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ba83908c | 1 | ;;; reveal.el --- Automatically reveal hidden text at point -*- lexical-binding: t -*- |
a0aa2a49 | 2 | |
acaf905b | 3 | ;; Copyright (C) 2000-2012 Free Software Foundation, Inc. |
a0aa2a49 | 4 | |
cc1eecfd | 5 | ;; Author: Stefan Monnier <monnier@iro.umontreal.ca> |
a0aa2a49 SM |
6 | ;; Keywords: outlines |
7 | ||
041f4d74 PJ |
8 | ;; This file is part of GNU Emacs. |
9 | ||
eb3fa2cf | 10 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
a0aa2a49 | 11 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
12 | ;; the Free Software Foundation, either version 3 of the License, or |
13 | ;; (at your option) any later version. | |
a0aa2a49 | 14 | |
7490a1e4 | 15 | ;; GNU Emacs is distributed in the hope that it will be useful, |
a0aa2a49 SM |
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 | |
eb3fa2cf | 21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
a0aa2a49 SM |
22 | |
23 | ;;; Commentary: | |
24 | ||
25 | ;; Reveal mode is a minor mode that makes sure that text around point | |
26 | ;; is always visible. When point enters a region of hidden text, | |
27 | ;; `reveal-mode' temporarily makes it visible. | |
28 | ;; | |
29 | ;; This is normally used in conjunction with `outline-minor-mode', | |
30 | ;; `hs-minor-mode', `hide-ifdef-mode', ... | |
31 | ;; | |
32 | ;; It only works with packages that hide text using overlays. | |
33 | ;; Packages can provide special support for it by placing | |
34 | ;; a function in the `reveal-toggle-invisible' property on the symbol | |
35 | ;; used as the value of the `invisible' overlay property. | |
36 | ;; The function is called right after revealing (or re-hiding) the | |
37 | ;; text with two arguments: the overlay and a boolean that's non-nil | |
38 | ;; if we have just revealed the text. When revealing, that function | |
39 | ;; may re-hide some of the text. | |
40 | ||
41 | ;;; Todo: | |
42 | ||
43 | ;; - find other hysteresis features. | |
4acbd507 SM |
44 | ;; - don't hide after a scroll command |
45 | ;; - delay hiding by a couple seconds (i.e. hide in the background) | |
a0aa2a49 SM |
46 | |
47 | ;;; Code: | |
48 | ||
a0aa2a49 SM |
49 | (defgroup reveal nil |
50 | "Reveal hidden text on the fly." | |
eba5b4dd | 51 | :group 'convenience) |
a0aa2a49 SM |
52 | |
53 | (defcustom reveal-around-mark t | |
54 | "Reveal text around the mark, if active." | |
f5307782 JB |
55 | :type 'boolean |
56 | :group 'reveal) | |
a0aa2a49 | 57 | |
4acbd507 SM |
58 | (defvar reveal-open-spots nil |
59 | "List of spots in the buffer which are open. | |
60 | Each element has the form (WINDOW . OVERLAY).") | |
a0aa2a49 SM |
61 | (make-variable-buffer-local 'reveal-open-spots) |
62 | ||
40a45fac SM |
63 | (defvar reveal-last-tick nil) |
64 | (make-variable-buffer-local 'reveal-last-tick) | |
65 | ||
a0aa2a49 SM |
66 | ;; Actual code |
67 | ||
68 | (defun reveal-post-command () | |
69 | ;; Refresh the spots that might have changed. | |
70 | ;; `Refreshing' here means to try and re-hide the corresponding text. | |
71 | ;; We don't refresh everything correctly: | |
72 | ;; - we only refresh spots in the current window. | |
73 | ;; FIXME: do we actually know that (current-buffer) = (window-buffer) ? | |
74 | (with-local-quit | |
ffb5fc37 SM |
75 | (condition-case err |
