/**
* @name Elastic
* @descripton Elastic is Jquery plugin that grow and shrink your textareas automaticliy
* @version 1.6.3
* @requires Jquery 1.2.6+
*
* @author Jan Jarfalk
* @author-email jan.jarfalk@unwrongest.com
* @author-website http://www.unwrongest.com
*
* @licens MIT License - http://www.opensource.org/licenses/mit-license.php
*
* Generate a pseudorandom unique ID for the $twin, and stores that ID in $textarea.data(?elastic-twin?). If elastic() is called on the same textarea a second time, it won?t create another hidden div; it will just update() and return.
*
* Have update() check (and fix) the width of the $twin in case it?s different from the width of the $textarea. This allows the textarea to remain properly elastic if it gets wider or narrower.
*
* Add a custom event handler ('lasticupdate') so that any other code on the page can force an update by calling (for example) $('textarea').trigger('elasticupdate').
*
*I created a github fork of your Google Code project so that I could commit my changes atomically. If you feel like pulling any or all of them back into your code, you can find them at http://github.com/mbklein/jquery-elastic
*
*/

(function(jQuery){
jQuery.fn.extend({
elastic: function() {

// We will create a div clone of the textarea
// by copying these attributes from the textarea to the div.
var mimics = [
'paddingTop',
'paddingRight',
'paddingBottom',
'paddingLeft',
'fontSize',
'lineHeight',
'fontFamily',
'width',
'fontWeight'];

var pseudoUUID = function(p) {
p = p || '';
var u = function() { return(((1+Math.random())*0x10000)|0).toString(16).substring(1); }
return(p+u()+u()+"-"+u()+"-"+u()+"-"+u()+"-"+u()+u()+u());
};

return this.each( function() {

// Elastic only works on textareas
if ( this.type != 'textarea' ) {
return false;
}

var $textarea = jQuery(this),
$twin = null,
twinId = $textarea.data('elastic-twin');

if ( twinId ) {
$twin = jQuery('#'+twinId);
update();
return false;
}


var lineHeight = parseInt($textarea.css('line-height'),10) || parseInt($textarea.css('font-size'),'10'),
minheight = parseInt($textarea.css('height'),10) || lineHeight*3,
maxheight = parseInt($textarea.css('max-height'),10) || Number.MAX_VALUE,
goalheight = 0,
i = 0;

twinId = pseudoUUID('elastic');
$twin = jQuery('<div />').css({'position': 'absolute','display':'none','word-wrap':'break-word'});
$twin.attr('id',twinId);
$textarea.data('elastic-twin',twinId);

// Opera returns max-height of -1 if not set
if (maxheight < 0) { maxheight = Number.MAX_VALUE; }

// Append the twin to the DOM
// We are going to meassure the height of this, not the textarea.
$twin.appendTo($textarea.parent());

// Copy the essential styles (mimics) from the textarea to the twin
var i = mimics.length;
while(i--){
$twin.css(mimics[i].toString(),$textarea.css(mimics[i].toString()));
}


// Sets a given height and overflow state on the textarea
function setHeightAndOverflow(height, overflow){
curratedHeight = Math.floor(parseInt(height,10));
if($textarea.height() != curratedHeight){
$textarea.css({'height': curratedHeight + 'px','overflow':overflow});

}
}


// This function will update the height of the textarea if necessary
function update() {

// Get curated content from the textarea.
var textareaContent = $textarea.val().replace(/&/g,'&amp;').replace(/ /g, '&nbsp;').replace(/<|>/g, '&gt;').replace(/\n/g, '<br />');

// Compare curated content with curated twin.
var twinContent = $twin.html().replace(/<br>/ig,'<br />');

if((textareaContent+'&nbsp;' != twinContent) || ($textarea.width() != $twin.width())){

// Set twin to the same width as the textarea
$twin.width($textarea.width());

// Add an extra white space so new rows are added when you are at the end of a row.
$twin.html(textareaContent+'&nbsp;');

// Change textarea height if twin plus the height of one line differs more than 3 pixel from textarea height
if(Math.abs($twin.height() + lineHeight - $textarea.height()) > 3){

var goalheight = $twin.height()+lineHeight;
if(goalheight >= maxheight) {
setHeightAndOverflow(maxheight,'auto');
} else if(goalheight <= minheight) {
setHeightAndOverflow(minheight,'hidden');
} else {
setHeightAndOverflow(goalheight,'hidden');
}

}

}

}

// Hide scrollbars
$textarea.css({'overflow':'hidden'});

// Update textarea size on keyup
$textarea.keyup(function(){ update(); });

// Define a custom event to allow manual updating
$textarea.bind('elasticupdate', function(){ update(); });

// And this line is to catch the browser paste event
$textarea.live('input paste',function(e){ setTimeout( update, 250); });

// Run update once when elastic is initialized
update();

});

        }
    });
})(jQuery);