Commit | Line | Data |
---|---|---|
e8af40ee | 1 | ;;; follow.el --- synchronize windows showing the same buffer |
acaf905b | 2 | ;; Copyright (C) 1995-1997, 1999, 2001-2012 Free Software Foundation, Inc. |
e79016aa | 3 | |
c86b6fd2 | 4 | ;; Author: Anders Lindgren <andersl@andersl.com> |
ec8d89ec | 5 | ;; Maintainer: FSF (Anders' email bounces, Sep 2005) |
c86b6fd2 | 6 | ;; Created: 1995-05-25 |
f5f727f8 | 7 | ;; Keywords: display, window, minor-mode, convenience |
e79016aa | 8 | |
dcde1278 RS |
9 | ;; This file is part of GNU Emacs. |
10 | ||
eb3fa2cf | 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
e79016aa | 12 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
13 | ;; the Free Software Foundation, either version 3 of the License, or |
14 | ;; (at your option) any later version. | |
e79016aa | 15 | |
dcde1278 | 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
e79016aa KH |
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 | |
eb3fa2cf | 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
e79016aa KH |
23 | |
24 | ;;; Commentary: | |
25 | ||
ff753438 | 26 | ;; `Follow mode' is a minor mode for Emacs and XEmacs that |
e79016aa KH |
27 | ;; combines windows into one tall virtual window. |
28 | ;; | |
29 | ;; The feeling of a "virtual window" has been accomplished by the use | |
30 | ;; of two major techniques: | |
31 | ;; | |
1ece6cdb | 32 | ;; * The windows always display adjacent sections of the buffer. |
e79016aa | 33 | ;; This means that whenever one window is moved, all the |
17f6d002 | 34 | ;; others will follow. (Hence the name Follow mode.) |
e79016aa | 35 | ;; |
cb02be17 KH |
36 | ;; * Should the point (cursor) end up outside a window, another |
37 | ;; window displaying that point is selected, if possible. This | |
38 | ;; makes it possible to walk between windows using normal cursor | |
e79016aa KH |
39 | ;; movement commands. |
40 | ;; | |
ff753438 | 41 | ;; Follow mode comes to its prime when a large screen and two |
08a1dbe6 | 42 | ;; side-by-side window are used. The user can, with the help of Follow |
1ece6cdb EZ |
43 | ;; mode, use two full-height windows as though they are one. |
44 | ;; Imagine yourself editing a large function, or section of text, | |
c8d05b03 | 45 | ;; and being able to use 144 lines instead of the normal 72... (your |
e79016aa KH |
46 | ;; mileage may vary). |
47 | ||
e79016aa | 48 | ;; To test this package, make sure `follow' is loaded, or will be |
08a1dbe6 | 49 | ;; autoloaded when activated (see below). Then do the following: |
e79016aa | 50 | ;; |
ff753438 | 51 | ;; * Find your favorite file (preferably a long one). |
e79016aa | 52 | ;; |
ff753438 RS |
53 | ;; * Resize Emacs so that it will be wide enough for two full size |
54 | ;; columns. Delete the other windows and split the window with | |
55 | ;; the commands `C-x 1 C-x 3'. | |
e79016aa KH |
56 | ;; |
57 | ;; * Give the command: | |
58 | ;; M-x follow-mode <RETURN> | |
59 | ;; | |
60 | ;; * Now the display should look something like (assuming the text "71" | |
61 | ;; is on line 71): | |
62 | ;; | |
63 | ;; +----------+----------+ | |
64 | ;; |1 |73 | | |
65 | ;; |2 |74 | | |
66 | ;; |3 |75 | | |
cb02be17 | 67 | ;; ... ... |
e79016aa KH |
68 | ;; |71 |143 | |
69 | ;; |72 |144 | | |
70 | ;; +----------+----------+ | |
71 | ;; | |
72 | ;; As you can see, the right-hand window starts at line 73, the line | |
08a1dbe6 | 73 | ;; immediately below the end of the left-hand window. As long as |
1ece6cdb | 74 | ;; `follow-mode' is active, the two windows will follow each other! |
e79016aa KH |
75 | ;; |
76 | ;; * Play around and enjoy! Scroll one window and watch the other. | |
