1013474 - Unable to drag scrollbars after scrolling

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Markus Stange [:mstange]]

This is with the patches in bug 944938 applied and enabled.

As soon as I scroll a page, I can no longer make the scrollbars on that page to react to mouse events.

Comment 1

[Markus Stange [:mstange]]

This bug and bug 1013484 go away if I disable the special casing of root subdocuments and make them use regular subframe APZ scrolling. This probably leads to the scrollbars being placed outside the APZ ContainerLayer.

Comment 2

[Markus Stange [:mstange]]

This bug is probably caused by this line: http://hg.mozilla.org/mozilla-central/annotate/9dc0ffca10f4/layout/generic/nsGfxScrollFrame.cpp#l2441

Comment 5

[Timothy Nikkel (:tnikkel)]

(In reply to Markus Stange [:mstange] from comment #2)
> This bug is probably caused by this line:
> http://hg.mozilla.org/mozilla-central/annotate/9dc0ffca10f4/layout/generic/
> nsGfxScrollFrame.cpp#l2441

nsLayoutUtils::GetFramesForArea doesn't set the ignore scroll frame on the display list builder, so we won't hit that code for the root scroll frame, but nsSubDocumentFrame::BuildDisplayList sets ignore scroll frames. Perhaps we should not do the ignore scroll frame thing there for the event delivery case.

Comment 7

[David Anderson [:dvander] - inactive, e-mail if emergency]

Even with containerless scrolling, I still get this on http://www.engadget.com/. It doesn't seem to happen on other sites.

Comment 8

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

I don't see this on planet.mozilla.org or engadget.com on OS X or Windows. David, re comment 7 - were you seeing this on windows? Can you still repro? Markus, can you still repro anywhere?

Comment 9

[Markus Stange [:mstange]]

This was only a problem with containerful scrolling. Since we only support containerless scrolling for Desktop APZ, we can close this.

Comment 10

[Markus Stange [:mstange]]

Oh, sorry, I hadn't seen comment 7.