[webkit-dev] question wrt knowing if some text or graphics will be drawn on next webkit render Thursday, June 9, 2011 10:11 AM From:

[D.J. Barrow]

Hi Simon,
We found the other problem in EWebLauncher regarding the
screen being blank while loading a new page.
When we were receiving a on_viewport,changed message
from Webkit on loading a new page this was calling
WebCore::FrameView::forceLayout on the page
so despite having no data the stupid thing
thought it had done a valid firstlayout of the page.


D.J. Barrow Linux kernel developer
email: dj_barrow at ariasoft.ie
Mobile Ireland: +353-86-1715438
www.travelsmart.ie, everyones favourite carpool website, works beautifully on the apple iphone
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--- On Thu, 6/9/11, Simon Fraser <simon.fraser at apple.com> wrote:

> From: Simon Fraser <simon.fraser at apple.com>
> Subject: Re: [webkit-dev] question wrt knowing if some text or graphics will be drawn on next webkit render Thursday, June 9, 2011 10:11 AM From:
> To: dj_barrow at ariasoft.ie
> Cc: webkit-dev at lists.webkit.org
> Date: Thursday, June 9, 2011, 2:57 PM
> On Jun 9, 2011, at 2:29 AM, D.J.
> Barrow wrote:
> 
> > Hi there,
> > I'm making enhancements to EWebLauncher & the ewk
> backend
> > on a low end mips box.
> > A colleague of mine is disappointed that the screen
> > goes blank for several seconds before displaying
> > more complex pages like bbc news.#
> > 
> > What we would like to be able to do is leave the old
> > page on the screen until there is some text or
> graphics
> > on the new page to be displayed.
> > 
> > We are not using WebKit2.
> > WebCore::FrameView::layout getting called only
> > invalidates stuff on the screen & doesn't
> gaurantee
> > that WebCore::FrameView::paintContents
> > has anything to draw other than blank the screen
> > in the next redraw session
> 
> WebKit1 on Mac has some logic for this.
> 
> WebFrameLoaderClient::provisionalLoadStarted() turns off
> drawing, and it
> gets turned back on via
> WebFrameLoaderClient::dispatchDidFirstLayout()
> and WebFrameLoaderClient::frameLoadCompleted(). This leaves
> stale
> pixels on the screen while the new page is early in the
> loading process,
> preventing a flash between pages.
> 
> Simon
> 
>