widget changes continued

IPython/html/static/widgets/js/widget.js

@@ -1,498 +1,496 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define(["widgets/js/manager",
         "underscore",
         "backbone", 
         "jquery",   
         "base/js/namespace",
 ], function(widgetmanager, _, Backbone, $, IPython){
 
     var WidgetModel = Backbone.Model.extend({
         constructor: function (widget_manager, model_id, comm) {
             // Constructor
             //
             // Creates a WidgetModel instance.
             //
             // Parameters
             // ----------
             // widget_manager : WidgetManager instance
             // model_id : string
             //      An ID unique to this model.
             // comm : Comm instance (optional)
             this.widget_manager = widget_manager;
             this._buffered_state_diff = {};
             this.pending_msgs = 0;
             this.msg_buffer = null;
             this.key_value_lock = null;
             this.id = model_id;
             this.views = [];
 
             if (comm !== undefined) {
                 // Remember comm associated with the model.
                 this.comm = comm;
                 comm.model = this;
 
                 // Hook comm messages up to model.
                 comm.on_close($.proxy(this._handle_comm_closed, this));
                 comm.on_msg($.proxy(this._handle_comm_msg, this));
             }
             return Backbone.Model.apply(this);
         },
 
         send: function (content, callbacks) {
             // Send a custom msg over the comm.
             if (this.comm !== undefined) {
                 var data = {method: 'custom', content: content};
                 this.comm.send(data, callbacks);
                 this.pending_msgs++;
             }
         },
 
         _handle_comm_closed: function (msg) {
             // Handle when a widget is closed.
             this.trigger('comm:close');
             delete this.comm.model; // Delete ref so GC will collect widget model.
             delete this.comm;
             delete this.model_id; // Delete id from model so widget manager cleans up.
             _.each(this.views, function(view, i) {
                 view.remove();
             });
         },
 
         _handle_comm_msg: function (msg) {
             // Handle incoming comm msg.
             var method = msg.content.data.method;
             switch (method) {
                 case 'update':
                     this.apply_update(msg.content.data.state);
                     break;
                 case 'custom':
                     this.trigger('msg:custom', msg.content.data.content);
                     break;
                 case 'display':
                     this.widget_manager.display_view(msg, this);
                     break;
             }
         },
 
         apply_update: function (state) {
             // Handle when a widget is updated via the python side.
             var that = this;
             _.each(state, function(value, key) {
                 that.key_value_lock = [key, value];
                 try {
                     WidgetModel.__super__.set.apply(that, [key, that._unpack_models(value)]);
                 } finally {
                     that.key_value_lock = null;
                 }
             });
         },
 
         _handle_status: function (msg, callbacks) {
             // Handle status msgs.
 
             // execution_state : ('busy', 'idle', 'starting')
             if (this.comm !== undefined) {
                 if (msg.content.execution_state ==='idle') {
                     // Send buffer if this message caused another message to be
                     // throttled.
                     if (this.msg_buffer !== null &&
                         (this.get('msg_throttle') || 3) === this.pending_msgs) {
                         var data = {method: 'backbone', sync_method: 'update', sync_data: this.msg_buffer};
                         this.comm.send(data, callbacks);
                         this.msg_buffer = null;
                     } else {
                         --this.pending_msgs;
                     }
                 }
             }
         },
 
         callbacks: function(view) {
             // Create msg callbacks for a comm msg.
             var callbacks = this.widget_manager.callbacks(view);
 
             if (callbacks.iopub === undefined) {
                 callbacks.iopub = {};
             }
 
             var that = this;
             callbacks.iopub.status = function (msg) {
                 that._handle_status(msg, callbacks);
             };
             return callbacks;
         },
 
         set: function(key, val, options) {
             // Set a value.
             var return_value = WidgetModel.__super__.set.apply(this, arguments);
 
             // Backbone only remembers the diff of the most recent set()
             // operation.  Calling set multiple times in a row results in a 
             // loss of diff information.  Here we keep our own running diff.
             this._buffered_state_diff = $.extend(this._buffered_state_diff, this.changedAttributes() || {});
             return return_value;
         },
 
         sync: function (method, model, options) {
             // Handle sync to the back-end.  Called when a model.save() is called.
 