08a1dbe6 SM |
77 | ;; Jump to the beginning or end. Press `Cursor down' at the last |
78 | ;; line of the left-hand window. Enter new lines into the | |
79 | ;; text. Enter long lines spanning several lines, or several | |
e79016aa KH |
80 | ;; windows. |
81 | ;; | |
82 | ;; * Should you find `Follow' mode annoying, just type | |
cb02be17 | 83 | ;; M-x follow-mode <RETURN> |
e79016aa KH |
84 | ;; to turn it off. |
85 | ||
86 | ||
53964682 | 87 | ;; The command `follow-delete-other-windows-and-split' maximizes the |
e79016aa KH |
88 | ;; visible area of the current buffer. |
89 | ;; | |
90 | ;; I recommend adding it, and `follow-mode', to hotkeys in the global | |
91 | ;; key map. To do so, add the following lines (replacing `[f7]' and | |
92 | ;; `[f8]' with your favorite keys) to the init file: | |
93 | ;; | |
e79016aa | 94 | ;; (global-set-key [f8] 'follow-mode) |
e79016aa KH |
95 | ;; (global-set-key [f7] 'follow-delete-other-windows-and-split) |
96 | ||
97 | ||
e4920bc9 | 98 | ;; There exist two system variables that control the appearance of |
1ece6cdb EZ |
99 | ;; lines wider than the window containing them. The default is to |
100 | ;; truncate long lines whenever a window isn't as wide as the frame. | |
e79016aa KH |
101 | ;; |
102 | ;; To make sure lines are never truncated, please place the following | |
103 | ;; lines in your init file: | |
104 | ;; | |
105 | ;; (setq truncate-lines nil) | |
106 | ;; (setq truncate-partial-width-windows nil) | |
107 | ||
108 | ||
da6062e6 | 109 | ;; The correct way to configure Follow mode, or any other mode for |
1ece6cdb EZ |
110 | ;; that matter, is to create one or more functions that do |
111 | ;; whatever you would like to do. These functions are then added to | |
e79016aa KH |
112 | ;; a hook. |
113 | ;; | |
e79016aa KH |
114 | ;; The keymap `follow-key-map' contains key bindings activated by |
115 | ;; `follow-mode'. | |
116 | ;; | |
117 | ;; Example: | |
118 | ;; (add-hook 'follow-mode-hook 'my-follow-mode-hook) | |
119 | ;; | |
120 | ;; (defun my-follow-mode-hook () | |
121 | ;; (define-key follow-mode-map "\C-ca" 'your-favorite-function) | |
122 | ;; (define-key follow-mode-map "\C-cb" 'another-function)) | |
123 | ||
124 | ||
125 | ;; Usage: | |
126 | ;; | |
1ece6cdb EZ |
127 | ;; To activate, issue the command "M-x follow-mode" |
128 | ;; and press Return. To deactivate, do it again. | |
e79016aa | 129 | ;; |
ff753438 RS |
130 | ;; The following is a list of commands useful when follow-mode is active. |
131 | ;; | |
e79016aa | 132 | ;; follow-scroll-up C-c . C-v |
17f6d002 | 133 | ;; Scroll text in a Follow mode window chain up. |
e79016aa KH |
134 | ;; |
135 | ;; follow-scroll-down C-c . v | |
136 | ;; Like `follow-scroll-up', but in the other direction. | |
137 | ;; | |
138 | ;; follow-delete-other-windows-and-split C-c . 1 | |
1ece6cdb | 139 | ;; Maximize the visible area of the current buffer, |
17f6d002 | 140 | ;; and enter Follow mode. This is a very convenient |
fe7a3057 | 141 | ;; way to start Follow mode, hence we recommend that |
1ece6cdb | 142 | ;; this command be added to the global keymap. |
e79016aa KH |
143 | ;; |
144 | ;; follow-recenter C-c . C-l | |
145 | ;; Place the point in the center of the middle window, | |
146 | ;; or a specified number of lines from either top or bottom. | |
147 | ;; | |
148 | ;; follow-switch-to-buffer C-c . b | |
149 | ;; Switch buffer in all windows displaying the current buffer | |
150 | ;; in this frame. | |
151 | ;; | |
152 | ;; follow-switch-to-buffer-all C-c . C-b | |
1ece6cdb | 153 | ;; Switch buffer in all windows in the selected frame. |
e79016aa KH |
154 | ;; |
