bug#28872: 26.0.90; non-native-fullscreen does not play well with ns-transparent-titlebar on macOS

[Alan Third <alan@idiocy.org>]

On Wed, Oct 18, 2017 at 08:08:25PM -0500, Aaron Jensen wrote:
> On October 17, 2017 at 7:26:01 AM, Alan Third
> (alan@idiocy.org(mailto:alan@idiocy.org)) wrote:
> 
> > The issue seems to be that when switching back to the non‐fullscreen
> > NSWindow the toolbar height calculation fails and produces a negative
> > value.
> >
> > We used to use a hard‐coded value for this, but the calculation works
> > better in every circumstance except, apparently, this one.
> 
> Would it be possible to use a hard-coded 0 for the case when there is
> no toolbar at least? Or do you have a proper fix in mind?

No, I was pretty much just thinking of returning a hard‐coded value
when it’s negative.

The toolbar size calculation takes the size of the actual contentView,
which should be the space below the toolbar, and subtracts that from
the size of a calculated contentView that doesn’t have a toolbar.

This is how apple recommend you calculate the size of the toolbar.

Non‐native fullscreen uses another NSWindow (like we were discussing
for undecorated frames), so when it switches back out of fullscreen it
changes back to the original NSWindow.

At this point, the calculated contentView is correctly sized, but the
actual contentView seems to take up the ENTIRE NSWindow, including the
titlebar.

I imagine we need to somehow force the NSWindow to recalculate its
sizes, but I’ve no idea how.
-- 
Alan Third