Re: Running with both PGTK and an X toolkit?

[Po Lu <luangruo@yahoo.com>]

Spencer Baugh <sbaugh@catern.com> writes:

> I'd like to configure an Emacs with both PGTK (for Wayland and Broadway)
> and an X toolkit (for X - probably Lucid).  The reason is that I'd like
> to simultaneously have X frames open and Wayland/Broadway frames open.
>
> (More specifically, I think it would be cool to be able to use Broadway
> to connect to my Emacs remotely through a web browser, but I use X for
> my normal Emacs setup.)
>
> Is it possible to have both PGTK and an X toolkit configured into Emacs?
> I'm willing to do development work to make this work, if it's not
> categorically impossible.
>
> And if that is possible, is it possible to have two frames using two
> different windowing systems at the same time?  (I feel like I've heard
> about people doing that before, at least for other combinations)

It is going to be very difficult to use those two window systems at the
time, but not impossible, unlike running the NS port along with other
window systems in the same process, where the very different event
handling systems make it impossible to design a `select' that works
reliably with both.

The problem here is that most of our code assumes that only one window
system has been built into Emacs: FRAME_WINDOW_P, the Fx_* functions in
each TERMfns.c file, ifdefs in xdisp.c and menu.c,
Fmenu_or_popup_active_p, et cetera.

So you will have to make all of those (the list I gave is nowhere near
exhaustive) aware of more than one window system; this probably means
moving the Fx_* functions out of each terminal's fns.[cm] file and
making them dispatch to the right function based on the frame's window
system, and tediously examining every other window system test to
determine what to do.

We also have a big Display_Info typedef that is always the current
window system's Display_Info structure.  Either each window system's
Display_Info structure will have to be made the same, or x*.c must stop
directly accessing display information.