             // Make sure a comm exists.
             var error = options.error || function() {
                 console.error('Backbone sync error:', arguments);
             };
             if (this.comm === undefined) {
                 error();
                 return false;
             }
 
             // Delete any key value pairs that the back-end already knows about.
             var attrs = (method === 'patch') ? options.attrs : model.toJSON(options);
             if (this.key_value_lock !== null) {
                 var key = this.key_value_lock[0];
                 var value = this.key_value_lock[1];
                 if (attrs[key] === value) {
                     delete attrs[key];
                 }
             }
 
             // Only sync if there are attributes to send to the back-end.
             attrs = this._pack_models(attrs);
             if (_.size(attrs) > 0) {
 
                 // If this message was sent via backbone itself, it will not
                 // have any callbacks.  It's important that we create callbacks
                 // so we can listen for status messages, etc...
                 var callbacks = options.callbacks || this.callbacks();
 
                 // Check throttle.
                 if (this.pending_msgs >= (this.get('msg_throttle') || 3)) {
                     // The throttle has been exceeded, buffer the current msg so
                     // it can be sent once the kernel has finished processing 
                     // some of the existing messages.
                     
                     // Combine updates if it is a 'patch' sync, otherwise replace updates
                     switch (method) {
                         case 'patch':
                             this.msg_buffer = $.extend(this.msg_buffer || {}, attrs);
                             break;
                         case 'update':
                         case 'create':
                             this.msg_buffer = attrs;
                             break;
                         default:
                             error();
                             return false;
                     }
                     this.msg_buffer_callbacks = callbacks;
 
                 } else {
                     // We haven't exceeded the throttle, send the message like 
                     // normal.
                     var data = {method: 'backbone', sync_data: attrs};
                     this.comm.send(data, callbacks);
                     this.pending_msgs++;
                 }
             }
             // Since the comm is a one-way communication, assume the message 
             // arrived.  Don't call success since we don't have a model back from the server
             // this means we miss out on the 'sync' event.
             this._buffered_state_diff = {};
         },
 
         save_changes: function(callbacks) {
             // Push this model's state to the back-end
             //
             // This invokes a Backbone.Sync.
             this.save(this._buffered_state_diff, {patch: true, callbacks: callbacks});
         },
 
         _pack_models: function(value) {
             // Replace models with model ids recursively.
             var that = this;
             var packed;
             if (value instanceof Backbone.Model) {
                 return "IPY_MODEL_" + value.id;
 
             } else if ($.isArray(value)) {
                 packed = [];
                 _.each(value, function(sub_value, key) {
                     packed.push(that._pack_models(sub_value));
                 });
                 return packed;
 
             } else if (value instanceof Object) {
                 packed = {};
                 _.each(value, function(sub_value, key) {
                     packed[key] = that._pack_models(sub_value);
                 });
                 return packed;
 
             } else {
                 return value;
             }
         },
 
         _unpack_models: function(value) {
             // Replace model ids with models recursively.
             var that = this;
             var unpacked;
             if ($.isArray(value)) {
                 unpacked = [];
                 _.each(value, function(sub_value, key) {
                     unpacked.push(that._unpack_models(sub_value));
                 });
                 return unpacked;
 
             } else if (value instanceof Object) {
                 unpacked = {};
                 _.each(value, function(sub_value, key) {
                     unpacked[key] = that._unpack_models(sub_value);
                 });
                 return unpacked;
 
             } else if (typeof value === 'string' && value.slice(0,10) === "IPY_MODEL_") {
 		var model = this.widget_manager.get_model(value.slice(10, value.length));
 		if (model) {
 		    return model;
 		} else {
 		    return value;
 		}
             } else {
                     return value;
             }
         },
 
