lisp/talk.el

   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, 2008 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 3, 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.
  35 Each 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 ;;;###autoload
  50 (defun talk ()
  51   "Connect to the Emacs talk group from the current X display or tty frame."
  52   (interactive)
  53   (let ((type (frame-live-p (selected-frame)))
  54         (display (frame-terminal (selected-frame))))
  55     (cond
  56      ((eq type t)
  57       (talk-add-display (selected-frame)))
  58      ((eq type 'x)
  59       (talk-add-display (frame-terminal (selected-frame))))
  60      (t
  61       (error "Unknown frame type"))))
  62   (talk-update-buffers))
  63
  64 (defun talk-add-display (frame)
  65   (let* ((display (if (frame-live-p frame)
  66                       (frame-terminal frame)
  67                     frame))
  68          (elt (assoc display talk-display-alist))
  69          (name (concat "*talk-" (terminal-name display) "*"))
  70          buffer)
  71     (unless (frame-live-p frame)
  72       (setq frame (make-frame-on-display display (list (cons 'name name)))))
  73     (if (and elt (frame-live-p (nth 1 elt)))
  74         (setq frame (nth 1 elt)))
  75     (if (not (and elt (buffer-name (get-buffer (setq buffer (nth 2 elt))))))
  76         (setq buffer (get-buffer-create name)))
  77     (add-to-list 'delete-frame-functions 'talk-handle-delete-frame)
  78     (setq talk-display-alist
  79           (cons (list display frame buffer) (delq elt talk-display-alist)))))
  80
  81 (defun talk-handle-delete-frame (frame)
  82   (dolist (d talk-display-alist)
  83     (when (eq (nth 1 d) frame)
  84       (setq talk-display-alist (delq d talk-display-alist))
  85       (talk-update-buffers))))
  86
  87 (defun talk-disconnect ()
  88   "Disconnect this display from the Emacs talk group."
  89   (interactive)
  90   (let* ((mydisp (cdr (assq 'display (frame-parameters (selected-frame)))))
  91          (elt (assoc mydisp talk-display-alist)))
  92     (delete-frame (nth 1 elt))
  93     (kill-buffer (nth 2 elt))
  94     (setq talk-display-alist (delq elt talk-display-alist))
  95     (talk-update-buffers)))
  96
  97 (defun talk-update-buffers ()
  98   "Update all the talk frames so that each shows all the talk buffers."
  99   (let ((tail talk-display-alist))
 100     (while tail
 101       (let ((frame (nth 1 (car tail)))
 102             (this-buffer (nth 2 (car tail)))
 103             (buffers
 104              (mapcar (function (lambda (elt) (nth 2 elt)))
 105                      talk-display-alist)))
 106         ;; Put this display's own talk buffer
 107         ;; at the front of the list.
 108         (setq buffers (cons this-buffer (delq this-buffer buffers)))
 109         (talk-split-up-frame frame buffers))
 110       (setq tail (cdr tail)))))
 111
 112 (defun talk-split-up-frame (frame buffers)
 113   "Split FRAME into equal-sized windows displaying the buffers in BUFFERS.
 114 Select the first of these windows, displaying the first of the buffers."
 115   (let ((lines-per-buffer (/ (frame-height frame) (length buffers)))
 116         (old-frame (selected-frame)))
 117     (unwind-protect
 118         (progn
 119           (select-frame frame)
 120           (select-window (frame-first-window frame))
 121           (delete-other-windows)
 122           (while (progn
 123                    (switch-to-buffer (car buffers))
 124                    (setq buffers (cdr buffers)))
 125             (split-window-vertically lines-per-buffer)
 126             (other-window 1))
 127           (select-window (frame-first-window frame)))
 128       (select-frame old-frame))))
 129
 130 (provide 'talk)
 131
 132 ;;; arch-tag: 7ab0ad88-1788-4886-a44c-ae685e6f8a1a
 133 ;;; talk.el ends here