/**
 * TextAreaExpander plugin for jQuery v1.0 Expands or contracts a textarea
 * height depending on the quatity of content entered by the user in the box. By
 * Craig Buckler, Optimalworks.net As featured on SitePoint.com:
 * http://www.sitepoint.com/blogs/2009/07/29/build-auto-expanding-textarea-1/
 * Please use as you wish at your own risk.
 */
/**
 * Usage: From JavaScript, use: $jqjq(<node>).TextAreaExpander(<minHeight>,
 * <maxHeight>); where: <node> is the DOM node selector, e.g. "textarea"
 * <minHeight> is the minimum textarea height in pixels (optional) <maxHeight>
 * is the maximum textarea height in pixels (optional) Alternatively, in you
 * HTML: Assign a class of "expand" to any <textarea> tag. e.g. <textarea
 * name="textarea1" rows="3" cols="40" class="expand"></textarea> Or assign a
 * class of "expandMIN-MAX" to set the <textarea> minimum and maximum height.
 * e.g. <textarea name="textarea1" rows="3" cols="40" class="expand50-200"></textarea>
 * The textarea will use an appropriate height between 50 and 200 pixels.
 */
(function($jq) {
	// jQuery plugin definition
	$jq.fn.TextAreaExpander = function(minHeight, maxHeight) {
		var hCheck = !($jq.browser.msie || $jq.browser.opera);
		// resize a textarea
		function ResizeTextarea(e) {
			// event or initialize element?
			e = e.target || e;
			// find content length and box width
			var vlen = e.value.length, ewidth = e.offsetWidth;
			if (vlen != e.valLength || ewidth != e.boxWidth) {
				if (hCheck && (vlen < e.valLength || ewidth != e.boxWidth))
					e.style.height = "0px";
				var h = Math.max(e.expandMin, Math.min(e.scrollHeight, e.expandMax));
				e.style.overflow = (e.scrollHeight > h ? "auto" : "hidden");
				e.style.height = h + "px";
				e.valLength = vlen;
				e.boxWidth = ewidth;
			}
			return true;
		};
		// initialize
		this.each(function() {
			// is a textarea?
			if (this.nodeName.toLowerCase() != "textarea")
				return;
			// set height restrictions
			var p = this.className.match(/expand(\d+)\-*(\d+)*/i);
			this.expandMin = minHeight || (p ? parseInt('0' + p[1], 10) : 0);
			this.expandMax = maxHeight || (p ? parseInt('0' + p[2], 10) : 99999);
			// initial resize
			ResizeTextarea(this);
			// zero vertical padding and add events
			if (!this.Initialized) {
				this.Initialized = true;
				$jq(this).css("padding-top", 0).css("padding-bottom", 0);
				$jq(this).bind("keyup", ResizeTextarea).bind("focus", ResizeTextarea);
			}
		});
		return this;
	};
})(jQuery);