[Development] QtBase WIP branch request

[Morten Sorvig]

> On 12 Oct 2016, at 22:57, James Turner <james.turner at kdab.com> wrote:
> 
> 
>> On 7 Oct 2016, at 02:32, Morten Sorvig <Morten.Sorvig at qt.io> wrote:
>> 
>> 
>> What is actually in development? The scope is outlined in QTBUG-49827 and includes
>> - Improving expose event handling
>> - Improving support for Core Animation layer-backed QWindows
>> - Improving support for embedding QWindow in NSView hierarchies
>> - Driving QWindow::requestUpdate() animations via CVDisplayLink
> 
> Morten, I was doing some work, and have some patches (not yet available) in this area, to do with embedding NSView hierarchies inside QWidgets. The approximate changes are in the Cocoa QPA, to ensure that child QWindows are inserted into the NSView heirarchy as subviews correctly, and re-ordered in the subviews list (by removing and re-adding, as the AppKit docs suggest).
> 
> One of the bugs hopefully fixed by this is:
> 
> 	https://bugreports.qt.io/browse/QTBUG-7140
> 
> I can provide the patches via email, but I wonder if they will be subsumed by this work you’re about to start.

Hi, I don’t think I’ve made this change. Perhaps you can post the patch(es) on
codereview? We could then either merge them or move them into the WIP branch.

What I’ve seen is that compositing using layer-backed views is required to get
proper stacking of QWindows with OpenGL content. But that presumably requires
correctly ordered views first.

Morten