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1 | ;;; reveal.el --- Automatically reveal hidden text at point |
2 | ||
0d30b337 TTN |
3 | ;; Copyright (C) 2000, 2001, 2002, 2003, 2004, |
4 | ;; 2005 Free Software Foundation, Inc. | |
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5 | |
6 | ;; Author: Stefan Monnier <monnier@cs.yale.edu> | |
7 | ;; Keywords: outlines | |
8 | ||
041f4d74 PJ |
9 | ;; This file is part of GNU Emacs. |
10 | ||
12b309f1 | 11 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
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12 | ;; it under the terms of the GNU General Public License as published by |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
14 | ;; any later version. | |
15 | ||
7490a1e4 | 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
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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. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
086add15 LK |
23 | ;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
24 | ;; Boston, MA 02110-1301, USA. | |
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25 | |
26 | ;;; Commentary: | |
27 | ||
28 | ;; Reveal mode is a minor mode that makes sure that text around point | |
29 | ;; is always visible. When point enters a region of hidden text, | |
30 | ;; `reveal-mode' temporarily makes it visible. | |
31 | ;; | |
32 | ;; This is normally used in conjunction with `outline-minor-mode', | |
33 | ;; `hs-minor-mode', `hide-ifdef-mode', ... | |
34 | ;; | |
35 | ;; It only works with packages that hide text using overlays. | |
36 | ;; Packages can provide special support for it by placing | |
37 | ;; a function in the `reveal-toggle-invisible' property on the symbol | |
38 | ;; used as the value of the `invisible' overlay property. | |
39 | ;; The function is called right after revealing (or re-hiding) the | |
40 | ;; text with two arguments: the overlay and a boolean that's non-nil | |
41 | ;; if we have just revealed the text. When revealing, that function | |
42 | ;; may re-hide some of the text. | |
43 | ||
44 | ;;; Todo: | |
45 | ||
46 | ;; - find other hysteresis features. | |
4acbd507 SM |
47 | ;; - don't hide after a scroll command |
48 | ;; - delay hiding by a couple seconds (i.e. hide in the background) | |
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49 | |
50 | ;;; Code: | |
51 | ||
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52 | (defgroup reveal nil |
53 | "Reveal hidden text on the fly." | |
54 | :group 'editing) | |
55 | ||
56 | (defcustom reveal-around-mark t | |
57 | "Reveal text around the mark, if active." | |
f5307782 JB |
58 | :type 'boolean |
59 | :group 'reveal) | |
a0aa2a49 | 60 | |
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61 | (defvar reveal-open-spots nil |
62 | "List of spots in the buffer which are open. | |
63 | Each element has the form (WINDOW . OVERLAY).") | |
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64 | (make-variable-buffer-local 'reveal-open-spots) |
65 | ||
40a45fac SM |
66 | (defvar reveal-last-tick nil) |
67 | (make-variable-buffer-local 'reveal-last-tick) | |
68 | ||
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69 | ;; Actual code |
70 | ||
71 | (defun reveal-post-command () | |
72 | ;; Refresh the spots that might have changed. | |
73 | ;; `Refreshing' here means to try and re-hide the corresponding text. | |
74 | ;; We don't refresh everything correctly: | |
75 | ;; - we only refresh spots in the current window. | |
76 | ;; FIXME: do we actually know that (current-buffer) = (window-buffer) ? | |
77 | (with-local-quit | |
f6961018 | 78 | (condition-case err |
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79 | (let ((old-ols (delq nil |
80 | (mapcar | |
81 | (lambda (x) | |
82 | ;; We refresh any spot in the current window as | |
83 | ;; well as any spots associated with a dead | |
84 | ;; window or a window which does not show this | |
85 | ;; buffer any more. | |
86 | (if (or (eq (car x) (selected-window)) | |
87 | (not (window-live-p (car x))) | |
88 | (not (eq (window-buffer (car x)) | |
89 | (current-buffer)))) | |
90 | (cdr x))) | |
91 | reveal-open-spots))) | |
92 | (repeat t)) | |
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93 | ;; Open new overlays. |
94 | (while repeat | |
95 | (setq repeat nil) | |
96 | (dolist (ol (nconc (when (and reveal-around-mark mark-active) | |
97 | (overlays-at (mark))) | |
98 | (overlays-at (point)))) | |
a0aa2a49 | 99 | (setq old-ols (delq ol old-ols)) |
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100 | (let ((inv (overlay-get ol 'invisible)) open) |
101 | (when (and inv | |
102 | ;; There's an `invisible' property. Make sure it's | |
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103 | ;; actually invisible, and ellipsised. |
104 | (and (consp buffer-invisibility-spec) | |
105 | (cdr (assq inv buffer-invisibility-spec))) | |
106 | (or (setq open | |
fc88c288 SM |
107 | (or (overlay-get ol 'reveal-toggle-invisible) |
108 | (and (symbolp inv) | |
109 | (get inv 'reveal-toggle-invisible)) | |
110 | (overlay-get ol 'isearch-open-invisible-temporary))) | |
111 | (overlay-get ol 'isearch-open-invisible) | |
112 | (and (consp buffer-invisibility-spec) | |
113 | (cdr (assq inv buffer-invisibility-spec)))) | |
114 | (overlay-put ol 'reveal-invisible inv)) | |
4acbd507 | 115 | (push (cons (selected-window) ol) reveal-open-spots) |
