[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:

[Simon Fraser]

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