Intermediate changes to javascript side of backbone widgets

IPython/html/static/notebook/js/widgetmanager.js

@@ -1,129 +1,214 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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // WidgetModel, WidgetView, and WidgetManager
 //============================================================================
 /**
  * Base Widget classes
  * @module IPython
  * @namespace IPython
  * @submodule widget
  */
 
 (function () {
     "use strict";
 
     // Use require.js 'define' method so that require.js is intelligent enough to
     // syncronously load everything within this file when it is being 'required' 
     // elsewhere.
     define(["underscore",
              "backbone",
             ], function (underscore, backbone) {
 
         //--------------------------------------------------------------------
         // WidgetManager class
         //--------------------------------------------------------------------
         var WidgetManager = function () {
             this.comm_manager = null;
             this.widget_model_types = {};
             this.widget_view_types = {};
             this._model_instances = {};
             
             Backbone.sync = function (method, model, options, error) {
                 var result = model._handle_sync(method, options);
                 if (options.success) {
                   options.success(result);
                 }
             }; 
         };
 
 
         WidgetManager.prototype.attach_comm_manager = function (comm_manager) {
             this.comm_manager = comm_manager;
 
-            // Register already register widget model types with the comm manager.
+            // Register already-registered widget model types with the comm manager.
             for (var widget_model_name in this.widget_model_types) {
-                this.comm_manager.register_target(widget_model_name, $.proxy(this._handle_com_open, this));
+                this.comm_manager.register_target(widget_model_name, $.proxy(this._handle_comm_open, this));
             }
         };
 
 
         WidgetManager.prototype.register_widget_model = function (widget_model_name, widget_model_type) {
             // Register the widget with the comm manager.  Make sure to pass this object's context
             // in so `this` works in the call back.
             if (this.comm_manager !== null) {
-                this.comm_manager.register_target(widget_model_name, $.proxy(this._handle_com_open, this));
+                this.comm_manager.register_target(widget_model_name, $.proxy(this._handle_comm_open, this));
             }
             this.widget_model_types[widget_model_name] = widget_model_type;
         };
 
 
         WidgetManager.prototype.register_widget_view = function (widget_view_name, widget_view_type) {
             this.widget_view_types[widget_view_name] = widget_view_type;
         };
-
+	WidgetManager.prototype.handle_msg = function(msg, model) {
+	    var method = msg.content.data.method;
+	    switch (method) {
+		case 'display':
+		    var cell = this.get_msg_cell(msg.parent_header.msg_id);
+		    if (cell === null) {
+			console.log("Could not determine where the display" + 
+				    " message was from.  Widget will not be displayed");
+		    } else {
+			var view = this.create_view(model, 
+						    msg.content.data.view_name, cell);
+			if (view !== undefined 
+			    && cell.widget_subarea !== undefined 
+			    && cell.widget_subarea !== null) {
+                            cell.widget_area.show();
+                            cell.widget_subarea.append(view.$el);
+			}
+		    }
+		    break;
+		case 'set_snapshot':
+                    var cell = this.get_msg_cell(msg.parent_header.msg_id);
+                    cell.metadata.snapshot = msg.content.data.snapshot;
+                    break;
+	    }
+	}
+
+	WidgetManager.prototype.create_view = function(model, view_name, cell) {
+	    view_name = view_name || model.get('default_view_name');
+            var ViewType = this.widget_view_types[view_name];
+            if (ViewType !== undefined && ViewType !== null) {
+                var view = new ViewType({model: model, widget_manager: this, cell: cell});
+                view.render();
+                //this.views.push(view);
+
+		/*
+                // jng: Handle when the view element is remove from the page.
+		// observe the view destruction event and do this.  We may need
+		// to override the view's remove method to trigger this event.
+                var that = this;
+                view.$el.on("remove", function () { 
+                    var index = that.views.indexOf(view);
+                    if (index > -1) {
+                        that.views.splice(index, 1);
+                    }
+                    view.remove(); // Clean-up view 
+
+                    // Close the comm if there are no views left.
+                    if (that.views.length() === 0) {
+			//jng: trigger comm close event
+                        }
+
+		        
+                        if (that.comm !== undefined) {
+                            that.comm.close();
+                            delete that.comm.model; // Delete ref so GC will collect widget model.
+                            delete that.comm;
+                        }
+                        delete that.widget_id; // Delete id from model so widget manager cleans up.
+                    });
+		*/
+                return view;
+            }
+        },
 
         WidgetManager.prototype.get_msg_cell = function (msg_id) {
+	    var cell = null;
+            // First, check to see if the msg was triggered by cell execution.
             if (IPython.notebook !== undefined && IPython.notebook !== null) {
-                return IPython.notebook.get_msg_cell(msg_id);
+                cell = IPython.notebook.get_msg_cell(msg_id);
+            }
+	    if (cell !== null) {
+		return cell
+	    }
+            // Second, check to see if a get_cell callback was defined
+            // for the message.  get_cell callbacks are registered for
+            // widget messages, so this block is actually checking to see if the
+            // message was triggered by a widget.
+            var kernel = this.get_kernel();
+            if (kernel !== undefined && kernel !== null) {
+                var callbacks = kernel.get_callbacks_for_msg(msg_id);
+                if (callbacks !== undefined && 
+                    callbacks.iopub !== undefined && 
+                    callbacks.iopub.get_cell !== undefined) {
+
+                    return callbacks.iopub.get_cell();
+                }    
             }
+            
+            // Not triggered by a cell or widget (no get_cell callback 
+            // exists).
+            return null;
         };
 
 
         WidgetManager.prototype.get_model = function (widget_id) {
             var model = this._model_instances[widget_id];
             if (model !== undefined && model.id == widget_id) {
                 return model;
             }
             return null;
         };
 
 
         WidgetManager.prototype.get_kernel = function () {
             if (this.comm_manager === null) {
                 return null;
             } else {
                 return this.comm_manager.kernel;
             }
         };
 
 
         WidgetManager.prototype.on_create_widget = function (callback) {
             this._create_widget_callback = callback;
         };
 
 
         WidgetManager.prototype._handle_create_widget = function (widget_model) {
             if (this._create_widget_callback) {
                 try {
                     this._create_widget_callback(widget_model);
                 } catch (e) {
                     console.log("Exception in WidgetManager callback", e, widget_model);
                 }
             }
         };
 
 
-        WidgetManager.prototype._handle_com_open = function (comm, msg) {
+        WidgetManager.prototype._handle_comm_open = function (comm, msg) {
             var widget_type_name = msg.content.target_name;
             var widget_model = new this.widget_model_types[widget_type_name](this, comm.comm_id, comm);
             this._model_instances[comm.comm_id] = widget_model;
             this._handle_create_widget(widget_model);
         };
         
         //--------------------------------------------------------------------
         // Init code
         //--------------------------------------------------------------------
         IPython.WidgetManager = WidgetManager;
         if (IPython.widget_manager === undefined || IPython.widget_manager === null) {
             IPython.widget_manager = new WidgetManager();    
         }
 
         return IPython.widget_manager;
     });
-}());
  No newline at end of file
+}());

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

@@ -1,555 +1,362 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.views = [];
             this.id = widget_id;
-            this._custom_msg_callbacks = [];
 
             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, cell) {
-            if (this._has_comm()) {
-                // 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 (cell === undefined) {
-                    if (this.last_modified_view !== undefined && 
-                        this.last_modified_view.cell !== undefined) {
-                        cell = this.last_modified_view.cell;
-                    }
-                }
-                var callbacks = this._make_callbacks(cell);
+        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);
             }
         },
 
-
-        on_view_created: function (callback) {
-            this._view_created_callback = callback;
-        },
-
-
-        on_close: function (callback) {
-            this._close_callback = callback;
-        },
-
-
-        on_msg: function (callback, remove) {
-            if (remove) {
-                var found_index = -1;
-                for (var index in this._custom_msg_callbacks) {
-                    if (callback === this._custom_msg_callbacks[index]) {
-                        found_index = index;
-                        break;
-                    }
-                }
-
-                if (found_index >= 0) {
-                    this._custom_msg_callbacks.splice(found_index, 1);
-                }
-            } else {
-                this._custom_msg_callbacks.push(callback);
-            }
-        },
-
-
-        _handle_custom_msg: function (content) {
-            for (var index in this._custom_msg_callbacks) {
-                try {
-                    this._custom_msg_callbacks[index](content);
-                } catch (e) {
-                    console.log("Exception in widget model msg callback", e, content);
-                }
-            }
-        },
-
-
         // Handle when a widget is closed.
         _handle_comm_closed: function (msg) {
-            this._execute_views_method('remove');
+	    // 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 incomming comm msg.
+        // Handle incoming comm msg.
         _handle_comm_msg: function (msg) {
             var method = msg.content.data.method;
             switch (method) {
-                case 'display':
-
-                    // Try to get the cell.
-                    var cell = this._get_msg_cell(msg.parent_header.msg_id);
-                    if (cell === null) {
-                        console.log("Could not determine where the display" + 
-                            " message was from.  Widget will not be displayed");
-                    } else {
-                        this.create_views(msg.content.data.view_name, 
-                        msg.content.data.parent,
-                        cell);
-                    }
-                    break;
                 case 'update':
                     this.apply_update(msg.content.data.state);
                     break;
-                case 'add_class':
-                case 'remove_class':
-                    var selector = msg.content.data.selector;
-                    if (selector === undefined) {
-                        selector = '';
-                    }
-
-                    var class_list = msg.content.data.class_list;
-                    this._execute_views_method(method, selector, class_list);
-                    break;
-                case 'set_snapshot':
-                    var cell = this._get_msg_cell(msg.parent_header.msg_id);
-                    cell.metadata.snapshot = msg.content.data.snapshot;
-                    break;
                 case 'custom':
-                    this._handle_custom_msg(msg.content.data.custom_content);
+                    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)) {
-                        if (key == "_css") {
-
-                            // Set the css value of the model as an attribute
-                            // instead of a backbone trait because we are only 
-                            // interested in backend css -> frontend css.  In
-                            // other words, if the css dict changes in the
-                            // frontend, we don't need to push the changes to
-                            // the backend.
-                            this.css = state[key];
-                        } else {
-                            this.set(key, state[key]); 
-                        }
+                            this.set(key, state[key]);
                     }
                 }
                 this.save();
             } finally {
                 this.updating = false;
             }
         },
 
 
-        _handle_status: function (cell, msg) {
+        _handle_status: function (msg, callbacks) {
             //execution_state : ('busy', 'idle', 'starting')
-            if (this._has_comm()) {
-                if (msg.content.execution_state=='idle') {
+            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 callbacks = this._make_callbacks(cell);
+                        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._has_comm()) {
+            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};
-
-                        var cell = null;
-                        if (this.last_modified_view !== undefined && this.last_modified_view !== null) {
-                            cell = this.last_modified_view.cell;    
-                        }
-                        
-                        var callbacks = this._make_callbacks(cell);
-                        this.comm.send(data, callbacks);    
+                        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;
         },
 
