/*!
 * jQuery UI Effects Drop @VERSION
 *
 * Copyright 2012, AUTHORS.txt (http://jqueryui.com/about)
 * Dual licensed under the MIT or GPL Version 2 licenses.
 * http://jquery.org/license
 *
 * http://docs.jquery.com/UI/Effects/Drop
 *
 * Depends:
 *	jquery.effects.core.js
 */
(function( $, undefined ) {

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

	var el = $( this ),
		props = [ "position", "top", "bottom", "left", "right", "opacity", "height", "width" ],
		mode = $.effects.setMode( el, o.mode || "hide" ),
		show = mode === "show",
		direction = o.direction || "left",
		ref = ( direction === "up" || direction === "down" ) ? "top" : "left",
		motion = ( direction === "up" || direction === "left" ) ? "pos" : "neg",
		animation = {
			opacity: show ? 1 : 0
		},
		distance;

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

	distance = o.distance || el[ ref === "top" ? "outerHeight": "outerWidth" ]({ margin: true }) / 2;

	if ( show ) {
		el
			.css( "opacity", 0 )
			.css( ref, motion === "pos" ? -distance : distance );
	}

	// Animation
	animation[ ref ] = ( show ?
		( motion === "pos" ? "+=" : "-=" ) :
		( motion === "pos" ? "-=" : "+=" ) ) +
		distance;

	// Animate
	el.animate( animation, {
		queue: false,
		duration: o.duration,
		easing: o.easing,
		complete: function() {
			if ( mode === "hide" ) {
				el.hide();
			}
			$.effects.restore( el, props );
			$.effects.removeWrapper( el );
			done();
		}
	});
};

})(jQuery);