155 | ;; follow-switch-to-current-buffer-all | |
156 | ;; Show the current buffer in all windows on the current | |
157 | ;; frame and turn on `follow-mode'. | |
158 | ;; | |
159 | ;; follow-first-window C-c . < | |
160 | ;; Select the first window in the frame showing the same buffer. | |
161 | ;; | |
162 | ;; follow-last-window C-c . > | |
163 | ;; Select the last window in the frame showing the same buffer. | |
164 | ;; | |
165 | ;; follow-next-window C-c . n | |
166 | ;; Select the next window in the frame showing the same buffer. | |
167 | ;; | |
168 | ;; follow-previous-window C-c . p | |
169 | ;; Select the previous window showing the same buffer. | |
170 | ||
171 | ||
172 | ;; Well, it seems ok, but what if I really want to look at two different | |
173 | ;; positions in the text? Here are two simple methods to use: | |
174 | ;; | |
175 | ;; 1) Use multiple frames; `follow' mode only affects windows displayed | |
5eba16a3 | 176 | ;; in the same frame. (My apologies to you who can't use frames.) |
e79016aa KH |
177 | ;; |
178 | ;; 2) Bind `follow-mode' to key so you can turn it off whenever | |
08a1dbe6 | 179 | ;; you want to view two locations. Of course, `follow' mode can |
e79016aa KH |
180 | ;; be reactivated by hitting the same key again. |
181 | ;; | |
182 | ;; Example from my ~/.emacs: | |
183 | ;; (global-set-key [f8] 'follow-mode) | |
184 | ||
cb02be17 | 185 | ;; Implementation: |
e79016aa | 186 | ;; |
782fbf2a CY |
187 | ;; The main method by which Follow mode aligns windows is via the |
188 | ;; function `follow-post-command-hook', which is run after each | |
189 | ;; command. This "fixes up" the alignment of other windows which are | |
190 | ;; showing the same Follow mode buffer, on the same frame as the | |
191 | ;; selected window. It does not try to deal with buffers other than | |
192 | ;; the buffer of the selected frame, or windows on other frames. | |
e79016aa | 193 | ;; |
782fbf2a CY |
194 | ;; Comint mode specially calls `follow-comint-scroll-to-bottom' on |
195 | ;; Follow mode buffers. This function scrolls the bottom-most window | |
196 | ;; in a window chain and aligns the other windows accordingly. Follow | |
197 | ;; mode adds a function to `compilation-filter-hook' to align | |
198 | ;; compilation buffers. | |
e79016aa | 199 | |
e79016aa KH |
200 | ;;; Code: |
201 | ||
9271083a JB |
202 | (require 'easymenu) |
203 | ||
c93b886f | 204 | ;;; Variables |
e79016aa | 205 | |
4bef9110 SE |
206 | (defgroup follow nil |
207 | "Synchronize windows showing the same buffer." | |
f5f727f8 DN |
208 | :group 'windows |
209 | :group 'convenience) | |
4bef9110 | 210 | |
4bef9110 | 211 | (defcustom follow-mode-hook nil |
eceb3266 | 212 | "Normal hook run by `follow-mode'." |
4bef9110 SE |
213 | :type 'hook |
214 | :group 'follow) | |
e79016aa | 215 | |
c93b886f | 216 | ;;; Keymap/Menu |
e79016aa | 217 | |
08a1dbe6 | 218 | ;; Define keys for the follow-mode minor mode map and replace some |
782fbf2a CY |
219 | ;; functions in the global map. All Follow mode special functions can |
220 | ;; be found on the `C-c .' prefix key. | |
08a1dbe6 | 221 | ;; |
782fbf2a CY |
222 | ;; To change the prefix, redefine `follow-mode-prefix' before `follow' |
223 | ;; is loaded, or see the section on `follow-mode-hook' above for an | |
224 | ;; example of how to bind the keys the way you like. | |
e79016aa | 225 | |
4bef9110 | 226 | (defcustom follow-mode-prefix "\C-c." |
08a1dbe6 | 227 | "Prefix key to use for follow commands in Follow mode. |
e79016aa | 228 | The value of this variable is checked as part of loading Follow mode. |
4bef9110 SE |
229 | After that, changing the prefix key requires manipulating keymaps." |
