Remove unused code and debugging statements

IPython/html/static/notebook/js/widgets/base.js

@@ -1,326 +1,322 b''
 //----------------------------------------------------------------------------
 //  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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // Base Widget Model and View classes
 //============================================================================
 
 /**
  * @module IPython
  * @namespace IPython
  **/
 
 define(["notebook/js/widgetmanager",
         "underscore",
         "backbone"], 
 function(widget_manager, underscore, backbone){
     
     //--------------------------------------------------------------------
     // WidgetModel class
     //--------------------------------------------------------------------
     var WidgetModel = Backbone.Model.extend({
         constructor: function (widget_manager, widget_id, comm) {
             this.widget_manager = widget_manager;
             this.pending_msgs = 0;
             this.msg_throttle = 3;
             this.msg_buffer = null;
             this.id = widget_id;
 
             if (comm !== undefined) {
                 // Remember comm associated with the model.
                 this.comm = comm;
                 comm.model = this;
 
                 // Hook comm messages up to model.
 		var that = this;
                 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) {
-	    console.log('send',content, callbacks);
             if (this.comm !== undefined) {
                 var data = {method: 'custom', custom_content: content};
                 this.comm.send(data, callbacks);
             }
         },
 
         // Handle when a widget is closed.
         _handle_comm_closed: function (msg) {
 	    // jng: widget manager should observe the comm_close event and delete views when triggered
 	    this.trigger('comm:close');
             if (this._has_comm()) {
                 delete this.comm.model; // Delete ref so GC will collect widget model.
                 delete this.comm;
             }
             delete this.widget_id; // Delete id from model so widget manager cleans up.
         },
 
 
         // Handle incoming comm msg.
         _handle_comm_msg: function (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.custom_content);
                     break;
 		default:
 		    // pass on to widget manager
 		    this.widget_manager.handle_msg(msg, this);
             }
         },
 
 
         // Handle when a widget is updated via the python side.
         apply_update: function (state) {
             this.updating = true;
             try {
                 for (var key in state) {
                     if (state.hasOwnProperty(key)) {
                             this.set(key, state[key]);
                     }
                 }
                 this.save();
             } finally {
                 this.updating = false;
             }
         },
 
 
         _handle_status: function (msg, callbacks) {
             //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.msg_throttle === 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 {
 
                         // Only decrease the pending message count if the buffer
                         // doesn't get flushed (sent).
                         --this.pending_msgs;
                     }
                 }
             }
         },
 
 
         // Custom syncronization logic.
         _handle_sync: function (method, options) {
             var model_json = this.toJSON();
             var attr;
 
             // Only send updated state if the state hasn't been changed 
             // during an update.
             if (this.comm !== undefined) {
                 if (!this.updating) {
                     if (this.pending_msgs >= this.msg_throttle) {
                         // 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.
                         if (method=='patch') {
                             if (this.msg_buffer === null) {
                                 this.msg_buffer = $.extend({}, model_json); // Copy
                             }
                             for (attr in options.attrs) {
                                 this.msg_buffer[attr] = options.attrs[attr];
                             }
                         } else {
                             this.msg_buffer = $.extend({}, model_json); // Copy
                         }
 
                     } else {
                         // We haven't exceeded the throttle, send the message like 
                         // normal.  If this is a patch operation, just send the 
                         // changes.
                         var send_json = model_json;
                         if (method =='patch') {
                             send_json = {};
                             for (attr in options.attrs) {
                                 send_json[attr] = options.attrs[attr];
                             }
                         }
 
                         var data = {method: 'backbone', sync_method: method, sync_data: send_json};
                         this.comm.send(data, this.cell_callbacks());
                         this.pending_msgs++;
                     }
                 }
             }
             
             // Since the comm is a one-way communication, assume the message 
             // arrived.
             return model_json;
         },
 
         // Build a callback dict.
         cell_callbacks: function (cell) {
             var callbacks = {};
-	    console.log('cell_callbacks A', cell);
             if (cell === undefined) {
 		// Used the last modified view as the sender of the message.  This
 		// will insure that any python code triggered by the sent message
 		// can create and display widgets and output.
                 if (this.last_modified_view !== undefined && 
                     this.last_modified_view.cell !== undefined) {
                     cell = this.last_modified_view.cell;
                 } else {
 		    cell = null;
 		}
             }
-	    console.log('cell_callbacks B', cell);
             if (cell !== null) {
                 
                 // Try to get output handlers
                 var handle_output = null;
                 var handle_clear_output = null;
                 if (cell.output_area !== undefined && cell.output_area !== null) {
                     handle_output = $.proxy(cell.output_area.handle_output, cell.output_area);
                     handle_clear_output = $.proxy(cell.output_area.handle_clear_output, cell.output_area);
                 }
 
                 // Create callback dict using what is known
                 var that = this;
                 callbacks = {
                     iopub : {
                         output : handle_output,
                         clear_output : handle_clear_output,
 
                         status : function (msg) {
                             that._handle_status(msg, that.cell_callbacks(cell));
                         },
 
                         // Special function only registered by widget messages.
                         // Allows us to get the cell for a message so we know
                         // where to add widgets if the code requires it.
                         get_cell : function () {
                             return cell;
                         },
                     },
                 };
             }
-	    console.log('constructed callbacks for',cell);
             return callbacks;
         },
     });
 