-
-        _handle_view_created: function (view) {
-            if (this._view_created_callback) {
-                try {
-                    this._view_created_callback(view);
-                } catch (e) {
-                    console.log("Exception in widget model view displayed callback", e, view, this);
-                }
-            }
-        },
-
-
-        _execute_views_method: function (/* method_name, [argument0], [argument1], [...] */) {
-            var method_name = arguments[0];
-            var args = null;
-            if (arguments.length > 1) {
-                args = [].splice.call(arguments,1);
-            }
-
-            for (var view_index in this.views) {
-                var view = this.views[view_index];
-                var method = view[method_name];
-                if (args === null) {
-                    method.apply(view);
-                } else {
-                    method.apply(view, args);
-                }
-            }
-        },
-
-
-        // Create view that represents the model.
-        create_views: function (view_name, parent_id, cell) {
-            var new_views = [];
-            var view;
-
-            // Try creating and adding the view to it's parent.
-            var displayed = false;
-            if (parent_id !== undefined) {
-                var parent_model = this.widget_manager.get_model(parent_id);
-                if (parent_model !== null) {
-                    var parent_views = parent_model.views; 
-                    for (var parent_view_index in parent_views) {
-                        var parent_view = parent_views[parent_view_index];
-                        if (parent_view.cell === cell) {
-                            if (parent_view.display_child !== undefined) {
-                                view = this._create_view(view_name, cell);
-                                if (view !== null) {
-                                    new_views.push(view);
-                                    parent_view.display_child(view);
-                                    displayed = true;
-                                    this._handle_view_created(view);
-                                }
-                            }    
-                        }
-                    }
-                }
-            }
-
-            // If no parent view is defined or exists.  Add the view's 
-            // element to cell's widget div.
-            if (!displayed) {
-                view = this._create_view(view_name, cell);
-                if (view !== null) {
-                    new_views.push(view);
-
-                    if (cell.widget_subarea !== undefined && cell.widget_subarea !== null) {
-                        cell.widget_area.show();
-                        cell.widget_subarea.append(view.$el);
-                        this._handle_view_created(view);
-                    }
-                }
-            }
-
-            // Force the new view(s) to update their selves
-            for (var view_index in new_views) {
-                view = new_views[view_index];
-                view.update();
-            }
-        },
-
-
-        // Create a view
-        _create_view: function (view_name, cell) {
-            var ViewType = this.widget_manager.widget_view_types[view_name]; 
-            if (ViewType !== undefined && ViewType !== null) {
-                var view = new ViewType({model: this});
-                view.render();
-                this.views.push(view);
-                view.cell = cell;
-
-                // Handle when the view element is remove from the page.
-                var that = this;
-                view.$el.on("remove", function () { 
-                    var index = that.views.indexOf(view);
-                    if (index > -1) {
-                        that.views.splice(index, 1);
-                    }
-                    view.remove(); // Clean-up view 
-
-                    // Close the comm if there are no views left.
-                    if (that.views.length() === 0) {
-                        if (that._close_callback) {
-                            try {
-                                that._close_callback(that);
-                            } catch (e) {
-                                console.log("Exception in widget model close callback", e, that);
-                            }
-                        }
-
-                        if (that._has_comm()) {
-                            that.comm.close();
-                            delete that.comm.model; // Delete ref so GC will collect widget model.
-                            delete that.comm;
-                        }
-                        delete that.widget_id; // Delete id from model so widget manager cleans up.
-                    }
-                });
-                return view;    
-            }
-            return null;
-        },
-
-
         // Build a callback dict.
-        _make_callbacks: function (cell) {
+        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 usign what is known
+                // 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(cell, 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;
         },
+    });
 
 
-        // Get the output area corresponding to the msg_id.
-        // cell is an instance of IPython.Cell
-        _get_msg_cell: function (msg_id) {
-
-            // First, check to see if the msg was triggered by cell execution.
-            var cell = this.widget_manager.get_msg_cell(msg_id);
-            if (cell !== null) {
-                return cell;
-            }
+    //--------------------------------------------------------------------
+    // 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
+	    this.render();
+	    // jng: maybe the following shouldn't be automatic---maybe the render method should take
+	    // care of knowing what needs to be added as a child?
+            var children_attr = this.model.get('_children_attr');
+            for (var i in children_attr) {
+                var child_attr = children_attr[i];
+                var child_model = this.comm_manager.comms[this.model.get(child_attr)].model;
+		var child_view_name = this.child_view_name(child_attr, child_model);
+                var child_view = this.widget_manager.create_view(child_model, child_view_name, this.cell);
+                this.add_child_view(child_attr, child_view);
+           }
+	   var children_lists_attr = this.model.get('_children_lists_attr')
+           for (var i in children_lists_attr) {
+               var child_attr = children_lists_attr[i];
+               var child_list = this.model.get(child_attr);
+               for (var j in child_list) {
+                   var child_model = this.comm_manager.comms[child_list[j]].model;
+		   var child_view_name = this.child_view_name(child_attr, child_model);
+                   var child_view =  this.widget_manager.create_view(child_model, child_view_name, this.cell);
+                   this.add_child_view(child_attr, child_view);
+               }
+           }
+        },
+	update: function(){
+	    // update thyself to be consistent with this.model
+	},
+
+	child_view: function(attr, viewname) {
+	    var child_model = this.comm_manager.comms[this.model.get(attr)].model;
+	    var child_view = this.widget_manager.create_view(child_model, view_name, this.cell);
+	    return child_view;
+	},
+
+	render: function(){
+	    // render thyself
+	},
+        child_view_name: function(attr, model) {
+	    // attr is the name of the attribute we are constructing a view for
+	    // model is the model stored in that attribute
+	    // return a valid view_name to construct a view of that type
+	    // or null for the default view for the model
+	    return null;
+	},
+	add_child_view: function(attr, view) {
+            //attr is the name of the attribute containing a reference to this child
+            //view is the child view that has been constructed
+            //typically this will just add the child view's view.el attribute to some dom element
+	},
+    
+        send: function (content) {
+            this.model.send(content, this.model.cell_callbacks(this.cell));
+        },
 
-            // Second, check to see if a get_cell callback was defined
-            // for the message.  get_cell callbacks are registered for
-            // widget messages, so this block is actually checking to see if the
-            // message was triggered by a widget.
-            var kernel = this.widget_manager.get_kernel();
-            if (kernel !== undefined && kernel !== null) {
-                var callbacks = kernel.get_callbacks_for_msg(msg_id);
-                if (callbacks !== undefined && 
-                    callbacks.iopub !== undefined && 
-                    callbacks.iopub.get_cell !== undefined) {
-
-                    return callbacks.iopub.get_cell();
-                }    
-            }
-            
-            // Not triggered by a cell or widget (no get_cell callback 
-            // exists).
-            return null;
+        touch: function () {
+            this.model.last_modified_view = this;
+            this.model.save(this.model.changedAttributes(), {patch: true});
         },
 
 
-        // Function that checks if a comm has been attached to this widget
-        // model.  Returns True if a valid comm is attached.
-        _has_comm: function() {
-            return this.comm !== undefined && this.comm !== null;
-        },
     });
 
-
-    //--------------------------------------------------------------------
-    // WidgetView class
-    //--------------------------------------------------------------------
-    var WidgetView = Backbone.View.extend({
-        
-        initialize: function () {
+    var WidgetView = BaseWidgetView.extend({
+        initialize: function (options) {
             this.visible = true;
-            this.model.on('sync',this.update,this);
+	    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);
             }
         },
     
-    
-        send: function (content) {
-            this.model.send(content, this.cell);
-        },
-
-
-        touch: function () {
-            this.model.last_modified_view = this;
-            this.model.save(this.model.changedAttributes(), {patch: true});
-        },
-
         update: function () {
-            if (this.model.get('visible') !== undefined) {
-                if (this.visible != this.model.get('visible')) {
-                    this.visible = this.model.get('visible');
-                    if (this.visible) {
-                        this.$el.show();
-                    } else {
-                        this.$el.hide();
-                    }
-                }
+	    // 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;
-});
  No newline at end of file
+});

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

@@ -1,259 +1,266 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 this.model.get('children')) {
+		
+	    this.update()
         },
         
         update: function(){
             set_flex_properties(this, this.$el);
             return IPython.WidgetView.prototype.update.call(this);
         },
-
-        display_child: function(view) {
-            this.$el.append(view.$el);
-        },
+	add_child_view: function(attr, view) {
+	    if (attr==='children') {
+		this.$el.append(view.$el);
+	    }
+	}
     });
 
     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);
         },
 
-        display_child: function(view) {
-            this.$body.append(view.$el);
+        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

@@ -1,255 +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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // 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

@@ -1,179 +1,183 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);
         },
 
-        display_child: function(view) {
+        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);
-
-            this.containers = [];
+	    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);
         },
 
-        display_child: function(view) {
-
+        add_child_view: function(attr, view) {
+	    console.log('adding child view', attr, 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);
 
             if (index === 0) {
                 tab_text.tab('show');
             }
             this.update();
         },
 
         select_page: function(index) {
             this.$tabs.find('li')
                 .removeClass('active');
             this.containers[index].tab('show');
         },
     });
 
     widget_manager.register_widget_view('TabView', TabView);
 });

IPython/html/static/services/kernels/js/comm.js

@@ -1,198 +1,198 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.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // Comm and CommManager bases
 //============================================================================
 /**
  * Base Comm classes
  * @module IPython
  * @namespace IPython
  * @submodule comm
  */
 
 var IPython = (function (IPython) {
     "use strict";
 
     //-----------------------------------------------------------------------
     // CommManager class
     //-----------------------------------------------------------------------
     
     var CommManager = function (kernel) {
         this.comms = {};
         this.targets = {};
         if (kernel !== undefined) {
             this.init_kernel(kernel);
         }
     };
     
     CommManager.prototype.init_kernel = function (kernel) {
         // connect the kernel, and register message handlers
         this.kernel = kernel;
         var msg_types = ['comm_open', 'comm_msg', 'comm_close'];
         for (var i = 0; i < msg_types.length; i++) {
             var msg_type = msg_types[i];
             kernel.register_iopub_handler(msg_type, $.proxy(this[msg_type], this));
         }
     };
     
     CommManager.prototype.new_comm = function (target_name, data, callbacks, metadata) {
         // Create a new Comm, register it, and open its Kernel-side counterpart
         // Mimics the auto-registration in `Comm.__init__` in the IPython Comm
         var comm = new Comm(target_name);
         this.register_comm(comm);
         comm.open(data, callbacks, metadata);
         return comm;
     };
     
     CommManager.prototype.register_target = function (target_name, f) {
         // Register a target function for a given target name
         this.targets[target_name] = f;
     };
     
     CommManager.prototype.unregister_target = function (target_name, f) {
         // Unregister a target function for a given target name
         delete this.targets[target_name];
     };
     
     CommManager.prototype.register_comm = function (comm) {
         // Register a comm in the mapping
         this.comms[comm.comm_id] = comm;
         comm.kernel = this.kernel;
         return comm.comm_id;
     };
     
     CommManager.prototype.unregister_comm = function (comm_id) {
         // Remove a comm from the mapping
         delete this.comms[comm_id];
     };
     
