/*
 * Auto Expanding Text Area (1.2.2)
 * by Chrys Bader (www.chrysbader.com)
 * chrysb@gmail.com
 *
 * Version 1.2.3 update
 * by Richard Vallee
 * richardvallee@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);
this.expand_tolerance = (!isNaN(this.options.expandTolerance) && this.options.expandTolerance >= 0) ? this.options.expandTolerance : 4;

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: '1.2.3'
  };

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

jQuery.autogrow.fn.extend({
init: function() {
var self = this;
this.textarea.css({overflow: 'hidden'});
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');
} else {
// If the dummy was already created, show it as it is hidden after expansion
this.dummy.show();
}

// 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.expand_tolerance*this.line_height) > this.max_height)) {
this.textarea.css('overflow-y', 'auto');
if (this.textarea.height() < this.max_height) {
this.textarea.animate({height: (this.max_height + (this.expand_tolerance*this.line_height)) + 'px'}, 100);
}
}
else {
this.textarea.css('overflow-y', 'hidden');
if (this.textarea.height() < this.dummy.height() + (this.expand_tolerance*this.line_height) || (this.dummy.height() < this.textarea.height())) {
if (this.dummy.height() < this.min_height) {
this.textarea.animate({height: (this.min_height + (this.expand_tolerance*this.line_height)) + 'px'}, 100);
} else {
this.textarea.animate({height: (this.dummy.height() + (this.expand_tolerance*this.line_height)) + 'px'}, 100);
}
}
}
}

// Hide the dummy, as otherwise it overflows the body when the content is long
this.dummy.hide();
}

});
})(jQuery);