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Images and animations

Generate a random color in RGB using Javascript

function randomColor() {
var chars = "0123456789abcdef";
var color = "#";
for (var i=0; i<6; i++) {
var rnd = Math.floor(16 * Math.random());
color += chars.charAt(rnd);
}
return color;
}

Show loading progress percentage of progress bar in Javascript

<script language="JavaScript" type="text/JavaScript">
function showprogress() {
if (document.images.length == 0) {
return false;
}
var loaded = 0;
for (var i=0; i<document.images.length; i++) {
if (document.images[i].complete) {
loaded++;
}
}
var percentage = Math.round(
100 * loaded / document.images.length);
document.getElementById("progress").innerHTML =
percentage + "% loaded";
if (percentage == 100) {
window.clearInterval(ID);
}
}
var ID = window.setInterval("showprogress();", 500);
</script>
<p name="progress">0% loaded</p>

A progress bar animated in Javascript

<script language="JavaScript"
type="text/JavaScript">
function progress() {
if (document.images["bar"].width < 200) {
document.images["bar"].width += 5;
document.images["bar"].height = 5;
} else {
clearInterval(ID);
}
}
var ID;
window.onload = function() {
ID = setInterval("progress();", 500);
}
</script>
<img src="black.gif" name="bar" />

The black.gif can be a 1×1 black pixel.


Animation images using Javascript

<script language="JavaScript" type="text/JavaScript">
var urls;
function animate(pos) {
pos %= urls.length;
document.images["animation"].src = urls[pos];
window.setTimeout("animate(" + (pos + 1) + ");", 500);
}
window.onload = function() {
urls = new Array(
"0.png", "1.png", "2.png", "3.png",
"4.png", "5.png", "6.png");
animate(0);
}
</script>
<img src="0.png" name="animation" />

Preloading multiple images in Javascript

<script language="JavaScript"
type="text/JavaScript">
function preloadImages(urls) {
var img = new Array();
for (var i=0; i<urls.length; i++) {
img[img.length] = new Image();
img[img.length - 1].src = urls[i];
}
}
window.onload = function() {
var img = new Array(
"active.gif", "inactive.gif", "other.gif");
preloadImages(img);
}
</script>

Preload images using Javascript

<script language="JavaScript"
type="text/JavaScript">
function preloadImage(url) {
var i = new Image();
i.src = url;
}
</script>
<body onload="preloadImage('active.gif');">
</body>

Change images on mouse over and mouse out in Javascript

<script language="JavaScript"
type="text/JavaScript">
function changeImage(name, url) {
if (document.images[name]) {
document.images[name].src = url;
}
}
</script>
<img
name="myImage"
src="inactive.gif"
onmouseover="changeImage('myImage', 'active.gif');"
onmouseout="changeImage('myImage', 'inactive.gif');"
/>

Create mouse sensitive buttons in Javascript

<img src="inactive.gif"
onmouseover="this.src='active.gif';"
onmouseover="this.src='inactive.gif';" />