     });
     widgetmanager.WidgetManager.register_widget_model('WidgetModel', WidgetModel);
 
 
     var WidgetView = Backbone.View.extend({
         initialize: function(parameters) {
             // Public constructor.
             this.model.on('change',this.update,this);
             this.options = parameters.options;
             this.child_model_views = {};
             this.child_views = {};
             this.model.views.push(this);
             this.id = this.id || IPython.utils.uuid();
             this.on('displayed', function() { 
                 this.is_displayed = true; 
             }, this);
         },
 
         update: function(){
             // Triggered on model change.
             //
             // Update view to be consistent with this.model
         },
 
         create_child_view: function(child_model, options) {
             // Create and return a child view.
             //
             // -given a model and (optionally) a view name if the view name is 
             // not given, it defaults to the model's default view attribute.
         
             // TODO: this is hacky, and makes the view depend on this cell attribute and widget manager behavior
             // it would be great to have the widget manager add the cell metadata
             // to the subview without having to add it here.
             options = $.extend({ parent: this }, options || {});
             var child_view = this.model.widget_manager.create_view(child_model, options, this);
             
             // Associate the view id with the model id.
             if (this.child_model_views[child_model.id] === undefined) {
                 this.child_model_views[child_model.id] = [];
             }
             this.child_model_views[child_model.id].push(child_view.id);
 
             // Remember the view by id.
             this.child_views[child_view.id] = child_view;
             return child_view;
         },
 
         pop_child_view: function(child_model) {
             // Delete a child view that was previously created using create_child_view.
             var view_ids = this.child_model_views[child_model.id];
             if (view_ids !== undefined) {
 
                 // Only delete the first view in the list.
                 var view_id = view_ids[0];
                 var view = this.child_views[view_id];
                 delete this.child_views[view_id];
                 view_ids.splice(0,1);
                 child_model.views.pop(view);
             
                 // Remove the view list specific to this model if it is empty.
                 if (view_ids.length === 0) {
                     delete this.child_model_views[child_model.id];
                 }
                 return view;
             }
             return null;
         },
 
         do_diff: function(old_list, new_list, removed_callback, added_callback) {
             // Difference a changed list and call remove and add callbacks for 
             // each removed and added item in the new list.
             //
             // Parameters
             // ----------
             // old_list : array
             // new_list : array
             // removed_callback : Callback(item)
             //      Callback that is called for each item removed.
             // added_callback : Callback(item)
             //      Callback that is called for each item added.
 
             // Walk the lists until an unequal entry is found.
             var i;
             for (i = 0; i < new_list.length; i++) {
                 if (i < old_list.length || new_list[i] !== old_list[i]) {
                     break;
                 }
             }
 
             // Remove the non-matching items from the old list.
             for (var j = i; j < old_list.length; j++) {
                 removed_callback(old_list[j]);
             }
 
             // Add the rest of the new list items.
             for (i; i < new_list.length; i++) {
                 added_callback(new_list[i]);
             }
         },
 
         callbacks: function(){
             // Create msg callbacks for a comm msg.
             return this.model.callbacks(this);
         },
 
         render: function(){
             // Render the view.
             //
             // By default, this is only called the first time the view is created
         },
 
         show: function(){
             // Show the widget-area
             if (this.options && this.options.cell &&
                 this.options.cell.widget_area !== undefined) {
                 this.options.cell.widget_area.show();
             }
         },
 
         send: function (content) {
             // Send a custom msg associated with this view.
             this.model.send(content, this.callbacks());
         },
 
         touch: function () {
             this.model.save_changes(this.callbacks());
         },
 
         after_displayed: function (callback, context) {
             // Calls the callback right away is the view is already displayed
             // otherwise, register the callback to the 'displayed' event.
             if (this.is_displayed) {
                 callback.apply(context);
             } else {
                 this.on('displayed', callback, context);
             }
         },
     });
 
