Zoom only works using trackpad on macbook (OSX 10.12)

[grubbins]

When I visit the demo page, Shift + two finger scroll on the trackpad zooms nicely. However, Shift + mousewheel (with any USB mouse I have tried) does nothing. Same behaviour in Chrome and Safari.

I suspect this is something funky with jquery.mousewheel on OSX. I noticed that Google Maps has the same problem on my macbook.

[grubbins]

Interestingly I tried changing the demo to use Ctrl instead of Shift and it seems to work just fine. I guess some confusion over horizontal scrolling?

[gavinchou]

I ran into this issue too, replacing shiftKey with ctrlKey makes it work for me (macOS 10.13.6).

    $element.mousewheel(function (evt) {
        if (evt.ctrlKey) {