bug#24579: [PATCH] borderless windows on OS X

[Jay McCarthy]

On Sat, Oct 1, 2016 at 4:44 AM, martin rudalics <rudalics@gmx.at> wrote:
>> There are two popular Emacs patches for OS X that make all its windows
>> have no title bar:
>>
>> https://github.com/nikhilunni/BorderlessEmacs
>>
>> https://github.com/gwydirsam/emacs-mac-borderless
>>
>> This patch integrates these by providing a variable
>> (ns-use-titled-windows) that allows this decision to be controlled at
>> runtime. The default is to use titles, like normal.
>
> Thank you.  I have a couple of questions:
>
> (1) Is there a way to mix behaviors in one and the same session - that
> is have at the same time a window with a title bar and one without?
> It's possible under X and Windows as can be seen with tooltip frames.

Yes, because as implemented the variable only affects new frames, so
you can switch it on and off as you create frames to get both styles.
Thus, it could be a frame parameter as well. I didn't do it this way
because I personally want it to be a global setting and because I
didn't see the existing window creation code looking at the frame
parameter alist and I didn't look around the file much to get a bigger
picture of how it works.

> (2) Is there an option to draw borders and, if so, borders of different
> width on a borderless frame?  Latter are available via X but not on
> Windows.

Yes, I believe that the

setContentBorderThickness:forEdge:

function on the win object would let you do that, but I haven't test
that. I know that iTerm2's title-less option gives the ability to add
a border, but I worry it is implement with a custom renderer.

https://developer.apple.com/reference/appkit/nswindow/1419541-setcontentborderthickness?language=objc

> (3) IIUC setting your option does not toggle titles/borders on existing
> frames.  Would it be possible to do so?  We could do that on Windows but
> it seems impossible with GNU/Linux window managers.

It is possible to do that with [win setStyleMask:
NSBorderlessWindowMask], so it would be conceivable to add some
functions that would flip that setting on real frames. Although, I
don't see a way to go from an Emacs frame structure to the window
object. So, this seems like it would be a big patch (because you'd
want to do it in as cross-platform a way as possible) and different
than this one, so I hope the current patch is judged independently.

> Thanks again, martin

FWIW, I am not an OS X developer, so I don't know all the ins-and-outs of this.

My preference would be for this patch to go in if someone isn't going
to immediately do the frame parameter thing, because I don't have the
bandwidth to do it, I don't think.

Jay

-- 
Jay McCarthy
Associate Professor
PLT @ CS @ UMass Lowell
http://jeapostrophe.github.io

           "Wherefore, be not weary in well-doing,
      for ye are laying the foundation of a great work.
And out of small things proceedeth that which is great."
                          - D&C 64:33