     // comm message handlers
     
     CommManager.prototype.comm_open = function (msg) {
         var content = msg.content;
         var f = this.targets[content.target_name];
         if (f === undefined) {
             console.log("No such target registered: ", content.target_name);
             console.log("Available targets are: ", this.targets);
             return;
         }
         var comm = new Comm(content.target_name, content.comm_id);
         this.register_comm(comm);
         try {
             f(comm, msg);
         } catch (e) {
-            console.log("Exception opening new comm:", e, msg);
+            console.log("Exception opening new comm:", e, e.stack, msg);
             comm.close();
             this.unregister_comm(comm);
         }
     };
     
     CommManager.prototype.comm_close = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         delete this.comms[content.comm_id];
         try {
             comm.handle_close(msg);
         } catch (e) {
-            console.log("Exception closing comm: ", e, msg);
+            console.log("Exception closing comm: ", e, e.stack, msg);
         }
     };
     
     CommManager.prototype.comm_msg = function (msg) {
         var content = msg.content;
         var comm = this.comms[content.comm_id];
         if (comm === undefined) {
             return;
         }
         try {
             comm.handle_msg(msg);
         } catch (e) {
-            console.log("Exception handling comm msg: ", e, msg);
+            console.log("Exception handling comm msg: ", e, e.stack, msg);
         }
     };
     
     //-----------------------------------------------------------------------
     // Comm base class
     //-----------------------------------------------------------------------
     
     var Comm = function (target_name, comm_id) {
         this.target_name = target_name;
         this.comm_id = comm_id || IPython.utils.uuid();
         this._msg_callback = this._close_callback = null;
     };
     
     // methods for sending messages
     Comm.prototype.open = function (data, callbacks, metadata) {
         var content = {
             comm_id : this.comm_id,
             target_name : this.target_name,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_open", content, callbacks, metadata);
     };
     
     Comm.prototype.send = function (data, callbacks, metadata) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_msg", content, callbacks, metadata);
     };
     
     Comm.prototype.close = function (data, callbacks, metadata) {
         var content = {
             comm_id : this.comm_id,
             data : data || {},
         };
         return this.kernel.send_shell_message("comm_close", content, callbacks, metadata);
     };
     
     // methods for registering callbacks for incoming messages
     Comm.prototype._register_callback = function (key, callback) {
         this['_' + key + '_callback'] = callback;
     };
     
     Comm.prototype.on_msg = function (callback) {
         this._register_callback('msg', callback);
     };
     
     Comm.prototype.on_close = function (callback) {
         this._register_callback('close', callback);
     };
     
     // methods for handling incoming messages
     
     Comm.prototype._maybe_callback = function (key, msg) {
         var callback = this['_' + key + '_callback'];
         if (callback) {
             try {
                 callback(msg);
             } catch (e) {
-                console.log("Exception in Comm callback", e, msg);
+                console.log("Exception in Comm callback", e, e.stack, msg);
             }
         }
     };
     
     Comm.prototype.handle_msg = function (msg) {
         this._maybe_callback('msg', msg);
     };
     
     Comm.prototype.handle_close = function (msg) {
         this._maybe_callback('close', msg);
     };
     
     IPython.CommManager = CommManager;
     IPython.Comm = Comm;
     
     return IPython;
 
 }(IPython));
 

IPython/html/widgets/widget.py

@@ -1,445 +1,450 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, help="List of keys comprising the state of the model.")
-    _children_attr = List(Unicode, help="List of keys of children objects of the model.")
-    _children_lists_attr = List(Unicode, help="List of keys containing lists of children objects of the model.")
+    _keys = List(Unicode, default_value = [], 
+                 help="List of keys comprising the state of the model.", allow_none=False)
+    _children_attr = List(Unicode, default_value = [], 
+                          help="List of keys of children objects of the model.", allow_none=False)
+    _children_lists_attr = List(Unicode, default_value = [],
+                                help="List of keys containing lists of children objects 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 = None
+    _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+self._children_attr+self._children_lists_attr)
         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 = ['_children_attr', '_children_lists_attr']
+        keys = ['_children_attr', '_children_lists_attr', '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 proeprty has been changed."""
+        """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)
+    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[:]
             children_attr = self._children_attr[:]
             children_lists_attr = self._children_lists_attr[:]
         else:
             keys = []
             children_attr = []
             children_lists_attr = []
             if key in self._children_attr:
                 children_attr.append(key)
             elif key in self._children_lists_attr:
                 children_lists_attr.append(key)
             else:
                 keys.append(key)
         for k in keys:
             state[k] = getattr(self, k)
         for k in children_attr:
             # automatically create models on the browser side if they aren't already created
             state[k] = getattr(self, k).comm.comm_id
         for k in children_lists_attr:
             # automatically create models on the browser side if they aren't already created
             state[k] = [i.comm.comm_id for i in getattr(self, k)]
         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 not hasattr(self, '_comm') or self._comm is None:
+        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 hasattr(self, '_comm') and self._comm is not None:
+        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):
-
-    _children = List(Instance('IPython.html.widgets.widget.Widget'))
-    _children_lists_attr = List(Unicode, ['_children'])
     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_button.py

@@ -1,93 +1,93 b''
 """ButtonWidget class.  
 
 Represents a button in the frontend using a widget.  Allows user to listen for
 click events on the button and trigger backend code when the clicks are fired.
 """
 #-----------------------------------------------------------------------------
 # 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
 #-----------------------------------------------------------------------------
 import inspect
 import types
 
 from .widget import Widget
 from IPython.utils.traitlets import Unicode, Bool, Int
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class ButtonWidget(Widget):
     target_name = Unicode('ButtonWidgetModel')
     default_view_name = Unicode('ButtonView')
 
     # Keys
     _keys = ['description', 'disabled']
     description = Unicode('', help="Description of the button (label).")
     disabled = Bool(False, help="Enable or disable user changes.")
     
 
     def __init__(self, **kwargs):
         super(ButtonWidget, self).__init__(**kwargs)
         
         self._click_handlers = []
         self.on_msg(self._handle_button_msg)
 
 
     def on_click(self, callback, remove=False):
         """Register a callback to execute when the button is clicked.  The
         callback can either accept no parameters or one sender parameter:
         - callback()
         - callback(sender)
         If the callback has a sender parameter, the ButtonWidget instance that
         called the callback will be passed into the method as the sender.
 
         Parameters
         ----------
         remove : bool (optional)
             Set to true to remove the callback from the list of callbacks."""
         if remove:
             self._click_handlers.remove(callback)
         elif not callback in self._click_handlers:
             self._click_handlers.append(callback)
 
 
     def _handle_button_msg(self, content):
-        """Hanlde a msg from the front-end
+        """Handle a msg from the front-end
 
         Parameters
         ----------
         content: dict
             Content of the msg."""
         if 'event' in content and content['event'] == 'click':
             self._handle_click()
 
 
     def _handle_click(self):
         """Handles when the button has been clicked.  Fires on_click
         callbacks when appropriate."""
         
         for handler in self._click_handlers:
             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)
                 else:
                     raise TypeError('ButtonWidget click callback must ' \
                         'accept 0 or 1 arguments.')
         

IPython/html/widgets/widget_container.py

@@ -1,200 +1,203 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
+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

@@ -1,56 +1,59 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
+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 pages
+        """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

IPython/utils/traitlets.py

@@ -1,1442 +1,1445 b''
 # encoding: utf-8
 """
 A lightweight Traits like module.
 
 This is designed to provide a lightweight, simple, pure Python version of
 many of the capabilities of enthought.traits.  This includes:
 
 * Validation
 * Type specification with defaults
 * Static and dynamic notification
 * Basic predefined types
 * An API that is similar to enthought.traits
 
 We don't support:
 
 * Delegation
 * Automatic GUI generation
 * A full set of trait types.  Most importantly, we don't provide container
   traits (list, dict, tuple) that can trigger notifications if their
   contents change.
 * API compatibility with enthought.traits
 
 There are also some important difference in our design:
 
 * enthought.traits does not validate default values.  We do.
 
 We choose to create this module because we need these capabilities, but
 we need them to be pure Python so they work in all Python implementations,
 including Jython and IronPython.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.utils.traitlets
    :parts: 3
 
 Authors:
 
 * Brian Granger
 * Enthought, Inc.  Some of the code in this file comes from enthought.traits
   and is licensed under the BSD license.  Also, many of the ideas also come
   from enthought.traits even though our implementation is very different.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 
 import inspect
 import re
 import sys
 import types
 from types import FunctionType
 try:
     from types import ClassType, InstanceType
     ClassTypes = (ClassType, type)
 except:
     ClassTypes = (type,)
 
 from .importstring import import_item
 from IPython.utils import py3compat
 from IPython.utils.py3compat import iteritems
 
 SequenceTypes = (list, tuple, set, frozenset)
 
 #-----------------------------------------------------------------------------
 # Basic classes
 #-----------------------------------------------------------------------------
 
 
 class NoDefaultSpecified ( object ): pass
 NoDefaultSpecified = NoDefaultSpecified()
 
 
 class Undefined ( object ): pass
 Undefined = Undefined()
 
 class TraitError(Exception):
     pass
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 
 def class_of ( object ):
     """ Returns a string containing the class name of an object with the
     correct indefinite article ('a' or 'an') preceding it (e.g., 'an Image',
     'a PlotValue').
     """
     if isinstance( object, py3compat.string_types ):
         return add_article( object )
 
     return add_article( object.__class__.__name__ )
 
 
 def add_article ( name ):
     """ Returns a string containing the correct indefinite article ('a' or 'an')
     prefixed to the specified string.
     """
     if name[:1].lower() in 'aeiou':
        return 'an ' + name
 
     return 'a ' + name
 
 
 def repr_type(obj):
     """ Return a string representation of a value and its type for readable
     error messages.
     """
     the_type = type(obj)
     if (not py3compat.PY3) and the_type is InstanceType:
         # Old-style class.
         the_type = obj.__class__
     msg = '%r %r' % (obj, the_type)
     return msg
 
 
 def is_trait(t):
     """ Returns whether the given value is an instance or subclass of TraitType.
     """
     return (isinstance(t, TraitType) or
             (isinstance(t, type) and issubclass(t, TraitType)))
 
 
 def parse_notifier_name(name):
     """Convert the name argument to a list of names.
 
     Examples
     --------
 
     >>> parse_notifier_name('a')
     ['a']
     >>> parse_notifier_name(['a','b'])
     ['a', 'b']
     >>> parse_notifier_name(None)
     ['anytrait']
     """
     if isinstance(name, str):
         return [name]
     elif name is None:
         return ['anytrait']
     elif isinstance(name, (list, tuple)):
         for n in name:
-            assert isinstance(n, str), "names must be strings"
+            assert isinstance(n, basestring), "names must be strings: %s, %r"%(type(n), n)
         return name
 
 
 class _SimpleTest:
     def __init__ ( self, value ): self.value = value
     def __call__ ( self, test  ):
         return test == self.value
     def __repr__(self):
         return "<SimpleTest(%r)" % self.value
     def __str__(self):
         return self.__repr__()
 
 
 def getmembers(object, predicate=None):
     """A safe version of inspect.getmembers that handles missing attributes.
 
