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