/* 
 * 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)
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 *
 *
 * 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;
	}

	if (this.min_height == NaN || this.min_height == 0) {
		this.min_height == this.textarea.height();
	}

	// 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 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);