//----------------------------------------------------------------------------
// 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, model_id, comm) {
// Construcctor
//
// Creates a WidgetModel instance.
//
// Parameters
// ----------
// widget_manager : WidgetManager instance
// model_id : string
// An ID unique to this model.
// comm : Comm instance (optional)
this.widget_manager = widget_manager;
this.pending_msgs = 0;
this.msg_throttle = 3;
this.msg_buffer = null;
this.key_value_lock = null;
this.id = model_id;
this.views = [];
if (comm !== undefined) {
// Remember comm associated with the model.
this.comm = comm;
comm.model = this;
// Hook comm messages up to model.
comm.on_close($.proxy(this._handle_comm_closed, this));
comm.on_msg($.proxy(this._handle_comm_msg, this));
}
return Backbone.Model.apply(this);
},
send: function (content, callbacks) {
if (this.comm !== undefined) {
var data = {method: 'custom', custom_content: content};
this.comm.send(data, callbacks);
}
},
// Handle when a widget is closed.
_handle_comm_closed: function (msg) {
this.trigger('comm:close');
delete this.comm.model; // Delete ref so GC will collect widget model.
delete this.comm;
delete this.model_id; // Delete id from model so widget manager cleans up.
// TODO: Handle deletion, like this.destroy(), and delete views, etc.
},
// Handle incoming comm msg.
_handle_comm_msg: function (msg) {
var method = msg.content.data.method;
switch (method) {
case 'update':
this.apply_update(msg.content.data.state);
break;
case 'custom':
this.trigger('msg:custom', msg.content.data.custom_content);
break;
case 'display':
this.widget_manager.display_view(msg.parent_header.msg_id, this);
break;
}
},
// Handle when a widget is updated via the python side.
apply_update: function (state) {
for (var key in state) {
if (state.hasOwnProperty(key)) {
var value = state[key];
this.key_value_lock = [key, value];
try {
this.set(key, state[key]);
} finally {
this.key_value_lock = null;
}
}
}
//TODO: are there callbacks that make sense in this case? If so, attach them here as an option
this.save();
},
_handle_status: function (msg, callbacks) {
//execution_state : ('busy', 'idle', 'starting')
if (this.comm !== undefined && msg.content.execution_state ==='idle') {
// Send buffer if this message caused another message to be
// throttled.
if (this.msg_buffer !== null &&
this.msg_throttle === this.pending_msgs) {
var data = {method: 'backbone', sync_method: 'update', sync_data: this.msg_buffer};
this.comm.send(data, callbacks);
this.msg_buffer = null;
} else {
// Only decrease the pending message count if the buffer
// doesn't get flushed (sent).
--this.pending_msgs;
}
}
},
// Custom syncronization logic.
_handle_sync: function (method, options) {
var model_json = this.toJSON();
var attr;
// Only send updated state if the state hasn't been changed
// during an update.
if (this.comm !== undefined) {
if (this.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) {
var value = options.attrs[attr];
if (this.key_value_lock === null || attr != this.key_value_lock[0] || value != this.key_value_lock[1]) {
this.msg_buffer[attr] = value;
}
}
} 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) {
var value = options.attrs[attr];
if (this.key_value_lock === null || attr != this.key_value_lock[0] || value != this.key_value_lock[1]) {
send_json[attr] = value;
}
}
}
var data = {method: 'backbone', sync_data: send_json};
this.comm.send(data, options.callbacks);
this.pending_msgs++;
}
}
// Since the comm is a one-way communication, assume the message
// arrived.
return model_json;
},
});
//--------------------------------------------------------------------
// WidgetView class
//--------------------------------------------------------------------
var WidgetView = Backbone.View.extend({
initialize: function(parameters) {
this.model.on('change',this.update,this);
this.options = parameters.options;
this.child_views = [];
this.model.views.push(this);
},
update: function(){
// update view to be consistent with this.model
// triggered on model change
},
child_view: function(model_id, options) {
// create and return a child view, given a model id for a model and (optionally) a view name
// if the view name is not given, it defaults to the model's default view attribute
var child_model = this.widget_manager.get_model(model_id);
var child_view = this.widget_manager.create_view(child_model, options);
this.child_views[model_id] = child_view;
return child_view;
},
update_child_views: function(old_list, new_list) {
// this function takes an old list and new list of model ids
// views in child_views that correspond to deleted ids are deleted
// views corresponding to added ids are added child_views
// delete old views
_.each(_.difference(old_list, new_list), function(element, index, list) {
var view = this.child_views[element];
delete this.child_views[element];
view.remove();
}, this);
// add new views
_.each(_.difference(new_list, old_list), function(element, index, list) {
// this function adds the view to the child_views dictionary
this.child_view(element);
}, this);
},
callbacks: function(){
return this.widget_manager.callbacks(this);
},
render: function(){
// render the view. By default, this is only called the first time the view is created
},
send: function (content) {
this.model.send(content, this.callbacks());
},
touch: function () {
this.model.save(this.model.changedAttributes(), {patch: true, callbacks: this.callbacks()});
},
});
var DOMWidgetView = WidgetView.extend({
initialize: function (options) {
// TODO: make changes more granular (e.g., trigger on visible:change)
this.model.on('change', this.update, this);
this.model.on('msg:custom', this.on_msg, this);
WidgetView.prototype.initialize.apply(this, arguments);
},
on_msg: function(msg) {
switch(msg.msg_type) {
case 'add_class':
this.add_class(msg.selector, msg.class_list);
break;
case 'remove_class':
this.remove_class(msg.selector, msg.class_list);
break;
}
},
add_class: function (selector, class_list) {
var elements = this._get_selector_element(selector);
if (elements.length > 0) {
elements.addClass(class_list);
}
},
remove_class: function (selector, class_list) {
var elements = this._get_selector_element(selector);
if (elements.length > 0) {
elements.removeClass(class_list);
}
},
update: function () {
// the very first update seems to happen before the element is finished rendering
// so we use setTimeout to give the element time to render
var e = this.$el;
var visible = this.model.get('visible');
setTimeout(function() {e.toggle(visible)},0);
var css = this.model.get('_css');
if (css === undefined) {return;}
for (var selector in css) {
if (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 = 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 $el_to_style element is not defined, use apply the
// style to the view's element.
var elements;
if (selector === undefined || selector === null || selector === '') {
if (this.$el_to_style === undefined) {
elements = this.$el;
} else {
elements = this.$el_to_style;
}
} else {
elements = this.$el.find(selector);
}
return elements;
},
});
IPython.WidgetModel = WidgetModel;
IPython.WidgetView = WidgetView;
IPython.DOMWidgetView = DOMWidgetView;
return widget_manager;
});