76 | (let ((old-ols | |
77 | (delq nil | |
78 | (mapcar | |
79 | (lambda (x) | |
80 | ;; We refresh any spot in the current window as well | |
81 | ;; as any spots associated with a dead window or | |
82 | ;; a window which does not show this buffer any more. | |
83 | (cond | |
84 | ((eq (car x) (selected-window)) (cdr x)) | |
23e0c1a3 SM |
85 | ((not (and (window-live-p (car x)) |
86 | (eq (window-buffer (car x)) (current-buffer)))) | |
ffb5fc37 SM |
87 | ;; Adopt this since it's owned by a window that's |
88 | ;; either not live or at least not showing this | |
89 | ;; buffer any more. | |
90 | (setcar x (selected-window)) | |
91 | (cdr x)))) | |
92 | reveal-open-spots)))) | |
93 | (setq old-ols (reveal-open-new-overlays old-ols)) | |
94 | (reveal-close-old-overlays old-ols)) | |
95 | (error (message "Reveal: %s" err))))) | |
96 | ||
97 | (defun reveal-open-new-overlays (old-ols) | |
98 | (let ((repeat t)) | |
99 | (while repeat | |
100 | (setq repeat nil) | |
101 | (dolist (ol (nconc (when (and reveal-around-mark mark-active) | |
102 | (overlays-at (mark))) | |
103 | (overlays-at (point)))) | |
104 | (setq old-ols (delq ol old-ols)) | |
23e0c1a3 SM |
105 | (when (overlay-start ol) ;Check it's still live. |
106 | (let ((inv (overlay-get ol 'invisible)) open) | |
107 | (when (and inv | |
108 | ;; There's an `invisible' property. Make sure it's | |
99d99081 | 109 | ;; actually invisible, and ellipsized. |
23e0c1a3 SM |
110 | (and (consp buffer-invisibility-spec) |
111 | (cdr (assq inv buffer-invisibility-spec))) | |
112 | (or (setq open | |
113 | (or (overlay-get ol 'reveal-toggle-invisible) | |
114 | (and (symbolp inv) | |
115 | (get inv 'reveal-toggle-invisible)) | |
116 | (overlay-get ol 'isearch-open-invisible-temporary))) | |
117 | (overlay-get ol 'isearch-open-invisible) | |
118 | (and (consp buffer-invisibility-spec) | |
119 | (cdr (assq inv buffer-invisibility-spec)))) | |
120 | (overlay-put ol 'reveal-invisible inv)) | |
121 | (push (cons (selected-window) ol) reveal-open-spots) | |
122 | (if (null open) | |
123 | (overlay-put ol 'invisible nil) | |
124 | ;; Use the provided opening function and repeat (since the | |
125 | ;; opening function might have hidden a subpart around point | |
126 | ;; or moved/killed some of the overlays). | |
127 | (setq repeat t) | |
128 | (condition-case err | |
129 | (funcall open ol nil) | |
130 | (error (message "!!Reveal-show (funcall %s %s nil): %s !!" | |
131 | open ol err) | |
132 | ;; Let's default to a meaningful behavior to avoid | |
133 | ;; getting stuck in an infinite loop. | |
134 | (setq repeat nil) | |
135 | (overlay-put ol 'invisible nil)))))))))) | |
ffb5fc37 SM |
136 | old-ols) |
137 | ||
138 | (defun reveal-close-old-overlays (old-ols) | |
139 | (if (not (eq reveal-last-tick | |
140 | (setq reveal-last-tick (buffer-modified-tick)))) | |
141 | ;; The buffer was modified since last command: let's refrain from | |
142 | ;; closing any overlay because it tends to behave poorly when | |
143 | ;; inserting text at the end of an overlay (basically the overlay | |
144 | ;; should be rear-advance when it's open, but things like | |
145 | ;; outline-minor-mode make it non-rear-advance because it's | |
146 | ;; a better choice when it's closed). | |
147 | nil | |
