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 (defmacro caar (conscell)
  24   (list 'car (list 'car conscell)))
  25
  26 (defmacro cdar (conscell)
  27   (list 'cdr (list 'car conscell)))
  28
  29 (defun x-menu-mode ()
  30   "Major mode for creating permanent menus for use with X.
  31 These menus are implemented entirely in Lisp; popup menus, implemented
  32 with x-popup-menu, are implemented using XMenu primitives."
  33   (make-local-variable 'x-menu-items-per-line)
  34   (make-local-variable 'x-menu-item-width)
  35   (make-local-variable 'x-menu-items-alist)
  36   (make-local-variable 'x-process-mouse-hook)
  37   (make-local-variable 'x-menu-assoc-buffer)
  38   (setq buffer-read-only t)
  39   (setq truncate-lines t)
  40   (setq x-process-mouse-hook 'x-menu-pick-entry)
  41   (setq mode-line-buffer-identification '("MENU: %32b")))
  42
  43 (defvar x-menu-max-width 0)
  44 (defvar x-menu-items-per-line 0)
  45 (defvar x-menu-item-width 0)
  46 (defvar x-menu-items-alist nil)
  47 (defvar x-menu-assoc-buffer nil)
  48
  49 (defvar x-menu-item-spacing 1
  50   "*Minimum horizontal spacing between objects in a permanent X menu.")
  51
  52 (defun x-menu-create-menu (name)
  53   "Create a permanent X menu.  Returns an item which should be used as a
  54 menu object whenever referring to the menu."
  55   (let ((old (current-buffer))
  56         (buf (get-buffer-create name)))
  57     (set-buffer buf)
  58     (x-menu-mode)
  59     (setq x-menu-assoc-buffer old)
  60     (set-buffer old)
  61     buf))
  62
  63 (defun x-menu-change-associated-buffer (menu buffer)
  64   "Change associated buffer of MENU to BUFFER.  BUFFER should be a buffer
  65 object."
  66   (let ((old (current-buffer)))
  67     (set-buffer menu)
  68     (setq x-menu-assoc-buffer buffer)
  69     (set-buffer old)))
  70
  71 (defun x-menu-add-item (menu item binding)
  72   "Adds to MENU an item with name ITEM, associated with BINDING.
  73 Following a sequence of calls to x-menu-add-item, a call to x-menu-compute
  74 should be performed before the menu will be made available to the user.
  75
  76 BINDING should be a function of one argument, which is the numerical
  77 button/key code as defined in x-menu.el."
  78   (let ((old (current-buffer))
  79         elt)
  80     (set-buffer menu)
  81     (if (setq elt (assoc item x-menu-items-alist))
  82         (rplacd elt binding)
  83       (setq x-menu-items-alist (append x-menu-items-alist
  84                                        (list (cons item binding)))))
  85     (set-buffer old)
  86     item))
  87
  88 (defun x-menu-delete-item (menu item)
  89   "Deletes from MENU the item named ITEM.  x-menu-compute should be called
  90 before the menu is made available to the user."
  91   (let ((old (current-buffer))
  92         elt)
  93     (set-buffer menu)
  94     (if (setq elt (assoc item x-menu-items-alist))
  95         (rplaca elt nil))
  96     (set-buffer old)
  97     item))
  98
  99 (defun x-menu-activate (menu)
 100   "Computes all necessary parameters for MENU.  This must be called whenever
 101 a menu is modified before it is made available to the user.
 102
 103 This also creates the menu itself."
 104   (let ((buf (current-buffer)))
 105     (pop-to-buffer menu)
 106     (let (buffer-read-only)
 107       (setq x-menu-max-width (1- (frame-width)))
 108       (setq x-menu-item-width 0)
 109       (let (items-head
 110             (items-tail x-menu-items-alist))
 111         (while items-tail
 112           (if (caar items-tail)
 113               (progn (setq items-head (cons (car items-tail) items-head))
 114                      (setq x-menu-item-width
 115                            (max x-menu-item-width
 116                                 (length (caar items-tail))))))
 117           (setq items-tail (cdr items-tail)))
 118         (setq x-menu-items-alist (reverse items-head)))
 119       (setq x-menu-item-width (+ x-menu-item-spacing x-menu-item-width))
 120       (setq x-menu-items-per-line
 121             (max 1 (/ x-menu-max-width x-menu-item-width)))
 122       (erase-buffer)
 123       (let ((items-head x-menu-items-alist))
 124         (while items-head
 125           (let ((items 0))
 126             (while (and items-head
 127                         (<= (setq items (1+ items)) x-menu-items-per-line))
 128               (insert (format (concat "%"
 129                                       (int-to-string x-menu-item-width) "s")
 130                               (caar items-head)))
 131               (setq items-head (cdr items-head))))
 132           (insert ?\n)))
 133       (shrink-window (max 0
 134                           (- (window-height)
 135                              (1+ (count-lines (point-min) (point-max))))))
 136       (goto-char (point-min)))
 137     (pop-to-buffer buf)))
 138
 139 (defun x-menu-pick-entry (position event)
 140   "Internal function for dispatching on mouse/menu events"
 141   (let* ((x (min (1- x-menu-items-per-line)
 142                  (/ (current-column) x-menu-item-width)))
 143          (y (- (count-lines (point-min) (point))
 144                (if (zerop (current-column)) 0 1)))
 145          (item (+ x (* y x-menu-items-per-line)))
 146          (litem (cdr (nth item x-menu-items-alist))))
 147     (and litem (funcall litem event)))
 148   (pop-to-buffer x-menu-assoc-buffer))
 149
 150 ;;; x-menu.el ends here