lisp/x-menu.el

   1 ;;; x-menu.el --- menu support for X
   2
   3 ;; Maintainer: FSF
   4 ;; Last-Modified: 15 Sep 1987
   5
   6 ;; Copyright (C) 1986 Free Software Foundation, Inc.
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 1, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Code:
  25
  26 (defmacro caar (conscell)
  27   (list 'car (list 'car conscell)))
  28
  29 (defmacro cdar (conscell)
  30   (list 'cdr (list 'car conscell)))
  31
  32 (defun x-menu-mode ()
  33   "Major mode for creating permanent menus for use with X.
  34 These menus are implemented entirely in Lisp; popup menus, implemented
  35 with x-popup-menu, are implemented using XMenu primitives."
  36   (make-local-variable 'x-menu-items-per-line)
  37   (make-local-variable 'x-menu-item-width)
  38   (make-local-variable 'x-menu-items-alist)
  39   (make-local-variable 'x-process-mouse-hook)
  40   (make-local-variable 'x-menu-assoc-buffer)
  41   (setq buffer-read-only t)
  42   (setq truncate-lines t)
  43   (setq x-process-mouse-hook 'x-menu-pick-entry)
  44   (setq mode-line-buffer-identification '("MENU: %32b")))
  45
  46 (defvar x-menu-max-width 0)
  47 (defvar x-menu-items-per-line 0)
  48 (defvar x-menu-item-width 0)
  49 (defvar x-menu-items-alist nil)
  50 (defvar x-menu-assoc-buffer nil)
  51
  52 (defvar x-menu-item-spacing 1
  53   "*Minimum horizontal spacing between objects in a permanent X menu.")
  54
  55 (defun x-menu-create-menu (name)
  56   "Create a permanent X menu.  Returns an item which should be used as a
  57 menu object whenever referring to the menu."
  58   (let ((old (current-buffer))
  59         (buf (get-buffer-create name)))
  60     (set-buffer buf)
  61     (x-menu-mode)
  62     (setq x-menu-assoc-buffer old)
  63     (set-buffer old)
  64     buf))
  65
  66 (defun x-menu-change-associated-buffer (menu buffer)
  67   "Change associated buffer of MENU to BUFFER.  BUFFER should be a buffer
  68 object."
  69   (let ((old (current-buffer)))
  70     (set-buffer menu)
  71     (setq x-menu-assoc-buffer buffer)
  72     (set-buffer old)))
  73
  74 (defun x-menu-add-item (menu item binding)
  75   "Adds to MENU an item with name ITEM, associated with BINDING.
  76 Following a sequence of calls to x-menu-add-item, a call to x-menu-compute
  77 should be performed before the menu will be made available to the user.
  78
  79 BINDING should be a function of one argument, which is the numerical
  80 button/key code as defined in x-menu.el."
  81   (let ((old (current-buffer))
  82         elt)
  83     (set-buffer menu)
  84     (if (setq elt (assoc item x-menu-items-alist))
  85         (rplacd elt binding)
  86       (setq x-menu-items-alist (append x-menu-items-alist
  87                                        (list (cons item binding)))))
  88     (set-buffer old)
  89     item))
  90
  91 (defun x-menu-delete-item (menu item)
  92   "Deletes from MENU the item named ITEM.  x-menu-compute should be called
  93 before the menu is made available to the user."
  94   (let ((old (current-buffer))
  95         elt)
  96     (set-buffer menu)
  97     (if (setq elt (assoc item x-menu-items-alist))
  98         (rplaca elt nil))
  99     (set-buffer old)
 100     item))
 101
 102 (defun x-menu-activate (menu)
 103   "Computes all necessary parameters for MENU.  This must be called whenever
 104 a menu is modified before it is made available to the user.
 105
 106 This also creates the menu itself."
 107   (let ((buf (current-buffer)))
 108     (pop-to-buffer menu)
 109     (let (buffer-read-only)
 110       (setq x-menu-max-width (1- (screen-width)))
 111       (setq x-menu-item-width 0)
 112       (let (items-head
 113             (items-tail x-menu-items-alist))
 114         (while items-tail
 115           (if (caar items-tail)
 116               (progn (setq items-head (cons (car items-tail) items-head))
 117                      (setq x-menu-item-width
 118                            (max x-menu-item-width
 119                                 (length (caar items-tail))))))
 120           (setq items-tail (cdr items-tail)))
 121         (setq x-menu-items-alist (reverse items-head)))
 122       (setq x-menu-item-width (+ x-menu-item-spacing x-menu-item-width))
 123       (setq x-menu-items-per-line
 124             (max 1 (/ x-menu-max-width x-menu-item-width)))
 125       (erase-buffer)
 126       (let ((items-head x-menu-items-alist))
 127         (while items-head
 128           (let ((items 0))
 129             (while (and items-head
 130                         (<= (setq items (1+ items)) x-menu-items-per-line))
 131               (insert (format (concat "%"
 132                                       (int-to-string x-menu-item-width) "s")
 133                               (caar items-head)))
 134               (setq items-head (cdr items-head))))
 135           (insert ?\n)))
 136       (shrink-window (max 0
 137                           (- (window-height)
 138                              (1+ (count-lines (point-min) (point-max))))))
 139       (goto-char (point-min)))
 140     (pop-to-buffer buf)))
 141
 142 (defun x-menu-pick-entry (position event)
 143   "Internal function for dispatching on mouse/menu events"
 144   (let* ((x (min (1- x-menu-items-per-line)
 145                  (/ (current-column) x-menu-item-width)))
 146          (y (- (count-lines (point-min) (point))
 147                (if (zerop (current-column)) 0 1)))
 148          (item (+ x (* y x-menu-items-per-line)))
 149          (litem (cdr (nth item x-menu-items-alist))))
 150     (and litem (funcall litem event)))
 151   (pop-to-buffer x-menu-assoc-buffer))
 152
 153 ;;; x-menu.el ends here