Monday, August 10, 2009

Fade Effects With Javascript

Fade Effects With Javascript
========================

Script
-------



var TimeToFade = 1000.0;

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);
}





How to Use
---------------
You can use this JavsScript this way.
Suppose, Your HTML layout is like this :





I'm Some Text




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