 
     var DOMWidgetView = WidgetView.extend({
         initialize: function () {
             // Public constructor
             DOMWidgetView.__super__.initialize.apply(this, arguments);
             this.on('displayed', this.show, this);
-
             this.model.on('msg:custom', this.on_msg, this);
             this.model.on('change:visible', this.update_visible, this);
             this.model.on('change:_css', this.update_css, this);
-
             this.update_visible(this.model, this.model.get("visible"));
             this.update_css(this.model, this.model.get("_css"));
         },
         
         on_msg: function(msg) {
             // Handle DOM specific msgs.
             switch(msg.msg_type) {
                 case 'add_class':
                     this.add_class(msg.selector, msg.class_list);
                     break;
                 case 'remove_class':
                     this.remove_class(msg.selector, msg.class_list);
                     break;
             }
         },
 
         add_class: function (selector, class_list) {
             // Add a DOM class to an element.
             this._get_selector_element(selector).addClass(class_list);
         },
         
         remove_class: function (selector, class_list) {
             // Remove a DOM class from an element.
             this._get_selector_element(selector).removeClass(class_list);
         },
     
         update_visible: function(model, value) {
             // Update visibility
             //      The very first update seems to happen before the element is 
             // finished rendering so we use setTimeout to give the element time 
             // to render
             var e = this.$el;
             setTimeout(function() {e.toggle(value);},0);
          },
 
         update_css: function (model, css) {
-            // Update the contents of this view
+            // Update the css styling of this view.
             var e = this.$el;
             if (css === undefined) {return;}
             for (var i = 0; i < css.length; i++) {
                 // Apply the css traits to all elements that match the selector.
                 var selector = css[i][0];
                 var elements = this._get_selector_element(selector);
                 if (elements.length > 0) {
                     var trait_key = css[i][1];
                     var trait_value = css[i][2];
                     elements.css(trait_key ,trait_value);
                 }
             }
         },
 
         _get_selector_element: function (selector) {
             // Get the elements via the css selector.
 
             // If the selector is blank, apply the style to the $el_to_style 
             // element.  If the $el_to_style element is not defined, use apply 
             // the style to the view's element.
             var elements;
             if (!selector) {
                 if (this.$el_to_style === undefined) {
                     elements = this.$el;
                 } else {
                     elements = this.$el_to_style;
                 }
             } else {
                 elements = this.$el.find(selector);
             }
             return elements;
         },
     });
 
     var widget = {
         'WidgetModel': WidgetModel,
         'WidgetView': WidgetView,
         'DOMWidgetView': DOMWidgetView,
     };
 
     // For backwards compatability.
     $.extend(IPython, widget);
 
     return widget;
 });

IPython/html/static/widgets/js/widget_container.js

@@ -1,284 +1,284 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     "widgets/js/widget",
     "jqueryui",
     "bootstrap",
 ], function(widget, $){
 
     var ContainerView = widget.DOMWidgetView.extend({
         initialize: function(){
             // Public constructor
             ContainerView.__super__.initialize.apply(this, arguments);
             this.update_children([], this.model.get('children'));
             this.model.on('change:children', function(model, value) {
                 this.update_children(model.previous('children'), value);
             }, this);
         },
 
         render: function(){
             // Called when view is rendered.
             this.$el.addClass('widget-container').addClass('vbox');
         },
         
         update_children: function(old_list, new_list) {
             // Called when the children list changes.
             this.do_diff(old_list, new_list, 
                 $.proxy(this.remove_child_model, this),
                 $.proxy(this.add_child_model, this));
         },
 
         remove_child_model: function(model) {
             // Called when a model is removed from the children list.
             this.pop_child_view(model).remove();
         },
 
         add_child_model: function(model) {
             // Called when a model is added to the children list.
             var view = this.create_child_view(model);
             this.$el.append(view.$el);
 
