/* 

 * Auto Expanding Text Area (1.02)

 * by Chrys Bader (www.chrysbader.com)

 * chrysb@gmail.com

 *

 * Special thanks to:

 * Jake Chapa - jake@hybridstudio.com

 * John Resig - jeresig@gmail.com

 *

 * Copyright (c) 2008 Chrys Bader (www.chrysbader.com)

 * Dual licensed under the MIT (MIT-LICENSE.txt)

 * and GPL (GPL-LICENSE.txt) licenses. 

 *

 *

 * NOTE: This script requires jQuery to work.  Download jQuery at www.jquery.com

 *

 */

 

(function(jQuery) {

		  

	var self = null;

 

	jQuery.fn.autogrow = function(o)

	{	

		return this.each(function() {

			new jQuery.autogrow(this, o);

		});

	};

	



    /**

     * The autogrow object.

     *

     * @constructor

     * @name jQuery.autogrow

     * @param Object e The textarea to create the autogrow for.

     * @param Hash o A set of key/value pairs to set as configuration properties.

     * @cat Plugins/autogrow

     */

	

	jQuery.autogrow = function (e, o)

	{

		this.dummy			  = null;

		this.interval	 	  = null;

		this.line_height	= 0, parseInt(jQuery(e).css('line-height'));

		if(this.line_height == NaN)

		  this.line_height = 0;

		this.min_height		= parseInt(jQuery(e).css('min-height'));

		this.options		  = o;

		this.textarea		  = jQuery(e);

		

		// Only one textarea activated at a time, the one being used

		this.init();

	};

	

	jQuery.autogrow.fn = jQuery.autogrow.prototype = {

    autogrow: '1.1'

  };

	

 	jQuery.autogrow.fn.extend = jQuery.autogrow.extend = jQuery.extend;

	

	jQuery.autogrow.fn.extend({

						 

		init: function() {			

			var self = this;			

			this.textarea.css({overflow: 'hidden', display: 'block'});

			this.textarea.bind('focus', function() { self.startExpand() } ).bind('blur', function() { self.stopExpand });

			this.checkExpand();	

		},

						 

		startExpand: function() {				

		  var self = this;

			this.interval = window.setInterval(function() {self.checkExpand()}, 400);

		},

		

		stopExpand: function() {

			clearInterval(this.interval);	

		},

		

		checkExpand: function() {

			

			if (this.dummy == null)

			{

				this.dummy = jQuery('<div></div>');

				this.dummy.css({

												'font-size'  : this.textarea.css('font-size'),

												'font-family': this.textarea.css('font-family'),

												'width'      : this.textarea.css('width'),

												'padding'    : this.textarea.css('padding'),

												'line-height': this.textarea.css('line-height'),

												'overflow-x' : 'hidden',

												'display'    : 'none',

												'position'   : 'absolute',

												'top'        : 0,

												'left'       : '-9999px'

												}).appendTo('body');

			}

			

			

			var html = this.textarea.val().replace(/\n/g, '<br>new');

			

			if (this.dummy.html() != html)

			{

				this.dummy.html(html);	

				

				if (this.textarea.height() != this.dummy.height() + this.line_height)

				{

					this.textarea.animate({height: (this.dummy.height() + this.line_height) + 'px'}, 100);	

				}

			}

		}

						 

	 });

})(jQuery);