MouseEvent movementX property apparently not supported in internet explorer

Question

I am developing an application that needs to be compatible on IE 9 and above. I am using the movementX property on a MouseEvent object, however this same MouseEvent object d

Answer 1

You will need to replicate it's behaviour by taking the delta between subsequent screenX and screenY values.

// Store previous screenX/screenY somewhere outside of callback
var prevX = 0;
var prevY = 0;

// Callback whenever the mouse moves
function mousemove(e) {
    var movementX = (prevX ? e.screenX - prevX : 0)
    var movementY = (prevY ? e.screenY - prevY : 0)

    prevX = e.screenX;
    prevY = e.screenY;
}

Note that if you are listening to mousemove to say, figure out if something is being dragged, you should reset prevX and prevY to 0 on mouseup or else you'll get the old screen values!