 
     //--------------------------------------------------------------------
     // WidgetView class
     //--------------------------------------------------------------------
     var BaseWidgetView = Backbone.View.extend({
         initialize: function(options) {
             this.model.on('change',this.update,this);
 	    this.widget_manager = options.widget_manager;
 	    this.comm_manager = options.widget_manager.comm_manager;
 	    this.cell = options.cell
         },
 
 	update: function(){
 	    // update thyself to be consistent with this.model
 	},
 
 	child_view: function(comm_id, view_name) {
 	    var child_model = this.comm_manager.comms[comm_id].model;
 	    var child_view = this.widget_manager.create_view(child_model, view_name, this.cell);
 	    return child_view;
 	},
 
 	render: function(){
 	    // render thyself
 	},
         send: function (content) {
             this.model.send(content, this.model.cell_callbacks(this.cell));
         },
 
         touch: function () {
             this.model.last_modified_view = this;
             this.model.save(this.model.changedAttributes(), {patch: true});
         },
     });
 
     var WidgetView = BaseWidgetView.extend({
         initialize: function (options) {
             this.visible = true;
 	    BaseWidgetView.prototype.initialize.apply(this, arguments);
         },
         
         add_class: function (selector, class_list) {
             var elements = this._get_selector_element(selector);
             if (elements.length > 0) {
                 elements.addClass(class_list);
             }
         },
         
         remove_class: function (selector, class_list) {
             var elements = this._get_selector_element(selector);
             if (elements.length > 0) {
                 elements.removeClass(class_list);
             }
         },
     
         update: function () {
 	    // jng: hook into change:visible trigger
 	    var visible = this.model.get('visible');
             if (visible !== undefined && this.visible !== visible) {
 		this.visible = visible;
 		this.$el.toggle(visible)
             }
 
             if (this.model.css !== undefined) {
                 for (var selector in this.model.css) {
                     if (this.model.css.hasOwnProperty(selector)) {
 
                         // Apply the css traits to all elements that match the selector.
                         var elements = this._get_selector_element(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]);
                                 }
                             }
                         }
                     }
                 }
             }
         },
 
         _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 $el_to_style element is not defined, use apply the 
             // style to the view's element.
             var elements = this.$el.find(selector);
             if (selector === undefined || selector === null || selector === '') {
                 if (this.$el_to_style === undefined) {
                     elements = this.$el;
                 } else {
                     elements = this.$el_to_style;
                 }
             }
             return elements;
         },
     });
 
     IPython.WidgetModel = WidgetModel;
     IPython.WidgetView = WidgetView;
 
     return widget_manager;
 });

IPython/html/static/notebook/js/widgets/container.js

@@ -1,263 +1,257 b''
 //----------------------------------------------------------------------------
 //  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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // ContainerWidget
 //============================================================================
 
 /**
  * @module IPython
  * @namespace IPython
  **/
 
 define(["notebook/js/widgets/base"], function(widget_manager) {
 
     var set_flex_property = function(element, property_name, enabled) {
         if (enabled) {
             element.addClass(property_name);
         } else {
             element.removeClass(property_name);
         }
     };
 
     var set_flex_properties = function(context, element) {
 
         // Apply flexible box model properties by adding and removing
         // corrosponding CSS classes.
         // Defined in IPython/html/static/base/less/flexbox.less
         set_flex_property(element, 'vbox', context.model.get('_vbox'));
         set_flex_property(element, 'hbox', context.model.get('_hbox'));
         set_flex_property(element, 'start', context.model.get('_pack_start'));
         set_flex_property(element, 'center', context.model.get('_pack_center'));
         set_flex_property(element, 'end', context.model.get('_pack_end'));
         set_flex_property(element, 'align-start', context.model.get('_align_start'));
         set_flex_property(element, 'align-center', context.model.get('_align_center'));
         set_flex_property(element, 'align-end', context.model.get('_align_end'));
         set_flex_property(element, 'box-flex0', context.model.get('_flex0'));
         set_flex_property(element, 'box-flex1', context.model.get('_flex1'));
         set_flex_property(element, 'box-flex2', context.model.get('_flex2'));
     };
 
 
 
     var ContainerModel = IPython.WidgetModel.extend({});
     widget_manager.register_widget_model('ContainerWidgetModel', ContainerModel);
 
     var ContainerView = IPython.WidgetView.extend({
         
         render: function(){
             this.$el
                 .addClass('widget-container');
 	    var children = this.model.get('children');
 	    for(var i in children) {
 		var view = this.child_view(children[i]);
 		this.$el.append(view.$el);
 	    }
 	    this.update()
         },
         
         update: function(){
             set_flex_properties(this, this.$el);
             return IPython.WidgetView.prototype.update.call(this);
         },
     });
 
     widget_manager.register_widget_view('ContainerView', ContainerView);
 
 
     var ModalView = IPython.WidgetView.extend({
         
         render: function(){
             var that = this;
             this.$el
                 .html('')
                 .on("remove", function(){
                     that.$window.remove();
                 });
             this.$window = $('<div />')
                 .addClass('modal widget-modal')
                 .appendTo($('#notebook-container'))
                 .mousedown(function(){
                     that.bring_to_front();
                 });
             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.$window
                             .draggable('destroy')
                             .resizable('destroy')
                             .removeClass('widget-modal modal')
                             .addClass('docked-widget-modal')
                             .detach()
                             .insertBefore(that.$show_button);
                         that.$show_button.hide();
                         that.$close.hide();
                     } else {
                         that.$minimize
                             .addClass('icon-arrow-down')
                             .removeClass('icon-arrow-up');
 
