$(document).ready(function(){
// Immerse yourself in squares.
var dim = Math.round(($('#boxen').parent().width() - 16) / 8) * 8;
$('#boxen').width(dim);
$('#boxen').height(dim);
var box_count = Math.pow(dim / 8, 2);
// A queue of function references
var work = [];
for (var i=0; i<box_count; i++){
/* Instead of executing the code and moving on to the next iteration,
just put the job in the queue as a function. */
var job = function(){
var r = Math.round(Math.random() * 255);
var g = Math.round(Math.random() * 255);
var b = Math.round(Math.random() * 255);
var color = 'rgb(' + r + ', ' + g + ', ' + b + ')';
$('<li>').attr('style', 'background-color: ' + color).appendTo('#boxen');
};
work.push(job);
}
/* How many milliseconds the browser should work before unlocking and working
on something else. */
var max_lock = 50;
/* How long the breather should be. 1 millisecond is enough to prompt the
browser to turn to another task and complete it before returning to this
queue. */
var timeout = 1;
// Turn over the queue for execution.
do_work(work, max_lock, timeout, null);
});
function do_work(work, max_lock, timeout, wrapup){
var curr_time,
start_time = new Date().getTime();
while (work.length){
curr_time = new Date().getTime();
if (curr_time - start_time < max_lock){
// Pull the first job function from the queue and execute it.
work.shift()();
}else{
/* We've worked on this long enough -- let's take a quick break,
making a note to come back and continue. */
setTimeout(function(){
do_work(work, max_lock, timeout, wrapup);
}, timeout);
return false;
}
}
// Optional callback function for when the queue is completed.
if (wrapup !== null){
wrapup();
}
}
<ul id="boxen"></ul>
#boxen{
background-color: #ccc;
}
#boxen li{
display: block;
width: 8px;
height: 8px;
float: left;
}