[Development] QtBase WIP branch request

[Morten Sorvig]

> On 6 Oct 2016, at 16:10, Oswald Buddenhagen <Oswald.Buddenhagen at qt.io> wrote:
> 
> On Thu, Oct 06, 2016 at 09:32:40PM +0800, Tim Blechmann wrote:
>>>> We’re working on an update to the macOS/Cocoa platform plugin,
>>>> and I would like to request a WIP branch where the changes can
>>>> be finalized:
>>>> 
>>>>   wip/remac
>>>> 
>>> you have Good Reasons (TM) for creating a branch according to
>>> https://wiki.qt.io/Branch_Guidelines#Creating_a_new_feature_branch , yes?
>> 
>> i'm experiencing many of the issues that this branch will address (and
>> hacked around them in my own version of the cocoa platform plugin).
>> having a branch which is easy to access would allow me test the changes
>> in a real-world context.
>> 
> as the wiki explains, a gerrit review series is also a branch, so you
> can just check it out.
> 
> the one thing the wiki doesn't mention (but probably should): why do you
> want to branch _at all_? i can think of two valid reasons:
> - the work is experimental and may end up being discarded wholesale. in
>  this case, having it in a separate branch is cleaner than reverts on
>  the mainline.
> - the development will take a long/unpredictable time, and you don't
>  want the unfinished parts to be in mainline for the time being, as per
>  feature integration policy.
> 

Those are the reasons, yes. (we won’t discard all of it; parts may be removed
or completely rewritten). As a bonus reason sharing becomes easier ('git checkout
wip/remac’ vs ‘find the current head of patch series on gerrit’).

I would like to develop on dev as soon as possible, once the branch is regression-free
(as verified by the CI system), and we have settled on major implementation decisions.

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