Multi-touch zoom not working on hybrid laptop

[bergwerf]

I have a Chromebook with both a touch screen and a touchpad. I can zoom using my touchpad but not using multi-touch on the touch screen.

[arose]

Is this on http://arose.github.io/ngl/, if not does it work there? Does it work on this site http://threejs.org/examples/#misc_controls_trackball? Are there any messages in the browser console?

[bergwerf]

It doesn't work on the three.js site and there are no console errors. The problem is basically that the system defaults to page zooming when you use multitouch zoom. I just discovered zooming out works (because the page cannot be zoomed out any more, so zooming the canvas is working again). You have to block the event from propagating to other elements/prevent the default action (e.g. e.preventDefault()).

[arose]

Thanks @hermanbergwerf added some e.preventDefault()s, see be33e14. Please let me know if it works for you http://arose.github.io/ngl/.

[bergwerf]

Unfortunately it did not work. I shortly looked into it and this oneliner solves the issue.

document.getElementById('viewport').addEventListener('touchmove',function(e){e.preventDefault();});

Preventing on scoll is probably not working since multitouch zoom is not considered a scroll event by the browser. You should block the propagation of touchmove.

[arose]

Cool, I add that later today. Thanks!

On Tue, Mar 15, 2016, at 11:30 AM, Herman Bergwerf wrote:

Unfortunately it did not work. I shortly looked into it and this
oneliner solves the issue.
document.getElementById('viewport').addEventListener('touchmove',func-
tion(e){e.preventDefault();});
Preventing on scoll is probably not working since multitouch zoom is
not considered a scroll event by the browser. You should block the
propagation of touchmove.
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Links:

1. Multi-touch zoom not working on hybrid laptop #53 (comment)

[arose]

Ok, could reproduce this and hopefully fixed it now (73983c5, 2f139f4). Thanks again.

[bergwerf]

Yep, fixed now (on my Chromebook). Awesome!