     This is useful when there are descriptor based attributes that for
     some reason raise AttributeError even though they exist.  This happens
     in zope.inteface with the __provides__ attribute.
     """
     results = []
     for key in dir(object):
         try:
             value = getattr(object, key)
         except AttributeError:
             pass
         else:
             if not predicate or predicate(value):
                 results.append((key, value))
     results.sort()
     return results
 
 
 #-----------------------------------------------------------------------------
 # Base TraitType for all traits
 #-----------------------------------------------------------------------------
 
 
 class TraitType(object):
     """A base class for all trait descriptors.
 
     Notes
     -----
     Our implementation of traits is based on Python's descriptor
     prototol.  This class is the base class for all such descriptors.  The
     only magic we use is a custom metaclass for the main :class:`HasTraits`
     class that does the following:
 
     1. Sets the :attr:`name` attribute of every :class:`TraitType`
        instance in the class dict to the name of the attribute.
     2. Sets the :attr:`this_class` attribute of every :class:`TraitType`
        instance in the class dict to the *class* that declared the trait.
        This is used by the :class:`This` trait to allow subclasses to
        accept superclasses for :class:`This` values.
     """
 
 
     metadata = {}
     default_value = Undefined
     info_text = 'any value'
 
     def __init__(self, default_value=NoDefaultSpecified, **metadata):
         """Create a TraitType.
         """
         if default_value is not NoDefaultSpecified:
             self.default_value = default_value
 
         if len(metadata) > 0:
             if len(self.metadata) > 0:
                 self._metadata = self.metadata.copy()
                 self._metadata.update(metadata)
             else:
                 self._metadata = metadata
         else:
             self._metadata = self.metadata
 
         self.init()
 
     def init(self):
         pass
 
     def get_default_value(self):
         """Create a new instance of the default value."""
         return self.default_value
 
     def instance_init(self, obj):
         """This is called by :meth:`HasTraits.__new__` to finish init'ing.
 
         Some stages of initialization must be delayed until the parent
         :class:`HasTraits` instance has been created.  This method is
         called in :meth:`HasTraits.__new__` after the instance has been
         created.
 
         This method trigger the creation and validation of default values
         and also things like the resolution of str given class names in
         :class:`Type` and :class`Instance`.
 
         Parameters
         ----------
         obj : :class:`HasTraits` instance
             The parent :class:`HasTraits` instance that has just been
             created.
         """
         self.set_default_value(obj)
 
     def set_default_value(self, obj):
         """Set the default value on a per instance basis.
 
         This method is called by :meth:`instance_init` to create and
         validate the default value.  The creation and validation of
         default values must be delayed until the parent :class:`HasTraits`
         class has been instantiated.
         """
         # Check for a deferred initializer defined in the same class as the
         # trait declaration or above.
         mro = type(obj).mro()
         meth_name = '_%s_default' % self.name
         for cls in mro[:mro.index(self.this_class)+1]:
             if meth_name in cls.__dict__:
                 break
         else:
             # We didn't find one. Do static initialization.
             dv = self.get_default_value()
             newdv = self._validate(obj, dv)
             obj._trait_values[self.name] = newdv
             return
         # Complete the dynamic initialization.
         obj._trait_dyn_inits[self.name] = cls.__dict__[meth_name]
 
     def __get__(self, obj, cls=None):
         """Get the value of the trait by self.name for the instance.
 
         Default values are instantiated when :meth:`HasTraits.__new__`
         is called.  Thus by the time this method gets called either the
         default value or a user defined value (they called :meth:`__set__`)
         is in the :class:`HasTraits` instance.
         """
         if obj is None:
             return self
         else:
             try:
                 value = obj._trait_values[self.name]
             except KeyError:
                 # Check for a dynamic initializer.
                 if self.name in obj._trait_dyn_inits:
                     value = obj._trait_dyn_inits[self.name](obj)
                     # FIXME: Do we really validate here?
                     value = self._validate(obj, value)
                     obj._trait_values[self.name] = value
                     return value
                 else:
                     raise TraitError('Unexpected error in TraitType: '
                         'both default value and dynamic initializer are '
                         'absent.')
             except Exception:
                 # HasTraits should call set_default_value to populate
                 # this.  So this should never be reached.
                 raise TraitError('Unexpected error in TraitType: '
                                     'default value not set properly')
             else:
                 return value
 
     def __set__(self, obj, value):
         new_value = self._validate(obj, value)
         old_value = self.__get__(obj)
         obj._trait_values[self.name] = new_value
         if old_value != new_value:
             obj._notify_trait(self.name, old_value, new_value)
 
     def _validate(self, obj, value):
         if hasattr(self, 'validate'):
             return self.validate(obj, value)
         elif hasattr(self, 'is_valid_for'):
             valid = self.is_valid_for(value)
             if valid:
                 return value
             else:
                 raise TraitError('invalid value for type: %r' % value)
         elif hasattr(self, 'value_for'):
             return self.value_for(value)
         else:
             return value
 
     def info(self):
         return self.info_text
 
     def error(self, obj, value):
         if obj is not None:
             e = "The '%s' trait of %s instance must be %s, but a value of %s was specified." \
                 % (self.name, class_of(obj),
                    self.info(), repr_type(value))
         else:
             e = "The '%s' trait must be %s, but a value of %r was specified." \
                 % (self.name, self.info(), repr_type(value))
         raise TraitError(e)
 
     def get_metadata(self, key):
         return getattr(self, '_metadata', {}).get(key, None)
 
     def set_metadata(self, key, value):
         getattr(self, '_metadata', {})[key] = value
 
 
 #-----------------------------------------------------------------------------
 # The HasTraits implementation
 #-----------------------------------------------------------------------------
 
 
 class MetaHasTraits(type):
     """A metaclass for HasTraits.
 
     This metaclass makes sure that any TraitType class attributes are
     instantiated and sets their name attribute.
     """
 
     def __new__(mcls, name, bases, classdict):
         """Create the HasTraits class.
 
         This instantiates all TraitTypes in the class dict and sets their
         :attr:`name` attribute.
         """
         # print "MetaHasTraitlets (mcls, name): ", mcls, name
         # print "MetaHasTraitlets (bases): ", bases
         # print "MetaHasTraitlets (classdict): ", classdict
         for k,v in iteritems(classdict):
             if isinstance(v, TraitType):
                 v.name = k
             elif inspect.isclass(v):
                 if issubclass(v, TraitType):
                     vinst = v()
                     vinst.name = k
                     classdict[k] = vinst
         return super(MetaHasTraits, mcls).__new__(mcls, name, bases, classdict)
 
     def __init__(cls, name, bases, classdict):
         """Finish initializing the HasTraits class.
 
         This sets the :attr:`this_class` attribute of each TraitType in the
         class dict to the newly created class ``cls``.
         """
         for k, v in iteritems(classdict):
             if isinstance(v, TraitType):
                 v.this_class = cls
         super(MetaHasTraits, cls).__init__(name, bases, classdict)
 
 class HasTraits(py3compat.with_metaclass(MetaHasTraits, object)):
 
     def __new__(cls, *args, **kw):
         # This is needed because in Python 2.6 object.__new__ only accepts
         # the cls argument.
         new_meth = super(HasTraits, cls).__new__
         if new_meth is object.__new__:
             inst = new_meth(cls)
         else:
             inst = new_meth(cls, **kw)
         inst._trait_values = {}
         inst._trait_notifiers = {}
         inst._trait_dyn_inits = {}
         # Here we tell all the TraitType instances to set their default
         # values on the instance.
         for key in dir(cls):
             # Some descriptors raise AttributeError like zope.interface's
             # __provides__ attributes even though they exist.  This causes
             # AttributeErrors even though they are listed in dir(cls).
             try:
                 value = getattr(cls, key)
             except AttributeError:
                 pass
             else:
                 if isinstance(value, TraitType):
                     value.instance_init(inst)
 
         return inst
 
     def __init__(self, *args, **kw):
         # Allow trait values to be set using keyword arguments.
         # We need to use setattr for this to trigger validation and
         # notifications.
         for key, value in iteritems(kw):
             setattr(self, key, value)
 
     def _notify_trait(self, name, old_value, new_value):
 
         # First dynamic ones
         callables = []
         callables.extend(self._trait_notifiers.get(name,[]))
         callables.extend(self._trait_notifiers.get('anytrait',[]))
 
         # Now static ones
         try:
             cb = getattr(self, '_%s_changed' % name)
         except:
             pass
         else:
             callables.append(cb)
 
         # Call them all now
         for c in callables:
             # Traits catches and logs errors here.  I allow them to raise
             if callable(c):
                 argspec = inspect.getargspec(c)
                 nargs = len(argspec[0])
                 # Bound methods have an additional 'self' argument
                 # I don't know how to treat unbound methods, but they
                 # can't really be used for callbacks.
                 if isinstance(c, types.MethodType):
                     offset = -1
                 else:
                     offset = 0
                 if nargs + offset == 0:
                     c()
                 elif nargs + offset == 1:
                     c(name)
                 elif nargs + offset == 2:
                     c(name, new_value)
                 elif nargs + offset == 3:
                     c(name, old_value, new_value)
                 else:
                     raise TraitError('a trait changed callback '
                                         'must have 0-3 arguments.')
             else:
                 raise TraitError('a trait changed callback '
                                     'must be callable.')
 
 
     def _add_notifiers(self, handler, name):
         if name not in self._trait_notifiers:
             nlist = []
             self._trait_notifiers[name] = nlist
         else:
             nlist = self._trait_notifiers[name]
         if handler not in nlist:
             nlist.append(handler)
 
     def _remove_notifiers(self, handler, name):
         if name in self._trait_notifiers:
             nlist = self._trait_notifiers[name]
             try:
                 index = nlist.index(handler)
             except ValueError:
                 pass
             else:
                 del nlist[index]
 
     def on_trait_change(self, handler, name=None, remove=False):
         """Setup a handler to be called when a trait changes.
 
         This is used to setup dynamic notifications of trait changes.
 
         Static handlers can be created by creating methods on a HasTraits
         subclass with the naming convention '_[traitname]_changed'.  Thus,
         to create static handler for the trait 'a', create the method
         _a_changed(self, name, old, new) (fewer arguments can be used, see
         below).
 
         Parameters
         ----------
         handler : callable
             A callable that is called when a trait changes.  Its
             signature can be handler(), handler(name), handler(name, new)
             or handler(name, old, new).
         name : list, str, None
             If None, the handler will apply to all traits.  If a list
             of str, handler will apply to all names in the list.  If a
             str, the handler will apply just to that name.
         remove : bool
             If False (the default), then install the handler.  If True
             then unintall it.
         """
         if remove:
             names = parse_notifier_name(name)
             for n in names:
                 self._remove_notifiers(handler, n)
         else:
             names = parse_notifier_name(name)
             for n in names:
                 self._add_notifiers(handler, n)
 
     @classmethod
     def class_trait_names(cls, **metadata):
         """Get a list of all the names of this classes traits.
 
         This method is just like the :meth:`trait_names` method, but is unbound.
         """
         return cls.class_traits(**metadata).keys()
 
     @classmethod
     def class_traits(cls, **metadata):
         """Get a list of all the traits of this class.
 
         This method is just like the :meth:`traits` method, but is unbound.
 
         The TraitTypes returned don't know anything about the values
         that the various HasTrait's instances are holding.
 
