//----------------------------------------------------------------------------
// 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",
"components/underscore/underscore-min",
"components/backbone/backbone-min"],
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.
comm.on_close($.proxy(this._handle_comm_closed, this));
comm.on_msg($.proxy(this._handle_comm_msg, this));
}
return Backbone.Model.apply(this);
},
update_other_views: function (caller) {
this.last_modified_view = caller;
this.save(this.changedAttributes(), {patch: true});
for (var view_index in this.views) {
var view = this.views[view_index];
if (view !== caller) {
view.update();
}
}
},
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);
var data = {method: 'custom', custom_content: content};
this.comm.send(data, callbacks);
}
},
on_view_displayed: function (callback) {
this._view_displayed_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');
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_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._display_view(msg.content.data.view_name,
msg.content.data.parent,
cell);
}
break;
case 'update':
this._handle_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);
break;
}
},
// Handle when a widget is updated via the python side.
_handle_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.save();
} finally {
this.updating = false;
}
},
_handle_status: function (cell, msg) {
//execution_state : ('busy', 'idle', 'starting')
if (this._has_comm()) {
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);
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.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.pending_msgs++;
}
}
}
// Since the comm is a one-way communication, assume the message
// arrived.
return model_json;
},
_handle_view_displayed: function (view) {
if (this._view_displayed_callback) {
try {
this._view_displayed_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.
_display_view: 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_displayed(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_displayed(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) {
var callbacks = {};
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
var that = this;
callbacks = {
iopub : {
output : handle_output,
clear_output : handle_clear_output,
status : function (msg) {
that._handle_status(cell, msg);
},
// 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;
},
},
};
}
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;
}
// 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;
},
// 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 () {
this.visible = true;
this.model.on('sync',this.update,this);
},
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);
},
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();
}
}
}
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;
});