/* 
 * Auto Expanding Text Area (1.2.2)
 * 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() {
                        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;
                this.line_height                = this.options.lineHeight || parseInt(jQuery(e).css('line-height'));
                this.min_height                 = this.options.minHeight || parseInt(jQuery(e).css('min-height'));
                this.max_height                 = this.options.maxHeight || parseInt(jQuery(e).css('max-height'));;
                this.textarea                   = jQuery(e);
                
                if(this.line_height == NaN)
                  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'
  };
        
        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.line_height + 'px',
                                                                                                'overflow-x' : 'hidden',
                                                                                                'position'   : 'absolute',
                                                                                                'top'        : 0,
                                                                                                'left'           : -9999
                                                                                                }).appendTo('body');
                        }
                        
                        // Strip HTML tags
                        var html = this.textarea.val().replace(/(<|>)/g, '');
                        
                        // IE is different, as per usual
                        if (jQuery.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()))
                                        {       
                                                this.textarea.animate({height: (this.dummy.height() + this.line_height) + 'px'}, 100);  
                                        }
                                }
                        }
                }
                                                 
         });
})(jQuery);