230 | :type 'string | |
231 | :group 'follow) | |
232 | ||
08a1dbe6 SM |
233 | (defvar follow-mode-map |
234 | (let ((mainmap (make-sparse-keymap)) | |
235 | (map (make-sparse-keymap))) | |
e79016aa KH |
236 | (define-key map "\C-v" 'follow-scroll-up) |
237 | (define-key map "\M-v" 'follow-scroll-down) | |
238 | (define-key map "v" 'follow-scroll-down) | |
239 | (define-key map "1" 'follow-delete-other-windows-and-split) | |
240 | (define-key map "b" 'follow-switch-to-buffer) | |
241 | (define-key map "\C-b" 'follow-switch-to-buffer-all) | |
242 | (define-key map "\C-l" 'follow-recenter) | |
243 | (define-key map "<" 'follow-first-window) | |
244 | (define-key map ">" 'follow-last-window) | |
245 | (define-key map "n" 'follow-next-window) | |
246 | (define-key map "p" 'follow-previous-window) | |
247 | ||
08a1dbe6 | 248 | (define-key mainmap follow-mode-prefix map) |
e79016aa | 249 | |
17f6d002 | 250 | ;; Replace the standard `end-of-buffer', when in Follow mode. (I |
ff753438 | 251 | ;; don't see the point in trying to replace every function that |
e79016aa KH |
252 | ;; could be enhanced in Follow mode. End-of-buffer is a special |
253 | ;; case since it is very simple to define and it greatly enhances | |
254 | ;; the look and feel of Follow mode.) | |
08a1dbe6 | 255 | (define-key mainmap [remap end-of-buffer] 'follow-end-of-buffer) |
e79016aa | 256 | |
782fbf2a CY |
257 | (define-key mainmap [remap scroll-bar-toolkit-scroll] 'follow-scroll-bar-toolkit-scroll) |
258 | (define-key mainmap [remap scroll-bar-drag] 'follow-scroll-bar-drag) | |
259 | (define-key mainmap [remap scroll-bar-scroll-up] 'follow-scroll-bar-scroll-up) | |
260 | (define-key mainmap [remap scroll-bar-scroll-down] 'follow-scroll-bar-scroll-down) | |
87233a14 | 261 | (define-key mainmap [remap mwheel-scroll] 'follow-mwheel-scroll) |
782fbf2a | 262 | |
08a1dbe6 SM |
263 | mainmap) |
264 | "Minor mode keymap for Follow mode.") | |
e79016aa | 265 | |
7dcef48d SM |
266 | ;; When the mode is not activated, only one item is visible to activate |
267 | ;; the mode. | |
268 | (defun follow-menu-filter (menu) | |
17f6d002 | 269 | (if (bound-and-true-p follow-mode) |
7dcef48d | 270 | menu |
17f6d002 | 271 | '(["Follow mode" follow-mode |
7dcef48d SM |
272 | :style toggle :selected follow-mode]))) |
273 | ||
7dcef48d SM |
274 | (easy-menu-add-item nil '("Tools") |
275 | '("Follow" | |
7dcef48d SM |
276 | :filter follow-menu-filter |
277 | ["Scroll Up" follow-scroll-up follow-mode] | |
278 | ["Scroll Down" follow-scroll-down follow-mode] | |
279 | "--" | |
280 | ["Delete Other Windows and Split" follow-delete-other-windows-and-split follow-mode] | |
281 | "--" | |
282 | ["Switch To Buffer" follow-switch-to-buffer follow-mode] | |
283 | ["Switch To Buffer (all windows)" follow-switch-to-buffer-all follow-mode] | |
284 | "--" | |
285 | ["First Window" follow-first-window follow-mode] | |
286 | ["Last Window" follow-last-window follow-mode] | |
287 | ["Next Window" follow-next-window follow-mode] | |
288 | ["Previous Window" follow-previous-window follow-mode] | |
289 | "--" | |
290 | ["Recenter" follow-recenter follow-mode] | |
291 | "--" | |
292 | ["Follow mode" follow-mode :style toggle :selected follow-mode])) | |
293 | ||
08a1dbe6 SM |
294 | (defcustom follow-mode-line-text " Follow" |
295 | "Text shown in the mode line when Follow mode is active. | |
296 | Defaults to \" Follow\". Examples of other values | |
297 | are \" Fw\", or simply \"\"." | |
298 | :type 'string | |
299 | :group 'follow) | |
300 | ||
301 | (defcustom follow-auto nil | |
302 | "Non-nil activates Follow mode whenever a file is loaded." | |