-            // Trigger the displayed event once this view is displayed.
+            // Trigger the displayed event of the child view.
             this.after_displayed(function() {
                 view.trigger('displayed');
             });
         },
     });
     
 
     var PopupView = widget.DOMWidgetView.extend({
         render: function(){
             // Called when view is rendered.
             var that = this;
             
             this.$el.on("remove", function(){
                     that.$backdrop.remove();
                 });
             this.$backdrop = $('<div />')
                 .appendTo($('#notebook-container'))
                 .addClass('modal-dialog')
                 .css('position', 'absolute')
                 .css('left', '0px')
                 .css('top', '0px');
             this.$window = $('<div />')
                 .appendTo(this.$backdrop)
                 .addClass('modal-content widget-modal')
                 .mousedown(function(){
                     that.bring_to_front();
                 });
 
             // Set the elements array since the this.$window element is not child
             // of this.$el and the parent widget manager or other widgets may
             // need to know about all of the top-level widgets.  The IPython
             // widget manager uses this to register the elements with the
             // keyboard manager.
             this.additional_elements = [this.$window];
 
             this.$title_bar = $('<div />')
                 .addClass('popover-title')
                 .appendTo(this.$window)
                 .mousedown(function(){
                     that.bring_to_front();
                 });
             this.$close = $('<button />')
                 .addClass('close icon-remove')
                 .css('margin-left', '5px')
                 .appendTo(this.$title_bar)
                 .click(function(){
                     that.hide();
                     event.stopPropagation();
                 });
             this.$minimize = $('<button />')
                 .addClass('close icon-arrow-down')
                 .appendTo(this.$title_bar)
                 .click(function(){
                     that.popped_out = !that.popped_out;
                     if (!that.popped_out) {
                         that.$minimize
                             .removeClass('icon-arrow-down')
                             .addClass('icon-arrow-up');
                             
                         that.$window
                             .draggable('destroy')
                             .resizable('destroy')
                             .removeClass('widget-modal modal-content')
                             .addClass('docked-widget-modal')
                             .detach()
                             .insertBefore(that.$show_button);
                         that.$show_button.hide();
                         that.$close.hide();
                     } else {
                         that.$minimize
                             .addClass('icon-arrow-down')
                             .removeClass('icon-arrow-up');
 
                         that.$window
                             .removeClass('docked-widget-modal')
                             .addClass('widget-modal modal-content')
                             .detach()
                             .appendTo(that.$backdrop)
                             .draggable({handle: '.popover-title', snap: '#notebook, .modal', snapMode: 'both'})
                             .resizable()
                             .children('.ui-resizable-handle').show();
                         that.show();
                         that.$show_button.show();
                         that.$close.show();
                     }
                     event.stopPropagation();
                 });
             this.$title = $('<div />')
                 .addClass('widget-modal-title')
                 .html("&nbsp;")
                 .appendTo(this.$title_bar);
             this.$body = $('<div />')
                 .addClass('modal-body')
                 .addClass('widget-modal-body')
                 .addClass('widget-container')
                 .addClass('vbox')
                 .appendTo(this.$window);
             
             this.$show_button = $('<button />')
                 .html("&nbsp;")
                 .addClass('btn btn-info widget-modal-show')
                 .appendTo(this.$el)
                 .click(function(){
                     that.show();
                 });
             
             this.$window.draggable({handle: '.popover-title', snap: '#notebook, .modal', snapMode: 'both'});
             this.$window.resizable();
             this.$window.on('resize', function(){
                 that.$body.outerHeight(that.$window.innerHeight() - that.$title_bar.outerHeight());
             });
 
             this.$el_to_style = this.$body;
             this._shown_once = false;
             this.popped_out = true;
 
             this.update_children([], this.model.get('children'));
             this.model.on('change:children', function(model, value) {
                 this.update_children(model.previous('children'), value);
             }, this);
         },
         
         hide: function() {
             // Called when the modal hide button is clicked.
             this.$window.hide();
             this.$show_button.removeClass('btn-info');
         },
         
