/* 
 * Auto Expanding Text Area (1.03)
 * by Chrys Bader (www.chrysbader.com  chrysb@gmail.com)
 * extended by Jan Bruder (JanBruder@web.de)
 *
 * 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
 *
 *
 *
 * TODOs:
 * >> handle options like: maxHeight, paddingBottom,
 * >> onFocusOut set height to fit perfect without paddingBottom
 *
 */
 
(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);
		e.isAutogrow = true;
		this.textarea.addClass('isAutogrow');

		// 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'),
					'font-weight'   : this.textarea.css('font-weight'),
					'text-align'    : 'left',
					'width'         : this.textarea.width(),
					'padding'       : this.textarea.css('padding'),
					'border'        : this.textarea.css('border'),
					'line-height'   : this.textarea.css('line-height'),
					'letter-spacing': this.textarea.css('letter-spacing'),
					'word-wrap'     : 'break-word',
					'overflow-x'    : 'hidden',
					'display'       : 'none',
					'position'      : 'absolute',
					'top'           : 0,
					'left'          : -9999
					//,'z-index'      : 1000
					//,backgrounColor : '#000'
				}).appendTo('body');
			}
			
			
			var html = this.textarea.val().replace(/\n/g, '<br>new');
			if(html == '') html = '&nbsp;';
			
			if(this.dummy.html() != html) {
				this.dummy.html(html);	
				
				if(this.textarea.height() != this.dummy.height() + this.line_height + 15) {
					this.textarea.animate({height: (this.dummy.height() + this.line_height) + 15}, 100);
				}
			}
		}
						 
	 });
})(jQuery);