lisp/frame.el

   1 ;;; screen.el --- multi-screen management independent of window systems.
   2
   3 ;;;; Copyright (C) 1990, 1992 Free Software Foundation, Inc.
   4
   5 ;;; This file is part of GNU Emacs.
   6 ;;;
   7 ;;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;;; it under the terms of the GNU General Public License as published by
   9 ;;; the Free Software Foundation; either version 1, or (at your option)
  10 ;;; any later version.
  11 ;;;
  12 ;;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;;; GNU General Public License for more details.
  16 ;;;
  17 ;;; You should have received a copy of the GNU General Public License
  18 ;;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 (defvar screen-creation-function nil
  22   "Window-system dependent function to call to create a new screen.
  23 The window system startup file should set this to its screen creation
  24 function, which should take an alist of parameters as its argument.")
  25
  26 ;;; The default value for this must ask for a minibuffer.  There must
  27 ;;; always exist a screen with a minibuffer, and after we delete the
  28 ;;; terminal screen, this will be the only screen.
  29 (defvar initial-screen-alist '((minibuffer . nil))
  30   "Alist of values used when creating the initial emacs text screen.
  31 These may be set in your init file, like this:
  32  (setq initial-screen-alist '((top . 1) (left . 1) (width . 80) (height . 55)))
  33 These supercede the values given in screen-default-alist.")
  34
  35 (defvar minibuffer-screen-alist nil
  36   "Alist of values to apply to a minibuffer screen.
  37 These may be set in your init file, like this:
  38  (setq minibuffer-screen-alist
  39    '((top . 1) (left . 1) (width . 80) (height . 1)))
  40 These supercede the values given in default-screen-alist.")
  41
  42 (defvar pop-up-screen-alist nil
  43   "Alist of values used when creating pop-up screens.
  44 Pop-up screens are used for completions, help, and the like.
  45 This variable can be set in your init file, like this:
  46   (setq pop-up-screen-alist '((width . 80) (height . 20)))
  47 These supercede the values given in default-screen-alist.")
  48
  49 (setq pop-up-screen-function
  50       (function (lambda ()
  51                   (new-screen pop-up-screen-alist))))
  52
  53 \f
  54 ;;;; Arrangement of screens at startup
  55
  56 ;;; 1) Load the window system startup file from the lisp library and read the
  57 ;;; high-priority arguments (-q and the like).  The window system startup
  58 ;;; file should create any screens specified in the window system defaults.
  59 ;;;
  60 ;;; 2) If no screens have been opened, we open an initial text screen.
  61 ;;;
  62 ;;; 3) Once the init file is done, we apply any newly set parameters
  63 ;;; in initial-screen-alist to the screen.
  64
  65 (add-hook 'pre-init-hook 'screen-initialize)
  66 (add-hook 'window-setup-hook 'screen-notice-user-settings)
  67
  68 ;;; If we create the initial screen, this is it.
  69 (defvar screen-initial-screen nil)
  70
  71 ;;; startup.el calls this function before loading the user's init
  72 ;;; file - if there is no screen with a minibuffer open now, create
  73 ;;; one to display messages while loading the init file.
  74 (defun screen-initialize ()
  75
  76   ;; Are we actually running under a window system at all?
  77   (if (and window-system (not noninteractive))
  78       (let ((screens (screen-list)))
  79
  80         ;; Look for a screen that has a minibuffer.
  81         (while (and screens
  82                     (or (eq (car screens) terminal-screen)
  83                         (not (cdr (assq 'minibuffer
  84                                         (screen-parameters
  85                                          (car screens)))))))
  86           (setq screens (cdr screens)))
  87
  88         ;; If there was none, then we need to create the opening screen.
  89         (or screens
  90             (setq default-minibuffer-screen
  91                   (setq screen-initial-screen
  92                         (new-screen initial-screen-alist))))
  93
  94         ;; At this point, we know that we have a screen open, so we
  95         ;; can delete the terminal screen.
  96         (delete-screen terminal-screen)
  97         (setq terminal-screen nil))
  98
  99     ;; No, we're not running a window system.  Arrange to cause errors.
 100     (setq screen-creation-function
 101           (function
 102            (lambda (parameters)
 103              (error
 104               "Can't create multiple screens without a window system."))))))
 105
 106 ;;; startup.el calls this function after loading the user's init file.
 107 ;;; If we created a minibuffer before knowing if we had permission, we
 108 ;;; need to see if it should go away or change.  Create a text screen
 109 ;;; here.
 110 (defun screen-notice-user-settings ()
 111   (if screen-initial-screen
 112       (progn
 113
 114         ;; If the user wants a minibuffer-only screen, we'll have to
 115         ;; make a new one; you can't remove or add a root window to/from
 116         ;; an existing screen.
 117         (if (eq (cdr (or (assq 'minibuffer initial-screen-alist)
 118                          '(minibuffer . t)))
 119                      'only)
 120             (progn
 121               (setq default-minibuffer-screen
 122                     (new-screen
 123                      (append initial-screen-alist
 124                              (screen-parameters screen-initial-screen))))
 125               (delete-screen screen-initial-screen))
 126           (modify-screen-parameters screen-initial-screen
 127                                     initial-screen-alist))))
 128
 129   ;; Make sure the initial screen can be GC'd if it is ever deleted.
 130   (makunbound 'screen-initial-screen))
 131
 132 \f
 133 ;;;; Creation of additional screens
 134
 135 ;;; Return some screen other than the current screen,
 136 ;;; creating one if neccessary.  Note that the minibuffer screen, if
 137 ;;; separate, is not considered (see next-screen).