         This follows the same algorithm as traits does and does not allow
         for any simple way of specifying merely that a metadata name
         exists, but has any value.  This is because get_metadata returns
         None if a metadata key doesn't exist.
         """
         traits = dict([memb for memb in getmembers(cls) if \
                      isinstance(memb[1], TraitType)])
 
         if len(metadata) == 0:
             return traits
 
         for meta_name, meta_eval in metadata.items():
             if type(meta_eval) is not FunctionType:
                 metadata[meta_name] = _SimpleTest(meta_eval)
 
         result = {}
         for name, trait in traits.items():
             for meta_name, meta_eval in metadata.items():
                 if not meta_eval(trait.get_metadata(meta_name)):
                     break
             else:
                 result[name] = trait
 
         return result
 
     def trait_names(self, **metadata):
         """Get a list of all the names of this classes traits."""
         return self.traits(**metadata).keys()
 
     def traits(self, **metadata):
         """Get a list of all the traits of this class.
 
         The TraitTypes returned don't know anything about the values
         that the various HasTrait's instances are holding.
 
         This follows the same algorithm as traits does and does not allow
         for any simple way of specifying merely that a metadata name
         exists, but has any value.  This is because get_metadata returns
         None if a metadata key doesn't exist.
         """
         traits = dict([memb for memb in getmembers(self.__class__) if \
                      isinstance(memb[1], TraitType)])
 
         if len(metadata) == 0:
             return traits
 
         for meta_name, meta_eval in metadata.items():
             if type(meta_eval) is not FunctionType:
                 metadata[meta_name] = _SimpleTest(meta_eval)
 
         result = {}
         for name, trait in traits.items():
             for meta_name, meta_eval in metadata.items():
                 if not meta_eval(trait.get_metadata(meta_name)):
                     break
             else:
                 result[name] = trait
 
         return result
 
     def trait_metadata(self, traitname, key):
         """Get metadata values for trait by key."""
         try:
             trait = getattr(self.__class__, traitname)
         except AttributeError:
             raise TraitError("Class %s does not have a trait named %s" %
                                 (self.__class__.__name__, traitname))
         else:
             return trait.get_metadata(key)
 
 #-----------------------------------------------------------------------------
 # Actual TraitTypes implementations/subclasses
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # TraitTypes subclasses for handling classes and instances of classes
 #-----------------------------------------------------------------------------
 
 
 class ClassBasedTraitType(TraitType):
     """A trait with error reporting for Type, Instance and This."""
 
     def error(self, obj, value):
         kind = type(value)
         if (not py3compat.PY3) and kind is InstanceType:
             msg = 'class %s' % value.__class__.__name__
         else:
             msg = '%s (i.e. %s)' % ( str( kind )[1:-1], repr( value ) )
 
         if obj is not None:
             e = "The '%s' trait of %s instance must be %s, but a value of %s was specified." \
                 % (self.name, class_of(obj),
                    self.info(), msg)
         else:
             e = "The '%s' trait must be %s, but a value of %r was specified." \
                 % (self.name, self.info(), msg)
 
         raise TraitError(e)
 
 
 class Type(ClassBasedTraitType):
     """A trait whose value must be a subclass of a specified class."""
 
     def __init__ (self, default_value=None, klass=None, allow_none=True, **metadata ):
         """Construct a Type trait
 
         A Type trait specifies that its values must be subclasses of
         a particular class.
 
         If only ``default_value`` is given, it is used for the ``klass`` as
         well.
 
         Parameters
         ----------
         default_value : class, str or None
             The default value must be a subclass of klass.  If an str,
             the str must be a fully specified class name, like 'foo.bar.Bah'.
             The string is resolved into real class, when the parent
             :class:`HasTraits` class is instantiated.
         klass : class, str, None
             Values of this trait must be a subclass of klass.  The klass
             may be specified in a string like: 'foo.bar.MyClass'.
             The string is resolved into real class, when the parent
             :class:`HasTraits` class is instantiated.
         allow_none : boolean
             Indicates whether None is allowed as an assignable value. Even if
             ``False``, the default value may be ``None``.
         """
         if default_value is None:
             if klass is None:
                 klass = object
         elif klass is None:
             klass = default_value
 
         if not (inspect.isclass(klass) or isinstance(klass, py3compat.string_types)):
             raise TraitError("A Type trait must specify a class.")
 
         self.klass       = klass
         self._allow_none = allow_none
 
         super(Type, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         """Validates that the value is a valid object instance."""
         try:
             if issubclass(value, self.klass):
                 return value
         except:
             if (value is None) and (self._allow_none):
                 return value
 
         self.error(obj, value)
 
     def info(self):
         """ Returns a description of the trait."""
         if isinstance(self.klass, py3compat.string_types):
             klass = self.klass
         else:
             klass = self.klass.__name__
         result = 'a subclass of ' + klass
         if self._allow_none:
             return result + ' or None'
         return result
 
     def instance_init(self, obj):
         self._resolve_classes()
         super(Type, self).instance_init(obj)
 
     def _resolve_classes(self):
         if isinstance(self.klass, py3compat.string_types):
             self.klass = import_item(self.klass)
         if isinstance(self.default_value, py3compat.string_types):
             self.default_value = import_item(self.default_value)
 
     def get_default_value(self):
         return self.default_value
 
 
 class DefaultValueGenerator(object):
     """A class for generating new default value instances."""
 
     def __init__(self, *args, **kw):
         self.args = args
         self.kw = kw
 
     def generate(self, klass):
         return klass(*self.args, **self.kw)
 
 
 class Instance(ClassBasedTraitType):
     """A trait whose value must be an instance of a specified class.
 
     The value can also be an instance of a subclass of the specified class.
     """
 
     def __init__(self, klass=None, args=None, kw=None,
                  allow_none=True, **metadata ):
         """Construct an Instance trait.
 
         This trait allows values that are instances of a particular
         class or its sublclasses.  Our implementation is quite different
         from that of enthough.traits as we don't allow instances to be used
         for klass and we handle the ``args`` and ``kw`` arguments differently.
 
         Parameters
         ----------
         klass : class, str
             The class that forms the basis for the trait.  Class names
             can also be specified as strings, like 'foo.bar.Bar'.
         args : tuple
             Positional arguments for generating the default value.
         kw : dict
             Keyword arguments for generating the default value.
         allow_none : bool
             Indicates whether None is allowed as a value.
 
         Notes
         -----
         If both ``args`` and ``kw`` are None, then the default value is None.
         If ``args`` is a tuple and ``kw`` is a dict, then the default is
         created as ``klass(*args, **kw)``.  If either ``args`` or ``kw`` is
         not (but not both), None is replace by ``()`` or ``{}``.
         """
 
         self._allow_none = allow_none
 
         if (klass is None) or (not (inspect.isclass(klass) or isinstance(klass, py3compat.string_types))):
             raise TraitError('The klass argument must be a class'
                                 ' you gave: %r' % klass)
         self.klass = klass
 
         # self.klass is a class, so handle default_value
         if args is None and kw is None:
             default_value = None
         else:
             if args is None:
                 # kw is not None
                 args = ()
             elif kw is None:
                 # args is not None
                 kw = {}
 
             if not isinstance(kw, dict):
                 raise TraitError("The 'kw' argument must be a dict or None.")
             if not isinstance(args, tuple):
                 raise TraitError("The 'args' argument must be a tuple or None.")
 
             default_value = DefaultValueGenerator(*args, **kw)
 
         super(Instance, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
             self.error(obj, value)
-
-        if isinstance(value, self.klass):
-            return value
-        else:
-            self.error(obj, value)
+        try:
+            if isinstance(value, self.klass):
+                return value
+            else:
+                self.error(obj, value)
+        except TypeError as e:
+            print self.klass, type(self.klass)
+            raise TypeError("validate, %s, %s"%(self.klass, type(self.klass)))
 
     def info(self):
         if isinstance(self.klass, py3compat.string_types):
             klass = self.klass
         else:
             klass = self.klass.__name__
         result = class_of(klass)
         if self._allow_none:
             return result + ' or None'
 
         return result
 
     def instance_init(self, obj):
         self._resolve_classes()
         super(Instance, self).instance_init(obj)
 
     def _resolve_classes(self):
         if isinstance(self.klass, py3compat.string_types):
             self.klass = import_item(self.klass)
 
     def get_default_value(self):
         """Instantiate a default value instance.
 
         This is called when the containing HasTraits classes'
         :meth:`__new__` method is called to ensure that a unique instance
         is created for each HasTraits instance.
         """
         dv  = self.default_value
         if isinstance(dv, DefaultValueGenerator):
             return dv.generate(self.klass)
         else:
             return dv
 
 
 class This(ClassBasedTraitType):
     """A trait for instances of the class containing this trait.
 
     Because how how and when class bodies are executed, the ``This``
     trait can only have a default value of None.  This, and because we
     always validate default values, ``allow_none`` is *always* true.
     """
 
     info_text = 'an instance of the same type as the receiver or None'
 
     def __init__(self, **metadata):
         super(This, self).__init__(None, **metadata)
 
     def validate(self, obj, value):
         # What if value is a superclass of obj.__class__?  This is
         # complicated if it was the superclass that defined the This
         # trait.
         if isinstance(value, self.this_class) or (value is None):
             return value
         else:
             self.error(obj, value)
 
 
 #-----------------------------------------------------------------------------
 # Basic TraitTypes implementations/subclasses
 #-----------------------------------------------------------------------------
 
 
 class Any(TraitType):
     default_value = None
     info_text = 'any value'
 
 
 class Int(TraitType):
     """An int trait."""
 
     default_value = 0
     info_text = 'an int'
 
     def validate(self, obj, value):
         if isinstance(value, int):
             return value
         self.error(obj, value)
 
 class CInt(Int):
     """A casting version of the int trait."""
 
     def validate(self, obj, value):
         try:
             return int(value)
         except:
             self.error(obj, value)
 
 if py3compat.PY3:
     Long, CLong = Int, CInt
     Integer = Int
 else:
     class Long(TraitType):
         """A long integer trait."""
 
         default_value = 0
         info_text = 'a long'
 
         def validate(self, obj, value):
             if isinstance(value, long):
                 return value
             if isinstance(value, int):
                 return long(value)
             self.error(obj, value)
 
 
     class CLong(Long):
         """A casting version of the long integer trait."""
 
         def validate(self, obj, value):
             try:
                 return long(value)
             except:
                 self.error(obj, value)
 
     class Integer(TraitType):
         """An integer trait.
 