f6961018 | 116 | (if (null open) |
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117 | (progn ;; (debug) |
118 | (overlay-put ol 'invisible nil)) | |
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119 | ;; Use the provided opening function and repeat (since the |
120 | ;; opening function might have hidden a subpart around point). | |
121 | (setq repeat t) | |
122 | (condition-case err | |
f6961018 | 123 | (funcall open ol nil) |
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124 | (error (message "!!Reveal-show (funcall %s %s nil): %s !!" |
125 | open ol err) | |
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126 | ;; Let's default to a meaningful behavior to avoid |
127 | ;; getting stuck in an infinite loop. | |
836be5ce | 128 | (setq repeat nil) |
a604e2b4 | 129 | (overlay-put ol 'invisible nil)))))))) |
a0aa2a49 | 130 | ;; Close old overlays. |
40a45fac SM |
131 | (if (not (eq reveal-last-tick |
132 | (setq reveal-last-tick (buffer-modified-tick)))) | |
133 | ;; The buffer was modified since last command: let's refrain from | |
134 | ;; closing any overlay because it tends to behave poorly when | |
135 | ;; inserting text at the end of an overlay (basically the overlay | |
136 | ;; should be rear-advance when it's open, but things like | |
137 | ;; outline-minor-mode make it non-rear-advance because it's | |
138 | ;; a better choice when it's closed). | |
4acbd507 | 139 | nil |
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140 | ;; The last command was only a point motion or some such |
141 | ;; non-buffer-modifying command. Let's close whatever can be closed. | |
142 | (dolist (ol old-ols) | |
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143 | (if (and (>= (point) (save-excursion |
144 | (goto-char (overlay-start ol)) | |
145 | (line-beginning-position 1))) | |
146 | (<= (point) (save-excursion | |
147 | (goto-char (overlay-end ol)) | |
148 | (line-beginning-position 2))) | |
149 | ;; If the application has moved the overlay to some other | |
150 | ;; buffer, we'd better reset the buffer to its | |
151 | ;; original state. | |
152 | (eq (current-buffer) (overlay-buffer ol))) | |
153 | ;; Still near the overlay: keep it open. | |
154 | nil | |
155 | ;; Really close it. | |
156 | (let ((open (overlay-get ol 'reveal-toggle-invisible)) inv) | |
157 | (if (or open | |
158 | (and (setq inv (overlay-get ol 'reveal-invisible)) | |
159 | (setq open (or (get inv 'reveal-toggle-invisible) | |
160 | (overlay-get ol 'isearch-open-invisible-temporary))))) | |
161 | (condition-case err | |
162 | (funcall open ol t) | |
163 | (error (message "!!Reveal-hide (funcall %s %s t): %s !!" | |
164 | open ol err))) | |
165 | (overlay-put ol 'invisible inv)) | |
166 | ;; Remove the olverlay from the list of open spots. | |
167 | (setq reveal-open-spots | |
168 | (delq (rassoc ol reveal-open-spots) | |
169 | reveal-open-spots))))))) | |
836be5ce | 170 | (error (message "Reveal: %s" err))))) |
a0aa2a49 | 171 | |
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172 | (defvar reveal-mode-map |
173 | (let ((map (make-sparse-keymap))) | |
88418e61 KS |
174 | ;; Override the default move-beginning-of-line and move-end-of-line |
175 | ;; which skips valuable invisible text. | |
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176 | (define-key map [remap move-beginning-of-line] 'beginning-of-line) |
177 | (define-key map [remap move-end-of-line] 'end-of-line) | |
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178 | map)) |
179 | ||
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180 | ;;;###autoload |
181 | (define-minor-mode reveal-mode | |
182 | "Toggle Reveal mode on or off. | |
183 | Reveal mode renders invisible text around point visible again. | |
184 | ||
185 | Interactively, with no prefix argument, toggle the mode. | |
186 | With universal prefix ARG (or if ARG is nil) turn mode on. | |
187 | With zero or negative ARG turn mode off." | |
28a1f13b | 188 | :group 'reveal |
7b73ae06 | 189 | :lighter (global-reveal-mode nil " Reveal") |
ea78522d | 190 | :keymap reveal-mode-map |
a0aa2a49 SM |
191 | (if reveal-mode |
192 | (progn | |
193 | (set (make-local-variable 'search-invisible) t) | |
194 | (add-hook 'post-command-hook 'reveal-post-command nil t)) | |
195 | (kill-local-variable 'search-invisible) | |
196 | (remove-hook 'post-command-hook 'reveal-post-command t))) | |
197 | ||
198 | ;;;###autoload | |
199 | (define-minor-mode global-reveal-mode | |
200 | "Toggle Reveal mode in all buffers on or off. | |
201 | Reveal mode renders invisible text around point visible again. | |
202 | ||
203 | Interactively, with no prefix argument, toggle the mode. | |
204 | With universal prefix ARG (or if ARG is nil) turn mode on. | |
205 | With zero or negative ARG turn mode off." | |
710a1280 | 206 | :global t :group 'reveal |
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207 | (setq-default reveal-mode global-reveal-mode) |
208 | (if global-reveal-mode | |
209 | (progn | |
210 | (setq search-invisible t) | |
211 | (add-hook 'post-command-hook 'reveal-post-command)) | |
212 | (setq search-invisible 'open) ;FIXME | |
213 | (remove-hook 'post-command-hook 'reveal-post-command))) | |
214 | ||
215 | (provide 'reveal) | |
710a1280 | 216 | |
40a45fac | 217 | ;; arch-tag: 96ba0242-2274-4ed7-8e10-26bc0707b4d8 |
a0aa2a49 | 218 | ;;; reveal.el ends here |