lisp/talk.el

   1 ;;; talk.el --- Allow several users to talk to each other through Emacs.
   2
   3 ;; Copyright (C) 1995 Free Software Foundation, Inc.
   4
   5 ;; Keywords: comm, frames
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; This is a multi-user talk package that runs in Emacs.
  27 ;; Use talk-connect to bring a new person into the conversation.
  28
  29 ;;; Code:
  30
  31 (defvar talk-display-alist nil
  32   "Alist of displays on which Emacs talk is now running.
  33 Each element has the form (DISPLAY FRAME BUFFER).")
  34
  35 ;;;###autoload
  36 (defun talk-connect (display)
  37   "Connect to display DISPLAY for the Emacs talk group."
  38   (interactive "sTalk to display: ")
  39   ;; Make sure we have an entry for the current display.
  40   (let ((mydisp (cdr (assq 'display (frame-parameters (selected-frame))))))
  41     (talk-add-display mydisp))
  42   ;; Make sure we have an entry for the specified display.
  43   (talk-add-display display)
  44   ;; Add the new buffers to all talk frames.
  45   (talk-update-buffers))
  46
  47 (defun talk-add-display (display)
  48   (let* ((elt (assoc display talk-display-alist))
  49          (name (concat "*talk-" display "*"))
  50          buffer frame)
  51     (if (not (and elt (frame-live-p (setq frame (nth 1 elt)))))
  52         (setq frame (make-frame-on-display display (list (cons 'name name)))))
  53     (if (not (and elt (buffer-name (get-buffer (setq buffer (nth 2 elt))))))
  54         (setq buffer (get-buffer-create name)))
  55     (setq talk-display-alist
  56           (cons (list display frame buffer) (delq elt talk-display-alist)))))
  57
  58 (defun talk-disconnect ()
  59   "Disconnect this display from the Emacs talk group."
  60   (interactive)
  61   (let* ((mydisp (cdr (assq 'display (frame-parameters (selected-frame)))))
  62          (elt (assoc mydisp talk-display-alist)))
  63     (delete-frame (nth 1 elt))
  64     (kill-buffer (nth 2 elt))
  65     (setq talk-display-alist (delq elt talk-display-alist))
  66     (talk-update-buffers)))
  67
  68 (defun talk-update-buffers ()
  69   "Update all the talk frames so that each shows all the talk buffers."
  70   (let ((tail talk-display-alist))
  71     (while tail
  72       (let ((frame (nth 1 (car tail)))
  73             (this-buffer (nth 2 (car tail)))
  74             (buffers
  75              (mapcar (function (lambda (elt) (nth 2 elt)))
  76                      talk-display-alist)))
  77         ;; Put this display's own talk buffer
  78         ;; at the front of the list.
  79         (setq buffers (cons this-buffer (delq this-buffer buffers)))
  80         (talk-split-up-frame frame buffers))
  81       (setq tail (cdr tail)))))
  82
  83 (defun talk-split-up-frame (frame buffers)
  84   "Split FRAME into equal-sized windows displaying the buffers in BUFFERS.
  85 Select the first of these windows, displaying the first of the buffers."
  86   (let ((lines-per-buffer (/ (frame-height frame) (length buffers)))
  87         (old-frame (selected-frame)))
  88     (unwind-protect
  89         (progn
  90           (select-frame frame)
  91           (select-window (frame-first-window frame))
  92           (delete-other-windows)
  93           (while (progn
  94                    (switch-to-buffer (car buffers))
  95                    (setq buffers (cdr buffers)))
  96             (split-window-vertically lines-per-buffer)
  97             (other-window 1))
  98           (select-window (frame-first-window frame)))
  99       (select-frame old-frame))))
 100
 101 (provide 'talk)
 102
 103 ;;; talk.el ends here