         Longs that are unnecessary (<= sys.maxint) are cast to ints."""
 
         default_value = 0
         info_text = 'an integer'
 
         def validate(self, obj, value):
             if isinstance(value, int):
                 return value
             if isinstance(value, long):
                 # downcast longs that fit in int:
                 # note that int(n > sys.maxint) returns a long, so
                 # we don't need a condition on this cast
                 return int(value)
             if sys.platform == "cli":
                 from System import Int64
                 if isinstance(value, Int64):
                     return int(value)
             self.error(obj, value)
 
 
 class Float(TraitType):
     """A float trait."""
 
     default_value = 0.0
     info_text = 'a float'
 
     def validate(self, obj, value):
         if isinstance(value, float):
             return value
         if isinstance(value, int):
             return float(value)
         self.error(obj, value)
 
 
 class CFloat(Float):
     """A casting version of the float trait."""
 
     def validate(self, obj, value):
         try:
             return float(value)
         except:
             self.error(obj, value)
 
 class Complex(TraitType):
     """A trait for complex numbers."""
 
     default_value = 0.0 + 0.0j
     info_text = 'a complex number'
 
     def validate(self, obj, value):
         if isinstance(value, complex):
             return value
         if isinstance(value, (float, int)):
             return complex(value)
         self.error(obj, value)
 
 
 class CComplex(Complex):
     """A casting version of the complex number trait."""
 
     def validate (self, obj, value):
         try:
             return complex(value)
         except:
             self.error(obj, value)
 
 # We should always be explicit about whether we're using bytes or unicode, both
 # for Python 3 conversion and for reliable unicode behaviour on Python 2. So
 # we don't have a Str type.
 class Bytes(TraitType):
     """A trait for byte strings."""
 
     default_value = b''
     info_text = 'a bytes object'
 
     def validate(self, obj, value):
         if isinstance(value, bytes):
             return value
         self.error(obj, value)
 
 
 class CBytes(Bytes):
     """A casting version of the byte string trait."""
 
     def validate(self, obj, value):
         try:
             return bytes(value)
         except:
             self.error(obj, value)
 
 
 class Unicode(TraitType):
     """A trait for unicode strings."""
 
     default_value = u''
     info_text = 'a unicode string'
 
     def validate(self, obj, value):
         if isinstance(value, py3compat.unicode_type):
             return value
         if isinstance(value, bytes):
             try:
                 return value.decode('ascii', 'strict')
             except UnicodeDecodeError:
                 msg = "Could not decode {!r} for unicode trait '{}' of {} instance."
                 raise TraitError(msg.format(value, self.name, class_of(obj)))
         self.error(obj, value)
 
 
 class CUnicode(Unicode):
     """A casting version of the unicode trait."""
 
     def validate(self, obj, value):
         try:
             return py3compat.unicode_type(value)
         except:
             self.error(obj, value)
 
 
 class ObjectName(TraitType):
     """A string holding a valid object name in this version of Python.
 
     This does not check that the name exists in any scope."""
     info_text = "a valid object identifier in Python"
 
     if py3compat.PY3:
         # Python 3:
         coerce_str = staticmethod(lambda _,s: s)
 
     else:
         # Python 2:
         def coerce_str(self, obj, value):
             "In Python 2, coerce ascii-only unicode to str"
             if isinstance(value, unicode):
                 try:
                     return str(value)
                 except UnicodeEncodeError:
                     self.error(obj, value)
             return value
 
     def validate(self, obj, value):
         value = self.coerce_str(obj, value)
 
         if isinstance(value, str) and py3compat.isidentifier(value):
             return value
         self.error(obj, value)
 
 class DottedObjectName(ObjectName):
     """A string holding a valid dotted object name in Python, such as A.b3._c"""
     def validate(self, obj, value):
         value = self.coerce_str(obj, value)
 
         if isinstance(value, str) and py3compat.isidentifier(value, dotted=True):
             return value
         self.error(obj, value)
 
 
 class Bool(TraitType):
     """A boolean (True, False) trait."""
 
     default_value = False
     info_text = 'a boolean'
 
     def validate(self, obj, value):
         if isinstance(value, bool):
             return value
         self.error(obj, value)
 
 
 class CBool(Bool):
     """A casting version of the boolean trait."""
 
     def validate(self, obj, value):
         try:
             return bool(value)
         except:
             self.error(obj, value)
 
 
 class Enum(TraitType):
     """An enum that whose value must be in a given sequence."""
 
     def __init__(self, values, default_value=None, allow_none=True, **metadata):
         self.values = values
         self._allow_none = allow_none
         super(Enum, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
 
         if value in self.values:
                 return value
         self.error(obj, value)
 
     def info(self):
         """ Returns a description of the trait."""
         result = 'any of ' + repr(self.values)
         if self._allow_none:
             return result + ' or None'
         return result
 
 class CaselessStrEnum(Enum):
     """An enum of strings that are caseless in validate."""
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
 
         if not isinstance(value, py3compat.string_types):
             self.error(obj, value)
 
         for v in self.values:
             if v.lower() == value.lower():
                 return v
         self.error(obj, value)
 
 class Container(Instance):
     """An instance of a container (list, set, etc.)
 
     To be subclassed by overriding klass.
     """
     klass = None
     _valid_defaults = SequenceTypes
     _trait = None
 
     def __init__(self, trait=None, default_value=None, allow_none=True,
                 **metadata):
         """Create a container trait type from a list, set, or tuple.
 
         The default value is created by doing ``List(default_value)``,
         which creates a copy of the ``default_value``.
 
         ``trait`` can be specified, which restricts the type of elements
         in the container to that TraitType.
 
         If only one arg is given and it is not a Trait, it is taken as
         ``default_value``:
 
         ``c = List([1,2,3])``
 
         Parameters
         ----------
 
         trait : TraitType [ optional ]
             the type for restricting the contents of the Container.  If unspecified,
             types are not checked.
 
         default_value : SequenceType [ optional ]
             The default value for the Trait.  Must be list/tuple/set, and
             will be cast to the container type.
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         # allow List([values]):
         if default_value is None and not is_trait(trait):
             default_value = trait
             trait = None
 
         if default_value is None:
             args = ()
         elif isinstance(default_value, self._valid_defaults):
             args = (default_value,)
         else:
             raise TypeError('default value of %s was %s' %(self.__class__.__name__, default_value))
 
         if is_trait(trait):
             self._trait = trait() if isinstance(trait, type) else trait
             self._trait.name = 'element'
         elif trait is not None:
             raise TypeError("`trait` must be a Trait or None, got %s"%repr_type(trait))
 
         super(Container,self).__init__(klass=self.klass, args=args,
                                   allow_none=allow_none, **metadata)
 
     def element_error(self, obj, element, validator):
         e = "Element of the '%s' trait of %s instance must be %s, but a value of %s was specified." \
             % (self.name, class_of(obj), validator.info(), repr_type(element))
         raise TraitError(e)
 
     def validate(self, obj, value):
         value = super(Container, self).validate(obj, value)
         if value is None:
             return value
 
         value = self.validate_elements(obj, value)
 
         return value
 
     def validate_elements(self, obj, value):
         validated = []
         if self._trait is None or isinstance(self._trait, Any):
             return value
         for v in value:
             try:
                 v = self._trait.validate(obj, v)
             except TraitError:
                 self.element_error(obj, v, self._trait)
             else:
                 validated.append(v)
         return self.klass(validated)
 
 
 class List(Container):
     """An instance of a Python list."""
     klass = list
 
     def __init__(self, trait=None, default_value=None, minlen=0, maxlen=sys.maxsize,
                 allow_none=True, **metadata):
         """Create a List trait type from a list, set, or tuple.
 
         The default value is created by doing ``List(default_value)``,
         which creates a copy of the ``default_value``.
 
         ``trait`` can be specified, which restricts the type of elements
         in the container to that TraitType.
 
         If only one arg is given and it is not a Trait, it is taken as
         ``default_value``:
 
         ``c = List([1,2,3])``
 
         Parameters
         ----------
 
         trait : TraitType [ optional ]
             the type for restricting the contents of the Container.  If unspecified,
             types are not checked.
 
         default_value : SequenceType [ optional ]
             The default value for the Trait.  Must be list/tuple/set, and
             will be cast to the container type.
 
         minlen : Int [ default 0 ]
             The minimum length of the input list
 
         maxlen : Int [ default sys.maxsize ]
             The maximum length of the input list
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         self._minlen = minlen
         self._maxlen = maxlen
         super(List, self).__init__(trait=trait, default_value=default_value,
                                 allow_none=allow_none, **metadata)
 
     def length_error(self, obj, value):
         e = "The '%s' trait of %s instance must be of length %i <= L <= %i, but a value of %s was specified." \
             % (self.name, class_of(obj), self._minlen, self._maxlen, value)
         raise TraitError(e)
 
     def validate_elements(self, obj, value):
         length = len(value)
         if length < self._minlen or length > self._maxlen:
             self.length_error(obj, value)
 
         return super(List, self).validate_elements(obj, value)
 
 
 class Set(Container):
     """An instance of a Python set."""
     klass = set
 
 class Tuple(Container):
     """An instance of a Python tuple."""
     klass = tuple
 
     def __init__(self, *traits, **metadata):
         """Tuple(*traits, default_value=None, allow_none=True, **medatata)
 
         Create a tuple from a list, set, or tuple.
 
         Create a fixed-type tuple with Traits:
 
         ``t = Tuple(Int, Str, CStr)``
 
         would be length 3, with Int,Str,CStr for each element.
 
         If only one arg is given and it is not a Trait, it is taken as
         default_value:
 
         ``t = Tuple((1,2,3))``
 
         Otherwise, ``default_value`` *must* be specified by keyword.
 
         Parameters
         ----------
 
         *traits : TraitTypes [ optional ]
             the tsype for restricting the contents of the Tuple.  If unspecified,
             types are not checked. If specified, then each positional argument
             corresponds to an element of the tuple.  Tuples defined with traits
             are of fixed length.
 
         default_value : SequenceType [ optional ]
             The default value for the Tuple.  Must be list/tuple/set, and
             will be cast to a tuple. If `traits` are specified, the
             `default_value` must conform to the shape and type they specify.
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         default_value = metadata.pop('default_value', None)
         allow_none = metadata.pop('allow_none', True)
 
         # allow Tuple((values,)):
         if len(traits) == 1 and default_value is None and not is_trait(traits[0]):
             default_value = traits[0]
             traits = ()
 
         if default_value is None:
             args = ()
         elif isinstance(default_value, self._valid_defaults):
             args = (default_value,)
         else:
             raise TypeError('default value of %s was %s' %(self.__class__.__name__, default_value))
 
         self._traits = []
         for trait in traits:
             t = trait() if isinstance(trait, type) else trait
             t.name = 'element'
             self._traits.append(t)
 
         if self._traits and default_value is None:
             # don't allow default to be an empty container if length is specified
             args = None
         super(Container,self).__init__(klass=self.klass, args=args,
                                   allow_none=allow_none, **metadata)
 
     def validate_elements(self, obj, value):
         if not self._traits:
             # nothing to validate
             return value
         if len(value) != len(self._traits):
             e = "The '%s' trait of %s instance requires %i elements, but a value of %s was specified." \
                 % (self.name, class_of(obj), len(self._traits), repr_type(value))
             raise TraitError(e)
 
         validated = []
         for t,v in zip(self._traits, value):
             try:
                 v = t.validate(obj, v)
             except TraitError:
                 self.element_error(obj, v, t)
             else:
                 validated.append(v)
         return tuple(validated)
 
 
 class Dict(Instance):
     """An instance of a Python dict."""
 
     def __init__(self, default_value=None, allow_none=True, **metadata):
         """Create a dict trait type from a dict.
 
         The default value is created by doing ``dict(default_value)``,
         which creates a copy of the ``default_value``.
         """
         if default_value is None:
             args = ((),)
         elif isinstance(default_value, dict):
             args = (default_value,)
         elif isinstance(default_value, SequenceTypes):
             args = (default_value,)
         else:
             raise TypeError('default value of Dict was %s' % default_value)
 
         super(Dict,self).__init__(klass=dict, args=args,
                                   allow_none=allow_none, **metadata)
 
 class TCPAddress(TraitType):
     """A trait for an (ip, port) tuple.
 
