/**
 * Class allowing to call a method only after a specific delay if no other call was made
 * It is useful to prevent triggering the same callback multiple times quickly. For instance
 * ajax calls on keyup. It introduces a delay before triggering the callback
 *
 * Usage:
 * 		var refreshResults = new DelayedCall(1000, function() { alert('Mouse not moved for 1 second'); })
 * 		$('body').mousemove(function() { refreshResults.trigger(); })
 *
 * @param delay Inactivity delay in millisecond before triggering the callback
 * @param callback Callback to trigger after a specific delay
 * @return void
 */
function DelayedCall(delay, callback) {
	this.delay = delay;
	this.callback = callback;
	this.timeout = null;

	this.trigger = function() {
		window.clearTimeout(this.timeout);
		this.timeout = setTimeout(this.callback, this.delay);
	};
}