         show: function() {
             // Called when the modal show button is clicked.
             this.$show_button.addClass('btn-info');
             this.$window.show();
             if (this.popped_out) {
                 this.$window.css("positon", "absolute");
                 this.$window.css("top", "0px");
                 this.$window.css("left", Math.max(0, (($('body').outerWidth() - this.$window.outerWidth()) / 2) + 
                     $(window).scrollLeft()) + "px");
                 this.bring_to_front();
             }
         },
         
         bring_to_front: function() {
             // Make the modal top-most, z-ordered about the other modals.
             var $widget_modals = $(".widget-modal");
             var max_zindex = 0;
             $widget_modals.each(function (index, el){
                 var zindex = parseInt($(el).css('z-index'));
                 if (!isNaN(zindex)) {
                     max_zindex = Math.max(max_zindex, zindex);
                 }
             });
             
             // Start z-index of widget modals at 2000
             max_zindex = Math.max(max_zindex, 2000);
             
             $widget_modals.each(function (index, el){
                 $el = $(el);
                 if (max_zindex == parseInt($el.css('z-index'))) {
                     $el.css('z-index', max_zindex - 1);
                 }
             });
             this.$window.css('z-index', max_zindex);
         },
         
         update_children: function(old_list, new_list) {
             // Called when the children list is modified.
             this.do_diff(old_list, new_list, 
                 $.proxy(this.remove_child_model, this),
                 $.proxy(this.add_child_model, this));
         },
 
         remove_child_model: function(model) {
             // Called when a child is removed from children list.
             this.pop_child_view(model).remove();
         },
 
         add_child_model: function(model) {
             // Called when a child is added to children list.
             var view = this.create_child_view(model);
             this.$body.append(view.$el);
 
-            // Trigger the displayed event once this view is displayed.
+            // Trigger the displayed event of the child view.
             this.after_displayed(function() {
                 view.trigger('displayed');
             });
         },
         
         update: function(){
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             var description = this.model.get('description');
             if (description.trim().length === 0) {
                 this.$title.html("&nbsp;"); // Preserve title height
             } else {
                 this.$title.text(description);
                 MathJax.Hub.Queue(["Typeset",MathJax.Hub,this.$title.get(0)]);
             }
             
             var button_text = this.model.get('button_text');
             if (button_text.trim().length === 0) {
                 this.$show_button.html("&nbsp;"); // Preserve button height
             } else {
                 this.$show_button.text(button_text);
             }
             
             if (!this._shown_once) {
                 this._shown_once = true;
                 this.show();
             }
             
             return PopupView.__super__.update.apply(this);
         },
         
         _get_selector_element: function(selector) {
             // Get an element view a 'special' jquery selector.  (see widget.js)
             //
             // Since the modal actually isn't within the $el in the DOM, we need to extend
             // the selector logic to allow the user to set css on the modal if need be.
             // The convention used is:
             // "modal" - select the modal div
             // "modal [selector]" - select element(s) within the modal div.
             // "[selector]" - select elements within $el
             // "" - select the $el_to_style
             if (selector.substring(0, 5) == 'modal') {
                 if (selector == 'modal') {
                     return this.$window;
                 } else {
                     return this.$window.find(selector.substring(6));
                 }
             } else {
                 return PopupView.__super__._get_selector_element.apply(this, [selector]);
             }
         },
     });
 
     return {
         'ContainerView': ContainerView,
         'PopupView': PopupView,
     };
 });

