1019999 - Possible to get stuck in overscrolled state

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect)

Description

[Botond Ballo [:botond]]

I don't have any better STR than "play around with overscrolling a lot", but we have observed pages get stuck in an overscrolled state.

You then can't get out of it because we ignore touch events when in an overscrolled state.

Kats said he suspects the problem might be that the OverscrollSnapBackAnimation is being cancelled during a scroll offset update [1].

[1] http://dxr.mozilla.org/mozilla-central/source/gfx/layers/apz/src/AsyncPanZoomController.cpp?from=AsyncPanZoomController.cpp#2106

Comment 1

[Botond Ballo [:botond]]

Attachment: bug1019999.patch

Speculative fix assuming the problem is what we think it is.

Comment 2

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

Comment on attachment 8435938 [details] [diff] [review]
bug1019999.patch

Review of attachment 8435938 [details] [diff] [review]:
-----------------------------------------------------------------

::: gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ +1591,1 @@
>    mAnimation = nullptr;

I think we might also want to do a RequestContentRepaint here, just to be safe.

Comment 3

[Botond Ballo [:botond]]

Attachment: bug1019999.patch

Updated to add RequestContentRepaint. Carrying r+.

Comment 4

[Botond Ballo [:botond]]

Try push: https://tbpl.mozilla.org/?tree=Try&rev=04557a4cb62e

Comment 5

[Botond Ballo [:botond]]

Attachment: bug1019999.patch

The patch had a bug where it didn't check if there actually was an animation before calling Cancel(). Updated to fix this, carrying r+.

Comment 6

[Botond Ballo [:botond]]

New Try push for this bug and bug 1014280 combined: https://tbpl.mozilla.org/?tree=Try&rev=6a8d59b67394

Comment 7

[Botond Ballo [:botond]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/fd43a33d7bae

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/fd43a33d7bae