadata later ?
         this.user_highlight = 'auto';
         this.cm_config = config.cm_config;
         this.cell_id = utils.uuid();
         this._options = config;
 
         // For JS VM engines optimization, attributes should be all set (even
         // to null) in the constructor, and if possible, if different subclass
         // have new attributes with same name, they should be created in the
         // same order. Easiest is to create and set to null in parent class.
 
         this.element = null;
         this.cell_type = this.cell_type || null;
         this.code_mirror = null;
 
         this.create_element();
         if (this.element !== null) {
             this.element.data("cell", this);
             this.bind_events();
             this.init_classes();
         }
     };
 
     Cell.options_default = {
         cm_config : {
             indentUnit : 4,
             readOnly: false,
             theme: "default",
             extraKeys: {
                 "Cmd-Right":"goLineRight",
                 "End":"goLineRight",
                 "Cmd-Left":"goLineLeft"
             }
         }
     };
     
     // FIXME: Workaround CM Bug #332 (Safari segfault on drag)
     // by disabling drag/drop altogether on Safari
     // https://github.com/codemirror/CodeMirror/issues/332    
     if (utils.browser[0] == "Safari") {
         Cell.options_default.cm_config.dragDrop = false;
     }
 
     /**
      * Empty. Subclasses must implement create_element.
      * This should contain all the code to create the DOM element in notebook
      * and will be called by Base Class constructor.
      * @method create_element
      */
     Cell.prototype.create_element = function () {
     };
 
     Cell.prototype.init_classes = function () {
         // Call after this.element exists to initialize the css classes
         // related to selected, rendered and mode.
         if (this.selected) {
             this.element.addClass('selected');
         } else {
             this.element.addClass('unselected');
         }
         if (this.rendered) {
             this.element.addClass('rendered');
         } else {
             this.element.addClass('unrendered');
         }
         if (this.mode === 'edit') {
             this.element.addClass('edit_mode');
         } else {
             this.element.addClass('command_mode');
         }
     };
 
     /**
      * Subclasses can implement override bind_events.
      * Be carefull to call the parent method when overwriting as it fires event.
      * this will be triggerd after create_element in constructor.
      * @method bind_events
      */
     Cell.prototype.bind_events = function () {
         var that = this;
         // We trigger events so that Cell doesn't have to depend on Notebook.
         that.element.click(function (event) {
             if (!that.selected) {
                 that.events.trigger('select.Cell', {'cell':that});
             }
         });
         that.element.focusin(function (event) {
             if (!that.selected) {
                 that.events.trigger('select.Cell', {'cell':that});
             }
         });
         if (this.code_mirror) {
             this.code_mirror.on("change", function(cm, change) {
                 that.events.trigger("set_dirty.Notebook", {value: true});
             });
         }
         if (this.code_mirror) {
             this.code_mirror.on('focus', function(cm, change) {
                 that.events.trigger('edit_mode.Cell', {cell: that});
             });
         }
         if (this.code_mirror) {
             this.code_mirror.on('blur', function(cm, change) {
                 that.events.trigger('command_mode.Cell', {cell: that});
             });
         }
     };
     
     /**
      * This method gets called in CodeMirror's onKeyDown/onKeyPress
      * handlers and is used to provide custom key handling.
      *
      * To have custom handling, subclasses should override this method, but still call it
      * in order to process the Edit mode keyboard shortcuts.
      *
      * @method handle_codemirror_keyevent
      * @param {CodeMirror} editor - The codemirror instance bound to the cell
      * @param {event} event - key press event which either should or should not be handled by CodeMirror
      * @return {Boolean} `true` if CodeMirror should ignore the event, `false` Otherwise
      */
     Cell.prototype.handle_codemirror_keyevent = function (editor, event) {
         var shortcuts = this.keyboard_manager.edit_shortcuts;
 
         // if this is an edit_shortcuts shortcut, the global keyboard/shortcut
         // manager will handle it
         if (shortcuts.handles(event)) { return true; }
         
         return false;
     };
 
 
     /**
      * Triger typsetting of math by mathjax on current cell element
      * @method typeset
      */
     Cell.prototype.typeset = function () {
         if (window.MathJax) {
             var cell_math = this.element.get(0);
             MathJax.Hub.Queue(["Typeset", MathJax.Hub, cell_math]);
         }
     };
 
     /**
      * handle cell level logic when a cell is selected
      * @method select
      * @return is the action being taken
      */
     Cell.prototype.select = function () {
         if (!this.selected) {
             this.element.addClass('selected');
             this.element.removeClass('unselected');
             this.selected = true;
             return true;
         } else {
             return false;
         }
     };
 