IPython/html/static/widgets/js/widget_selectioncontainer.js

@@ -1,267 +1,248 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     "widgets/js/widget",
     "base/js/utils",
     "jquery",
     "bootstrap",
 ], function(widget, utils, $){
 
     var AccordionView = widget.DOMWidgetView.extend({
         render: function(){
             // Called when view is rendered.
             var guid = 'panel-group' + utils.uuid();
             this.$el
                 .attr('id', guid)
                 .addClass('panel-group');
             this.containers = [];
             this.model_containers = {};
             this.update_children([], this.model.get('children'));
             this.model.on('change:children', function(model, value, options) {
                 this.update_children(model.previous('children'), value);
             }, this);
             this.model.on('change:selected_index', function(model, value, options) {
                 this.update_selected_index(model.previous('selected_index'), value, options);
             }, this);
             this.model.on('change:_titles', function(model, value, options) {
                 this.update_titles(value);
             }, this);
             var that = this;
             this.on('displayed', function() {
                 this.update_titles();
-                // Trigger model displayed events for any models that are child to 
-                // this model when this model is displayed.
-                that.is_displayed = true;
-                for (var property in that.child_views) {
-                    if (that.child_views.hasOwnProperty(property)) {
-                        that.child_views[property].trigger('displayed');
-                    }
-                }
-            }, this);
+            }
         },
 
         update_titles: function(titles) {
             // Set tab titles
             if (!titles) {
                 titles = this.model.get('_titles');
             }
 
             var that = this;
             _.each(titles, function(title, page_index) {
                 var accordian = that.containers[page_index];
                 if (accordian !== undefined) {
                     accordian
                         .find('.panel-heading')
                         .find('.accordion-toggle')
                         .text(title);
                 }
             });
         },
 
         update_selected_index: function(old_index, new_index, options) {
             // Only update the selection if the selection wasn't triggered
             // by the front-end.  It must be triggered by the back-end.
             if (options === undefined || options.updated_view != this) {
                 this.containers[old_index].find('.panel-collapse').collapse('hide');
                 if (0 <= new_index && new_index < this.containers.length) {
                     this.containers[new_index].find('.panel-collapse').collapse('show');
                 }
             }
         },
         
         update_children: function(old_list, new_list) {
             // Called when the children list is modified.
             this.do_diff(old_list, 
                 new_list, 
                 $.proxy(this.remove_child_model, this),
                 $.proxy(this.add_child_model, this));
         },
 
         remove_child_model: function(model) {
             // Called when a child is removed from children list.
             var accordion_group = this.model_containers[model.id];
             this.containers.splice(accordion_group.container_index, 1);
             delete this.model_containers[model.id];
             accordion_group.remove();
             this.pop_child_view(model);
         },
 
         add_child_model: function(model) {
             // Called when a child is added to children list.
             var view = this.create_child_view(model);
             var index = this.containers.length;
             var uuid = utils.uuid();
             var accordion_group = $('<div />')
                 .addClass('panel panel-default')
                 .appendTo(this.$el);
             var accordion_heading = $('<div />')
                 .addClass('panel-heading')
                 .appendTo(accordion_group);
             var that = this;
             var accordion_toggle = $('<a />')
                 .addClass('accordion-toggle')
                 .attr('data-toggle', 'collapse')
                 .attr('data-parent', '#' + this.$el.attr('id'))
                 .attr('href', '#' + uuid)
                 .click(function(evt){ 
             
                     // Calling model.set will trigger all of the other views of the 
                     // model to update.
                     that.model.set("selected_index", index, {updated_view: that});
                     that.touch();
                  })
                 .text('Page ' + index)
                 .appendTo(accordion_heading);
             var accordion_body = $('<div />', {id: uuid})
                 .addClass('panel-collapse collapse')
                 .appendTo(accordion_group);
             var accordion_inner = $('<div />')
                 .addClass('panel-body')
                 .appendTo(accordion_body);
             var container_index = this.containers.push(accordion_group) - 1;
             accordion_group.container_index = container_index;
             this.model_containers[model.id] = accordion_group;
             accordion_inner.append(view.$el);
 
             this.update();
             this.update_titles();
 
