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Output Widget
Output Widget

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widget.js
603 lines | 23.6 KiB | application/javascript | JavascriptLexer
// Copyright (c) IPython Development Team.
// Distributed under the terms of the Modified BSD License.
define(["widgets/js/manager",
"underscore",
"backbone",
"jquery",
"base/js/utils",
"base/js/namespace",
], function(widgetmanager, _, Backbone, $, utils, IPython){
var WidgetModel = Backbone.Model.extend({
constructor: function (widget_manager, model_id, comm) {
// Constructor
//
// Creates a WidgetModel instance.
//
// Parameters
// ----------
// widget_manager : WidgetManager instance
// model_id : string
// An ID unique to this model.
// comm : Comm instance (optional)
this.widget_manager = widget_manager;
this.state_change = Promise.resolve();
this._buffered_state_diff = {};
this.pending_msgs = 0;
this.msg_buffer = null;
this.state_lock = null;
this.id = model_id;
this.views = {};
if (comm !== undefined) {
// Remember comm associated with the model.
this.comm = comm;
comm.model = this;
// Hook comm messages up to model.
comm.on_close($.proxy(this._handle_comm_closed, this));
comm.on_msg($.proxy(this._handle_comm_msg, this));
}
return Backbone.Model.apply(this);
},
send: function (content, callbacks) {
// Send a custom msg over the comm.
if (this.comm !== undefined) {
var data = {method: 'custom', content: content};
this.comm.send(data, callbacks);
this.pending_msgs++;
}
},
_handle_comm_closed: function (msg) {
// Handle when a widget is closed.
this.trigger('comm:close');
this.stopListening();
this.trigger('destroy', this);
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.
for (var id in this.views) {
if (this.views.hasOwnProperty(id)) {
this.views[id].remove();
}
}
},
_handle_comm_msg: function (msg) {
// Handle incoming comm msg.
var method = msg.content.data.method;
var that = this;
switch (method) {
case 'update':
this.state_change = this.state_change.then(function() {
return that.set_state(msg.content.data.state);
}).catch(utils.reject("Couldn't process update msg for model id '" + String(that.id) + "'", true));
break;
case 'custom':
this.trigger('msg:custom', msg.content.data.content);
break;
case 'display':
this.widget_manager.display_view(msg, this);
break;
}
},
set_state: function (state) {
var that = this;
// Handle when a widget is updated via the python side.
return this._unpack_models(state).then(function(state) {
that.state_lock = state;
try {
WidgetModel.__super__.set.call(that, state);
} finally {
that.state_lock = null;
}
return Promise.resolve();
}, utils.reject("Couldn't set model state", true));
},
_handle_status: function (msg, callbacks) {
// Handle status msgs.
// execution_state : ('busy', 'idle', 'starting')
if (this.comm !== undefined) {
if (msg.content.execution_state ==='idle') {
// Send buffer if this message caused another message to be
// throttled.
if (this.msg_buffer !== null &&
(this.get('msg_throttle') || 3) === this.pending_msgs) {
var data = {method: 'backbone', sync_method: 'update', sync_data: this.msg_buffer};
this.comm.send(data, callbacks);
this.msg_buffer = null;
} else {
--this.pending_msgs;
}
}
}
},
callbacks: function(view) {
// Create msg callbacks for a comm msg.
var callbacks = this.widget_manager.callbacks(view);
if (callbacks.iopub === undefined) {
callbacks.iopub = {};
}
var that = this;
callbacks.iopub.status = function (msg) {
that._handle_status(msg, callbacks);
};
return callbacks;
},
set: function(key, val, options) {
// Set a value.
var return_value = WidgetModel.__super__.set.apply(this, arguments);
// Backbone only remembers the diff of the most recent set()
// operation. Calling set multiple times in a row results in a
// loss of diff information. Here we keep our own running diff.
this._buffered_state_diff = $.extend(this._buffered_state_diff, this.changedAttributes() || {});
return return_value;
},
sync: function (method, model, options) {
// Handle sync to the back-end. Called when a model.save() is called.
