// Perfect Day Photo - Javascript for page / image effects and faders.

var W3CDOM;

// is browser OK for true W3C DOM scripting and standards compliance ? (excludes IE6)
if (document.getElementById && document.createElement && document.childNodes && window.XMLHttpRequest)
	W3CDOM = true;
else
	W3CDOM = false;


	window.onload = InitEffects;


	var msg = "The content of this website is copyrighted.\nPlease contact us if you want to use any images.";
document.oncontextmenu=new Function("alert(msg);return false");


var TimeToFade = 1500.0;
var TimeRotatePics = 5000;


var ImagesHome = new Array();
ImagesHome[0] = "";
ImagesHome[1] = "pg-bride-father.jpg";
ImagesHome[2] = "pg-bridesmaid-1.jpg";
ImagesHome[3] = "pg-bridesmaid-2.jpg";
ImagesHome[4] = "pg-bride-smiling.jpg";

var ImagesAbout = new Array();
ImagesAbout[0] = "";
ImagesAbout[1] = "pg-2girls-bw.jpg";
ImagesAbout[2] = "pg-2girls-colour.jpg";
ImagesAbout[3] = "pg-2girls-sepia.jpg";

var intRotateImgCounter = 1;
var ImgFlag = "bottom";


function InitEffects()
{
	if (W3CDOM)
	{
	SetTrans('Content');

	Fade('Content');

	if (document.getElementById('PageGraphicHome'))
		setTimeout("ChangePicsHomePage()", 2000);

	if (document.getElementById('PageGraphicAbout'))
		setTimeout("ChangePicsAboutPage()", 2000);
	}
}


function ChangePicsHomePage()
{
	strNewImage = "images/" + ImagesHome[intRotateImgCounter] + "";

	if (ImgFlag=="bottom")
	{
	document.getElementById('PGHomeImage1').src = strNewImage;
	Fade('PGHomeImage2');
	}

	if (ImgFlag=="top")
	{
	document.getElementById('PGHomeImage2').src = strNewImage;
	Fade('PGHomeImage2');
	ImgFlag=="bottom";
	}

	if (ImgFlag=="bottom") ImgFlag="top"; else ImgFlag="bottom";

	intRotateImgCounter++;
	if (intRotateImgCounter > 4) intRotateImgCounter=1;

	setTimeout("ChangePicsHomePage()", TimeRotatePics);
}


function ChangePicsAboutPage()
{
	strNewImage = "images/" + ImagesAbout[intRotateImgCounter] + "";

	if (ImgFlag=="bottom")
	{
	document.getElementById('PGAboutImage1').src = strNewImage;
	Fade('PGAboutImage2');
	}

	if (ImgFlag=="top")
	{
	document.getElementById('PGAboutImage2').src = strNewImage;
	Fade('PGAboutImage2');
	ImgFlag=="bottom";
	}

	if (ImgFlag=="bottom") ImgFlag="top"; else ImgFlag="bottom";

	intRotateImgCounter++;
	if (intRotateImgCounter > 3) intRotateImgCounter=1;

	setTimeout("ChangePicsAboutPage()", TimeRotatePics);
}


function SetTrans(eid)
{
	var element = document.getElementById(eid);

	element.style.opacity = 0;
	element.style.filter = 'alpha(opacity = 100)';
	element.FadeState = element.FadeState == 1;
}


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.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;
  }
 
  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);
}