                         that.$window
                             .removeClass('docked-widget-modal')
                             .addClass('widget-modal modal')
                             .detach()
                             .appendTo($('#notebook-container'))
                             .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 = $('<div />')
                 .addClass('modal-body')
                 .addClass('widget-modal-body')
                 .addClass('widget-container')
                 .appendTo(this.$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;
         },
         
         hide: function() {
             this.$window.hide();
             this.$show_button.removeClass('btn-info');
         },
         
         show: function() {
             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() {
             var $widget_modals = $(".widget-modal");
             var max_zindex = 0;
             $widget_modals.each(function (index, el){
                 max_zindex = Math.max(max_zindex, parseInt($(el).css('z-index')));
             });
             
             // 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: function(){
             set_flex_properties(this, this.$body);
             
             var description = this.model.get('description');
             description = description.replace(/ /g, '&nbsp;', 'm');
             description = description.replace(/\n/g, '<br>\n', 'm');
             if (description.length === 0) {
                 this.$title.html('&nbsp;'); // Preserve title height
             } else {
                 this.$title.html(description);
             }
             
             var button_text = this.model.get('button_text');
             button_text = button_text.replace(/ /g, '&nbsp;', 'm');
             button_text = button_text.replace(/\n/g, '<br>\n', 'm');
             if (button_text.length === 0) {
                 this.$show_button.html('&nbsp;'); // Preserve button height
             } else {
                 this.$show_button.html(button_text);
             }
             
             if (!this._shown_once) {
                 this._shown_once = true;
                 this.show();
             }
             
             return IPython.WidgetView.prototype.update.call(this);
         },
 
-        add_child_view: function(attr, view) {
-	    if (attr==='children') {
-		this.$body.append(view.$el);
-	    }
-        },
-        
         _get_selector_element: function(selector) {
 
             // 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 IPython.WidgetView.prototype._get_selector_element.call(this, selector);
             }
         },
         
     });
 
     widget_manager.register_widget_view('ModalView', ModalView);
 });

IPython/html/static/notebook/js/widgets/float_range.js

@@ -1,257 +1,255 b''
 //----------------------------------------------------------------------------
 //  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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // FloatRangeWidget
 //============================================================================
 
 /**
  * @module IPython
  * @namespace IPython
  **/
 
 define(["notebook/js/widgets/base"], function(widget_manager){
     var FloatRangeWidgetModel = IPython.WidgetModel.extend({});
     widget_manager.register_widget_model('FloatRangeWidgetModel', FloatRangeWidgetModel);
 
     var FloatSliderView = IPython.WidgetView.extend({
         
         // Called when view is rendered.
         render : function(){
             this.$el
                 .addClass('widget-hbox-single')
                 .html('');
             this.$label = $('<div />')
                 .appendTo(this.$el)
                 .addClass('widget-hlabel')
                 .hide();
             this.$slider = $('<div />')
                 .slider({})
                 .addClass('slider');
             
             // Put the slider in a container 
             this.$slider_container = $('<div />')
                 .addClass('widget-hslider')
                 .append(this.$slider);    
             this.$el_to_style = this.$slider_container; // Set default element to style
             this.$el.append(this.$slider_container);
             
             // Set defaults.
             this.update();
         },
         
         // Handles: Backend -> Frontend Sync
         //          Frontent -> Frontend Sync
         update : function(){
             // Slider related keys.
             var _keys = ['step', 'max', 'min', 'disabled'];
             for (var index in _keys) {
                 var key = _keys[index];
                 if (this.model.get(key) !== undefined) {
                     this.$slider.slider("option", key, this.model.get(key));
                 }
             }
 
             // WORKAROUND FOR JQUERY SLIDER BUG.
             // The horizontal position of the slider handle
             // depends on the value of the slider at the time
             // of orientation change.  Before applying the new
             // workaround, we set the value to the minimum to
             // make sure that the horizontal placement of the
             // handle in the vertical slider is always 
             // consistent.
             var orientation = this.model.get('orientation');
             var value = this.model.get('min');
             this.$slider.slider('option', 'value', value);
             this.$slider.slider('option', 'orientation', orientation);
             value = this.model.get('value');
             this.$slider.slider('option', 'value', value);
-	    console.log('updating value',value)
 
             // Use the right CSS classes for vertical & horizontal sliders
             if (orientation=='vertical') {
                 this.$slider_container
                     .removeClass('widget-hslider')
                     .addClass('widget-vslider');
                 this.$el
                     .removeClass('widget-hbox-single')
                     .addClass('widget-vbox-single');
                 this.$label
                     .removeClass('widget-hlabel')
                     .addClass('widget-vlabel');
 
             } else {
                 this.$slider_container
                     .removeClass('widget-vslider')
                     .addClass('widget-hslider');
                 this.$el
                     .removeClass('widget-vbox-single')
                     .addClass('widget-hbox-single');
                 this.$label
                     .removeClass('widget-vlabel')
                     .addClass('widget-hlabel');
             }
 
             var description = this.model.get('description');
             if (description.length === 0) {
                 this.$label.hide();
             } else {
                 this.$label.html(description);
                 this.$label.show();
             }
             return IPython.WidgetView.prototype.update.call(this);
         },
         
