/*!
 * jQuery UI Effects Shake @VERSION
 * http://jqueryui.com
 *
 * Copyright 2012 jQuery Foundation and other contributors
 * Released under the MIT license.
 * http://jquery.org/license
 *
 * http://api.jqueryui.com/shake-effect/
 *
 * Depends:
 *	jquery.ui.effect.js
 */
(function( $, undefined ) {

$.effects.effect.shake = function( o, done ) {

	var el = $( this ),
		props = [ "position", "top", "bottom", "left", "right", "height", "width" ],
		mode = $.effects.setMode( el, o.mode || "effect" ),
		direction = o.direction || "left",
		distance = o.distance || 20,
		times = o.times || 3,
		anims = times * 2 + 1,
		speed = Math.round(o.duration/anims),
		ref = (direction === "up" || direction === "down") ? "top" : "left",
		positiveMotion = (direction === "up" || direction === "left"),
		animation = {},
		animation1 = {},
		animation2 = {},
		i,

		// we will need to re-assemble the queue to stack our animations in place
		queue = el.queue(),
		queuelen = queue.length;

	$.effects.save( el, props );
	el.show();
	$.effects.createWrapper( el );

	// Animation
	animation[ ref ] = ( positiveMotion ? "-=" : "+=" ) + distance;
	animation1[ ref ] = ( positiveMotion ? "+=" : "-=" ) + distance * 2;
	animation2[ ref ] = ( positiveMotion ? "-=" : "+=" ) + distance * 2;

	// Animate
	el.animate( animation, speed, o.easing );

	// Shakes
	for ( i = 1; i < times; i++ ) {
		el.animate( animation1, speed, o.easing ).animate( animation2, speed, o.easing );
	}
	el
		.animate( animation1, speed, o.easing )
		.animate( animation, speed / 2, o.easing )
		.queue(function() {
			if ( mode === "hide" ) {
				el.hide();
			}
			$.effects.restore( el, props );
			$.effects.removeWrapper( el );
			done();
		});

	// inject all the animations we just queued to be first in line (after "inprogress")
	if ( queuelen > 1) {
		queue.splice.apply( queue,
			[ 1, 0 ].concat( queue.splice( queuelen, anims + 1 ) ) );
	}
	el.dequeue();

};

})(jQuery);