     /**
      * handle cell level logic when a cell is unselected
      * @method unselect
      * @return is the action being taken
      */
     Cell.prototype.unselect = function () {
         if (this.selected) {
             this.element.addClass('unselected');
             this.element.removeClass('selected');
             this.selected = false;
             return true;
         } else {
             return false;
         }
     };
 
     /**
      * handle cell level logic when a cell is rendered
      * @method render
      * @return is the action being taken
      */
     Cell.prototype.render = function () {
         if (!this.rendered) {
             this.element.addClass('rendered');
             this.element.removeClass('unrendered');
             this.rendered = true;
             return true;
         } else {
             return false;
         }
     };
 
     /**
      * handle cell level logic when a cell is unrendered
      * @method unrender
      * @return is the action being taken
      */
     Cell.prototype.unrender = function () {
         if (this.rendered) {
             this.element.addClass('unrendered');
             this.element.removeClass('rendered');
             this.rendered = false;
             return true;
         } else {
             return false;
         }
     };
 
     /**
      * Delegates keyboard shortcut handling to either IPython keyboard
      * manager when in command mode, or CodeMirror when in edit mode
      *
      * @method handle_keyevent
      * @param {CodeMirror} editor - The codemirror instance bound to the cell
      * @param {event} - key event to be handled
      * @return {Boolean} `true` if CodeMirror should ignore the event, `false` Otherwise
      */
     Cell.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);
         }
     };
 
     /**
      * @method at_top
      * @return {Boolean}
      */
     Cell.prototype.at_top = function () {
         var cm = this.code_mirror;
         var cursor = cm.getCursor();
         if (cursor.line === 0 && cursor.ch === 0) {
             return true;
         }
         return false;
     };
 
     /**
      * @method at_bottom
      * @return {Boolean}
      * */
     Cell.prototype.at_bottom = function () {
         var cm = this.code_mirror;
         var cursor = cm.getCursor();
         if (cursor.line === (cm.lineCount()-1) && cursor.ch === cm.getLine(cursor.line).length) {
             return true;
         }
         return false;
     };
 
     /**
      * enter the command mode for the cell
      * @method command_mode
      * @return is the action being taken
      */
     Cell.prototype.command_mode = function () {
         if (this.mode !== 'command') {
             this.element.addClass('command_mode');
             this.element.removeClass('edit_mode');
             this.mode = 'command';
             return true;
         } else {
             return false;
         }
     };
 
     /**
      * enter the edit mode for the cell
      * @method command_mode
      * @return is the action being taken
      */
     Cell.prototype.edit_mode = function () {
         if (this.mode !== 'edit') {
             this.element.addClass('edit_mode');
             this.element.removeClass('command_mode');
             this.mode = 'edit';
             return true;
         } else {
             return false;
         }
     };
     
     /**
      * Focus the cell in the DOM sense
      * @method focus_cell
      */
     Cell.prototype.focus_cell = function () {
         this.element.focus();
     };
 
     /**
      * Focus the editor area so a user can type
      *
      * NOTE: If codemirror is focused via a mouse click event, you don't want to
      * call this because it will cause a page jump.
      * @method focus_editor
      */
     Cell.prototype.focus_editor = function () {
         this.refresh();
         this.code_mirror.focus();
     };
 
     /**
      * Refresh codemirror instance
      * @method refresh
      */
     Cell.prototype.refresh = function () {
         this.code_mirror.refresh();
     };
 
     /**
      * should be overritten by subclass
      * @method get_text
      */
     Cell.prototype.get_text = function () {
     };
 
     /**
      * should be overritten by subclass
      * @method set_text
      * @param {string} text
      */
     Cell.prototype.set_text = function (text) {
     };
 
     /**
      * should be overritten by subclass
      * serialise cell to json.
      * @method toJSON
      **/
     Cell.prototype.toJSON = function () {
         var data = {};
         // deepcopy the metadata so copied cells don't share the same object
         data.metadata = JSON.parse(JSON.stringify(this.metadata));
         data.cell_type = this.cell_type;
         return data;
     };
 
 
     /**
      * should be overritten by subclass
      * @method fromJSON
      **/
     Cell.prototype.fromJSON = function (data) {
         if (data.metadata !== undefined) {
             this.metadata = data.metadata;
         }
         this.celltoolbar.rebuild();
     };
 
 
     /**
      * can the cell be split into two cells (false if not deletable)
      * @method is_splittable
      **/
     Cell.prototype.is_splittable = function () {
         return this.is_deletable();
     };
 
 
     /**
      * can the cell be merged with other cells (false if not deletable)
      * @method is_mergeable
      **/
     Cell.prototype.is_mergeable = function () {
         return this.is_deletable();
     };
 
