code.delx.au - gnu-emacs/blob - 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
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 ;;; Code:
  22
  23 (defun x-menu-mode ()
  24   "Major mode for creating permanent menus for use with X.
  25 These menus are implemented entirely in Lisp; popup menus, implemented
  26 with x-popup-menu, are implemented using XMenu primitives."
  27   (make-local-variable 'x-menu-items-per-line)
  28   (make-local-variable 'x-menu-item-width)
  29   (make-local-variable 'x-menu-items-alist)
  30   (make-local-variable 'x-process-mouse-hook)
  31   (make-local-variable 'x-menu-assoc-buffer)
  32   (setq buffer-read-only t)
  33   (setq truncate-lines t)
  34   (setq x-process-mouse-hook 'x-menu-pick-entry)
  35   (setq mode-line-buffer-identification '("MENU: %32b")))
  36
  37 (defvar x-menu-max-width 0)
  38 (defvar x-menu-items-per-line 0)
  39 (defvar x-menu-item-width 0)
  40 (defvar x-menu-items-alist nil)
  41 (defvar x-menu-assoc-buffer nil)
  42
  43 (defvar x-menu-item-spacing 1
  44   "*Minimum horizontal spacing between objects in a permanent X menu.")
  45
  46 (defun x-menu-create-menu (name)
  47   "Create a permanent X menu.
  48 Returns an item which should be used as a
  49 menu object whenever referring to the menu."
  50   (let ((old (current-buffer))
  51         (buf (get-buffer-create name)))
  52     (set-buffer buf)
  53     (x-menu-mode)
  54     (setq x-menu-assoc-buffer old)
  55     (set-buffer old)
  56     buf))
  57
  58 (defun x-menu-change-associated-buffer (menu buffer)
  59   "Change associated buffer of MENU to BUFFER.
  60 BUFFER should be a buffer object."
  61   (let ((old (current-buffer)))
  62     (set-buffer menu)
  63     (setq x-menu-assoc-buffer buffer)
  64     (set-buffer old)))
  65
  66 (defun x-menu-add-item (menu item binding)
  67   "Add to MENU an item with name ITEM, associated with BINDING.
  68 Following a sequence of calls to x-menu-add-item, a call to x-menu-compute
  69 should be performed before the menu will be made available to the user.
  70
  71 BINDING should be a function of one argument, which is the numerical
  72 button/key code as defined in x-menu.el."
  73   (let ((old (current-buffer))
  74         elt)
  75     (set-buffer menu)
  76     (if (setq elt (assoc item x-menu-items-alist))
  77         (rplacd elt binding)
  78       (setq x-menu-items-alist (append x-menu-items-alist
  79                                        (list (cons item binding)))))
  80     (set-buffer old)
  81     item))
  82
  83 (defun x-menu-delete-item (menu item)
  84   "Delete from MENU the item named ITEM.
  85 Call `x-menu-compute' before making the menu available to the user."
  86   (let ((old (current-buffer))
  87         elt)
  88     (set-buffer menu)
  89     (if (setq elt (assoc item x-menu-items-alist))
  90         (rplaca elt nil))
  91     (set-buffer old)
  92     item))
  93
  94 (defun x-menu-activate (menu)
  95   "Compute all necessary parameters for MENU.
  96 This must be called whenever a menu is modified before it is made
  97 available to the user.  This also creates the menu itself."
  98   (let ((buf (current-buffer)))
  99     (pop-to-buffer menu)
 100     (let (buffer-read-only)
 101       (setq x-menu-max-width (1- (frame-width)))
 102       (setq x-menu-item-width 0)
 103       (let (items-head
 104             (items-tail x-menu-items-alist))
 105         (while items-tail
 106           (if (car (car items-tail))
 107               (progn (setq items-head (cons (car items-tail) items-head))
 108                      (setq x-menu-item-width
 109                            (max x-menu-item-width
 110                                 (length (car (car items-tail)))))))
 111           (setq items-tail (cdr items-tail)))
 112         (setq x-menu-items-alist (reverse items-head)))
 113       (setq x-menu-item-width (+ x-menu-item-spacing x-menu-item-width))
 114       (setq x-menu-items-per-line
 115             (max 1 (/ x-menu-max-width x-menu-item-width)))
 116       (erase-buffer)
 117       (let ((items-head x-menu-items-alist))
 118         (while items-head
 119           (let ((items 0))
 120             (while (and items-head
 121                         (<= (setq items (1+ items)) x-menu-items-per-line))
 122               (insert (format (concat "%"
 123                                       (int-to-string x-menu-item-width) "s")
 124                               (car (car items-head))))
 125               (setq items-head (cdr items-head))))
 126           (insert ?\n)))
 127       (shrink-window (max 0
 128                           (- (window-height)
 129                              (1+ (count-lines (point-min) (point-max))))))
 130       (goto-char (point-min)))
 131     (pop-to-buffer buf)))
 132
 133 (defun x-menu-pick-entry (position event)
 134   "Internal function for dispatching on mouse/menu events"
 135   (let* ((x (min (1- x-menu-items-per-line)
 136                  (/ (current-column) x-menu-item-width)))
 137          (y (- (count-lines (point-min) (point))
 138                (if (zerop (current-column)) 0 1)))
 139          (item (+ x (* y x-menu-items-per-line)))
 140          (litem (cdr (nth item x-menu-items-alist))))
 141     (and litem (funcall litem event)))
 142   (pop-to-buffer x-menu-assoc-buffer))
 143
 144 ;;; x-menu.el ends here