         // Handles: User input
         events: { "slide" : "handleSliderChange" }, 
         handleSliderChange: function(e, ui) { 
             this.model.set('value', ui.value); 
-	    console.log('triggered value change', ui.value, this.model);
             this.touch();
         },
     });
 
     widget_manager.register_widget_view('FloatSliderView', FloatSliderView);
 
 
     var FloatTextView = IPython.WidgetView.extend({
         
         // Called when view is rendered.
         render : function(){
             this.$el
                 .addClass('widget-hbox-single')
                 .html('');
             this.$label = $('<div />')
                 .appendTo(this.$el)
                 .addClass('widget-hlabel')
                 .hide();
             this.$textbox = $('<input type="text" />')
                 .addClass('input')
                 .addClass('widget-numeric-text')
                 .appendTo(this.$el);
             this.$el_to_style = this.$textbox; // Set default element to style
             this.update(); // Set defaults.
         },
         
         // Handles: Backend -> Frontend Sync
         //          Frontent -> Frontend Sync
         update : function(){
             var value = this.model.get('value');
             if (!this.changing && parseFloat(this.$textbox.val()) != value) {
                 this.$textbox.val(value);
             }
             
             if (this.model.get('disabled')) {
                 this.$textbox.attr('disabled','disabled');
             } else {
                 this.$textbox.removeAttr('disabled');
             }
 
             var description = this.model.get('description');
             if (description.length === 0) {
                 this.$label.hide();
             } else {
                 this.$label.html(description);
                 this.$label.show();
             }
             return IPython.WidgetView.prototype.update.call(this);
         },
         
         
         events: {"keyup input" : "handleChanging",
                 "paste input" : "handleChanging",
                 "cut input" : "handleChanging",
                 "change input" : "handleChanged"}, // Fires only when control is validated or looses focus.
         
         // Handles and validates user input.
         handleChanging: function(e) { 
             
             // Try to parse value as a float.
             var numericalValue = 0.0;
             if (e.target.value !== '') {
                 numericalValue = parseFloat(e.target.value);
             }
             
             // If parse failed, reset value to value stored in model.
             if (isNaN(numericalValue)) {
                 e.target.value = this.model.get('value');
             } else if (!isNaN(numericalValue)) {
                 if (this.model.get('max') !== undefined) {
                     numericalValue = Math.min(this.model.get('max'), numericalValue);
                 }
                 if (this.model.get('min') !== undefined) {
                     numericalValue = Math.max(this.model.get('min'), numericalValue);
                 }
 
                 // Apply the value if it has changed.
                 if (numericalValue != this.model.get('value')) {
                     this.changing = true;
                     this.model.set('value', numericalValue);
                     this.touch();
                     this.changing = false;
                 }
             }
         },
         
         // Applies validated input.
         handleChanged: function(e) { 
             // Update the textbox
             if (this.model.get('value') != e.target.value) {
                 e.target.value = this.model.get('value');
             }
         }
     });
 
     widget_manager.register_widget_view('FloatTextView', FloatTextView);
 
 
     var ProgressView = IPython.WidgetView.extend({
         
         // Called when view is rendered.
         render : function(){
             this.$el
                 .addClass('widget-hbox-single')
                 .html('');
             this.$label = $('<div />')
                 .appendTo(this.$el)
                 .addClass('widget-hlabel')
                 .hide();
             this.$progress = $('<div />')
                 .addClass('progress')
                 .addClass('widget-progress')
                 .appendTo(this.$el);
             this.$el_to_style = this.$progress; // Set default element to style
             this.$bar = $('<div />')
                 .addClass('bar')
                 .css('width', '50%')
                 .appendTo(this.$progress);
             this.update(); // Set defaults.
         },
         
         // Handles: Backend -> Frontend Sync
         //          Frontent -> Frontend Sync
         update : function(){
             var value = this.model.get('value');
             var max = this.model.get('max');
             var min = this.model.get('min');
             var percent = 100.0 * (value - min) / (max - min);
             this.$bar.css('width', percent + '%');
             
             var description = this.model.get('description');
             if (description.length === 0) {
                 this.$label.hide();
             } else {
                 this.$label.html(description);
                 this.$label.show();
             }
             return IPython.WidgetView.prototype.update.call(this);
         },
         
     });
 
     widget_manager.register_widget_view('ProgressView', ProgressView);
 });

IPython/html/static/notebook/js/widgets/multicontainer.js

@@ -1,181 +1,180 b''
 //----------------------------------------------------------------------------
 //  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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // MultiContainerWidget
 //============================================================================
 
 /**
  * @module IPython
  * @namespace IPython
  **/
 
 define(["notebook/js/widgets/base"], function(widget_manager){
     var MulticontainerModel = IPython.WidgetModel.extend({});
     widget_manager.register_widget_model('MulticontainerWidgetModel', MulticontainerModel);
 
     var AccordionView = IPython.WidgetView.extend({
         
         render: function(){
             var guid = 'accordion' + IPython.utils.uuid();
             this.$el
                 .attr('id', guid)
                 .addClass('accordion');
             this.containers = [];
         },
         update: function() {
             // Set tab titles
             var titles = this.model.get('_titles');
             for (var page_index in titles) {
 
                 var accordian = this.containers[page_index];
                 if (accordian !== undefined) {
                     accordian
                         .find('.accordion-heading')
                         .find('.accordion-toggle')
                         .html(titles[page_index]);
                 }
             }
 
