Re: src/nsterm.m: fix window tabbing on macOS

[Paul W. Rankin]

> On 7 Jun 2021, at 4:56 am, Alan Third <alan@idiocy.org> wrote:
> 
> On Sun, Jun 06, 2021 at 10:19:57PM +1000, Paul W. Rankin wrote:
> 
>> Alan did you see my video of this in action?
>> https://f002.backblazeb2.com/file/pwr-share/emacs_nsterm.mov
> 
> Yeah, I was wrong, it is there and it's very annoying. I think there's
> a mismatch between the calculation of the height of the content and
> the actual height of the content. But if it's that I have no idea why
> it disappears when the toolbar is turned off, because the calculation
> should still be wrong.

I've forgotten, what macOS version are you on? macOS 11 combines native 
toolbars in with the titlebar, so I suspect that the calculations Emacs is 
doing expect a separate titlebar and toolbar.

>> Yeah we're considering this a separate nice-to-have, right?
> 
> Yeah, the tabs work exactly as I'd expect them to in fullscreen given
> the way fullscreen works just now.
> 
> I have to say I've spent most of the afternoon on this and I'm no
> closer to a solution to the height changing thing, so I'm tempted to
> revert the commit, or put it behind a build flag or something until we
> have a better solution.

I do not think that is necessary. I'm going to go out on a limb here and 
speculate that the problem lies with the way Emacs is calculating its frame 
size, not with the OS window manager. The heart of it is, someone can open up 
Xcode and whip up a demo app with zero code that will function perfectly well 
with native tabs, it's not functionality that a program needs to implement, so 
whatever it is with Emacs that is interfering with or overriding that 
functionality has been added in between.