bug#25408: Remove Decorations Around Emacs Frame (NS port)

[Alan Third]

On Sun, Jun 11, 2017 at 10:10:44AM +0200, martin rudalics wrote:
> > no-accept-focus is done, but no-focus-on-map is harder. I believe I
> > can get a new frame to not be focused on creation, but I don’t see any
> > way to prevent a minimized frame from becoming focused when
> > unminimized.
> 
> Don't worry.  Unminimizing is different from mapping.  The former works
> on already mapped frames only, the latter on invisible frames only.
> "on-map" stands for "on making the frame visible" which might happen
> some time after the frame was created.  Once visible you cannot map the
> frame until you make it invisible again.
> 
> Alt-tabbing and unminimizing OTOH work on visible frames only, you
> cannot really unminimize an invisible window (although the window
> manager might remember the requested fullscreen status somewhere and
> later, when it makes the window visible, apply that state).
> 
> ‘no-focus-on-map’ behaves well for all platforms and builds I tried so
> far.  It would be nice to have it for NS builds too.  So all that is
> afforded by ‘no-focus-on-map’ is that, whenever a frame changes from the
> invisible to the visible state, it does not get focus.

Your explanation made it much clearer what was required. I believe
I’ve got it sorted now. I’ve attached a patch.

> >> And please have a look into the Elisp manual: Maybe you find something
> >> worth mentioning (the fact that removing decorations removes the tool
> >> bar should certainly go there).
> 
> This one still stupefies me because it's a deviation from the other
> builds.  It certainly should be documented.  Did you document that a
> fullscreen NS screen doesn't have a toolbar either?

It actually does, it’s just hidden, along with the title‐bar and
menu‐bar. At least that’s how it works on macOS, I’m unsure how
GNUStep deals with full‐screen as it’s using a different mechanism, if
it handles it at all.

I’m struggling to find where this should be documented. Any ideas
which part of the manual covers full‐screen?

> BTW, I meanwhile wrote some code to resize and move undecorated frames
> with the mouse.  For this purpose I need some mouse pointers indicating
> that a frame corner (not a frame edge) can be dragged.  Under X I use
> XC_top_left_corner, XC_top_right_corner, ...  On Windows I use the
> IDC_SIZENWSE and IDC_SIZENESW arrows.  I have not found any equivalent
> for NS.  How does NS indicate that the corner of a decorated frame can
> be dragged when the mouse is over it?

macOS uses double‐headed diagonal arrows, but they’re undocumented:

    
https://stackoverflow.com/questions/27242353/cocoa-predefined-resize-mouse-cursor

GNUStep doesn’t implement them and doesn’t seem to have any
equivalent.

On macOS we can actually make undecorated frames resizable quite
easily just by including the resizable style mask. GNUstep doesn’t
like that, of course.
-- 
Alan Third

0001-Add-no-focus-on-map-to-NS-build-bug-25408.patch
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