             // Set selected page
             var selected_index = this.model.get("selected_index");
             if (0 <= selected_index && selected_index < this.containers.length) {
                 for (var index in this.containers) {
                     if (index==selected_index) {
                         this.containers[index].find('.accordion-body').collapse('show');    
                     } else {
                         this.containers[index].find('.accordion-body').collapse('hide');    
                     }
                     
                 }
             }
             
             return IPython.WidgetView.prototype.update.call(this);
         },
 
         add_child_view: function(attr, view) {
 
             var index = this.containers.length;
             var uuid = IPython.utils.uuid();
             var accordion_group = $('<div />')
                 .addClass('accordion-group')
                 .appendTo(this.$el);
             var accordion_heading = $('<div />')
                 .addClass('accordion-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){ 
                     that.model.set("selected_index", index);
                     that.touch();
                  })
                 .html('Page ' + index)
                 .appendTo(accordion_heading);
             var accordion_body = $('<div />', {id: uuid})
                 .addClass('accordion-body collapse')
                 .appendTo(accordion_group);
             var accordion_inner = $('<div />')
                 .addClass('accordion-inner')
                 .appendTo(accordion_body);
             this.containers.push(accordion_group);
             accordion_inner.append(view.$el);
 
             this.update();
 
             // Stupid workaround to close the bootstrap accordion tabs which
             // open by default even though they don't have the `in` class
             // attached to them.  For some reason a delay is required.  
             // TODO: Better fix.
             setTimeout(function(){ that.update(); }, 500);
         },
     });
 
     widget_manager.register_widget_view('AccordionView', AccordionView);
     
     var TabView = IPython.WidgetView.extend({
         
 	initialize: function() {
 	    this.containers = [];
 	    IPython.WidgetView.prototype.initialize.apply(this, arguments);
 	},
 
         render: function(){
-	    console.log('rendering tabs', this);
             var uuid = 'tabs'+IPython.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);
 	    var children = this.model.get('children');
 	    for (var i in children) {
 		this.add_child_view(this.child_view(children[i]))
 	    }
 	    this.update();
         },
 
         update: function() {
             // Set tab titles
             var titles = this.model.get('_titles');
             for (var page_index in titles) {
                 var tab_text = this.containers[page_index];
                 if (tab_text !== undefined) {
                     tab_text.html(titles[page_index]);
                 }
             }
 
             var selected_index = this.model.get('selected_index');
             if (0 <= selected_index && selected_index < this.containers.length) {
                 this.select_page(selected_index);
             }
 
             return IPython.WidgetView.prototype.update.call(this);
         },
 
         add_child_view: function(view) {
             var index = this.containers.length;
             var uuid = IPython.utils.uuid();
 
             var that = this;
             var tab = $('<li />')
                 .css('list-style-type', 'none')
                 .appendTo(this.$tabs);
             var tab_text = $('<a />')
                 .attr('href', '#' + uuid)
                 .attr('data-toggle', 'tab') 
                 .html('Page ' + index)
                 .appendTo(tab)
                 .click(function (e) {
                     that.model.set("selected_index", index);
                     that.touch();
                     that.select_page(index);
                 });
             this.containers.push(tab_text);
 
             var contents_div = $('<div />', {id: uuid})
                 .addClass('tab-pane')
                 .addClass('fade')
                 .append(view.$el)
                 .appendTo(this.$tab_contents);
         },
 
         select_page: function(index) {
             this.$tabs.find('li')
                 .removeClass('active');
             this.containers[index].tab('show');
         },
     });
 
     widget_manager.register_widget_view('TabView', TabView);
 });

IPython/html/widgets/widget.py

@@ -1,441 +1,438 b''
 """Base Widget class.  Allows user to create widgets in the backend that render
 in the IPython notebook frontend.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from copy import copy
 from glob import glob
 import uuid
 import sys
 import os
 import inspect
 import types
 
 import IPython
 from IPython.kernel.comm import Comm
 from IPython.config import LoggingConfigurable
 from IPython.utils.traitlets import Unicode, Dict, List, Instance, Bool
 from IPython.display import Javascript, display
 from IPython.utils.py3compat import string_types
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 
 class BaseWidget(LoggingConfigurable):
 
     # Shared declarations (Class level)
     _keys = List(Unicode, default_value = [], 
                  help="List of keys comprising the state of the model.", allow_none=False)
     widget_construction_callback = None
 
     def on_widget_constructed(callback):
         """Class method, registers a callback to be called when a widget is
         constructed.  The callback must have the following signature:
         callback(widget)"""
         Widget.widget_construction_callback = callback
 
     def _handle_widget_constructed(widget):
         """Class method, called when a widget is constructed."""
         if Widget.widget_construction_callback is not None and callable(Widget.widget_construction_callback):
             Widget.widget_construction_callback(widget)
 
     
 
     # Public declarations (Instance level)
     target_name = Unicode('widget', help="""Name of the backbone model 
         registered in the frontend to create and sync this widget with.""")
     default_view_name = Unicode(help="""Default view registered in the frontend
         to use to represent the widget.""")
 
