//Inserts Banner in DIV Banner.
//T-Creator 2010 - info@t-creator.pt

//config

var  TimeToFade = 1000.0;
var bannerInterval = 8000;

var banners=["site/html/themes/tcreatorNew/images/banner/Banner1.png",
             		"site/html/themes/tcreatorNew/images/banner/Banner2.png",
             		"site/html/themes/tcreatorNew/images/banner/Banner3.png",
             		"site/html/themes/tcreatorNew/images/banner/Banner4.png"]

             		
             		
//Code             		
var numOfBanners = 4;             		
var currentBanner = 0;
var nextBanner;
var bannerInt;

function updateBanner(content) {
	
	if ($('Banner')) {
		
		//Creates a div for each banner
		for (var i=0; i <= numOfBanners;i++) {
			
			//creates div for help and inser the content
			var divBanner = document.createElement('div');
			divBanner.style.width = '927px';
			divBanner.style.height =  '201px';
			divBanner.style.overflow =  'hidden';
			divBanner.style.align =  'center';
			divBanner.style.position =  'absolute';
			divBanner.id = 'BN_' + i;
			divBanner.innerHTML = "<img src=\"" + banners[i] + "\" class=\"imgSem\">";
			$('Banner').appendChild(divBanner);
			
			//Hide all
			if (i > 0) {
				divBanner.style.visibility = 'hidden';
				fade(divBanner.id);
			}
		}
		
		bannerInt = setInterval( function(pe) {
			if ($('Banner')) {
				showNextBanner()
			}
			else {
				clearInterval(bannerInterval);
			}
		}, bannerInterval);
		
	}	
}

function showNextBanner() {
	
	//Hide current banner
	nextBanner = (currentBanner+1)%numOfBanners;
	
	
	$('BN_' + nextBanner).style.visibility = '';

	//Fade effects
	fade('BN_' + nextBanner);
	fade('BN_' + currentBanner);
	currentBanner = nextBanner;

}

function fade(eid) {
  var element = document.getElementById(eid);
  if(element == null)
    return;
   
  if(element.FadeState == null) {
    if(element.style.opacity == null || element.style.opacity == '' || element.style.opacity == '1') {
      element.FadeState = 2;
    }
    else {
      element.FadeState = -2;
    }
  }
   
  if(element.FadeState == 1 || element.FadeState == -1) {
    element.FadeState = element.FadeState == 1 ? -1 : 1;
    element.FadeTimeLeft = TimeToFade - element.FadeTimeLeft;
  }
  else {
    element.FadeState = element.FadeState == 2 ? -1 : 1;
    element.FadeTimeLeft = TimeToFade;
    setTimeout("animateFade(" + new Date().getTime() + ",'" + eid + "')", 33);
  }  
}

function  animateFade(lastTick, eid) {  
  var curTick = new Date().getTime();
  var elapsedTicks = curTick - lastTick;
 
  var element = document.getElementById(eid);
 
  if (element) {
	  if(element.FadeTimeLeft <= elapsedTicks) {
	    element.style.opacity = element.FadeState == 1 ? '1' : '0';
	    element.style.filter = 'alpha(opacity = ' + (element.FadeState == 1 ? '100' : '0') + ')';
	    element.FadeState = element.FadeState == 1 ? 2 : -2;
	    return;
	  }
  } 
  else {
	  return;
  }
 
  element.FadeTimeLeft -= elapsedTicks;
  var newOpVal = element.FadeTimeLeft/TimeToFade;
  
  if (element.FadeState == 1)
    newOpVal = 1 - newOpVal;

  element.style.opacity = newOpVal;
  element.style.filter = 'alpha(opacity = ' + (newOpVal*100) + ')';
 
  setTimeout("animateFade(" + curTick + ",'" + eid + "')", 33);
}