JavaScript / jQuery: Test if window has focus

Question

How do you test if the browser has focus?

Answer 1

use the hasFocus method of the document. You can find detailed description and an example here: hasFocus method

EDIT: Added fiddle http://jsfiddle.net/Msjyv/3/

HTML

Currently <b id="status">without</b> focus...

JS

function check()
{
    if(document.hasFocus() == lastFocusStatus) return;

    lastFocusStatus = !lastFocusStatus;
    statusEl.innerText = lastFocusStatus ? 'with' : 'without';
}

window.statusEl = document.getElementById('status');
window.lastFocusStatus = document.hasFocus();

check();
setInterval(check, 200);