detect mouse direction

daniel__ picture daniel__ · Dec 9, 2011 · Viewed 19.1k times · Source

I am trying this code to detect if the mouse direction is going up or down:

<html>  
    <head></head>
    <body>
        <div style="width: 500px; height: 500px; background: red;"></div>
    </body>
</html>

var mY = 0;
$('body').mousemove(function(e) {
    mY = e.pageY;
    if (e.pageY < mY) {
        console.log('From Bottom');
        return;

    } else {
        console.log('From Top');
    }

});

However this code doesn't work was i expect. Console log always show "from top"

Any idea ?

demo

Answer

maček picture maček · Dec 9, 2011
var mY = 0;
$('body').mousemove(function(e) {

    // moving upward
    if (e.pageY < mY) {
        console.log('From Bottom');

    // moving downward
    } else {
        console.log('From Top');
    }

    // set new mY after doing test above
    mY = e.pageY;

});