lisp/x-menu.el

   1 ;;; x-menu.el --- menu support for X
   2
   3 ;; Copyright (C) 1986 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 2, 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 the
  19 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 ;; Boston, MA 02111-1307, USA.
  21
  22 ;;; Code:
  23
  24 (defun x-menu-mode ()
  25   "Major mode for creating permanent menus for use with X.
  26 These menus are implemented entirely in Lisp; popup menus, implemented
  27 with x-popup-menu, are implemented using XMenu primitives."
  28   (make-local-variable 'x-menu-items-per-line)
  29   (make-local-variable 'x-menu-item-width)
  30   (make-local-variable 'x-menu-items-alist)
  31   (make-local-variable 'x-process-mouse-hook)
  32   (make-local-variable 'x-menu-assoc-buffer)
  33   (setq buffer-read-only t)
  34   (setq truncate-lines t)
  35   (setq x-process-mouse-hook 'x-menu-pick-entry)
  36   (setq mode-line-buffer-identification '("MENU: %32b")))
  37
  38 (defvar x-menu-max-width 0)
  39 (defvar x-menu-items-per-line 0)
  40 (defvar x-menu-item-width 0)
  41 (defvar x-menu-items-alist nil)
  42 (defvar x-menu-assoc-buffer nil)
  43
  44 (defvar x-menu-item-spacing 1
  45   "*Minimum horizontal spacing between objects in a permanent X menu.")
  46
  47 (defun x-menu-create-menu (name)
  48   "Create a permanent X menu.
  49 Returns an item which should be used as a
  50 menu object whenever referring to the menu."
  51   (let ((old (current-buffer))
  52         (buf (get-buffer-create name)))
  53     (set-buffer buf)
  54     (x-menu-mode)
  55     (setq x-menu-assoc-buffer old)
  56     (set-buffer old)
  57     buf))
  58
  59 (defun x-menu-change-associated-buffer (menu buffer)
  60   "Change associated buffer of MENU to BUFFER.
  61 BUFFER should be a buffer object."
  62   (let ((old (current-buffer)))
  63     (set-buffer menu)
  64     (setq x-menu-assoc-buffer buffer)
  65     (set-buffer old)))
  66
  67 (defun x-menu-add-item (menu item binding)
  68   "Add to MENU an item with name ITEM, associated with BINDING.
  69 Following a sequence of calls to x-menu-add-item, a call to x-menu-compute
  70 should be performed before the menu will be made available to the user.
  71
  72 BINDING should be a function of one argument, which is the numerical
  73 button/key code as defined in x-menu.el."
  74   (let ((old (current-buffer))
  75         elt)
  76     (set-buffer menu)
  77     (if (setq elt (assoc item x-menu-items-alist))
  78         (rplacd elt binding)
  79       (setq x-menu-items-alist (append x-menu-items-alist
  80                                        (list (cons item binding)))))
  81     (set-buffer old)
  82     item))
  83
  84 (defun x-menu-delete-item (menu item)
  85   "Delete from MENU the item named ITEM.
  86 Call `x-menu-compute' before making the menu available to the user."
  87   (let ((old (current-buffer))
  88         elt)
  89     (set-buffer menu)
  90     (if (setq elt (assoc item x-menu-items-alist))
  91         (rplaca elt nil))
  92     (set-buffer old)
  93     item))
  94
  95 (defun x-menu-activate (menu)
  96   "Compute all necessary parameters for MENU.
  97 This must be called whenever a menu is modified before it is made
  98 available to the user.  This also creates the menu itself."
  99   (let ((buf (current-buffer)))
 100     (pop-to-buffer menu)
 101     (let (buffer-read-only)
 102       (setq x-menu-max-width (1- (frame-width)))
 103       (setq x-menu-item-width 0)
 104       (let (items-head
 105             (items-tail x-menu-items-alist))
 106         (while items-tail
 107           (if (car (car items-tail))
 108               (progn (setq items-head (cons (car items-tail) items-head))
 109                      (setq x-menu-item-width
 110                            (max x-menu-item-width
 111                                 (length (car (car items-tail)))))))
 112           (setq items-tail (cdr items-tail)))
 113         (setq x-menu-items-alist (reverse items-head)))
 114       (setq x-menu-item-width (+ x-menu-item-spacing x-menu-item-width))
 115       (setq x-menu-items-per-line
 116             (max 1 (/ x-menu-max-width x-menu-item-width)))
 117       (erase-buffer)
 118       (let ((items-head x-menu-items-alist))
 119         (while items-head
 120           (let ((items 0))
 121             (while (and items-head
 122                         (<= (setq items (1+ items)) x-menu-items-per-line))
 123               (insert (format (concat "%"
 124                                       (int-to-string x-menu-item-width) "s")
 125                               (car (car items-head))))
 126               (setq items-head (cdr items-head))))
 127           (insert ?\n)))
 128       (shrink-window (max 0
 129                           (- (window-height)
 130                              (1+ (count-lines (point-min) (point-max))))))
 131       (goto-char (point-min)))
 132     (pop-to-buffer buf)))
 133
 134 (defun x-menu-pick-entry (position event)
 135   "Internal function for dispatching on mouse/menu events"
 136   (let* ((x (min (1- x-menu-items-per-line)
 137                  (/ (current-column) x-menu-item-width)))
 138          (y (- (count-lines (point-min) (point))
 139                (if (zerop (current-column)) 0 1)))
 140          (item (+ x (* y x-menu-items-per-line)))
 141          (litem (cdr (nth item x-menu-items-alist))))
 142     (and litem (funcall litem event)))
 143   (pop-to-buffer x-menu-assoc-buffer))
 144
 145 (provide 'x-menu)
 146
 147 ;;; x-menu.el ends here