Handle widget hide/show logic

also only create a widget manager once

IPython/html/widgets/widget.js

@@ -1,241 +1,257
 //----------------------------------------------------------------------------
 //  Copyright (C) 2013  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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // WidgetModel, WidgetView, and WidgetManager
 //============================================================================
 /**
  * Base Widget classes
  * @module IPython
  * @namespace IPython
  * @submodule widget
  */
 
 
 // require(['components/underscore/underscore-min.js',
 //          'components/backbone/backbone-min.js'],
 
-var IPython = (function (IPython) {
     "use strict";
 
+// Only run once on a notebook.
+if (IPython.notebook.widget_manager == undefined) {
+
     //-----------------------------------------------------------------------
     // WidgetModel class
     //-----------------------------------------------------------------------
     var WidgetModel = Backbone.Model.extend({
         apply: function(sender) {
             this.save();
 
             for (var index in this.views) {
                 var view = this.views[index];
                 if (view !== sender) {
                     view.refresh();    
                 }
             }
         }
     });
 
 
     //-----------------------------------------------------------------------
     // WidgetView class
     //-----------------------------------------------------------------------
     var WidgetView = Backbone.View.extend({
         
         initialize: function() {
             this.model.on('change',this.refresh,this);
         },
         
         refresh: function() {
             this.update();
             
             if (this.model.css != undefined) {
                 for (var selector in this.model.css) {
                     if (this.model.css.hasOwnProperty(selector)) {
                         
                         // Get the elements via the css selector.  If the selector is
                         // blank, assume the current element is the target.
                         var elements = this.$el.find(selector);
                         if (selector=='') {
                             elements = this.$el;
                         }
                         
                         // Apply the css traits to all elements that match the selector.
                         if (elements.length>0){
                             var css_traits = this.model.css[selector];    
                             for (var css_key in css_traits) {
                                 if (css_traits.hasOwnProperty(css_key)) {
                                     elements.css(css_key, css_traits[css_key]);
                                 }
                             }
                         }
                     }
                 }
             }
         },
     });
 
 
     //-----------------------------------------------------------------------
     // WidgetManager class
     //-----------------------------------------------------------------------
     // Public constructor
     var WidgetManager = function(comm_manager){
         this.comm_manager = comm_manager;
         this.widget_model_types = {};
         this.widget_view_types = {};
         this.model_widget_views = {};
         
         var that = this;
         Backbone.sync = function(method, model, options, error) {
             var result = that.send_sync(method, model);
             if (options.success) {
               options.success(result);
             }
         }; 
     }
 
     // Register a widget model type.
     WidgetManager.prototype.register_widget_model = function (widget_model_name, widget_model_type) {
         
         // Register the widget with the comm manager.  Make sure to pass this object's context
         // in so `this` works in the call back.
         this.comm_manager.register_target(widget_model_name, $.proxy(this.handle_com_open, this));
         
         // Register the types of the model and view correspong to this widget type.  Later
         // the widget manager will initialize these when the comm is opened.
         this.widget_model_types[widget_model_name] = widget_model_type;
     }
 
     // Register a widget view type.
     WidgetManager.prototype.register_widget_view = function (widget_view_name, widget_view_type) {
         this.widget_view_types[widget_view_name] = widget_view_type;
     }
 
     // Handle when a comm is opened.
     WidgetManager.prototype.handle_com_open = function (comm, msg) {
         var widget_type_name = msg.content.target_name;
         
         // Create the corresponding widget model.
         var widget_model = new this.widget_model_types[widget_type_name];
         
         // Remember comm associated with the model.
         widget_model.comm = comm;
         comm.model = widget_model;
         
         // Create an array to remember the views associated with the model.
         widget_model.views = [];
         
         // Add a handle to delete the control when the comm is closed.
         var that = this;
         var handle_close = function(msg) {
             that.handle_comm_closed(comm, msg);
         }
         comm.on_close(handle_close);
         
