374762 - page is blanked for an instant by resizing the view

Status: RESOLVED WORKSFORME

(Core :: Web Painting, defect)

Description

[Hideo Saito]

After the page was loaded using reload button or back button, if the scroll bar is moved to the bottom and the window is resized vertically or moved to the right edge and the window is resized horizontally, the page is blanked first for an instant.

This problem is caused by calling |::UpdateWindow(mWnd)| at nsWindow::Scroll(), although mRefreshEnabled is not true on viewmanagers. I think that the following patch can fix this problem.

If already fixed, I am sorry this report is spam.

diff -p8 -Naur view/src/nsScrollPortView.cpp.org view/src/nsScrollPortView.cpp
--- view/src/nsScrollPortView.cpp.org	Sat Feb 17 22:10:48 2007
+++ view/src/nsScrollPortView.cpp	Wed Mar 21 21:08:39 2007
@@ -579,18 +579,20 @@ void nsScrollPortView::Scroll(nsView *aS
       AdjustChildWidgets(aScrolledView,
                          GetPosition() - topLeft, aP2A, PR_FALSE);
       // We should call this after fixing up the widget positions to be
       // consistent with the view hierarchy.
       mViewManager->UpdateView(this, 0);
     } else { // if we can blit and have a scrollwidget then scroll.
       // Scroll the contents of the widget by the specified amount, and scroll
       // the child widgets
-      scrollWidget->Scroll(aPixDelta.x, aPixDelta.y, nsnull);
-      mViewManager->UpdateViewAfterScroll(this, updateRegion);
+      if (mViewManager->IsRefreshEnabled()) {
+        scrollWidget->Scroll(aPixDelta.x, aPixDelta.y, nsnull);
+        mViewManager->UpdateViewAfterScroll(this, updateRegion);
+      }
     }
   }
 }
 
 NS_IMETHODIMP nsScrollPortView::ScrollToImpl(nscoord aX, nscoord aY, PRUint32 aUpdateFlags)
 {
   PRInt32           dxPx = 0, dyPx = 0;

Comment 1

[Hideo Saito]

I can also see this problem on own build of trunc-20070324/ppclinux.

Comment 2

[Hideo Saito]

Attachment: patch

Comment 3

[Hideo Saito]

Comment on attachment 261091 [details] [diff] [review]
patch

roc, could you review this patch?

While resize reflow, mViewManager->BeginUpdateViewBatch() is called from PresShell::ResizeReflow(), mRefreshEnabled is then false, meanwhile, I think that the refreshment should be restrained.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

We can't not scroll just because mRefreshEnabled is false. We have to scroll the widget at some point. The basic problem here is that scrolling is synchronous and breaks suppression; fixing that requires compositor. I don't think we can fix it for 1.9.

Comment 5

[Eli Friedman]

Hmm, I can't reproduce, but would it be sufficient to just set canBitBlt to false when refresh is disabled?  I think that would have the right effect, although it would be a perf hit if we're in this situation frequently.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

That is a very good idea.

Comment 7

[Lucas Malor (mail: c6kfnkn2uc AT snkmail DOT c0m)]

I can't reproduce. Can you test it with the latest trunk?

Anyway, is this bug related to Bug 422659?

Comment 8

[Hideo Saito]

(In reply to comment #7)
> I can't reproduce. Can you test it with the latest trunk?
> 
> Anyway, is this bug related to Bug 422659?
> 

I can see it yet. I think that Bug 422659 is other bug because this bug is in the scrolling issues.

Comment 9

[Lucas Malor (mail: c6kfnkn2uc AT snkmail DOT c0m)]

Can you post a link where you can see that bug and your build identifier?

Comment 10

[Hideo Saito]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9pre) Gecko/2008061418 Minefield/3.0pre

For reproducing, in the any page which has vertical scrollbar,
1. put down the var on the bottom of the window,
2. reload the page and 
3. spread the window downward.

Comment 11

[Lucas Malor (mail: c6kfnkn2uc AT snkmail DOT c0m)]

Attachment: Minimal testcase

I found why I can't reproduce the bug in past. This bug happens when you have not disabled the option to see the content of the page when resized (In Windows: My Computer -> properties -> Advanced -> Performance settings -> show window content when you move it) (or something similar...)

Anyway what I notice is only a little flickering, the page was not blanked. So I don't confirm the bug for now, I wait for a third confirmation.

Comment 12

[Gregory Pappas [:gregp]]

Unable to reproduce.