// Make sure a comm exists.
var error = options.error || function() {
console.error('Backbone sync error:', arguments);
};
if (this.comm === undefined) {
error();
return false;
}
// Delete any key value pairs that the back-end already knows about.
var attrs = (method === 'patch') ? options.attrs : model.toJSON(options);
if (this.state_lock !== null) {
var keys = Object.keys(this.state_lock);
for (var i=0; i<keys.length; i++) {
var key = keys[i];
if (attrs[key] === this.state_lock[key]) {
delete attrs[key];
}
}
}
// Only sync if there are attributes to send to the back-end.
attrs = this._pack_models(attrs);
if (_.size(attrs) > 0) {
// If this message was sent via backbone itself, it will not
// have any callbacks. It's important that we create callbacks
// so we can listen for status messages, etc...
var callbacks = options.callbacks || this.callbacks();
// Check throttle.
if (this.pending_msgs >= (this.get('msg_throttle') || 3)) {
// The throttle has been exceeded, buffer the current msg so
// it can be sent once the kernel has finished processing
// some of the existing messages.
// Combine updates if it is a 'patch' sync, otherwise replace updates
switch (method) {
case 'patch':
this.msg_buffer = $.extend(this.msg_buffer || {}, attrs);
break;
case 'update':
case 'create':
this.msg_buffer = attrs;
break;
default:
error();
return false;
}
this.msg_buffer_callbacks = callbacks;
} else {
// We haven't exceeded the throttle, send the message like
// normal.
var data = {method: 'backbone', sync_data: attrs};
this.comm.send(data, callbacks);
this.pending_msgs++;
}
}
// Since the comm is a one-way communication, assume the message
// arrived. Don't call success since we don't have a model back from the server
// this means we miss out on the 'sync' event.
this._buffered_state_diff = {};
},
save_changes: function(callbacks) {
// Push this model's state to the back-end
//
// This invokes a Backbone.Sync.
this.save(this._buffered_state_diff, {patch: true, callbacks: callbacks});
},
_pack_models: function(value) {
// Replace models with model ids recursively.
var that = this;
var packed;
if (value instanceof Backbone.Model) {
return "IPY_MODEL_" + value.id;
} else if ($.isArray(value)) {
packed = [];
_.each(value, function(sub_value, key) {
packed.push(that._pack_models(sub_value));
});
return packed;
} else if (value instanceof Date || value instanceof String) {
return value;
} else if (value instanceof Object) {
packed = {};
_.each(value, function(sub_value, key) {
packed[key] = that._pack_models(sub_value);
});
return packed;
} else {
return value;
}
},
_unpack_models: function(value) {
// Replace model ids with models recursively.
var that = this;
var unpacked;
if ($.isArray(value)) {
unpacked = [];
_.each(value, function(sub_value, key) {
unpacked.push(that._unpack_models(sub_value));
});
return Promise.all(unpacked);
} else if (value instanceof Object) {
unpacked = {};
_.each(value, function(sub_value, key) {
unpacked[key] = that._unpack_models(sub_value);
});
return utils.resolve_promises_dict(unpacked);
} else if (typeof value === 'string' && value.slice(0,10) === "IPY_MODEL_") {
// get_model returns a promise already
return this.widget_manager.get_model(value.slice(10, value.length));
} else {
return Promise.resolve(value);
}
},
on_some_change: function(keys, callback, context) {
// on_some_change(["key1", "key2"], foo, context) differs from
// on("change:key1 change:key2", foo, context).
// If the widget attributes key1 and key2 are both modified,
// the second form will result in foo being called twice
// while the first will call foo only once.
this.on('change', function() {
if (keys.some(this.hasChanged, this)) {
callback.apply(context);
}
}, this);
},
});
widgetmanager.WidgetManager.register_widget_model('WidgetModel', WidgetModel);
var WidgetView = Backbone.View.extend({
initialize: function(parameters) {
// Public constructor.
this.model.on('change',this.update,this);
this.options = parameters.options;
this.child_model_views = {};
this.child_views = {};
this.id = this.id || utils.uuid();
this.model.views[this.id] = this;
this.on('displayed', function() {
this.is_displayed = true;
}, this);
},
update: function(){
// Triggered on model change.
