1658919 - (Maybe) disable one-touch-pinch gesture on desktop

Status: RESOLVED FIXED

(Core :: Panning and Zooming, task, P3)

Description

[Kartikaya Gupta (email:[e-mail])]

The one-touch-pinch gesture is enabled on desktop with apz.allow_zooming=true. However this gesture is an Android-ism that we might not want to keep on desktop. In particular, if web content wants to disable browser zooming (because e.g. they implement it themselves like in Google Maps or pdf.js) then there's no way for them to prevent the one-touch-pinch. On Android it's possible to use meta-viewport tags to block all zooming, but meta-viewport tags are ignored on desktop. The best you can do is call preventDefault() on touchstart events with >1 points (which is what I did for pdf.js) but that only blocks two-finger pinch gestures and not one-touch-pinch.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

I guess technically it's still possible for web content to block the gesture, but it would have to implement a touch gesture recognizer that exactly matches the one in the APZ code, and call preventDefault on that second touchstart. But that's not a reasonable thing to be doing.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1658919 - Disable one-touch-pinch on desktop. r?botond

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2ae89d8c812e
Disable one-touch-pinch on desktop. r=botond

Comment 4

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/2ae89d8c812e