Re: Question about child frames + menu bar

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Emacs Devel <emacs-devel@gnu.org>
> Date: Tue, 17 Sep 2024 12:47:24 +0200
> 
> martin rudalics <rudalics@gmx.at> writes:
> 
> >> Do you perhaps remember what this change was about? I read the bug that
> >> the commit message references but couldn't figure out how this bug is
> >> related. Or, maybe, is there something special about menu bars on child
> >> frames, like they may not have a menu bar, or something?
> >
> > As far as this change for the selected frame case
> >
> > -      update_menu_bar (sf, true, false);
> > +
> > +      if (!FRAME_PARENT_FRAME (sf))
> > +	update_menu_bar (sf, true, false);
> >
> > is concerned, I can only guess that when I tried to fix the bug above I
> > noticed that we did call update_menu_bar for the case that the selected
> > frame is a child frame and tried to avoid that.  The rationale was that
> > when I implemented child frames, I noticed that menu bars don't work
> > with child frames under X while they worked well on MS Windows.  Now at
> > that time there was a strict policy that we were not allowed to
> > implement features that worked on non-free systems only.  So I switched
> > off menu bars in child frames everywhere and made the change above to be
> > on the safe side.
> 
> Thanks, that explains it, I guess, although on macOS child frames seem
> to support menus, heaven knows how that works.
> 
> > If you want to implement menu bars on TTY child frames, you probably
> > will have to special case that here and maybe in other places as well.
> 
> Hm, not sure what I should do.
> 
> On one hand, I could suppress the menu bar on chlid frames in some way,
> which would hopefully be easy (haven't looked, but maybe not accepting
> menu-bar-lines changes to non-zero.
> 
> Or I could make the condition "!PARENT_FRAME || on tty" plus fix the
> menu position bug. Should also not be too difficult I guess, but a bit
> more work.
> 
> Any preferences, anyone?

Are menu bars on child frame useful? what for?

If they are not very useful (and it seems like they aren't given that
we didn't have too many complaints), then I guess leaving them
disabled on TTY child frames would be okay.