/* 
 * Auto Expanding Text Area (1.2.2 - k2s fix)
 * 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)
 * Licensed under the GPL (GPL-LICENSE.txt) license. 
 *
 *
 * 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() {
			var d = 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.options            = o || {};
		this.dummy              = null;
		this.interval           = null;
        // TODO this is not correct if it is not in pixels, for example IE will return text "normal"
		this.line_height        = this.options.lineHeight || parseInt(jQuery(e).css('line-height'), 10);
		this.min_height         = this.options.minHeight || parseInt(jQuery(e).css('min-height'), 10) || parseInt(jQuery(e).css('height'), 10);
		this.max_height         = this.options.maxHeight || parseInt(jQuery(e).css('max-height'), 10);

		// FIX for IE
		if (!this.line_height) { this.line_height = 15; }
		if (!this.min_height) { this.min_height = 50; }

		this.textarea           = jQuery(e);
		
		if(isNaN(this.line_height)) {
		  this.line_height = 0;
        }
		
		// Only one textarea activated at a time, the one being used
		this.init();
	};
	
	jQuery.autogrow.fn = jQuery.autogrow.prototype = {
        autogrow: '1.2.2 (k2s fix)'
    };
	
    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)
			{
                var dummyCss = {
                    'font-size'  : this.textarea.css('font-size'),
                    'font-family': this.textarea.css('font-family'),
                    'width'      : this.textarea.css('width'),
                    'padding'    : this.textarea.css('padding'),
                    'overflow-x' : 'hidden',
                    'position'   : 'absolute',
                    'top'        : 0,
                    'left'		 : -9999
                };
                if (this.line_height !== 0) {
                    dummyCss['line-height'] = this.line_height + 'px';
                }
				this.dummy = jQuery('<div></div>');				
                this.dummy.css(dummyCss).appendTo('body');
			}
			
			// Strip HTML tags
			var html = this.textarea.val().replace(/(<|>)/g, '');
			
			// IE is different, as per usual
			if ($.browser.msie)
			{
				html = html.replace(/\n/g, '<BR>new');
			}
			else
			{
				html = html.replace(/\n/g, '<br>new');
			}
			
			if (this.dummy.html() != html)
			{
				this.dummy.html(html);	

				if (this.max_height > 0 && (this.dummy.height() + this.line_height > this.max_height))
				{
					this.textarea.css('overflow-y', 'auto');	
				}
				else
				{
					this.textarea.css('overflow-y', 'hidden');
					if (this.textarea.height() < this.dummy.height() + this.line_height || (this.dummy.height() < this.textarea.height()))
					{					
						var px = this.dummy.height() + this.line_height;
						if (px < this.min_height) 
						{
							px = this.min_height;
						}
						this.textarea.animate({height: px + 'px'}, 100);	
					}
				}
			}
		}
						 
	 });
})(jQuery);