lisp/mb-depth.el

   1 ;;; mb-depth.el --- Indicate minibuffer-depth in prompt
   2 ;;
   3 ;; Copyright (C) 2006, 2007, 2008  Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Miles Bader <miles@gnu.org>
   6 ;; Keywords: convenience
   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 3, 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 the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;;; Commentary:
  26 ;;
  27 ;; Defines the minor mode `minibuffer-indicate-depth-mode'.
  28 ;;
  29 ;; When active, any recursive use of the minibuffer will show
  30 ;; the recursion depth in the minibuffer prompt.  This is only
  31 ;; useful if `enable-recursive-minibuffers' is non-nil.
  32
  33 ;;; Code:
  34
  35 (defvar minibuf-depth-indicator-function nil
  36   "If non-nil, function to set up the minibuffer depth indicator.
  37 It is called with one argument, the minibuffer depth,
  38 and must return a string.")
  39
  40 ;; An overlay covering the prompt.  This is a buffer-local variable in
  41 ;; each affected minibuffer.
  42 ;;
  43 (defvar minibuf-depth-overlay)
  44 (make-variable-buffer-local 'minibuf-depth-overlay)
  45
  46 ;; This function goes on minibuffer-setup-hook
  47 (defun minibuf-depth-setup-minibuffer ()
  48   "Set up a minibuffer for `minibuffer-indicate-depth-mode'.
  49 The prompt should already have been inserted."
  50   (when (> (minibuffer-depth) 1)
  51     (setq minibuf-depth-overlay (make-overlay (point-min) (1+ (point-min))))
  52     (overlay-put minibuf-depth-overlay 'before-string
  53                  (if minibuf-depth-indicator-function
  54                      (funcall minibuf-depth-indicator-function (minibuffer-depth))
  55                    (propertize (format "[%d]" (minibuffer-depth)) 'face 'highlight)))
  56     (overlay-put minibuf-depth-overlay 'evaporate t)))
  57
  58 ;;;###autoload
  59 (define-minor-mode minibuffer-indicate-depth-mode
  60   "Toggle Minibuffer Indicate Depth mode.
  61 When active, any recursive use of the minibuffer will show
  62 the recursion depth in the minibuffer prompt.  This is only
  63 useful if `enable-recursive-minibuffers' is non-nil.
  64
  65 With prefix argument ARG, turn on if positive, otherwise off.
  66 Returns non-nil if the new state is enabled."
  67   :global t
  68   :group 'minibuffer
  69   (if minibuffer-indicate-depth-mode
  70       ;; Enable the mode
  71       (add-hook 'minibuffer-setup-hook 'minibuf-depth-setup-minibuffer)
  72     ;; Disable the mode
  73     (remove-hook 'minibuffer-setup-hook 'minibuf-depth-setup-minibuffer)))
  74
  75 (provide 'mb-depth)
  76
  77 ;; arch-tag: 50224089-5bf5-46f8-803d-18f018c5eacf
  78 ;;; mb-depth.el ends here