Use make-temp-file in rst.el (Bug#7646).
[emacs.git] / lisp / reveal.el
blob9838ade89f1c39665e90a66e7f3233b313d94d16
1 ;;; reveal.el --- Automatically reveal hidden text at point
3 ;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
7 ;; Keywords: outlines
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
24 ;;; Commentary:
26 ;; Reveal mode is a minor mode that makes sure that text around point
27 ;; is always visible. When point enters a region of hidden text,
28 ;; `reveal-mode' temporarily makes it visible.
30 ;; This is normally used in conjunction with `outline-minor-mode',
31 ;; `hs-minor-mode', `hide-ifdef-mode', ...
33 ;; It only works with packages that hide text using overlays.
34 ;; Packages can provide special support for it by placing
35 ;; a function in the `reveal-toggle-invisible' property on the symbol
36 ;; used as the value of the `invisible' overlay property.
37 ;; The function is called right after revealing (or re-hiding) the
38 ;; text with two arguments: the overlay and a boolean that's non-nil
39 ;; if we have just revealed the text. When revealing, that function
40 ;; may re-hide some of the text.
42 ;;; Todo:
44 ;; - find other hysteresis features.
45 ;; - don't hide after a scroll command
46 ;; - delay hiding by a couple seconds (i.e. hide in the background)
48 ;;; Code:
50 (defgroup reveal nil
51 "Reveal hidden text on the fly."
52 :group 'editing)
54 (defcustom reveal-around-mark t
55 "Reveal text around the mark, if active."
56 :type 'boolean
57 :group 'reveal)
59 (defvar reveal-open-spots nil
60 "List of spots in the buffer which are open.
61 Each element has the form (WINDOW . OVERLAY).")
62 (make-variable-buffer-local 'reveal-open-spots)
64 (defvar reveal-last-tick nil)
65 (make-variable-buffer-local 'reveal-last-tick)
67 ;; Actual code
69 (defun reveal-post-command ()
70 ;; Refresh the spots that might have changed.
71 ;; `Refreshing' here means to try and re-hide the corresponding text.
72 ;; We don't refresh everything correctly:
73 ;; - we only refresh spots in the current window.
74 ;; FIXME: do we actually know that (current-buffer) = (window-buffer) ?
75 (with-local-quit
76 (condition-case err
77 (let ((old-ols
78 (delq nil
79 (mapcar
80 (lambda (x)
81 ;; We refresh any spot in the current window as well
82 ;; as any spots associated with a dead window or
83 ;; a window which does not show this buffer any more.
84 (cond
85 ((eq (car x) (selected-window)) (cdr x))
86 ((not (and (window-live-p (car x))
87 (eq (window-buffer (car x)) (current-buffer))))
88 ;; Adopt this since it's owned by a window that's
89 ;; either not live or at least not showing this
90 ;; buffer any more.
91 (setcar x (selected-window))
92 (cdr x))))
93 reveal-open-spots))))
94 (setq old-ols (reveal-open-new-overlays old-ols))
95 (reveal-close-old-overlays old-ols))
96 (error (message "Reveal: %s" err)))))
98 (defun reveal-open-new-overlays (old-ols)
99 (let ((repeat t))
100 (while repeat
101 (setq repeat nil)
102 (dolist (ol (nconc (when (and reveal-around-mark mark-active)
103 (overlays-at (mark)))
104 (overlays-at (point))))
105 (setq old-ols (delq ol old-ols))
106 (when (overlay-start ol) ;Check it's still live.
107 (let ((inv (overlay-get ol 'invisible)) open)
108 (when (and inv
109 ;; There's an `invisible' property. Make sure it's
110 ;; actually invisible, and ellipsised.
111 (and (consp buffer-invisibility-spec)
112 (cdr (assq inv buffer-invisibility-spec)))
113 (or (setq open
114 (or (overlay-get ol 'reveal-toggle-invisible)
115 (and (symbolp inv)
116 (get inv 'reveal-toggle-invisible))
117 (overlay-get ol 'isearch-open-invisible-temporary)))
118 (overlay-get ol 'isearch-open-invisible)
119 (and (consp buffer-invisibility-spec)
120 (cdr (assq inv buffer-invisibility-spec))))
121 (overlay-put ol 'reveal-invisible inv))
122 (push (cons (selected-window) ol) reveal-open-spots)
123 (if (null open)
124 (overlay-put ol 'invisible nil)
125 ;; Use the provided opening function and repeat (since the
126 ;; opening function might have hidden a subpart around point
127 ;; or moved/killed some of the overlays).