     # Private/protected declarations
     # todo: change this to a context manager
     _property_lock = (None, None) # Last updated (key, value) from the front-end.  Prevents echo.
     _displayed = False
     _comm = Instance('IPython.kernel.comm.Comm')
     
     def __init__(self, **kwargs):
         """Public constructor
         """
         self._display_callbacks = []
         self._msg_callbacks = []
         super(BaseWidget, self).__init__(**kwargs)
 
-        # Register after init to allow default values to be specified
-        # TODO: register three different handlers, one for each list, and abstract out the common parts
-        #print self.keys, self._children_attr, self._children_lists_attr
         self.on_trait_change(self._handle_property_changed, self.keys)
         Widget._handle_widget_constructed(self)
 
     def __del__(self):
         """Object disposal"""
         self.close()
 
 
     def close(self):
         """Close method.  Closes the widget which closes the underlying comm.
         When the comm is closed, all of the widget views are automatically
         removed from the frontend."""
         self._close_communication()
     
     
     # Properties
     @property
     def keys(self):
         keys = ['default_view_name']
         keys.extend(self._keys)
         return keys
     
     @property
     def comm(self):
         if self._comm is None:
             self._open_communication()
         return self._comm
 
     # Event handlers
     def _handle_msg(self, msg):
         """Called when a msg is recieved from the frontend"""
         data = msg['content']['data']
         method = data['method']
 
         # Handle backbone sync methods CREATE, PATCH, and UPDATE
         if method == 'backbone':
             if 'sync_method' in data and 'sync_data' in data:
                 sync_method = data['sync_method']
                 sync_data = data['sync_data']
                 self._handle_recieve_state(sync_data) # handles all methods
 
         # Handle a custom msg from the front-end
         elif method == 'custom':
             if 'custom_content' in data:
                 self._handle_custom_msg(data['custom_content'])
 
     def _handle_custom_msg(self, content):
         """Called when a custom msg is recieved."""
         for handler in self._msg_callbacks:
             if callable(handler):
                 argspec = inspect.getargspec(handler)
                 nargs = len(argspec[0])
 
                 # Bound methods have an additional 'self' argument
                 if isinstance(handler, types.MethodType):
                     nargs -= 1
 
                 # Call the callback
                 if nargs == 1:
                     handler(content)
                 elif nargs == 2:
                     handler(self, content)
                 else:
                     raise TypeError('Widget msg callback must ' \
                         'accept 1 or 2 arguments, not %d.' % nargs)
 
 
     def _handle_recieve_state(self, sync_data):
         """Called when a state is recieved from the frontend."""
         # Use _keys instead of keys - Don't get retrieve the css from the client side.
         for name in self._keys:
             if name in sync_data:
                 try:
                     self._property_lock = (name, sync_data[name])
                     setattr(self, name, sync_data[name])
                 finally:
                     self._property_lock = (None, None)
 
 
     def _handle_property_changed(self, name, old, new):
         """Called when a property has been changed."""
         # Make sure this isn't information that the front-end just sent us.
         if self._property_lock[0] != name and self._property_lock[1] != new:
             # Send new state to frontend
             self.send_state(key=name)
 
     def _handle_displayed(self, **kwargs):
         """Called when a view has been displayed for this widget instance
 
         Parameters
         ----------
         [view_name]: unicode (optional kwarg)
             Name of the view that was displayed."""
         for handler in self._display_callbacks:
             if callable(handler):
                 argspec = inspect.getargspec(handler)
                 nargs = len(argspec[0])
 
                 # Bound methods have an additional 'self' argument
                 if isinstance(handler, types.MethodType):
                     nargs -= 1
 
                 # Call the callback
                 if nargs == 0:
                     handler()
                 elif nargs == 1:
                     handler(self)
                 elif nargs == 2:
                     handler(self, kwargs.get('view_name', None))
                 else:
                     handler(self, **kwargs)
 
     # Public methods
     def send_state(self, key=None):
         """Sends the widget state, or a piece of it, to the frontend.
 
         Parameters
         ----------
         key : unicode (optional)
             A single property's name to sync with the frontend.
         """
         self._send({"method": "update",
                     "state": self.get_state()})
 
     def get_state(self, key=None):
         """Gets the widget state, or a piece of it.
 
         Parameters
         ----------
         key : unicode (optional)
             A single property's name to get.
         """
         state = {}
 
         # If a key is provided, just send the state of that key.
         if key is None:
             keys = self.keys[:]
         else:
             keys = [key]
         for k in keys:
             value = getattr(self, k)
 
             # a more elegant solution to encoding BaseWidgets would be
             # to tap into the JSON encoder and teach it how to deal
             # with BaseWidget objects, or maybe just teach the JSON
             # encoder to look for a _repr_json property before giving
             # up encoding
             if isinstance(value, BaseWidget):
                 value = value.comm.comm_id
             elif isinstance(value, list) and isinstance(value[0], BaseWidget):
                 # assume all elements of the list are widgets
                 value = [i.comm.comm_id for i in value]
             state[k] = value
         return state
 
 
     def send(self, content):
         """Sends a custom msg to the widget model in the front-end.
 
