1;;; talk.el --- allow several users to talk to each other through Emacs
2
3;; Copyright (C) 1995, 2001, 2002, 2003, 2004, 2005,
4;;   2006, 2007 Free Software Foundation, Inc.
5
6;; Maintainer: FSF
7;; Keywords: comm, frames
8
9;; This file is part of GNU Emacs.
10
11;; GNU Emacs is free software; you can redistribute it and/or modify
12;; it under the terms of the GNU General Public License as published by
13;; the Free Software Foundation; either version 2, or (at your option)
14;; any later version.
15
16;; GNU Emacs is distributed in the hope that it will be useful,
17;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19;; GNU General Public License for more details.
20
21;; You should have received a copy of the GNU General Public License
22;; along with GNU Emacs; see the file COPYING.  If not, write to the
23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;; This is a multi-user talk package that runs in Emacs.
29;; Use talk-connect to bring a new person into the conversation.
30
31;;; Code:
32
33(defvar talk-display-alist nil
34  "Alist of displays on which Emacs talk is now running.
35Each element has the form (DISPLAY FRAME BUFFER).")
36
37;;;###autoload
38(defun talk-connect (display)
39  "Connect to display DISPLAY for the Emacs talk group."
40  (interactive "sTalk to display: ")
41  ;; Make sure we have an entry for the current display.
42  (let ((mydisp (cdr (assq 'display (frame-parameters (selected-frame))))))
43    (talk-add-display mydisp))
44  ;; Make sure we have an entry for the specified display.
45  (talk-add-display display)
46  ;; Add the new buffers to all talk frames.
47  (talk-update-buffers))
48
49(defun talk-add-display (display)
50  (let* ((elt (assoc display talk-display-alist))
51	 (name (concat "*talk-" display "*"))
52	 buffer frame)
53    (if (not (and elt (frame-live-p (setq frame (nth 1 elt)))))
54	(setq frame (make-frame-on-display display (list (cons 'name name)))))
55    (if (not (and elt (buffer-name (get-buffer (setq buffer (nth 2 elt))))))
56	(setq buffer (get-buffer-create name)))
57    (setq talk-display-alist
58	  (cons (list display frame buffer) (delq elt talk-display-alist)))))
59
60(defun talk-disconnect ()
61  "Disconnect this display from the Emacs talk group."
62  (interactive)
63  (let* ((mydisp (cdr (assq 'display (frame-parameters (selected-frame)))))
64	 (elt (assoc mydisp talk-display-alist)))
65    (delete-frame (nth 1 elt))
66    (kill-buffer (nth 2 elt))
67    (setq talk-display-alist (delq elt talk-display-alist))
68    (talk-update-buffers)))
69
70(defun talk-update-buffers ()
71  "Update all the talk frames so that each shows all the talk buffers."
72  (let ((tail talk-display-alist))
73    (while tail
74      (let ((frame (nth 1 (car tail)))
75	    (this-buffer (nth 2 (car tail)))
76	    (buffers
77	     (mapcar (function (lambda (elt) (nth 2 elt)))
78		     talk-display-alist)))
79	;; Put this display's own talk buffer
80	;; at the front of the list.
81	(setq buffers (cons this-buffer (delq this-buffer buffers)))
82	(talk-split-up-frame frame buffers))
83      (setq tail (cdr tail)))))
84
85(defun talk-split-up-frame (frame buffers)
86  "Split FRAME into equal-sized windows displaying the buffers in BUFFERS.
87Select the first of these windows, displaying the first of the buffers."
88  (let ((lines-per-buffer (/ (frame-height frame) (length buffers)))
89	(old-frame (selected-frame)))
90    (unwind-protect
91	(progn
92	  (select-frame frame)
93	  (select-window (frame-first-window frame))
94	  (delete-other-windows)
95	  (while (progn
96		   (switch-to-buffer (car buffers))
97		   (setq buffers (cdr buffers)))
98	    (split-window-vertically lines-per-buffer)
99	    (other-window 1))
100	  (select-window (frame-first-window frame)))
101      (select-frame old-frame))))
102
103(provide 'talk)
104
105;;; arch-tag: 7ab0ad88-1788-4886-a44c-ae685e6f8a1a
106;;; talk.el ends here
107