//
// Update view to be consistent with this.model
},
create_child_view: function(child_model, options) {
// Create and promise that resolves to a child view of a given model
var that = this;
options = $.extend({ parent: this }, options || {});
return this.model.widget_manager.create_view(child_model, options).then(function(child_view) {
// Associate the view id with the model id.
if (that.child_model_views[child_model.id] === undefined) {
that.child_model_views[child_model.id] = [];
}
that.child_model_views[child_model.id].push(child_view.id);
// Remember the view by id.
that.child_views[child_view.id] = child_view;
return child_view;
}, utils.reject("Couldn't create child view"));
},
pop_child_view: function(child_model) {
// Delete a child view that was previously created using create_child_view.
var view_ids = this.child_model_views[child_model.id];
if (view_ids !== undefined) {
// Only delete the first view in the list.
var view_id = view_ids[0];
var view = this.child_views[view_id];
delete this.child_views[view_id];
view_ids.splice(0,1);
delete child_model.views[view_id];
// Remove the view list specific to this model if it is empty.
if (view_ids.length === 0) {
delete this.child_model_views[child_model.id];
}
return view;
}
return null;
},
do_diff: function(old_list, new_list, removed_callback, added_callback) {
// Difference a changed list and call remove and add callbacks for
// each removed and added item in the new list.
//
// Parameters
// ----------
// old_list : array
// new_list : array
// removed_callback : Callback(item)
// Callback that is called for each item removed.
// added_callback : Callback(item)
// Callback that is called for each item added.
// Walk the lists until an unequal entry is found.
var i;
for (i = 0; i < new_list.length; i++) {
if (i >= old_list.length || new_list[i] !== old_list[i]) {
break;
}
}
// Remove the non-matching items from the old list.
for (var j = i; j < old_list.length; j++) {
removed_callback(old_list[j]);
}
// Add the rest of the new list items.
for (; i < new_list.length; i++) {
added_callback(new_list[i]);
}
},
callbacks: function(){
// Create msg callbacks for a comm msg.
return this.model.callbacks(this);
},
render: function(){
// Render the view.
//
// By default, this is only called the first time the view is created
},
show: function(){
// Show the widget-area
if (this.options && this.options.cell &&
this.options.cell.widget_area !== undefined) {
this.options.cell.widget_area.show();
}
},
send: function (content) {
// Send a custom msg associated with this view.
this.model.send(content, this.callbacks());
},
touch: function () {
this.model.save_changes(this.callbacks());
},
after_displayed: function (callback, context) {
// Calls the callback right away is the view is already displayed
// otherwise, register the callback to the 'displayed' event.
if (this.is_displayed) {
callback.apply(context);
} else {
this.on('displayed', callback, context);
}
},
});
var DOMWidgetView = WidgetView.extend({
initialize: function (parameters) {
// Public constructor
DOMWidgetView.__super__.initialize.apply(this, [parameters]);
this.on('displayed', this.show, this);
this.model.on('change:visible', this.update_visible, this);
this.model.on('change:_css', this.update_css, this);
this.model.on('change:_dom_classes', function(model, new_classes) {
var old_classes = model.previous('_dom_classes');
this.update_classes(old_classes, new_classes);
}, this);
this.model.on('change:color', function (model, value) {
this.update_attr('color', value); }, this);
this.model.on('change:background_color', function (model, value) {
this.update_attr('background', value); }, this);
this.model.on('change:width', function (model, value) {
this.update_attr('width', value); }, this);
this.model.on('change:height', function (model, value) {
this.update_attr('height', value); }, this);
this.model.on('change:border_color', function (model, value) {
this.update_attr('border-color', value); }, this);
this.model.on('change:border_width', function (model, value) {
this.update_attr('border-width', value); }, this);
this.model.on('change:border_style', function (model, value) {
this.update_attr('border-style', value); }, this);
this.model.on('change:font_style', function (model, value) {
this.update_attr('font-style', value); }, this);
this.model.on('change:font_weight', function (model, value) {
