:focus selector
focus selector
version added: 1.6jQuery(':focus')
Description: Selects element if it is currently focused.
As with other pseudo-class selectors (those that begin with a ":"), it is recommended to precede :focus with a tag name or some other selector; otherwise, the universal selector ("*") is implied. In other words, the bare $(':focus') is equivalent to $('*:focus'). If you are looking for the currently focused element, $( document.activeElement ) will retrieve it without having to search the whole DOM tree.
Example:
Adds the focused class to whatever element has focus
<!DOCTYPE html>
<html>
<head>
<style>
.focused {
background: #abcdef;
}
</style>
<script src="http://code.jquery.com/jquery-1.7rc2.js"></script>
</head>
<body>
<div id="content">
<input tabIndex="1">
<input tabIndex="2">
<select tabIndex="3">
<option>select menu</option>
</select>
<div tabIndex="4">
a div
</div>
</div>
<script>
$( "#content" ).delegate( "*", "focus blur", function( event ) {
var elem = $( this );
setTimeout(function() {
elem.toggleClass( "focused", elem.is( ":focus" ) );
}, 0);
});
</script>
</body>
</html>