960859 - [e10s] Can't scroll content when text in chrome UI is focused

Status: VERIFIED FIXED

(Core :: DOM: Events, defect)

Description

[Reuben Morais [:reuben]]

STR:

1) Click on awesome bar or search bar
2) Hover content with the mouse and try to scroll it

Comment 1

[Reuben Morais [:reuben]]

Untriaged because I don't know what component to put this under.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: mouse-wheel-guess

I'm just looking for feedback here since this patch is probably wrong. Here's what I'm seeing when I try this STR.

1. We enter nsEventStateManager::PreHandleEvent for an NS_WHEEL_WHEEL event. It sets mCurrentTargetContent to the be the URL bar (assuming it was in focus).
2. (In non-e10s builds) We enter nsEventStateManager::PostHandleEvent for the same event. aTargetFrame is a frame in the actual HTML document. All the scrolling stuff is done in terms of aTargetFrame.
2. (In e10s builds) We enter nsEventStateManager::PostHandleEvent and call HandleCrossProcessEvent. It looks at mCurrentTargetContent, which is still the URL bar, and ignores the event because mCurrentTargetContent isn't a remote target.

My patch just changes HandleCrossProcessEvent so that it uses aTargetFrame instead of mCurrentTargetContent. With this change, the mouse wheel works. I didn't notice any other problems, but I didn't do much testing.

I don't really understand the purpose of mCurrentTargetContent. Maybe you guys can explain it?

Comment 3

[:Felipe Gomes (needinfo for replies!)]

Comment on attachment 8362736 [details] [diff] [review]
mouse-wheel-guess

Review of attachment 8362736 [details] [diff] [review]:
-----------------------------------------------------------------

Olli knows for sure, but this looks reasonable. I wonder if it's worth to keep the opposite logic, i.e. if aTargetFrame = null use mCurrentTargetContent

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

Could you make that code
nsIFrame* frame = GetEventTarget();
nsIContent* target = frame ? frame->GetContent() : null;
if (IsRemoteTarget(target)) {
  targets.AppendElement(target);
}

(I need to cleanup mCurrentTargetContent handling a bit. That stuff is _old_.)

Comment 5

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: scrollwheel-fix

Thanks for the help!

Comment 6

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/0fbf19e7ed9c

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/0fbf19e7ed9c

Comment 8

[Paul Silaghi, QA [:pauly]]

Reproduced in Nightly 2014-01-17, Win 7 x64.
Verified fixed FF 31 RC 2.