303 | :type 'boolean | |
782fbf2a CY |
304 | :group 'follow |
305 | :set (lambda (symbol value) | |
306 | (if value | |
307 | (add-hook 'find-file-hook 'follow-find-file-hook t) | |
308 | (remove-hook 'find-file-hook 'follow-find-file-hook)) | |
309 | (set-default symbol value))) | |
08a1dbe6 SM |
310 | |
311 | (defvar follow-cache-command-list | |
312 | '(next-line previous-line forward-char backward-char) | |
313 | "List of commands that don't require recalculation. | |
314 | ||
315 | In order to be able to use the cache, a command should not change the | |
316 | contents of the buffer, nor should it change selected window or current | |
317 | buffer. | |
318 | ||
319 | The commands in this list are checked at load time. | |
320 | ||
321 | To mark other commands as suitable for caching, set the symbol | |
322 | property `follow-mode-use-cache' to non-nil.") | |
323 | ||
78f3273a CY |
324 | (defcustom follow-debug nil |
325 | "If non-nil, emit Follow mode debugging messages." | |
326 | :type 'boolean | |
327 | :group 'follow) | |
08a1dbe6 SM |
328 | |
329 | ;; Internal variables: | |
330 | ||
331 | (defvar follow-internal-force-redisplay nil | |
332 | "True when Follow mode should redisplay the windows.") | |
333 | ||
08a1dbe6 SM |
334 | (defvar follow-active-menu nil |
335 | "The menu visible when Follow mode is active.") | |
336 | ||
72b255c7 PE |
337 | (defvar follow-inactive-menu nil |
338 | "The menu visible when Follow mode is inactive.") | |
08a1dbe6 SM |
339 | |
340 | (defvar follow-inside-post-command-hook nil | |
341 | "Non-nil when inside Follow modes `post-command-hook'. | |
342 | Used by `follow-window-size-change'.") | |
343 | ||
344 | (defvar follow-windows-start-end-cache nil | |
345 | "Cache used by `follow-window-start-end'.") | |
346 | ||
c93b886f | 347 | ;;; Debug messages |
08a1dbe6 SM |
348 | |
349 | ;; This inline function must be as small as possible! | |
350 | ;; Maybe we should define a macro that expands to nil if | |
351 | ;; the variable is not set. | |
352 | ||
353 | (defsubst follow-debug-message (&rest args) | |
5eba16a3 | 354 | "Like `message', but only active when `follow-debug' is non-nil." |
08a1dbe6 SM |
355 | (if (and (boundp 'follow-debug) follow-debug) |
356 | (apply 'message args))) | |
e79016aa | 357 | |
c93b886f | 358 | ;;; Cache |
f3bfa025 | 359 | |
08a1dbe6 SM |
360 | (dolist (cmd follow-cache-command-list) |
361 | (put cmd 'follow-mode-use-cache t)) | |
f3bfa025 | 362 | |
c93b886f | 363 | ;;; The mode |
e79016aa KH |
364 | |
365 | ;;;###autoload | |
366 | (defun turn-on-follow-mode () | |
08a1dbe6 | 367 | "Turn on Follow mode. Please see the function `follow-mode'." |
e79016aa KH |
368 | (follow-mode 1)) |
369 | ||
370 | ||
371 | ;;;###autoload | |
372 | (defun turn-off-follow-mode () | |
08a1dbe6 | 373 | "Turn off Follow mode. Please see the function `follow-mode'." |
e79016aa KH |
374 | (follow-mode -1)) |
375 | ||
08a1dbe6 | 376 | (put 'follow-mode 'permanent-local t) |
e79016aa | 377 | ;;;###autoload |
08a1dbe6 | 378 | (define-minor-mode follow-mode |
06e21633 CY |
379 | "Toggle Follow mode. |
380 | With a prefix argument ARG, enable Follow mode if ARG is | |
381 | positive, and disable it otherwise. If called from Lisp, enable | |
382 | the mode if ARG is omitted or nil. | |
e79016aa | 383 | |
06e21633 CY |
384 | Follow mode is a minor mode that combines windows into one tall |
385 | virtual window. This is accomplished by two main techniques: | |
e79016aa | 386 | |
cb02be17 | 387 | * The windows always displays adjacent sections of the buffer. |
e79016aa | 388 | This means that whenever one window is moved, all the |
