I'm Programming a Website and want that it changes it Backgroundimage when i reached a div Box i found it like i have to do it when i want to change the color of it (the Background) but not how it goes with Images, kinda like this
but just with Images
here is the code how to do it with colors if its help for someone
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style>
body{
margin:0;
padding:0;
background:white;
}
div{
width:100%;
height:1600px;
}
</style>
<script type="text/javascript">
var section = {
sections: [
'section1',
'section2',
'section3'
],
sectionOffset: {},
sectionBackground: {
'section1': 'rgb(0, 0, 0)',
'section2': 'rgb(132, 132, 132)',
'section3': 'rgb(255, 255, 255)'
},
currentSection: null
}
window.onload = function()
{
var looplen = section.sections.length;
for(var i = 0; i < looplen; ++i)
{
section.sectionOffset[section.sections[i]] = document.getElementById(section.sections[i]).offsetTop;
}
setTimeout("initialBackgroundChange()", 50);
}
window.onscroll = function()
{
tryBackgroundChange();
};
function tryBackgroundChange()
{
var looplen = section.sections.length,
match,
backgroundColor;
for(var i = 0; i < looplen; ++i)
{
if(pageYOffset >= section.sectionOffset[section.sections[i]])
{
match = section.sections[i];
}
}
if(match != section.currentSection)
{
section.currentSection = match;
changeBackground();
}
}
function changeBackground()
{
var cbc, // Current background-color
tbc, // Target backgrounc-color
ri, // Red incrementation
gi, // Green incrementation
bi, // Blue incrementation
rgb, // Temporary color from cbc to tbc
smoothness = 20; // Higher is smoother
cbc = getStyle(document.body, 'background-color');
cbc = cbc.substr(4, cbc.length-5);
cbc = cbc.split(", ");
tbc = section.sectionBackground[section.currentSection];
tbc = tbc.substr(4, tbc.length-5);
tbc = tbc.split(", ");
ri = (tbc[0] - cbc[0]) / smoothness;
gi = (tbc[1] - cbc[1]) / smoothness;
bi = (tbc[2] - cbc[2]) / smoothness;
for(var i = 1; i <= smoothness; ++i)
{
rgb = [
Math.ceil(parseInt(cbc[0]) + (ri * i)),
Math.ceil(parseInt(cbc[1]) + (gi * i)),
Math.ceil(parseInt(cbc[2]) + (bi * i))
];
setTimeout("document.body.style.backgroundColor = 'rgb(" + rgb.join(",") + ")'", i * (240/smoothness));
}
}
function initialBackgroundChange()
{
if(pageYOffset == 0)
tryBackgroundChange();
}
function getStyle(elem, name)
{
if (document.defaultView && document.defaultView.getComputedStyle)
{
name = name.replace(/([A-Z])/g, "-$1");
name = name.toLowerCase();
s = document.defaultView.getComputedStyle(elem, "");
return s && s.getPropertyValue(name);
}
else if (elem.currentStyle)
{
if (/backgroundcolor/i.test(name))
{
return (function (el)
{ // get a rgb based color on IE
var oRG=document.body.createTextRange();
oRG.moveToElementText(el);
var iClr=oRG.queryCommandValue("BackColor");
return "rgb("+(iClr & 0xFF)+","+((iClr & 0xFF00)>>8)+","+
((iClr & 0xFF0000)>>16)+")";
})(elem);
}
return elem.currentStyle[name];
}
else if (elem.style[name])
{
return elem.style[name];
}
else
{
return null;
}
}
</script>
</head>
<body>
<div id="section1"></div>
<div id="section2"></div>
<div id="section3"></div>
</body>
</html>