How can I detect when the mouse leaves the window?
I want to be able to detect when the mouse leaves the window so I can stop events from firing while the user's mouse is elsewhere.
Any ideas of how to do this?
Answer
Please keep in mind that my answer has aged a lot.
This type of behavior is usually desired while implementing drag-drop behavior on an html page. The solution below was tested on IE 8.0.6, FireFox 3.6.6, Opera 10.53, and Safari 4 on an MS Windows XP machine.
First a little function from Peter-Paul Koch; cross browser event handler:
function addEvent(obj, evt, fn) {
if (obj.addEventListener) {
obj.addEventListener(evt, fn, false);
}
else if (obj.attachEvent) {
obj.attachEvent("on" + evt, fn);
}
}
And then use this method to attach an event handler to the document objects mouseout event:
addEvent(document, "mouseout", function(e) {
e = e ? e : window.event;
var from = e.relatedTarget || e.toElement;
if (!from || from.nodeName == "HTML") {
// stop your drag event here
// for now we can just use an alert
alert("left window");
}
});
Finally, here is an html page with the script embedded for debugging:
<html>
<head>
<script type="text/javascript">
function addEvent(obj, evt, fn) {
if (obj.addEventListener) {
obj.addEventListener(evt, fn, false);
}
else if (obj.attachEvent) {
obj.attachEvent("on" + evt, fn);
}
}
addEvent(window,"load",function(e) {
addEvent(document, "mouseout", function(e) {
e = e ? e : window.event;
var from = e.relatedTarget || e.toElement;
if (!from || from.nodeName == "HTML") {
// stop your drag event here
// for now we can just use an alert
alert("left window");
}
});
});
</script>
</head>
<body></body>
</html>