         // Handle incomming messages.
         var handle_msg = function(msg) {
             that.handle_comm_msg(comm, msg);
         }
         comm.on_msg(handle_msg);
     }
 
     // Create view that represents the model.
     WidgetManager.prototype.show_view = function (widget_area, widget_model, widget_view_name) {
         var widget_view = new this.widget_view_types[widget_view_name]({model: widget_model});
         widget_view.render();
         widget_model.views.push(widget_view);
         
+        // Handle when the view element is remove from the page.
+        widget_view.$el.on("remove", function(){ 
+            var index = widget_model.views.indexOf(widget_view);
+            if (index > -1) {
+                widget_model.views.splice(index, 1);
+            }
+            widget_view.remove(); // Clean-up view 
+
+            // Close the comm if there are no views left.
+            if (widget_model.views.length()==0) {
+                widget_model.comm.close();     
+            }
+        });
+
         // Add the view's element to cell's widget div.
         widget_area
-            .append($("<div />").append(widget_view.$el));   
+            .append($("<div />").append(widget_view.$el))
+            .parent().show(); // Show the widget_area (parent of widget_subarea)
         
         // Update the view based on the model contents.
         widget_view.refresh();
     }
 
     // Handle incomming comm msg.
     WidgetManager.prototype.handle_comm_msg = function (comm, msg) {
         // Different logic for different methods.
         var method = msg.content.data.method;
         switch (method){
             case 'show':
                 
                 // TODO: Get cell from registered output handler.
                 var cell = IPython.notebook.get_cell(IPython.notebook.get_selected_index()-1);
                 var widget_subarea = cell.element.find('.widget_area').find('.widget_subarea');
                 
                 if (msg.content.data.parent != undefined) {
                     var find_results = widget_subarea.find("." + msg.content.data.parent);
                     if (find_results.length > 0) {
                         widget_subarea = find_results;
                     }
                 }
                 
                 this.show_view(widget_subarea, comm.model, msg.content.data.view_name);
                 break;
             case 'update':
                 this.handle_update(comm, msg.content.data.state);
                 break;
         }
     }
 
     // Handle when a widget is updated via the python side.
     WidgetManager.prototype.handle_update = function (comm, state) {
         for (var key in state) {
             if (state.hasOwnProperty(key)) {
                 if (key=="_css"){
                     comm.model.css = state[key];
                 } else {
                     comm.model.set(key, state[key]); 
                 }
             }
         }
         comm.model.save();
     }
 
     // Handle when a widget is closed.
     WidgetManager.prototype.handle_comm_closed = function (comm, msg) {
         for (var view_index in comm.model.views) {
             var view = comm.model.views[view_index];
             view.remove();
         }
     }
 
     // Get the cell output area corresponding to the comm.
     WidgetManager.prototype._get_comm_outputarea = function (comm) {
         // TODO: get element from comm instead of guessing
         var cell = IPython.notebook.get_cell(IPython.notebook.get_selected_index())
         return cell.output_area;
     }
 
     // Send widget state to python backend.
     WidgetManager.prototype.send_sync = function (method, model) {
         
         // Create a callback for the output if the widget has an output area associate with it.
         var callbacks = {};
         var comm = model.comm;
         var outputarea = this._get_comm_outputarea(comm);
         if (outputarea != null) {
             callbacks = {
                 iopub : {
                 output : $.proxy(outputarea.handle_output, outputarea),
                 clear_output : $.proxy(outputarea.handle_clear_output, outputarea)}
             };
         };
         var model_json = model.toJSON();
         var data = {sync_method: method, sync_data: model_json};
         comm.send(data, callbacks);
         return model_json;
     }
 
     IPython.WidgetManager = WidgetManager;
     IPython.WidgetModel = WidgetModel;
     IPython.WidgetView = WidgetView;
 
+    IPython.notebook.widget_manager = new WidgetManager(IPython.notebook.kernel.comm_manager);    
   
-    return IPython;
-
-}(IPython));
+}