Re: "Final" version of tty child frames

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: rudalics@gmx.at,  jared@finder.org,  emacs-devel@gnu.org
> Date: Thu, 16 Jan 2025 11:22:44 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > If we do that, i.e. set w->cursor.x negative, which is an indication
> > that the cursor position of the window is unknown, we'd need to make
> > sure set_cursor_from_row is called when the underlying frame is
> > exposed.  So the separate-matrix alternative still sounds simpler.
> 
> >From the top of my head, I have some points though, that one would have
> to take into account when using separate matrices:
> 
> - I don't know if the copying of root's matrix is fast enough to not be
>   noticeable. I think it's well possible one won't notice anything, but if
>   it is noticeable, one would have to arrange that the "terminal
>   matrices" are only used in case we have a visible child frame. I don't
>   have a clear picture of how complicated that would be.
> 
> - Tty menus work currently by saving/restoring the current frmae matrix,
>   That would have to be adapted.

I agree, but these seem to be simpler and more straightforward to fix
than the problems of what to do in set_cursor_from_row, for which I
currently don't even see a good solution.