17f6d002 | 389 | others will follow. (Hence the name Follow mode.) |
e79016aa | 390 | |
cb02be17 KH |
391 | * Should the point (cursor) end up outside a window, another |
392 | window displaying that point is selected, if possible. This | |
393 | makes it possible to walk between windows using normal cursor | |
e79016aa KH |
394 | movement commands. |
395 | ||
396 | Follow mode comes to its prime when used on a large screen and two | |
3eaf40f7 | 397 | side-by-side windows are used. The user can, with the help of Follow |
e79016aa | 398 | mode, use two full-height windows as though they would have been |
8cd3480b | 399 | one. Imagine yourself editing a large function, or section of text, |
c8d05b03 | 400 | and being able to use 144 lines instead of the normal 72... (your |
e79016aa KH |
401 | mileage may vary). |
402 | ||
403 | To split one large window into two side-by-side windows, the commands | |
2d197ffb | 404 | `\\[split-window-right]' or \ |
e79016aa KH |
405 | `M-x follow-delete-other-windows-and-split' can be used. |
406 | ||
8cd3480b | 407 | Only windows displayed in the same frame follow each other. |
e79016aa | 408 | |
eceb3266 | 409 | This command runs the normal hook `follow-mode-hook'. |
e79016aa KH |
410 | |
411 | Keys specific to Follow mode: | |
412 | \\{follow-mode-map}" | |
08a1dbe6 | 413 | :keymap follow-mode-map |
782fbf2a CY |
414 | (if follow-mode |
415 | (progn | |
416 | (add-hook 'compilation-filter-hook 'follow-align-compilation-windows t t) | |
417 | (add-hook 'post-command-hook 'follow-post-command-hook t) | |
418 | (add-hook 'window-size-change-functions 'follow-window-size-change t)) | |
419 | ;; Remove globally-installed hook functions only if there is no | |
420 | ;; other Follow mode buffer. | |
421 | (let ((buffers (buffer-list)) | |
422 | following) | |
423 | (while (and (not following) buffers) | |
424 | (setq following (buffer-local-value 'follow-mode (car buffers)) | |
425 | buffers (cdr buffers))) | |
426 | (unless following | |
427 | (remove-hook 'post-command-hook 'follow-post-command-hook) | |
428 | (remove-hook 'window-size-change-functions 'follow-window-size-change))) | |
429 | (remove-hook 'compilation-filter-hook 'follow-align-compilation-windows t))) | |
e79016aa KH |
430 | |
431 | (defun follow-find-file-hook () | |
17f6d002 | 432 | "Find-file hook for Follow mode. See the variable `follow-auto'." |
782fbf2a | 433 | (if follow-auto (follow-mode 1))) |
e79016aa | 434 | |
c93b886f | 435 | ;;; User functions |
e79016aa | 436 | |
c93b886f | 437 | ;;; Scroll |
e79016aa | 438 | |
17f6d002 | 439 | ;; `scroll-up' and `-down', but for windows in Follow mode. |
e79016aa | 440 | ;; |
4c36be58 | 441 | ;; Almost like the real thing, except when the cursor ends up outside |
e79016aa | 442 | ;; the top or bottom... In our case however, we end up outside the |
40ba43b4 | 443 | ;; window and hence we are recentered. Should we let `recenter' handle |
e79016aa KH |
444 | ;; the point position we would never leave the selected window. To do |
445 | ;; it ourselves we would need to do our own redisplay, which is easier | |
446 | ;; said than done. (Why didn't I do a real display abstraction from | |
447 | ;; the beginning?) | |
448 | ;; | |
449 | ;; We must sometimes set `follow-internal-force-redisplay', otherwise | |
450 | ;; our post-command-hook will move our windows back into the old | |
451 | ;; position... (This would also be corrected if we would have had a | |
452 | ;; good redisplay abstraction.) | |
453 | ||
454 | (defun follow-scroll-up (&optional arg) | |
17f6d002 | 455 | "Scroll text in a Follow mode window chain up. |
e79016aa KH |
456 | |
457 | If called with no ARG, the `next-screen-context-lines' last lines of | |