148 | ;; The last command was only a point motion or some such | |
149 | ;; non-buffer-modifying command. Let's close whatever can be closed. | |
150 | (dolist (ol old-ols) | |
151 | (if (and (overlay-start ol) ;Check it's still live. | |
152 | (>= (point) (save-excursion | |
153 | (goto-char (overlay-start ol)) | |
154 | (line-beginning-position 1))) | |
155 | (<= (point) (save-excursion | |
156 | (goto-char (overlay-end ol)) | |
157 | (line-beginning-position 2))) | |
158 | ;; If the application has moved the overlay to some other | |
159 | ;; buffer, we'd better reset the buffer to its | |
160 | ;; original state. | |
161 | (eq (current-buffer) (overlay-buffer ol))) | |
162 | ;; Still near the overlay: keep it open. | |
163 | nil | |
164 | ;; Really close it. | |
165 | (let* ((inv (overlay-get ol 'reveal-invisible)) | |
166 | (open (or (overlay-get ol 'reveal-toggle-invisible) | |
167 | (get inv 'reveal-toggle-invisible) | |
168 | (overlay-get ol 'isearch-open-invisible-temporary)))) | |
169 | (if (and (overlay-start ol) ;Check it's still live. | |
170 | open) | |
171 | (condition-case err | |
172 | (funcall open ol t) | |
173 | (error (message "!!Reveal-hide (funcall %s %s t): %s !!" | |
174 | open ol err))) | |
175 | (overlay-put ol 'invisible inv)) | |
176 | ;; Remove the overlay from the list of open spots. | |
177 | (overlay-put ol 'reveal-invisible nil) | |
178 | (setq reveal-open-spots | |
179 | (delq (rassoc ol reveal-open-spots) | |
180 | reveal-open-spots))))))) | |
a0aa2a49 | 181 | |
ea78522d SM |
182 | (defvar reveal-mode-map |
183 | (let ((map (make-sparse-keymap))) | |
88418e61 KS |
184 | ;; Override the default move-beginning-of-line and move-end-of-line |
185 | ;; which skips valuable invisible text. | |
8d194e3e SM |
186 | (define-key map [remap move-beginning-of-line] 'beginning-of-line) |
187 | (define-key map [remap move-end-of-line] 'end-of-line) | |
ea78522d SM |
188 | map)) |
189 | ||
a0aa2a49 SM |
190 | ;;;###autoload |
191 | (define-minor-mode reveal-mode | |
fa463103 | 192 | "Toggle uncloaking of invisible text near point (Reveal mode). |
06e21633 CY |
193 | With a prefix argument ARG, enable Reveal mode if ARG is |
194 | positive, and disable it otherwise. If called from Lisp, enable | |
195 | Reveal mode if ARG is omitted or nil. | |
a0aa2a49 | 196 | |
fa463103 | 197 | Reveal mode is a buffer-local minor mode. When enabled, it |
06e21633 | 198 | reveals invisible text around point." |
28a1f13b | 199 | :group 'reveal |
7b73ae06 | 200 | :lighter (global-reveal-mode nil " Reveal") |
ea78522d | 201 | :keymap reveal-mode-map |
a0aa2a49 SM |
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))) | |
208 | ||
209 | ;;;###autoload | |
210 | (define-minor-mode global-reveal-mode | |
06e21633 | 211 | "Toggle Reveal mode in all buffers (Global Reveal mode). |
a0aa2a49 SM |
212 | Reveal mode renders invisible text around point visible again. |
213 | ||
06e21633 CY |
214 | With a prefix argument ARG, enable Global Reveal mode if ARG is |
215 | positive, and disable it otherwise. If called from Lisp, enable | |
216 | the mode if ARG is omitted or nil." | |
710a1280 | 217 | :global t :group 'reveal |
a0aa2a49 SM |
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))) | |
225 | ||
226 | (provide 'reveal) | |
710a1280 | 227 | |
a0aa2a49 | 228 | ;;; reveal.el ends here |