/*
 * Paper.js
 *
 * This file is part of Paper.js, a JavaScript Vector Graphics Library,
 * based on Scriptographer.org and designed to be largely API compatible.
 * http://paperjs.org/
 * http://scriptographer.org/
 *
 * Distributed under the MIT license. See LICENSE file for details.
 *
 * Copyright (c) 2011, Juerg Lehni & Jonathan Puckey
 * http://lehni.org/ & http://jonathanpuckey.com/
 *
 * All rights reserved.
 */

var Size = this.Size = Base.extend({
	initialize: function(arg0, arg1) {
		if (arguments.length == 2) {
			this.width = arg0;
			this.height = arg1;
		} else if (arguments.length == 1) {
			if (arg0 == null) {
				this.width = this.height = 0;
			} else if (arg0.width !== undefined) {
				this.width = arg0.width;
				this.height = arg0.height;
			} else if (arg0.x !== undefined) {
				this.width = arg0.x;
				this.height = arg0.y;
			} else if (Array.isArray(arg0)) {
				this.width = arg0[0];
				this.height = arg0.length > 1 ? arg0[1] : arg0[0];
			} else if (typeof arg0 === 'number') {
				this.width = this.height = arg0;
			} else {
				this.width = this.height = 0;
			}
		} else {
			this.width = this.height = 0;
		}
	},

	set: function(width, height) {
		this.width = width;
		this.height = height;
		return this;
	},

	add: function(size) {
		size = Size.read(arguments);
		return Size.create(this.width + size.width, this.height + size.height);
	},

	subtract: function(size) {
		size = Size.read(arguments);
		return Size.create(this.width - size.width, this.height - size.height);
	},

	multiply: function(size) {
		size = Size.read(arguments);
		return Size.create(this.width * size.width, this.height * size.height);
	},

	divide: function(size) {
		size = Size.read(arguments);
		return Size.create(this.width / size.width, this.height / size.height);
	},

	modulo: function(size) {
		size = Size.read(arguments);
		return Size.create(this.width % size.width, this.height % size.height);
	},

	negate: function() {
		return Size.create(-this.width, -this.height);
	},

	equals: function(size) {
		size = Size.read(arguments);
		return this.width == size.width && this.height == size.height;
	},

	/**
	 * Checks if this size has both the width and height set to 0.
	 * 
	 * @return true if both width and height are 0, false otherwise.
	 */
	isZero: function() {
		return this.width == 0 && this.width == 0;
	},

	isNaN: function() {
		return isNaN(this.width) || isNaN(this.height);
	},

	toString: function() {
		var format = Base.formatNumber;
		return '{ width: ' + format(this.width)
				+ ', height: ' + format(this.height) + ' }';
	},

	statics: {
		// See Point.create()
		create: function(width, height) {
			return new Size(Size.dont).set(width, height);
		},

		min: function(size1, size2) {
			return Size.create(
				Math.min(size1.width, size2.width),
				Math.min(size1.height, size2.height));
		},

		max: function(size1, size2) {
			return Size.create(
				Math.max(size1.width, size2.width),
				Math.max(size1.height, size2.height));
		},

		random: function() {
			return Size.create(Math.random(), Math.random());
		}
	}
}, new function() { // Scope for injecting round, ceil, floor, abs:
	return Base.each(['round', 'ceil', 'floor', 'abs'], function(name) {
		var op = Math[name];
		this[name] = function() {
			return Size.create(op(this.width), op(this.height));
		};
	}, {});
});

/**
 * An internal version of Size that notifies its owner of each change through
 * setting itself again on the setter that corresponds to the getter that
 * produced this LinkedSize. See uses of LinkedSize.create()
 * Note: This prototype is not exported.
 */
var LinkedSize = Size.extend({
	beans: true,

	set: function(width, height, dontNotify) {
		this._width = width;
		this._height = height;
		if (!dontNotify)
			this._owner[this._setter](this);
		return this;
	},

	getWidth: function() {
		return this._width;
	},

	setWidth: function(width) {
		this._width = width;
		this._owner[this._setter](this);
	},

	getHeight: function() {
		return this._height;
	},

	setHeight: function(height) {
		this._height = height;
		this._owner[this._setter](this);
	},

	statics: {
		create: function(owner, setter, width, height) {
			var point = new LinkedSize(LinkedSize.dont);
			point._width = width;
			point._height = height;
			point._owner = owner;
			point._setter = setter;
			return point;
		}
	}
});