[comp.emacs] multiple X windows for emacs

john@renoir.Berkeley.EDU.UUCP (02/16/87)

I'm working on an emacs-like editor for the text processing system
we've been calling VorTeX here at Berkeley.  At this point, I have
an editor which runs under X with a built-in lisp interpreter (a real
lisp, not a mock-lisp).  It also supports multiple X windows.

In designing the window interface, I added a level to the existing
heirarchy established back in the days of terminals.  Emacs' screen
becomes one of (possbly) many frames and its windows becomes panes.
(The change in terminology was necessary, we though, since window
is such an overloaded term now).  Instead of spreading the panes
(emacs windows) over several X windows, we added a level.  Frames
(X windows) each have a minibuffer and a set of panes.  The commands
to split, resize and delete panes on a frame are analogous to those
for emacs windows.  And there are similar commands to split, delete
and resize frames (and of course X can change the frames too).

This is a simple generalization of the emacs window notion to multiple
screens.  We've run into relatively few difficulties so far with this
approach.  One serious one arises from the notion of multiple minibuffers
(there is a separate buffer, a separate minibuffer, for each frame).
The lisp I've written is still a single-threaded lisp interpreter, meaning
that while one can initiate commands from different frames simultaneously,
the commands cannot run simultaneously (thus, for one thing ^G must be
global to all frames).

I'm interested in what people think of this approach, especially
those who've used a multiple-window editor.  Feedback is always
appreciated (but please mail to me, not to the newsgroup).

The basic paradigm of emacs was well enough thought out that this extra
level was easy to implement and to allow the same style of manipulation
of frames that one has with panes (sorry about the terminology, sigh).
I'm still impressed with the structure Stallman designed.

					John Coker
					University of California, Berkeley
					Berkeley VorTeX Project
					john@renoir.Berkeley.EDU

bh01@CLUTX.BITNET.UUCP (02/16/87)

Just goes to show you that every hacker writes his own editor sooner or later,
and that everyone likes best the first editor they used.  :-)
 
I'm guilty of both of the above counts.  Repeatedly.
-russ