/*

* Paper.js - The Swiss Army Knife of Vector Graphics Scripting.

* http://paperjs.org/

*

* Copyright (c) 2011 - 2013, Juerg Lehni & Jonathan Puckey

* http://lehni.org/ & http://jonathanpuckey.com/

*

* Distributed under the MIT license. See LICENSE file for details.

*

* All rights reserved.

*/

/**

* @name PaperScopeItem

*

* @class A private base class for all classes that have lists and references in

* the {@link PaperScope} ({@link Project}, {@link View}, {@link Tool}), so

* functionality can be shared.

*

* @private

*/

var PaperScopeItem = Base.extend(Callback, /** @lends PaperScopeItem# */{

/**

* Creates a PaperScopeItem object.

*/

initialize: function(activate) {

// Store reference to the currently active global paper scope:

this._scope = paper;

// Push it onto this._scope[this._list] and set _index:

this._index = this._scope[this._list].push(this) - 1;

// If the project has no active reference, activate this one

if (activate || !this._scope[this._reference])

this.activate();

},

activate: function() {

if (!this._scope)

return false;

var prev = this._scope[this._reference];

if (prev && prev != this)

prev.fire('deactivate');

this._scope[this._reference] = this;

this.fire('activate', prev);

return true;

},

isActive: function() {

return this._scope[this._reference] === this;

},

remove: function() {

if (this._index == null)

return false;

Base.splice(this._scope[this._list], null, this._index, 1);

// Clear the active tool reference if it was pointint to this.

if (this._scope[this._reference] == this)

this._scope[this._reference] = null;

this._scope = null;

return true;

}

});