this.update_attr('font-weight', value); }, this);
this.model.on('change:font_size', function (model, value) {
this.update_attr('font-size', this._default_px(value)); }, this);
this.model.on('change:font_family', function (model, value) {
this.update_attr('font-family', value); }, this);
this.model.on('change:padding', function (model, value) {
this.update_attr('padding', value); }, this);
this.model.on('change:margin', function (model, value) {
this.update_attr('margin', this._default_px(value)); }, this);
this.model.on('change:border_radius', function (model, value) {
this.update_attr('border-radius', this._default_px(value)); }, this);
this.after_displayed(function() {
this.update_visible(this.model, this.model.get("visible"));
this.update_classes([], this.model.get('_dom_classes'));
this.update_attr('color', this.model.get('color'));
this.update_attr('background', this.model.get('background_color'));
this.update_attr('width', this.model.get('width'));
this.update_attr('height', this.model.get('height'));
this.update_attr('border-color', this.model.get('border_color'));
this.update_attr('border-width', this.model.get('border_width'));
this.update_attr('border-style', this.model.get('border_style'));
this.update_attr('font-style', this.model.get('font_style'));
this.update_attr('font-weight', this.model.get('font_weight'));
this.update_attr('font-size', this.model.get('font_size'));
this.update_attr('font-family', this.model.get('font_family'));
this.update_attr('padding', this.model.get('padding'));
this.update_attr('margin', this.model.get('margin'));
this.update_attr('border-radius', this.model.get('border_radius'));
this.update_css(this.model, this.model.get("_css"));
}, this);
},
_default_px: function(value) {
// Makes browser interpret a numerical string as a pixel value.
if (/^\d+\.?(\d+)?$/.test(value.trim())) {
return value.trim() + 'px';
}
return value;
},
update_attr: function(name, value) {
// Set a css attr of the widget view.
this.$el.css(name, value);
},
update_visible: function(model, value) {
// Update visibility
this.$el.toggle(value);
},
update_css: function (model, css) {
// Update the css styling of this view.
var e = this.$el;
if (css === undefined) {return;}
for (var i = 0; i < css.length; i++) {
// Apply the css traits to all elements that match the selector.
var selector = css[i][0];
var elements = this._get_selector_element(selector);
if (elements.length > 0) {
var trait_key = css[i][1];
var trait_value = css[i][2];
elements.css(trait_key ,trait_value);
}
}
},
update_classes: function (old_classes, new_classes, $el) {
// Update the DOM classes applied to an element, default to this.$el.
if ($el===undefined) {
$el = this.$el;
}
this.do_diff(old_classes, new_classes, function(removed) {
$el.removeClass(removed);
}, function(added) {
$el.addClass(added);
});
},
update_mapped_classes: function(class_map, trait_name, previous_trait_value, $el) {
// Update the DOM classes applied to the widget based on a single
// trait's value.
//
// Given a trait value classes map, this function automatically
// handles applying the appropriate classes to the widget element
// and removing classes that are no longer valid.
//
// Parameters
// ----------
// class_map: dictionary
// Dictionary of trait values to class lists.
// Example:
// {
// success: ['alert', 'alert-success'],
// info: ['alert', 'alert-info'],
// warning: ['alert', 'alert-warning'],
// danger: ['alert', 'alert-danger']
// };
// trait_name: string
// Name of the trait to check the value of.
// previous_trait_value: optional string, default ''
// Last trait value
// $el: optional jQuery element handle, defaults to this.$el
// Element that the classes are applied to.
var key = previous_trait_value;
if (key === undefined) {
key = this.model.previous(trait_name);
}
var old_classes = class_map[key] ? class_map[key] : [];
key = this.model.get(trait_name);
var new_classes = class_map[key] ? class_map[key] : [];
this.update_classes(old_classes, new_classes, $el || this.$el);
},
_get_selector_element: function (selector) {
// Get the elements via the css selector.
var elements;
if (!selector) {
elements = this.$el;
} else {
elements = this.$el.find(selector).addBack(selector);
}
return elements;
},
});
var widget = {
'WidgetModel': WidgetModel,
'WidgetView': WidgetView,
'DOMWidgetView': DOMWidgetView,
};
// For backwards compatability.
$.extend(IPython, widget);
return widget;
});