 138 (defun get-screen ()
 139   (let ((s (if (equal (next-screen (selected-screen)) (selected-screen))
 140                (new-screen)
 141              (next-screen (selected-screen)))))
 142     s))
 143
 144 (defun next-multiscreen-window ()
 145   "Select the next window, regardless of which screen it is on."
 146   (interactive)
 147   (select-window (next-window (selected-window)
 148                               (> (minibuffer-depth) 0)
 149                               t)))
 150
 151 (defun previous-multiscreen-window ()
 152   "Select the previous window, regardless of which screen it is on."
 153   (interactive)
 154   (select-window (previous-window (selected-window)
 155                                   (> (minibuffer-depth) 0)
 156                                   t)))
 157
 158 (defun new-screen (&optional parameters)
 159   "Create a new screen, displaying the current buffer.
 160
 161 Optional argument PARAMETERS is an alist of parameters for the new
 162 screen.  Specifically, PARAMETERS is a list of pairs, each having one
 163 of the following forms:
 164
 165 (name . STRING) - The screen should be named STRING.
 166
 167 (height . NUMBER) - The screen should be NUMBER text lines high.  If
 168         this parameter is present, the width parameter must also be
 169         given.
 170
 171 (width . NUMBER) - The screen should be NUMBER characters in width.
 172         If this parameter is present, the height parameter must also
 173         be given.
 174
 175 (minibuffer . t) - the screen should have a minibuffer
 176 (minibuffer . none) - the screen should have no minibuffer
 177 (minibuffer . only) - the screen should contain only a minibuffer
 178 (minibuffer . WINDOW) - the screen should use WINDOW as its minibuffer window.
 179
 180 (NAME . VALUE), specifying the parameter and the value it should have.
 181 NAME should be one of the following symbols:
 182   name          VALUE
 183
 184 The documentation for the function x-create-screen describes
 185 additional screen parameters that Emacs will recognize when running
 186 under the X Window System."
 187   (interactive)
 188   (funcall screen-creation-function parameters))
 189
 190 \f
 191 ;;;; Iconification
 192
 193 ;;; A possible enhancement for the below: if you iconify a surrogate
 194 ;;; minibuffer screen, iconify all of its minibuffer's users too;
 195 ;;; de-iconify them as a group.  This will need to wait until screens
 196 ;;; have mapping and unmapping hooks.
 197
 198 (defun iconify ()
 199   "Iconify or deiconify the selected screen."
 200   (interactive)
 201   (let ((screen (selected-screen)))
 202     (if (eq (screen-visible-p screen) t)
 203         (iconify-screen screen)
 204       (deiconify-screen screen))))
 205
 206 \f
 207 ;;;; Convenience functions for dynamically changing screen parameters
 208
 209 (defun set-screen-height (h)
 210   (interactive "NHeight: ")
 211   (let* ((screen (selected-screen))
 212          (width (cdr (assoc 'width (screen-parameters (selected-screen))))))
 213     (set-screen-size (selected-screen) width h)))
 214
 215 (defun set-screen-width (w)
 216   (interactive "NWidth: ")
 217   (let* ((screen (selected-screen))
 218          (height (cdr (assoc 'height (screen-parameters (selected-screen))))))
 219     (set-screen-size (selected-screen) w height)))
 220
 221 (defun set-default-font (font-name)
 222   (interactive "sFont name: ")
 223   (modify-screen-parameters (selected-screen)
 224                             (list (cons 'font font-name))))
 225
 226 (defun set-screen-background (color-name)
 227   (interactive "sColor: ")
 228   (modify-screen-parameters (selected-screen)
 229                             (list (cons 'background-color color-name))))
 230
 231 (defun set-screen-foreground (color-name)
 232   (interactive "sColor: ")
 233   (modify-screen-parameters (selected-screen)
 234                             (list (cons 'foreground-color color-name))))
 235
 236 (defun set-cursor-color (color-name)
 237   (interactive "sColor: ")
 238   (modify-screen-parameters (selected-screen)
 239                             (list (cons 'cursor-color color-name))))
 240
 241 (defun set-pointer-color (color-name)
 242   (interactive "sColor: ")
 243   (modify-screen-parameters (selected-screen)
 244                             (list (cons 'mouse-color color-name))))
 245
 246 (defun set-auto-raise (toggle)
 247   (interactive "xt or nil? ")
 248   (modify-screen-parameters (selected-screen)
 249                             (list (cons 'auto-raise toggle))))
 250
 251 (defun set-auto-lower (toggle)
 252   (interactive "xt or nil? ")
 253   (modify-screen-parameters (selected-screen)
 254                             (list (cons 'auto-lower toggle))))
 255
 256 (defun set-vertical-bar (toggle)
 257   (interactive "xt or nil? ")
 258   (modify-screen-parameters (selected-screen)
 259                             (list (cons 'vertical-scroll-bar toggle))))
 260
 261 (defun set-horizontal-bar (toggle)
 262   (interactive "xt or nil? ")
 263   (modify-screen-parameters (selected-screen)
 264                             (list (cons 'horizontal-scroll-bar toggle))))
 265 \f
 266 ;;;; Key bindings
 267 (define-prefix-command 'ctl-x-3-map)
 268 (define-key ctl-x-map "3" 'ctl-x-3-map)
 269
 270 (define-key ctl-x-3-map "2" 'new-screen)
 271 (define-key ctl-x-3-map "0" 'delete-screen)
 272
 273 (provide 'screen)
 274
 275 ;;; screen.el ends here