/*
 * 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 SegmentPoint
 * @class An internal version of Point that notifies its segment of each change
 * Note: This prototype is not exported.
 *
 * @private
 */
var SegmentPoint = Point.extend({
	initialize: function SegmentPoint(point, owner, key) {
		var x, y, selected;
		if (!point) {
			x = y = 0;
		} else if ((x = point[0]) !== undefined) { // Array-like
			y = point[1];
		} else {
			// If not Point-like already, read Point from arguments
			if ((x = point.x) === undefined) {
				point = Point.read(arguments);
				x = point.x;
			}
			y = point.y;
			selected = point.selected;
		}
		this._x = x;
		this._y = y;
		this._owner = owner;
		// We have to set the owner's property that points to this point already
		// now, so #setSelected(true) can work.
		owner[key] = this;
		if (selected)
			this.setSelected(true);
	},

	set: function(x, y) {
		this._x = x;
		this._y = y;
		this._owner._changed(this);
		return this;
	},

	_serialize: function(options) {
		var f = options.formatter,
			x = f.number(this._x),
			y = f.number(this._y);
		return this.isSelected()
				? { x: x, y: y, selected: true }
				: [x, y];
	},

	getX: function() {
		return this._x;
	},

	setX: function(x) {
		this._x = x;
		this._owner._changed(this);
	},

	getY: function() {
		return this._y;
	},

	setY: function(y) {
		this._y = y;
		this._owner._changed(this);
	},

	isZero: function() {
		// Provide our own version of Point#isZero() that does not use the x / y
		// accessors but the internal properties directly, for performance
		// reasons, since it is used a lot internally.
		return Numerical.isZero(this._x) && Numerical.isZero(this._y);
	},

	setSelected: function(selected) {
		this._owner._setSelected(this, selected);
	},

	isSelected: function() {
		return this._owner._isSelected(this);
	}
});