// -*- Mode:Javascript-Generic -*-
// Copyright (C) 2005, Halloo Communciations, Inc.
// All rights reserved.
//
var IPeriodicalExecuter = Class.create();
IPeriodicalExecuter.prototype = {
initialize: function(callback, frequency) {
this.callback = callback;
this.frequency = frequency;
this.currentlyExecuting = false;
this.intervalId = 0;
this.registerCallback();
},
registerCallback: function() {
this.intervalId = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
},
onTimerEvent: function() {
if (!this.currentlyExecuting) {
try {
this.currentlyExecuting = true;
this.callback();
} finally {
this.currentlyExecuting = false;
}
}
},
clearCallback: function() {
if (this.intervalId != 0)
{
window.clearInterval( this.intervalId);
}
}
}
/********* UTILITIES *********************************/
function URLEncode( plaintext)
{
// The Javascript escape and unescape functions do not correspond
// with what browsers actually do...
var SAFECHARS = "0123456789" + // Numeric
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" + // Alphabetic
"abcdefghijklmnopqrstuvwxyz" +
"-_.!~*'()"; // RFC2396 Mark characters
var HEX = "0123456789ABCDEF";
var encoded = "";
for (var i = 0; i < plaintext.length; i++ ) {
		var ch = plaintext.charAt(i);
	    if (ch == " ") {
		    encoded += "+";				// x-www-urlencoded, rather than %20
		} else if (SAFECHARS.indexOf(ch) != -1) {
		    encoded += ch;
		} else {
		    var charCode = ch.charCodeAt(0);
			if (charCode > 255) {
			    alert( "Unicode Character '" 
                        + ch 
                        + "' cannot be encoded using standard URL encoding.\n" +
				          "(URL encoding only supports 8-bit characters.)\n" +
						  "A space (+) will be substituted." );
				encoded += "+";
			} else {
				encoded += "%";
				encoded += HEX.charAt((charCode >> 4) & 0xF);
				encoded += HEX.charAt(charCode & 0xF);
			}
		}
	} // for

	return encoded;
};


function getPageWidth() {	
    if (typeof( window.innerWidth)=='number')
		return window.innerWidth;
	else if ( document.documentElement && document.documentElement.clientWidth)
		return document.documentElement.clientWidth;
	else 
		return document.body.clientWidth;
}
function getPageHeight() {
    if (typeof( window.innerHeight)=='number')
		return window.innerHeight;
	else if ( document.documentElement && document.documentElement.clientHeight)
		return document.documentElement.clientHeight;
	else 
		return document.body.clientHeight;
}
function getPosLeft() {		return window.pageXOffset != null? window.pageXOffset: document.body.scrollLeft != null? document.body.scrollLeft:0;}
function getPosTop() {		return window.pageYOffset != null? window.pageYOffset: document.body.scrollTop != null? document.body.scrollTop:0;}
function getPosRight() {	return getPosLeft()+getPageWidth();}
function getPosBottom() {	return getPosTop()+getPageHeight();}

function randomvalue(low, high) { return Math.floor(Math.random() * (1 + high - low) + low); }