Initial revision

lisp/talk.el

+;;; talk.el --- Allow several users to talk to each other through Emacs.
+
+;; Copyright (C) 1995 Free Software Foundation, Inc.
+;; Keywords: comm, frames
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Commentary:
+
+;;; This is a multi-user talk package that runs in Emacs.
+;;; Use talk-connect to bring a new person into the conversation.
+
+;;; Code:
+
+(defvar talk-display-alist nil
+  "Alist of displays on which Emacs talk is now running.
+Each element has the form (DISPLAY FRAME BUFFER).")
+
+;;;###autoload
+(defun talk-connect (display)
+  "Connect to display DISPLAY for the Emacs talk group."
+  (interactive "sTalk to display: ")
+  ;; Make sure we have an entry for the current display.
+  (let ((mydisp (cdr (assq 'display (frame-parameters (selected-frame))))))
+    (talk-add-display mydisp))
+  ;; Make sure we have an entry for the specified display.
+  (talk-add-display display)
+  ;; Add the new buffers to all talk frames.
+  (talk-update-buffers))
+
+(defun talk-add-display (display)
+  (or (assoc display talk-display-alist)
+      (let* ((name (concat "*talk-" display "*"))
+	     (buffer (get-buffer-create name))
+	     (frame (make-frame-on-display display
+					   (list (cons 'name name)))))
+	(setq talk-display-alist
+	      (cons (list display frame buffer)
+		    talk-display-alist)))))
+
+(defun talk-disconnect ()
+  "Disconnect this display from the Emacs talk group."
+  (let* ((mydisp (cdr (assq 'display (frame-parameters (selected-frame)))))
+	 (elt (assoc mydisp talk-display-alist)))
+    (delete-frame (nth 1 elt))
+    (kill-buffer (nth 2 elt))
+    (setq talk-display-alist (delq elt talk-display-alist))
+    (talk-update-buffers)))
+
+(defun talk-update-buffers ()
+  "Update all the talk frames so that each shows all the talk buffers."
+  (let ((tail talk-display-alist))
+    (while tail
+      (let ((frame (nth 1 (car tail)))
+	    (this-buffer (nth 2 (car tail)))
+	    (buffers
+	     (mapcar (function (lambda (elt) (nth 2 elt)))
+		     talk-display-alist)))
+	;; Put this display's own talk buffer
+	;; at the front of the list.
+	(setq buffers (cons this-buffer (delq this-buffer buffers)))
+	(talk-split-up-frame frame buffers))
+      (setq tail (cdr tail)))))
+
+(defun talk-split-up-frame (frame buffers)
+  "Split FRAME into equal-sized windows displaying the buffers in BUFFERS.
+Select the first of these windows, displaying the first of the buffers."
+  (let ((lines-per-buffer (/ (frame-height frame) (length buffers)))
+	(old-frame (selected-frame)))
+    (unwind-protect
+	(progn
+	  (select-frame frame)
+	  (select-window (frame-first-window frame))
+	  (delete-other-windows)
+	  (while (progn
+		   (switch-to-buffer (car buffers))
+		   (setq buffers (cdr buffers)))
+	    (split-window-vertically lines-per-buffer)
+	    (other-window 1))
+	  (select-window (frame-first-window frame)))
+      (select-frame old-frame))))
+
+;;; talk.el ends here