Question

I’m trying to capture the mouse event. Here is the code I’m trying:

if(window.addEventListener) { document.addEventListener('DOMMouseScroll', zoom_handler, false); } 
else { document.onmousewheel = zoom_handler; }

alert("test"); //I see this alert so I assume the code above it is run

//…

function zoom_handler(event) {

    var delta = 0;

    if (!event) event = window.event;
    // normalize the delta
    if (event.wheelDelta) {
        // IE and Opera
        delta = event.wheelDelta / 60;
    } else if (event.detail) {
        // W3C
        delta = -event.detail / 2;
    }

    alert("Delta: " + delta);


}

Except the problem is I see nothing when I try wheeling up and down on my page, so I guess I’m not capturing the event properly. For reference, I’ve been trying to follow this tutorial: http://viralpatel.net/blogs/2009/08/javascript-mouse-scroll-event-down-example.html

Thanks for any help.

Answer 1

I guess that the way you implemented it, is going to work only in some browsers, not in Chrome for example. Did you try to put the

document.onmousewheel = zoom_handler;

outside the else statement?
Doing so, makes it work on my Chrome Browser running on OSX Lion (Mac).

This is how I tested on my computer:

if(window.addEventListener) { document.addEventListener('DOMMouseScroll', zoom_handler, false); } 
document.onmousewheel = zoom_handler;

alert("test"); //I see this alert so I assume the code above it is run

Hope that fixes it.