Bug 82600 – [Qt][WK2] contentViewportChanged is triggered twice after gesture end

• Status: RESOLVED
• Resolution: INVALID
• Component: Platform

[Balazs Kelemen]

Not a very big issue, just a small bug I have noticed.
After a gesture ended, we clear the ViewportUpdateDeferrer, and it emits contentResumeRequested and contentViewportChanged (via the interaction engine). The first is connected to QQuickWebViewFlickablePrivate::_q_resume the second is to QQuickWebViewFlickablePrivate::_q_contentViewportChanged. But _q_resume also calls directly the second which is unnecessary and there is no check later so we will schedule a layerflush in LayerTreeHostQt (and send a message unnecessarily). I have removed the call in _q_resume, put a call to _q_contentViewportChanged to onComponentComplete where _q_resume is called explicitly, and it seems like everything works fine with it.

[Balazs Kelemen]

Created attachment 134555 [details]
Patch

[Kenneth Rohde Christiansen]

Comment on attachment 134555 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=134555&action=review

> Source/WebKit2/ChangeLog:11
> +        [Qt][WK2] contentViewportChanged is triggered twice after gesture end
> +        https://bugs.webkit.org/show_bug.cgi?id=82600
> +
> +        Reviewed by NOBODY (OOPS!).
> +
> +        Remove explicit call to _q_contentViewportChanged from _q_resume.
> +        It is called through the ViewportUpdateDeferrer when necessary.
> +
> +        * UIProcess/API/qt/qquickwebview.cpp:

I am not convinced which is why I havent removed this myself.

In the future we will also call resume when brought back fro the background (visibility change) so we will need to make sure to call this on resume. it also seems like the proper place.