/*
 * testUserDevice.js 1.2
 * Authored by Scott Jehl, Filament Group (filamentgroup.com)
 * Date: July 2007 (rev. Feb 2008)
 * Notes: This script is used to test the capability of a browser before providing enhanced javascript and css functionality.
          The script waits until the document.body is ready and then performs the test. Upon passing, any arguments will be passed on to the domReady function (jQuery's if available). This allows you to enclose your existing domReady scripting in the test function call.
          
          Upon successful completion of the test, the following steps occur to allow for easy separation of enhanced style:
               1. a class of "enhanced" is assigned to the body element to be used for optional css scoping (such as: body.enhanced {background: red;})
               2. Any links to alternate stylesheets that have a class of "enhanced" will be enabled.
               3. Any links to stylesheets that have a class of "basicNoCascade" will be disabled. This is optional depending on whether your enhanced stylesheets cascade or conflict with your basic sheets.
          A cookie is set as well to notify the script on future page loads that the browser has already passed and can receive an enhanced experience. 
          * the cookie is (enhanced = true) and can be used on the backend to speed things up even further!
 * Usage: To use this script, simply enclose any scripting within the following function:
			 					 enhancedDomReady(function(){
									 //put scripts here to be executed after the dom is ready and the browser has passed the test
			 					 });

 * Changes: 1.2: class and cookie name has been changed to "enhanced". This may break backward compatibility with older implementations of this test.
 * Additional Info: For more information, visit filamentgroup.com/lab/browserTest/*/



/*waits until body is ready, runs test, passes domReady events to preferred domReady function*/
function enhancedDomReady(func){
	function bodyReady(){
		if(document.body){
			clearInterval(checkBody);
			if(testUserDevice()){
				enhanceDocument();
				//forward functions to domReady event with available library
				if(jQuery){$(function(){func();});}
				else indepDomReady(function(){func();});
			}
		}
	}
	var checkBody = setInterval(bodyReady, 10);
}

//this gets called after test is passed
function enhanceDocument(){
	//add class to body "hasJS" for css scoping
	document.body.className += ' enhanced';
	//function to enable enhanced stylesheets (enables alt stylesheet links with class name "enhanced)
	var allLinks = document.getElementsByTagName('link');
	for(i=0; i<allLinks.length; i++){
		//if the link has a class of "basicNoCascade", disable it
		if (/\bbasicNoCascade\b/.exec(allLinks[i].className)){
			allLinks[i].disabled = true;
		}
		//if the link has a class of "enhanced", enable it
		if (/\benhanced\b/.exec(allLinks[i].className)){
			allLinks[i].disabled = true; //opera likes to have it toggled
			allLinks[i].disabled = false;
		}
	}
}

//test function - runs a variety of tests to weed out any unqualified browsers from enhanced functionality
var testUserDevice = function (){	
	if(readCookie('enhanced')){
		enhanceDocument();
		return true;
	}
	if(document.getElementById && document.createElement){
		var newDiv = document.createElement('div');
		document.body.appendChild(newDiv);
		newDiv.style.visibility = 'hidden';
		newDiv.style.width = '20px';
		newDiv.style.padding = '10px';
		var divWidth = newDiv.offsetWidth;
		if(divWidth != 40) {
			document.body.removeChild(newDiv);
			document.writeln("0001 failed");
			return false;
		}
		newDiv.style.position = 'absolute';
		newDiv.style.left = '10px';
		var leftVal = newDiv.offsetLeft;
		if(leftVal != 10) { 
			document.body.removeChild(newDiv);
			document.writeln("0002 failed"); 
			return false;
		}
		var newInnerDiv = document.createElement('div');
		newInnerDiv.style.width = '5px';
		newInnerDiv.style.cssFloat = 'left';
		newInnerDiv.style.styleFloat = 'left';
		newDiv.appendChild(newInnerDiv);
		var secondInnerDiv = newInnerDiv.cloneNode(true); 
		newDiv.appendChild(secondInnerDiv);
		var newInnerDivTop = newInnerDiv.offsetTop;
		var secondInnerDivTop = secondInnerDiv.offsetTop;
		if(newInnerDivTop != secondInnerDivTop) { 
			document.body.removeChild(newDiv);
			document.writeln("0003 failed"); 
			return false;
		}
		newDiv.innerHTML = '<ul><li style="width: 5px; float: left;">test</li><li style="width: 5px; float: left;clear: left;">test</li></ul>';
		var top1 = newDiv.getElementsByTagName('li')[0].offsetTop;
		var top2 = newDiv.getElementsByTagName('li')[1].offsetTop;
		if(top1 == top2){
			document.writeln("0004 failed");
			return false;
		}
		newDiv.innerHTML = '<div style="height: 20px;"></div>';
		newDiv.style.padding = '0';
		newDiv.style.height = '10px';
		newDiv.style.overflow = 'auto';
		var newDivHeight = newDiv.offsetHeight;
		if(newDivHeight != 10){
			document.body.removeChild(newDiv); 
			document.writeln("0005 failed");
			return false;
		}
		newDiv.innerHTML = '<div style="line-height: 2; font-size: 10px;">Te<br />st</div>';
		newDiv.style.padding = '0';
		newDiv.style.height = 'auto';
		newDiv.style.overflow = '';
		var newDivHeight = newDiv.offsetHeight;
		if(newDivHeight > 40){
			document.body.removeChild(newDiv); 
			document.writeln("0006 failed");
			return false;
		}
		if(window.onresize == false){
			document.body.removeChild(newDiv); 
			document.writeln("0007 failed");
			return false;
		}
		if(!window.print){ 
			document.body.removeChild(newDiv); 
			document.writeln("0008 failed");
			return false;
		}
		if(window.clientInformation && window.opera){
			document.body.removeChild(newDiv); 
			document.writeln("0009 failed");
			return false;
		}
		document.body.removeChild(newDiv);
		enhanceDocument();
		createCookie('enhanced', 'true');
		return true;
	}
	else{return false; }
}

/*Utilities for this script*/


/* library-independent domReady script (used if jQuery is not available) Note: can't find script source.. tba */
function indepDomReady(func){
	if (!window.__load_events){
		var init = function (){
				if (arguments.callee.done) return;
				arguments.callee.done = true;
				if (window.__load_timer){
					clearInterval(window.__load_timer);
					window.__load_timer = null;
				}
				for (var i=0;i < window.__load_events.length;i++){
					window.__load_events[i]();
				}
				window.__load_events = null;
		};
		if (document.addEventListener){
			document.addEventListener("DOMContentLoaded", init, false);
		}
		if (/WebKit/i.test(navigator.userAgent)){
			window.__load_timer = setInterval(function(){
				if (/loaded|complete/.test(document.readyState)){
					init();
				}
			}
			, 10);
		}
	window.onload = init;
	window.__load_events = [];
	}
	window.__load_events.push(func);
}

//cookie functions from quirksmode
function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}