/* protoload 0.1 beta by Andreas Kalsch
 * last change: 09.07.2007
 *
 * This simple piece of code automates the creating of Ajax loading symbols.
 * The loading symbol covers an HTML element with correct position and size - example:
 * $('myElement').startWaiting() and $('myElement').stopWaiting()
 */
YAHOO.widget.Protoload = {
	// the script to wait this amount of msecs until it shows the loading element
	timeUntilShow: 250,
	
	// opacity of loading element
	opacity: 0.8,

	// Start waiting status - show loading element
	startWaiting: function(element, className, timeUntilShow) {
		if (typeof element == 'string')
			element = document.getElementById(element);
		if (className == undefined)
			className = 'waiting';
		if (timeUntilShow == undefined)
			timeUntilShow = this.timeUntilShow;
		
		element._waiting = true;
		if (!element._loading) {
			var e = document.createElement('div');
			(element.offsetParent || document.body).appendChild(element._loading = e);
			e.style.position = 'absolute';
			try {e.style.opacity = this.opacity;} catch(e) {}
			try {e.style.MozOpacity = this.opacity;} catch(e) {}
			try {e.style.filter = 'alpha(opacity='+Math.round(this.opacity * 100)+')';} catch(e) {}
			try {e.style.KhtmlOpacity = this.opacity;} catch(e) {}
		}
		element._loading.className = className;
		window.setTimeout((function() {
			if (this._waiting) {
				var left = this.offsetLeft, 
					top = this.offsetTop,
					width = this.offsetWidth,
					height = this.offsetHeight,
					l = this._loading;
				l.style.left =  left+'px';
				l.style.top = top+'px'; 
				l.style.width = width+'px';
				l.style.height = height+'px'; 
				l.style.display = 'inline'; 
			}
		}).bind(element), timeUntilShow);
	},
	
	// Stop waiting status - hide loading element
	stopWaiting: function(element) {
		if (element._waiting) {
			element._waiting = false;
			element._loading.parentNode.removeChild(element._loading);
			element._loading = null;
		}
	}
};
var A = function(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) {
    return iterable.toArray();
  } else {
    var results = [];
    for (var i = 0, length = iterable.length; i < length; i++)
      results.push(iterable[i]);
    return results;
  }
}

Function.prototype.bind = function() {
	var __method = this, args = A(arguments), object = args.shift();
	return function() {
		return __method.apply(object, args.concat(A(arguments)));
	};
};