-            // Trigger the displayed event if this model is displayed.
-            if (this.is_displayed) {
+            // Trigger the displayed event of the child view.
+            this.after_displayed(function() {
                 view.trigger('displayed');
-            }
+            });
         },
     });
     
 
     var TabView = widget.DOMWidgetView.extend({    
         initialize: function() {
             // Public constructor.
             this.containers = [];
             TabView.__super__.initialize.apply(this, arguments);
         },
 
         render: function(){
             // Called when view is rendered.
             var uuid = 'tabs'+utils.uuid();
             var that = this;
             this.$tabs = $('<div />', {id: uuid})
                 .addClass('nav')
                 .addClass('nav-tabs')
                 .appendTo(this.$el);
             this.$tab_contents = $('<div />', {id: uuid + 'Content'})
                 .addClass('tab-content')
                 .appendTo(this.$el);
             this.containers = [];
             this.update_children([], this.model.get('children'));
             this.model.on('change:children', function(model, value, options) {
                 this.update_children(model.previous('children'), value);
             }, this);
-
-            // Trigger model displayed events for any models that are child to 
-            // this model when this model is displayed.
-            this.on('displayed', function(){
-                that.is_displayed = true;
-                for (var property in that.child_views) {
-                    if (that.child_views.hasOwnProperty(property)) {
-                        that.child_views[property].trigger('displayed');
-                    }
-                }
-            });
         },
 
         update_children: function(old_list, new_list) {
             // Called when the children list is modified.
             this.do_diff(old_list, 
                 new_list, 
                 $.proxy(this.remove_child_model, this),
                 $.proxy(this.add_child_model, this));
         },
 
         remove_child_model: function(model) {
             // Called when a child is removed from children list.
             var view = this.pop_child_view(model);
             this.containers.splice(view.parent_tab.tab_text_index, 1);
             view.parent_tab.remove();
             view.parent_container.remove();
             view.remove();
         },
 
         add_child_model: function(model) {
             // Called when a child is added to children list.
             var view = this.create_child_view(model);
             var index = this.containers.length;
             var uuid = utils.uuid();
 
             var that = this;
             var tab = $('<li />')
                 .css('list-style-type', 'none')
                 .appendTo(this.$tabs);
             view.parent_tab = tab;
 
             var tab_text = $('<a />')
                 .attr('href', '#' + uuid)
                 .attr('data-toggle', 'tab') 
                 .text('Page ' + index)
                 .appendTo(tab)
                 .click(function (e) {
             
                     // Calling model.set will trigger all of the other views of the 
                     // model to update.
                     that.model.set("selected_index", index, {updated_view: this});
                     that.touch();
                     that.select_page(index);
                 });
             tab.tab_text_index = this.containers.push(tab_text) - 1;
 
             var contents_div = $('<div />', {id: uuid})
                 .addClass('tab-pane')
                 .addClass('fade')
                 .append(view.$el)
                 .appendTo(this.$tab_contents);
             view.parent_container = contents_div;
 
-            // Trigger the displayed event if this model is displayed.
-            if (this.is_displayed) {
+            // Trigger the displayed event of the child view.
+            this.after_displayed(function() {
                 view.trigger('displayed');
-            }
+            });
         },
 
         update: function(options) {
             // Update the contents of this view
             //
             // Called when the model is changed.  The model may have been 
             // changed by another view or by a state update from the back-end.
             if (options === undefined || options.updated_view != this) {
                 // Set tab titles
                 var titles = this.model.get('_titles');
                 var that = this;
                 _.each(titles, function(title, page_index) {
                    var tab_text = that.containers[page_index];
                     if (tab_text !== undefined) {
                         tab_text.text(title);
                     } 
                 });
 
                 var selected_index = this.model.get('selected_index');
                 if (0 <= selected_index && selected_index < this.containers.length) {
                     this.select_page(selected_index);
                 }
             }
             return TabView.__super__.update.apply(this);
         },
 
         select_page: function(index) {
             // Select a page.
             this.$tabs.find('li')
                 .removeClass('active');
             this.containers[index].tab('show');
         },
     });
 
     return {
         'AccordionView': AccordionView,
         'TabView': TabView,
     };
 });