128 (setq repeat t)
129 (condition-case err
130 (funcall open ol nil)
131 (error (message "!!Reveal-show (funcall %s %s nil): %s !!"
132 open ol err)
133 ;; Let's default to a meaningful behavior to avoid
134 ;; getting stuck in an infinite loop.
135 (setq repeat nil)
136 (overlay-put ol 'invisible nil))))))))))
137 old-ols)
139 (defun reveal-close-old-overlays (old-ols)
140 (if (not (eq reveal-last-tick
141 (setq reveal-last-tick (buffer-modified-tick))))
142 ;; The buffer was modified since last command: let's refrain from
143 ;; closing any overlay because it tends to behave poorly when
144 ;; inserting text at the end of an overlay (basically the overlay
145 ;; should be rear-advance when it's open, but things like
146 ;; outline-minor-mode make it non-rear-advance because it's
147 ;; a better choice when it's closed).
149 ;; The last command was only a point motion or some such
150 ;; non-buffer-modifying command. Let's close whatever can be closed.
151 (dolist (ol old-ols)
152 (if (and (overlay-start ol) ;Check it's still live.
153 (>= (point) (save-excursion
154 (goto-char (overlay-start ol))
155 (line-beginning-position 1)))
156 (<= (point) (save-excursion
157 (goto-char (overlay-end ol))
158 (line-beginning-position 2)))
159 ;; If the application has moved the overlay to some other
160 ;; buffer, we'd better reset the buffer to its
161 ;; original state.
162 (eq (current-buffer) (overlay-buffer ol)))
163 ;; Still near the overlay: keep it open.
165 ;; Really close it.
166 (let* ((inv (overlay-get ol 'reveal-invisible))
167 (open (or (overlay-get ol 'reveal-toggle-invisible)
168 (get inv 'reveal-toggle-invisible)
169 (overlay-get ol 'isearch-open-invisible-temporary))))
170 (if (and (overlay-start ol) ;Check it's still live.
171 open)
172 (condition-case err
173 (funcall open ol t)
174 (error (message "!!Reveal-hide (funcall %s %s t): %s !!"
175 open ol err)))
176 (overlay-put ol 'invisible inv))
177 ;; Remove the overlay from the list of open spots.
178 (overlay-put ol 'reveal-invisible nil)
179 (setq reveal-open-spots
180 (delq (rassoc ol reveal-open-spots)
181 reveal-open-spots)))))))
183 (defvar reveal-mode-map
184 (let ((map (make-sparse-keymap)))
185 ;; Override the default move-beginning-of-line and move-end-of-line
186 ;; which skips valuable invisible text.
187 (define-key map [remap move-beginning-of-line] 'beginning-of-line)
188 (define-key map [remap move-end-of-line] 'end-of-line)
189 map))
191 ;;;###autoload
192 (define-minor-mode reveal-mode
193 "Toggle Reveal mode on or off.
194 Reveal mode renders invisible text around point visible again.
196 Interactively, with no prefix argument, toggle the mode.
197 With universal prefix ARG (or if ARG is nil) turn mode on.
198 With zero or negative ARG turn mode off."
199 :group 'reveal
200 :lighter (global-reveal-mode nil " Reveal")
201 :keymap reveal-mode-map
202 (if reveal-mode
203 (progn
204 (set (make-local-variable 'search-invisible) t)
205 (add-hook 'post-command-hook 'reveal-post-command nil t))
206 (kill-local-variable 'search-invisible)
207 (remove-hook 'post-command-hook 'reveal-post-command t)))
209 ;;;###autoload
210 (define-minor-mode global-reveal-mode
211 "Toggle Reveal mode in all buffers on or off.
212 Reveal mode renders invisible text around point visible again.
214 Interactively, with no prefix argument, toggle the mode.
215 With universal prefix ARG (or if ARG is nil) turn mode on.
216 With zero or negative ARG turn mode off."
217 :global t :group 'reveal
218 (setq-default reveal-mode global-reveal-mode)
219 (if global-reveal-mode
220 (progn
221 (setq search-invisible t)
222 (add-hook 'post-command-hook 'reveal-post-command))
223 (setq search-invisible 'open) ;FIXME
224 (remove-hook 'post-command-hook 'reveal-post-command)))
226 (provide 'reveal)
228 ;; arch-tag: 96ba0242-2274-4ed7-8e10-26bc0707b4d8
229 ;;; reveal.el ends here