Prevent default event action not working...?

Question

I'm trying to add keyboard shortcuts on my website to make fast navigation possible using the keyboard. I'm running into a slight problem, however, with my attempted Alt+X shortcut. The event runs just fine and returns false as it should, but the browser's File menu comes up regardless. I've also tried the preventDefault method, but no change.

The cut-down version of the script is:

document.documentElement.onkeydown = function(e) {
    e = e || window.event;
    switch( e.keyCode || e.which) {
        // some cases here - most notably:
        case 116: // F5 key
            if( activeFrame) {
                activeFrame.contentWindow.location.reload();
                // reloads an iframe if one is active
                return false;
            }
            break;
        // more cases...
        case 88: // X key
            if( e.altKey) {
                // do something
                return false;
            }
    }
}

As noted above, overriding the default action of the F5 key works just fine - the browser reloads the page only if no iframe is active. I don't quite see how to prevent the menu from appearing when Alt+X is pressed.

Answer 1

I actually had a web app working just fine with CTRL shortcut keys, but then decided I'd be clever and use the accesskey attribute, and ran into this exact issue with IE.

The problem with going to CTRL shortcut keys is that many of those are more standard/useful across many applications (eg: cut, copy, paste, select all).

Ctrl+Alt is fairly safe, but requires more work on the user's part.

I tend to just try to stick to ALT shortcuts IE doesn't stubbornly insist on handling.

Demo of CTRL + A/CTRL + F being cancelled successfully: http://jsfiddle.net/egJyT/

This answer seems to imply it isn't possible to disable the menu shortcuts without putting IE into kiosk mode.