     This allows for both IPv4 IP addresses as well as hostnames.
     """
 
     default_value = ('127.0.0.1', 0)
     info_text = 'an (ip, port) tuple'
 
     def validate(self, obj, value):
         if isinstance(value, tuple):
             if len(value) == 2:
                 if isinstance(value[0], py3compat.string_types) and isinstance(value[1], int):
                     port = value[1]
                     if port >= 0 and port <= 65535:
                         return value
         self.error(obj, value)
 
 class CRegExp(TraitType):
     """A casting compiled regular expression trait.
 
     Accepts both strings and compiled regular expressions. The resulting
     attribute will be a compiled regular expression."""
 
     info_text = 'a regular expression'
 
     def validate(self, obj, value):
         try:
             return re.compile(value)
         except:
             self.error(obj, value)

examples/widgets/Part 1 - Basics.ipynb

@@ -1,327 +1,390 b''
 {
  "metadata": {
   "cell_tags": [
    [
     "<None>",
     null
    ]
   ],
   "name": ""
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "To use IPython widgets in the notebook, the widget namespace and display function need to be imported."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "from IPython.html import widgets # Widget definitions\n",
       "from IPython.display import display # Used to display widgets in the notebook"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 1
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Basic Widgets"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The IPython notebook comes preloaded with basic widgets that represent common data types.  These widgets are\n",
       "\n",
       "- BoolWidget : boolean  \n",
       "- FloatRangeWidget : bounded float  \n",
       "- FloatWidget : unbounded float  \n",
       "- ImageWidget : image\n",
       "- IntRangeWidget : bounded integer  \n",
       "- IntWidget : unbounded integer  \n",
       "- SelectionWidget : enumeration  \n",
       "- StringWidget : string  \n",
       "\n",
       "A few special widgets are also included, that can be used to capture events and change how other widgets are displayed.  These widgets are\n",
       "\n",
       "- ButtonWidget  \n",
       "- ContainerWidget  \n",
       "- MulticontainerWidget  \n",
       "\n",
       "To see the complete list of widgets, one can execute the following"
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "[widget for widget in dir(widgets) if widget.endswith('Widget')]"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "metadata": {},
        "output_type": "pyout",
        "prompt_number": 2,
        "text": [
         "['BoolWidget',\n",
         " 'ButtonWidget',\n",
         " 'ContainerWidget',\n",
         " 'FloatRangeWidget',\n",
         " 'FloatWidget',\n",
         " 'ImageWidget',\n",
         " 'IntRangeWidget',\n",
         " 'IntWidget',\n",
         " 'MulticontainerWidget',\n",
         " 'SelectionWidget',\n",
         " 'StringWidget',\n",
         " 'Widget']"
        ]
       }
      ],
      "prompt_number": 2
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The basic widgets can all be constructed without arguments.  The following creates a FloatRangeWidget without displaying it"
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mywidget = widgets.FloatRangeWidget()"
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'value', 'step', 'max', 'min', 'disabled', 'orientation', 'description']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      }
+     ],
      "prompt_number": 3
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Constructing a widget does not display it on the page.  To display a widget, the widget must be passed to the IPython `display(object)` method.  `mywidget` is displayed by"
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "display(mywidget)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 4
     },
     {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "mywidget.value"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 13,
+       "text": [
+        "55.1"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "It's important to realize that widgets are not the same as output, even though they are displayed with `display`.  Widgets are drawn in a special widget area.  That area is marked with a close button which allows you to collapse the widgets.  Widgets cannot be interleaved with output.  Doing so would break the ability to make simple animations using `clear_output`.\n",
       "\n",
       "Widgets are manipulated via special instance properties (traitlets).  The names of these instance properties are listed in the widget's `keys` property (as seen below).  A few of these properties are common to most, if not all, widgets.  The common properties are `value`, `description`, `visible`, and `disabled`.  `_css`, `_add_class`, and `_remove_class` are internal properties that exist in all widgets and should not be modified."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mywidget.keys"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 5,
+       "prompt_number": 11,
        "text": [
         "['visible',\n",
         " '_css',\n",
+        " '_children_attr',\n",
+        " '_children_lists_attr',\n",
+        " 'default_view_name',\n",
         " 'value',\n",
         " 'step',\n",
         " 'max',\n",
         " 'min',\n",
         " 'disabled',\n",
         " 'orientation',\n",
         " 'description']"
        ]
       }
      ],
-     "prompt_number": 5
+     "prompt_number": 11
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Changing a widget's property value will automatically update that widget everywhere it is displayed in the notebook.  Here the value of `mywidget` is set.  The slider shown above (after input 4) updates automatically to the new value.  In reverse, changing the value of the displayed widget will update the property's value."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mywidget.value = 25.0"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 6
+     "prompt_number": 12
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "After changing the widget's value in the notebook by hand to 0.0 (sliding the bar to the far left)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mywidget.value"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 7,
+       "prompt_number": 30,
        "text": [
-        "0.0"
+        "25.0"
        ]
       }
      ],
-     "prompt_number": 7
+     "prompt_number": 30
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Widget property values can also be set with kwargs during the construction of the widget (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mysecondwidget = widgets.SelectionWidget(values=[\"Item A\", \"Item B\", \"Item C\"], value=\"Nothing Selected\")\n",
       "display(mysecondwidget)"
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
-     "prompt_number": 8
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'value', 'values', 'disabled', 'description']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "mysecondwidget.value"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 15,
+       "text": [
+        "u'Item C'"
+       ]
+      }
+     ],
+     "prompt_number": 15
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Views"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The data types that most of the widgets represent can be displayed more than one way.  A `view` is a visual representation of a widget in the notebook.  In the example in the section above, the default `view` for the `FloatRangeWidget` is used.  The default view is set in the widgets `default_view_name` instance property (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "mywidget.default_view_name"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 9,
+       "prompt_number": 16,
        "text": [
         "u'FloatSliderView'"
        ]
       }
      ],
-     "prompt_number": 9
+     "prompt_number": 16
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "When a widget is displayed using `display(...)`, the `default_view_name` is used to determine what view type should be used to display the widget.  View names are case sensitive.  Sometimes the default view isn't the best view to represent a piece of data.  To change what view is used, either the `default_view_name` can be changed or the `view_name` kwarg of `display` can be set.  This also can be used to display one widget multiple ways in one output (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "display(mywidget)\n",
       "display(mywidget, view_name=\"FloatTextView\")"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 10
+     "prompt_number": 17
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Some views work with multiple different widget types and some views only work with one.  The complete list of views and supported widgets is below.  The default views are italicized.\n",
       "\n",
       "| Widget Name            | View Names          |\n",
       "|:-----------------------|:--------------------|\n",
       "| BoolWidget             |   *CheckboxView*    |\n",
       "|                        |   ToggleButtonView  |\n",
       "| ButtonWidget           |   *ButtonView*      |\n",
       "| ContainerWidget        |   *ContainerView*   |\n",
       "|                        |   ModalView         |\n",
       "| FloatRangeWidget       |   *FloatSliderView* |\n",
       "|                        |   FloatTextView     |\n",
       "|                        |   ProgressView      |\n",
       "| FloatWidget            |   *FloatTextView*   |\n",
       "| ImageWidget            |   *ImageView*       |\n",
       "| IntRangeWidget         |   *IntSliderView*   |\n",
       "|                        |   IntTextView       |\n",
       "|                        |   ProgressView      |\n",
       "| IntWidget              |   *IntTextView*     |\n",
       "| MulticontainerWidget   |   AccordionView     |\n",
       "|                        |   *TabView*         |\n",
       "| SelectionWidget        |   ToggleButtonsView |\n",
       "|                        |   RadioButtonsView  |\n",
       "|                        |   *DropdownView*    |\n",
       "|                        |   ListBoxView       |\n",
       "| StringWidget           |   HTMLView          |\n",
       "|                        |   LatexView         |\n",
       "|                        |   TextAreaView      |\n",
       "|                        |   *TextBoxView*     |\n"
      ]
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file