     /**
-     * is the cell deletable? (true by default)
+     * is the cell deletable? only false (undeletable) if
+     * metadata.deletable is explicitly false -- everything else
+     * counts as true
+     *
      * @method is_deletable
      **/
     Cell.prototype.is_deletable = function () {
-        if (this.metadata.deletable === undefined) {
-            return true;
+        if (this.metadata.deletable === false) {
+            return false;
         }
-        return Boolean(this.metadata.deletable);
+        return true;
     };
 
     /**
      * @return {String} - the text before the cursor
      * @method get_pre_cursor
      **/
     Cell.prototype.get_pre_cursor = function () {
         var cursor = this.code_mirror.getCursor();
         var text = this.code_mirror.getRange({line:0, ch:0}, cursor);
         text = text.replace(/^\n+/, '').replace(/\n+$/, '');
         return text;
     };
 
 
     /**
      * @return {String} - the text after the cursor
      * @method get_post_cursor
      **/
     Cell.prototype.get_post_cursor = function () {
         var cursor = this.code_mirror.getCursor();
         var last_line_num = this.code_mirror.lineCount()-1;
         var last_line_len = this.code_mirror.getLine(last_line_num).length;
         var end = {line:last_line_num, ch:last_line_len};
         var text = this.code_mirror.getRange(cursor, end);
         text = text.replace(/^\n+/, '').replace(/\n+$/, '');
         return text;
     };
 
     /**
      * Show/Hide CodeMirror LineNumber
      * @method show_line_numbers
      *
      * @param value {Bool}  show (true), or hide (false) the line number in CodeMirror
      **/
     Cell.prototype.show_line_numbers = function (value) {
         this.code_mirror.setOption('lineNumbers', value);
         this.code_mirror.refresh();
     };
 
     /**
      * Toggle  CodeMirror LineNumber
      * @method toggle_line_numbers
      **/
     Cell.prototype.toggle_line_numbers = function () {
         var val = this.code_mirror.getOption('lineNumbers');
         this.show_line_numbers(!val);
     };
 
     /**
      * Force codemirror highlight mode
      * @method force_highlight
      * @param {object} - CodeMirror mode
      **/
     Cell.prototype.force_highlight = function(mode) {
         this.user_highlight = mode;
         this.auto_highlight();
     };
 
     /**
      * Try to autodetect cell highlight mode, or use selected mode
      * @methods _auto_highlight
      * @private
      * @param {String|object|undefined} - CodeMirror mode | 'auto'
      **/
     Cell.prototype._auto_highlight = function (modes) {
         //Here we handle manually selected modes
         var mode;
         if( this.user_highlight !== undefined &&  this.user_highlight != 'auto' )
         {
             mode = this.user_highlight;
             CodeMirror.autoLoadMode(this.code_mirror, mode);
             this.code_mirror.setOption('mode', mode);
             return;
         }
         var current_mode = this.code_mirror.getOption('mode', mode);
         var first_line = this.code_mirror.getLine(0);
         // loop on every pairs
         for(mode in modes) {
             var regs = modes[mode].reg;
             // only one key every time but regexp can't be keys...
             for(var i=0; i<regs.length; i++) {
                 // here we handle non magic_modes
                 if(first_line.match(regs[i]) !== null) {
                     if(current_mode == mode){
                         return;
                     }
                     if (mode.search('magic_') !== 0) {
                         this.code_mirror.setOption('mode', mode);
                         CodeMirror.autoLoadMode(this.code_mirror, mode);
                         return;
                     }
                     var open = modes[mode].open || "%%";
                     var close = modes[mode].close || "%%end";
                     var mmode = mode;
                     mode = mmode.substr(6);
                     if(current_mode == mode){
                         return;
                     }
                     CodeMirror.autoLoadMode(this.code_mirror, mode);
                     // create on the fly a mode that swhitch between
                     // plain/text and smth else otherwise `%%` is
                     // source of some highlight issues.
                     // we use patchedGetMode to circumvent a bug in CM
                     CodeMirror.defineMode(mmode , function(config) {
                         return CodeMirror.multiplexingMode(
                         CodeMirror.patchedGetMode(config, 'text/plain'),
                             // always set someting on close
                             {open: open, close: close,
                              mode: CodeMirror.patchedGetMode(config, mode),
                              delimStyle: "delimit"
                             }
                         );
                     });
                     this.code_mirror.setOption('mode', mmode);
                     return;
                 }
             }
         }
         // fallback on default
         var default_mode;
         try {
             default_mode = this._options.cm_config.mode;
         } catch(e) {
             default_mode = 'text/plain';
         }
         if( current_mode === default_mode){
             return;
         }
         this.code_mirror.setOption('mode', default_mode);
     };
 
     // Backwards compatibility.
     IPython.Cell = Cell;
 
     return {'Cell': Cell};
 });