Bug 113269 – [BlackBerry] Scrolling up and down can cause the screen to flash black

• Component: WebKit BlackBerry
• Status: RESOLVED FIXED

[Arvid Nilsson]

Various flaws in the code can conspire to make the screen cleared to black before rendering the web page. This only happens when the BackingStore is inactive, and the LayerTiler takes on the job of drawing the root layer. When tiles are missing, this makes the "checkerboard" effect especially noticeable since you see a black color where the tile should have been. It would be better to clear to the web page background color.

PR 296106

[Arvid Nilsson]

Created attachment 194991 [details]
Patch

[Jakob Petsovits]

Comment on attachment 194991 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=194991&action=review

Looks good to me, worthwhile improvements.

> Source/WebKit/blackberry/Api/WebPage.cpp:6316
> +    if (!m_mainFrame || !m_mainFrame->view())
> +        return;

With this early return, the BackingStore won't get color updates from WebSettings until a page is loaded. I don't think this makes a difference in practice as we wouldn't draw contents in that case anyways, but I thought I'd mention it since it's a change in program logic. (Just in case you have further thoughts on it.)

[Jakob Petsovits]

(In reply to comment #2)
> (From update of attachment 194991 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=194991&action=review
> 
> Looks good to me, worthwhile improvements.
> 
> > Source/WebKit/blackberry/Api/WebPage.cpp:6316
> > +    if (!m_mainFrame || !m_mainFrame->view())
> > +        return;
> 
> With this early return, the BackingStore won't get color updates from WebSettings until a page is loaded.

Correction; "until the main frame is created". Please excuse the inaccuracy.

[Rob Buis]

Comment on attachment 194991 [details]
Patch

LGTM.

[Arvid Nilsson]

Comment on attachment 194991 [details]
Patch

Thanks Jakob and Rob!

[WebKit Review Bot]

Comment on attachment 194991 [details]
Patch

Clearing flags on attachment: 194991

Committed r146911: <http://trac.webkit.org/changeset/146911>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.