examples/widgets/Part 2 - Events.ipynb

@@ -1,271 +1,479 b''
 {
  "metadata": {
   "cell_tags": [
    [
     "<None>",
     null
    ]
   ],
   "name": ""
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "from __future__ import print_function # 2.7 compatability\n",
       "\n",
       "from IPython.html import widgets # Widget definitions\n",
       "from IPython.display import display # Used to display widgets in the notebook"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 1
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Traitlet Events"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The widget properties are IPython traitlets.  Traitlets are eventful.  To handle property value changes, the `on_trait_change` method of the widget can be used to register an event handling callback.  The doc string for `on_trait_change` can be seen below.  Both the `name` and `remove` properties are optional."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "print(widgets.Widget.on_trait_change.__doc__)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "Setup a handler to be called when a trait changes.\n",
         "\n",
         "        This is used to setup dynamic notifications of trait changes.\n",
         "\n",
         "        Static handlers can be created by creating methods on a HasTraits\n",
         "        subclass with the naming convention '_[traitname]_changed'.  Thus,\n",
         "        to create static handler for the trait 'a', create the method\n",
         "        _a_changed(self, name, old, new) (fewer arguments can be used, see\n",
         "        below).\n",
         "\n",
         "        Parameters\n",
         "        ----------\n",
         "        handler : callable\n",
         "            A callable that is called when a trait changes.  Its\n",
         "            signature can be handler(), handler(name), handler(name, new)\n",
         "            or handler(name, old, new).\n",
         "        name : list, str, None\n",
         "            If None, the handler will apply to all traits.  If a list\n",
         "            of str, handler will apply to all names in the list.  If a\n",
         "            str, the handler will apply just to that name.\n",
         "        remove : bool\n",
         "            If False (the default), then install the handler.  If True\n",
         "            then unintall it.\n",
         "        \n"
        ]
       }
      ],
      "prompt_number": 2
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Mentioned in the doc string, the callback registered can have 4 possible signatures:\n",
       "\n",
       "- callback()\n",
       "- callback(trait_name)\n",
       "- callback(trait_name, new_value)\n",
       "- callback(trait_name, old_value, new_value)\n",
       "\n",
       "An example of how to output an IntRangeWiget's value as it is changed can be seen below."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "intrange = widgets.IntRangeWidget()\n",
       "display(intrange)\n",
       "\n",
       "def on_value_change(name, value):\n",
       "    print(value)\n",
       "\n",
-      "intrange.on_trait_change(on_value_change, 'value')"
+      "#intrange.on_trait_change(on_value_change, 'value')"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
-        "28\n"
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "55\n"
-       ]
-      },
-      {
-       "output_type": "stream",
-       "stream": "stdout",
-       "text": [
-        "94\n"
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'value', 'step', 'max', 'min', 'disabled', 'orientation', 'description']\n",
+        "[]\n",
+        "[]\n"
        ]
       }
      ],
-     "prompt_number": 3
+     "prompt_number": 9
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Specialized Events"
      ]
     },
     {
      "cell_type": "heading",
      "level": 2,
      "metadata": {},
      "source": [
       "Button On Click Event"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The `ButtonWidget` is a special widget, like the `ContainerWidget` and `MulticontainerWidget`, that isn't used to represent a data type.  Instead the button widget is used to handle mouse clicks.  The `on_click` method of the `ButtonWidget` can be used to register a click even handler.  The doc string of the `on_click` can be seen below."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "print(widgets.ButtonWidget.on_click.__doc__)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "Register a callback to execute when the button is clicked.  The\n",
         "        callback can either accept no parameters or one sender parameter:\n",
         "        - callback()\n",
         "        - callback(sender)\n",
         "        If the callback has a sender parameter, the ButtonWidget instance that\n",
         "        called the callback will be passed into the method as the sender.\n",
         "\n",
         "        Parameters\n",
         "        ----------\n",
         "        remove : bool (optional)\n",
         "            Set to true to remove the callback from the list of callbacks.\n"
        ]
       }
      ],
      "prompt_number": 4
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Button clicks are transmitted from the front-end to the back-end using custom messages.  By using the `on_click` method, a button that prints a message when it has been clicked is shown below."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
+      "display(intrange)\n",
+      "print('hi')"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "hi\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
       "button = widgets.ButtonWidget(description=\"Click Me!\")\n",
       "display(button)\n",
       "\n",
       "def on_button_clicked(sender):\n",
       "    print(\"Button clicked.\")\n",
+      "    intrange.value +=1\n",
       "\n",
       "button.on_click(on_button_clicked)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Button clicked.\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
         "Button clicked.\n"
        ]
       },
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "Button clicked.\n"
        ]
       },
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "Button clicked.\n"
        ]
       }
      ],
-     "prompt_number": 5
+     "prompt_number": 12
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Event handlers can also be used to create widgets.  In the example below, clicking a button spawns another button with a description equal to how many times the parent button had been clicked at the time."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 11,
+       "text": [
+        "{'content': {'data': \"{'parent_header': {}, 'msg_type': u'comm_msg', 'msg_id': u'3DBB06AD83C942DD85DC6477B08F1FBF', 'content': {u'data': {u'method': u'custom', u'custom_content': {u'event': u'click'}}, u'comm_id': u'eea5f11ae7aa473993dd0c81d6016648'}, 'header': {u'username': u'username', u'msg_id': u'3DBB06AD83C942DD85DC6477B08F1FBF', u'msg_type': u'comm_msg', u'session': u'0F6D6BE728DA47A38CFC4BDEACF34FC4'}, 'buffers': [], 'metadata': {}}\\ncustom message {'parent_header': {}, 'msg_type': u'comm_msg', 'msg_id': u'3DBB06AD83C942DD85DC6477B08F1FBF', 'content': {u'data': {u'method': u'custom', u'custom_content': {u'event': u'click'}}, u'comm_id': u'eea5f11ae7aa473993dd0c81d6016648'}, 'header': {u'username': u'username', u'msg_id': u'3DBB06AD83C942DD85DC6477B08F1FBF', u'msg_type': u'comm_msg', u'session': u'0F6D6BE728DA47A38CFC4BDEACF34FC4'}, 'buffers': [], 'metadata': {}}\\nhandling click\\n{u'event': u'click'}\\nButton clicked.\\n2\\n\",\n",
+        "  'name': 'stdout'},\n",
+        " 'header': {'msg_id': 'd9dc144a-d86c-42c1-8bab-f8a6bc525723',\n",
+        "  'msg_type': 'stream',\n",
+        "  'session': '9b9408d8-7420-4e0c-976d-cdda9f8d2564',\n",
+        "  'username': 'kernel'},\n",
+        " 'metadata': {},\n",
+        " 'msg_id': 'd9dc144a-d86c-42c1-8bab-f8a6bc525723',\n",
+        " 'msg_type': 'stream',\n",
+        " 'parent_header': {'msg_id': '3DBB06AD83C942DD85DC6477B08F1FBF',\n",
+        "  'msg_type': 'comm_msg',\n",
+        "  'session': '0F6D6BE728DA47A38CFC4BDEACF34FC4',\n",
+        "  'username': 'username'}}"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
      "input": [
       "def show_button(sender=None):\n",
       "    button = widgets.ButtonWidget()\n",
       "    button.clicks = 0\n",
       "    if sender is None:\n",
       "        button.description = \"0\"\n",
       "    else:\n",
       "        sender.clicks += 1\n",
       "        button.description = \"%d\" % sender.clicks\n",
       "    display(button)\n",
       "    button.on_click(show_button)\n",
       "show_button()\n",
       "    "
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
-     "prompt_number": 6
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'description', 'disabled']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file

examples/widgets/Part 3 - Placement.ipynb

@@ -1,258 +1,345 b''
 {
  "metadata": {
   "cell_tags": [
    [
     "<None>",
     null
    ]
   ],
   "name": ""
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "from IPython.html import widgets # Widget definitions\n",
       "from IPython.display import display # Used to display widgets in the notebook"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 1
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Parent/Child Relationships"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "To display widget A inside widget B, widget A must be a child of widget B.  With IPython widgets, the widgets are instances that live in the back-end (usally Python).  There can be multiple views displayed in the front-end that represent one widget in the backend.  Each view can be displayed at a different time, or even displayed two or more times in the same output.   Because of this, the parent of a widget can only be set before the widget has been displayed.\n",
       "\n",
       "Every widget has a `parent` property.  This property can be set via a kwarg in the widget's constructor or after construction, but before display.  Calling display on an object with children automatically displays those children too (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "container = widgets.MulticontainerWidget()\n",
       "\n",
-      "floatrange = widgets.FloatRangeWidget(parent=container) # You can set the parent in the constructor,\n",
+      "floatrange = widgets.FloatRangeWidget() # You can set the parent in the constructor,\n",
       "\n",
-      "string = widgets.StringWidget()\n",
-      "string.parent = container # or after the widget has been created.\n",
+      "string = widgets.StringWidget(value='hi')\n",
+      "container = widgets.MulticontainerWidget(children=[floatrange, string])\n",
       "\n",
       "display(container) # Displays the `container` and all of it's children."
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 2
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Children can also be added to parents after the parent has been displayed.  If the children are added after the parent has already been displayed, the children must be displayed themselves.\n",
       "\n",
       "In the example below, the IntRangeWidget is never rendered since display was called on the parent before the parent/child relationship was established."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "container = widgets.MulticontainerWidget()\n",
       "display(container)\n",
       "\n",
       "intrange = widgets.IntRangeWidget(parent=container) # Never gets displayed."
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 3
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Calling display on the child fixes the problem."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "container = widgets.MulticontainerWidget()\n",
       "display(container)\n",
       "\n",
       "intrange = widgets.IntRangeWidget(parent=container)\n",
       "display(intrange) # This line is needed since the `container` has already been displayed."
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 4
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Changing Child Views"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The view used to display a widget must defined by the time the widget is displayed.  If children widgets are to be displayed along with the parent in one call, their `view_name`s can't be set since all of the widgets are sharing the same display call.  Instead, their `default_view_name`s must be set (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "container = widgets.MulticontainerWidget()\n",
       "\n",
       "floatrange = widgets.FloatRangeWidget(parent=container)\n",
       "floatrange.default_view_name = \"FloatTextView\" # It can be set as a property.\n",
       "\n",
       "string = widgets.StringWidget(default_view_name = \"TextAreaView\") # It can also be set in the constructor.\n",
       "string.parent = container\n",
       "\n",
       "display(container)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 5
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "However, if the children are displayed after the parent, their `view_name` can also be set like normal.  Both methods will work.  The code below produces the same output as the code above."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "container = widgets.MulticontainerWidget()\n",
       "display(container)\n",
       "\n",
       "floatrange = widgets.FloatRangeWidget()\n",
       "floatrange.parent=container\n",
       "display(floatrange, view_name = \"FloatTextView\") # view_name can be set during display.\n",
       "\n",
       "string = widgets.StringWidget()\n",
       "string.parent = container\n",
       "string.default_view_name = \"TextAreaView\" # Setting default_view_name still works.\n",
       "display(string)\n"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 6
     },
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Visibility"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Sometimes it's necessary to hide/show widget views in place, without ruining the order that they have been displayed on the page.  Using the `display` method, the views are always added to the end of their respective containers.  Instead the `visibility` property of widgets can be used to hide/show widgets that have already been displayed (as seen below)."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "string = widgets.StringWidget(value=\"Hello World!\")\n",
-      "display(string, view_name=\"LabelView\") "
+      "display(string, view_name=\"HTMLView\") "
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
-     "prompt_number": 7
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "['visible', '_css', '_children_attr', '_children_lists_attr', 'default_view_name', 'value', 'disabled', 'description']\n",
+        "[]\n",
+        "[]\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "string.visible=False"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 8
+     "prompt_number": 12
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "string.visible=True"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": 9
+     "prompt_number": 13
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "In the example below, a form is rendered which conditionally displays widgets depending on the state of other widgets.  Try toggling the student checkbox."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "form = widgets.ContainerWidget()\n",
-      "first = widgets.StringWidget(description=\"First Name:\", parent=form)\n",
-      "last = widgets.StringWidget(description=\"Last Name:\", parent=form)\n",
+      "first = widgets.StringWidget(description=\"First Name:\")\n",
+      "last = widgets.StringWidget(description=\"Last Name:\")\n",
       "\n",
-      "student = widgets.BoolWidget(description=\"Student:\", value=False, parent=form)\n",
-      "school_info = widgets.ContainerWidget(visible=False, parent=form)\n",
-      "school = widgets.StringWidget(description=\"School:\", parent=school_info)\n",
-      "grade = widgets.IntRangeWidget(description=\"Grade:\", min=0, max=12, default_view_name='IntTextView', parent=school_info)\n",
+      "student = widgets.BoolWidget(description=\"Student:\", value=False)\n",
+      "form.children=[first, last, student]\n",
+      "display(form)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "form = widgets.ContainerWidget()\n",
+      "first = widgets.StringWidget(description=\"First Name:\")\n",
+      "last = widgets.StringWidget(description=\"Last Name:\")\n",
+      "\n",
+      "student = widgets.BoolWidget(description=\"Student:\", value=False)\n",
+      "school_info = widgets.ContainerWidget(visible=False, children=[\n",
+      "    widgets.StringWidget(description=\"School:\"),\n",
+      "    widgets.IntRangeWidget(description=\"Grade:\", min=0, max=12, default_view_name='IntTextView')\n",
+      "    ])\n",
       "\n",
-      "pet = widgets.StringWidget(description=\"Pet's Name:\", parent=form)\n",
+      "pet = widgets.StringWidget(description=\"Pet's Name:\")\n",
+      "form.children = [first, last, student, school_info, pet]\n",
       "display(form)\n",
       "\n",
       "def on_student_toggle(name, value):\n",
+      "    print value\n",
       "    if value:\n",
       "        school_info.visible = True\n",
       "    else:\n",
       "        school_info.visible = False\n",
       "student.on_trait_change(on_student_toggle, 'value')\n"
      ],
      "language": "python",
      "metadata": {},
-     "outputs": [],
-     "prompt_number": 10
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "True\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "False\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "True\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "False\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "True\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "False\n"
+       ]
+      },
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "True\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file