         Parameters
         ----------
         content : dict
             Content of the message to send.
         """
         self._send({"method": "custom",
                         "custom_content": content})
 
 
     def on_msg(self, callback, remove=False):
         """Register a callback for when a custom msg is recieved from the front-end
 
         Parameters
         ----------
         callback: method handler
             Can have a signature of:
             - callback(content)
             - callback(sender, content)
         remove: bool
             True if the callback should be unregistered."""
         if remove and callback in self._msg_callbacks:
             self._msg_callbacks.remove(callback)
         elif not remove and not callback in self._msg_callbacks:
             self._msg_callbacks.append(callback)
 
 
     def on_displayed(self, callback, remove=False):
         """Register a callback to be called when the widget has been displayed
 
         Parameters
         ----------
         callback: method handler
             Can have a signature of:
             - callback()
             - callback(sender)
             - callback(sender, view_name)
             - callback(sender, **kwargs)
               kwargs from display call passed through without modification.
         remove: bool
             True if the callback should be unregistered."""
         if remove and callback in self._display_callbacks:
             self._display_callbacks.remove(callback)
         elif not remove and not callback in self._display_callbacks:
             self._display_callbacks.append(callback)
 
 
     # Support methods
     def _repr_widget_(self, **kwargs):
         """Function that is called when `IPython.display.display` is called on
         the widget.
 
         Parameters
         ----------
         view_name: unicode (optional)
             View to display in the frontend.  Overrides default_view_name."""
         view_name = kwargs.get('view_name', self.default_view_name)
         
         # Create a communication.
         self._open_communication()
         
         # Make sure model is syncronized
         self.send_state()
             
         # Show view.
         self._send({"method": "display", "view_name": view_name})
         self._displayed = True
         self._handle_displayed(**kwargs)
 
 
     def _open_communication(self):
         """Opens a communication with the front-end."""
         # Create a comm.
         if self._comm is None:
             self._comm = Comm(target_name=self.target_name)
             self._comm.on_msg(self._handle_msg)
             self._comm.on_close(self._close_communication)
 
         # first update
         self.send_state()
 
 
     def _close_communication(self):
         """Closes a communication with the front-end."""
         if self._comm is not None:
             try:
                 self._comm.close()
             finally:
                 self._comm = None
 
 
     def _send(self, msg):
         """Sends a message to the model in the front-end"""
         if self._comm is not None:
             self._comm.send(msg)
             return True
         else:
             return False        
 
 class Widget(BaseWidget):
     visible = Bool(True, help="Whether or not the widget is visible.")
 
     # Private/protected declarations
     _css = Dict() # Internal CSS property dict
 
     # Properties
     @property
     def keys(self):
         keys = ['visible', '_css']
         keys.extend(super(Widget, self).keys)
         return keys
 
     def get_css(self, key, selector=""):
         """Get a CSS property of the widget.  Note, this function does not
         actually request the CSS from the front-end;  Only properties that have
         been set with set_css can be read.
 
         Parameters
         ----------
         key: unicode
             CSS key
         selector: unicode (optional)
             JQuery selector used when the CSS key/value was set.
         """
         if selector in self._css and key in self._css[selector]:
             return self._css[selector][key]
         else:
             return None
 
 
     def set_css(self, *args, **kwargs):
         """Set one or more CSS properties of the widget (shared among all of the
         views).  This function has two signatures:
         - set_css(css_dict, [selector=''])
         - set_css(key, value, [selector=''])
 
         Parameters
         ----------
         css_dict : dict
             CSS key/value pairs to apply
         key: unicode
             CSS key
         value
             CSS value
         selector: unicode (optional)
             JQuery selector to use to apply the CSS key/value.
         """
         selector = kwargs.get('selector', '')
 
         # Signature 1: set_css(css_dict, [selector=''])
         if len(args) == 1:
             if isinstance(args[0], dict):
                 for (key, value) in args[0].items():
                     self.set_css(key, value, selector=selector)
             else:
                 raise Exception('css_dict must be a dict.')
 
         # Signature 2: set_css(key, value, [selector=''])
         elif len(args) == 2 or len(args) == 3:
 
             # Selector can be a positional arg if it's the 3rd value
             if len(args) == 3:
                 selector = args[2]
             if selector not in self._css:
                 self._css[selector] = {}
 
             # Only update the property if it has changed.
             key = args[0]
             value = args[1]
             if not (key in self._css[selector] and value in self._css[selector][key]):
                 self._css[selector][key] = value
                 self.send_state('_css') # Send new state to client.
         else:
             raise Exception('set_css only accepts 1-3 arguments')
 
 
     def add_class(self, class_name, selector=""):
         """Add class[es] to a DOM element
 
         Parameters
         ----------
         class_name: unicode
             Class name(s) to add to the DOM element(s).  Multiple class names
             must be space separated.
         selector: unicode (optional)
             JQuery selector to select the DOM element(s) that the class(es) will
             be added to.
         """
         self._send({"method": "add_class",
                         "class_list": class_name,
                         "selector": selector})
 
 
     def remove_class(self, class_name, selector=""):
         """Remove class[es] from a DOM element
 
         Parameters
         ----------
         class_name: unicode
             Class name(s) to remove from  the DOM element(s).  Multiple class
             names must be space separated.
         selector: unicode (optional)
             JQuery selector to select the DOM element(s) that the class(es) will
             be removed from.
         """
         self._send({"method": "remove_class",
                         "class_list": class_name,
                         "selector": selector})

IPython/html/widgets/widget_container.py

@@ -1,203 +1,202 b''
 """ContainerWidget class.  
 
