/*
* 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 ($.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);