513922 - AutoErase() should invalidate the erased region on WinCE

Status: RESOLVED FIXED

(Core :: Widget: Win32, defect)

Description

[Brian Crowder]

Attachment: AutoErase calls Invalidate on WinCE

This fixes a bug introduced, I think, by bug 510979.

Would ask blassey for review, but the idea is essentially his.

Comment 1

[Brian Crowder]

The symptom of this is that opening the keyboard (which causes the screen to be re-oriented) wasn't redrawing the screen.

Comment 2

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

This will cause the entire window to be repainted anytime any part of it is uncovered. Is that OK?

Do our own Invalidate calls trigger a call to WM_ERASEBKGND? If so, this would be really bad...

Comment 3

[Brad Lassey [:blassey] (use needinfo?)]

(In reply to comment #2)
> This will cause the entire window to be repainted anytime any part of it is
> uncovered. Is that OK?
Perhaps we should use GetClipRgn and only invalidate those rects. 

> Do our own Invalidate calls trigger a call to WM_ERASEBKGND? If so, this would
> be really bad...

No, I don't see that.

Comment 4

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

(In reply to comment #3)
> (In reply to comment #2)
> > This will cause the entire window to be repainted anytime any part of it is
> > uncovered. Is that OK?
> Perhaps we should use GetClipRgn and only invalidate those rects. 

That sounds like a good idea, although you should verify that GetClipRgn can return a region less than the whole window when part of the window is uncovered.

> > Do our own Invalidate calls trigger a call to WM_ERASEBKGND? If so, this would
> > be really bad...
> 
> No, I don't see that.

Great.

Comment 5

[Brian Crowder]

Attachment: new version

blassey suggests that this patch has the issue of invalidating the whole region, rather than its sub-rects (ie., we should be using GetClipRgn, and then adding the clip regions individual sub-rects), but this seems adequate and minimal for now.

Am I allowed to change the signature of AutoErase?   Why is this function virtual?  I can't find any usage of it in mxr other than the reference in nsWindow.cpp for the erase-background message handler.

Comment 6

[Brian Crowder]

Comment on attachment 398245 [details] [diff] [review]
new version

More to your liking, roc?

Comment 7

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

Comment on attachment 398245 [details] [diff] [review]
new version

This looks like a good solution! congrats :-)

Comment 8

[Brad Lassey [:blassey] (use needinfo?)]

pushed http://hg.mozilla.org/mozilla-central/rev/985139e9ecea 

and followed up with a build bustage fix http://hg.mozilla.org/mozilla-central/rev/70e87cce109f

Comment 9

[Brian Crowder]

http://hg.mozilla.org/releases/mozilla-1.9.2/rev/dbd6f214769b