 Represents a container that can be used to group other widgets.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import Widget
 from IPython.utils.traitlets import Unicode, Bool, List, Instance
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class ContainerWidget(Widget):
     target_name = Unicode('ContainerWidgetModel')
     default_view_name = Unicode('ContainerView')
 
     children = []#List(Instance('IPython.html.widgets.widget.Widget'))
-    _children_lists_attr = List(Unicode, ['children'])
 
     # Keys, all private and managed by helper methods.  Flexible box model
     # classes...
     _keys = ['_vbox', '_hbox', '_align_start', '_align_end', '_align_center',
             '_pack_start', '_pack_end', '_pack_center', '_flex0', '_flex1', 
             '_flex2', 'description', 'button_text']
     description = Unicode()
     button_text = Unicode()
     _hbox = Bool(False)
     _vbox = Bool(False)
     _align_start = Bool(False)
     _align_end = Bool(False)
     _align_center = Bool(False)
     _pack_start = Bool(False)
     _pack_end = Bool(False)
     _pack_center = Bool(False)
     _flex0 = Bool(False)
     _flex1 = Bool(False)
     _flex2 = Bool(False)
     
     def hbox(self, enabled=True):
         """Make this container an hbox.  Automatically disables conflicting
         features.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the hbox feature of the container, defaults to 
             True."""
         self._hbox = enabled
         if enabled:
             self._vbox = False
     
     def vbox(self, enabled=True):
         """Make this container an vbox.  Automatically disables conflicting
         features.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the vbox feature of the container, defaults to 
             True."""
         self._vbox = enabled
         if enabled:
             self._hbox = False
             
     def align_start(self, enabled=True):
         """Make the contents of this container align to the start of the axis.  
         Automatically disables conflicting alignments.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the start alignment of the container, defaults to 
             True."""
         self._align_start = enabled
         if enabled:
             self._align_end = False
             self._align_center = False
             
     def align_end(self, enabled=True):
         """Make the contents of this container align to the end of the axis.  
         Automatically disables conflicting alignments.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the end alignment of the container, defaults to 
             True."""
         self._align_end = enabled
         if enabled:
             self._align_start = False
             self._align_center = False
             
     def align_center(self, enabled=True):
         """Make the contents of this container align to the center of the axis.  
         Automatically disables conflicting alignments.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the center alignment of the container, defaults to 
             True."""
         self._align_center = enabled
         if enabled:
             self._align_start = False
             self._align_end = False
 
             
     def pack_start(self, enabled=True):
         """Make the contents of this container pack to the start of the axis.  
         Automatically disables conflicting packings.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the start packing of the container, defaults to 
             True."""
         self._pack_start = enabled
         if enabled:
             self._pack_end = False
             self._pack_center = False
             
     def pack_end(self, enabled=True):
         """Make the contents of this container pack to the end of the axis.  
         Automatically disables conflicting packings.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the end packing of the container, defaults to 
             True."""
         self._pack_end = enabled
         if enabled:
             self._pack_start = False
             self._pack_center = False
             
     def pack_center(self, enabled=True):
         """Make the contents of this container pack to the center of the axis.  
         Automatically disables conflicting packings.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the center packing of the container, defaults to 
             True."""
         self._pack_center = enabled
         if enabled:
             self._pack_start = False
             self._pack_end = False
 
             
     def flex0(self, enabled=True):
         """Put this container in flex0 mode.  Automatically disables conflicting
         flex modes.  See the widget tutorial part 5 example notebook for more
         information.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the flex0 attribute of the container, defaults to 
             True."""
         self._flex0 = enabled
         if enabled:
             self._flex1 = False
             self._flex2 = False
             
     def flex1(self, enabled=True):
         """Put this container in flex1 mode.  Automatically disables conflicting
         flex modes.  See the widget tutorial part 5 example notebook for more
         information.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the flex1 attribute of the container, defaults to 
             True."""
         self._flex1 = enabled
         if enabled:
             self._flex0 = False
             self._flex2 = False
             
     def flex2(self, enabled=True):
         """Put this container in flex2 mode.  Automatically disables conflicting
         flex modes.  See the widget tutorial part 5 example notebook for more
         information.
 
         Parameters
         ----------
         enabled: bool (optional)
             Enabled or disable the flex2 attribute of the container, defaults to 
             True."""
         self._flex2 = enabled
         if enabled:
             self._flex0 = False
             self._flex1 = False

IPython/html/widgets/widget_multicontainer.py

@@ -1,59 +1,58 b''
 """MulticontainerWidget class.  
 
 Represents a multipage container that can be used to group other widgets into
 pages.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, the IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from .widget import Widget
 from IPython.utils.traitlets import Unicode, Dict, Int, List, Instance
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class MulticontainerWidget(Widget):
     target_name = Unicode('MulticontainerWidgetModel')
     default_view_name = Unicode('TabView')
 
     # Keys
     _keys = ['_titles', 'selected_index']
     _titles = Dict(help="Titles of the pages")
     selected_index = Int(0)
 
     children = []#List(Instance('IPython.html.widgets.widget.Widget'))
-    _children_lists_attr = List(Unicode, ['children'])
 
     # Public methods
     def set_title(self, index, title):
         """Sets the title of a container page
 
         Parameters
         ----------
         index : int
             Index of the container page
         title : unicode
             New title"""
         self._titles[index] = title
         self.send_state('_titles')
 
 
     def get_title(self, index):
         """Gets the title of a container pages
 
         Parameters
         ----------
         index : int
             Index of the container page"""
         if index in self._titles:
             return self._titles[index]
         else:
             return None