MouseMove event repeating every second

Question

http://jsfiddle.net/MrkY9/

My computer (and so far, no other computer among my coworkers) is exhibiting an issue in Chrome, IE, and Safari (but not in Firefox). Sim

Answer 1

Ok, I found the problem, though I don't fully understand why it was an issue.

I had Task Manager running in the background. And for some reason, every time it updated itself, it was causing IE, Safari and Chrome to receive a mousemove event.

It doesn't make sense, but at least the fix is simple: close the Task Manager.

(It's very obvious if you are in the Applications tab. If you're in Performance, it depends on what the values are set to.)

Answer 2

For me the issue happens sometimes when iTunes is playing. I know iTunes (for Windows) has had a focus issue for ages - it tends to steal focus from its own popup windows.

You pointed out the problem in your (accepted) answer: other applications can steal the browser's focus, firing the mousemove event at will. However for a live website we cannot assume a user is not running certain programs like Task Manager or iTunes.

As suggested in the question's comment section, please save the mouse position and keep checking if it changed.

Example code using jQuery:

var old_pos = [0, 0];
$(el).on("mousemove", function(e) {
    var new_pos = [e.clientX, e.clientY];

    // Quit if the mouse position did not change.
    if(old_pos[0] == new_pos[0] && old_pos[1] == new_pos[1])
        return;

    // Your code.
});

(Note: you're better off using the touchmove event with the touches and changedTouches arrays for touch gestures.)

Hope this helps anyone bumping into similar problems.

Edit: additional functionality to separate mouse events from touch events based on Scott's comment below:

var old_pos = [0, 0];
$(el).on("mousemove touchmove", function(e) {
    var new_pos = [e.clientX, e.clientY];

    // Quit if the mouse position did not change.
    if(e.type == "mousemove" && old_pos[0] == new_pos[0] && old_pos[1] == new_pos[1])
        return;

    // Your code.
});

Answer 3

I faced the exact same issue. For Pure Javascript, I replaced onmousemove with onmouseover. For jQuery, I replaced mousemove with mouseover. Fastest fix for me.