458 | the bottom window in the chain will be visible in the top window. | |
459 | ||
460 | If called with an argument, scroll ARG lines up. | |
461 | Negative ARG means scroll downward. | |
462 | ||
17f6d002 | 463 | Works like `scroll-up' when not in Follow mode." |
e79016aa | 464 | (interactive "P") |
782fbf2a | 465 | (cond ((not follow-mode) |
e79016aa KH |
466 | (scroll-up arg)) |
467 | (arg | |
468 | (save-excursion (scroll-up arg)) | |
469 | (setq follow-internal-force-redisplay t)) | |
470 | (t | |
471 | (let* ((windows (follow-all-followers)) | |
472 | (end (window-end (car (reverse windows))))) | |
473 | (if (eq end (point-max)) | |
474 | (signal 'end-of-buffer nil) | |
475 | (select-window (car windows)) | |
ff753438 RS |
476 | ;; `window-end' might return nil. |
477 | (if end | |
478 | (goto-char end)) | |
e79016aa KH |
479 | (vertical-motion (- next-screen-context-lines)) |
480 | (set-window-start (car windows) (point))))))) | |
481 | ||
482 | ||
483 | (defun follow-scroll-down (&optional arg) | |
17f6d002 | 484 | "Scroll text in a Follow mode window chain down. |
e79016aa KH |
485 | |
486 | If called with no ARG, the `next-screen-context-lines' top lines of | |
487 | the top window in the chain will be visible in the bottom window. | |
488 | ||
489 | If called with an argument, scroll ARG lines down. | |
490 | Negative ARG means scroll upward. | |
491 | ||
17f6d002 | 492 | Works like `scroll-up' when not in Follow mode." |
e79016aa | 493 | (interactive "P") |
782fbf2a | 494 | (cond ((not follow-mode) |
e79016aa KH |
495 | (scroll-up arg)) |
496 | (arg | |
497 | (save-excursion (scroll-down arg))) | |
498 | (t | |
499 | (let* ((windows (follow-all-followers)) | |
500 | (win (car (reverse windows))) | |
501 | (start (window-start (car windows)))) | |
502 | (if (eq start (point-min)) | |
503 | (signal 'beginning-of-buffer nil) | |
504 | (select-window win) | |
505 | (goto-char start) | |
cb02be17 | 506 | (vertical-motion (- (- (window-height win) |
99dfcc0d | 507 | (if header-line-format 2 1) |
e79016aa KH |
508 | next-screen-context-lines))) |
509 | (set-window-start win (point)) | |
510 | (goto-char start) | |
511 | (vertical-motion (- next-screen-context-lines 1)) | |
512 | (setq follow-internal-force-redisplay t)))))) | |
513 | ||
782fbf2a CY |
514 | (declare-function comint-adjust-point "comint" (window)) |
515 | (defvar comint-scroll-show-maximum-output) | |
516 | ||
517 | (defun follow-comint-scroll-to-bottom (&optional window) | |
518 | "Scroll the bottom-most window in the current Follow chain. | |
519 | This is to be called by `comint-postoutput-scroll-to-bottom'." | |
520 | (let* ((buffer (current-buffer)) | |
521 | (selected (selected-window)) | |
522 | (is-selected (eq (window-buffer) buffer)) | |
523 | some-window) | |
524 | (when (or is-selected | |
525 | (setq some-window (get-buffer-window))) | |
526 | (let* ((pos (progn (comint-adjust-point nil) (point))) | |
527 | (win (if is-selected | |
528 | selected | |
529 | (car (last (follow-all-followers some-window)))))) | |
530 | (select-window win) | |
531 | (goto-char pos) | |
532 | (setq follow-windows-start-end-cache nil) | |
533 | (follow-adjust-window win pos) | |
534 | (unless is-selected | |
535 | (select-window selected) | |
536 | (set-buffer buffer)))))) | |
537 | ||
538 | (defun follow-align-compilation-windows () | |
539 | "Align the windows of the current Follow mode buffer. | |
540 | This is to be called from `compilation-filter-hook'." | |
541 | (let ((buffer (current-buffer)) | |
542 | (win (get-buffer-window)) | |
543 | (selected (selected-window))) | |
544 | (when (and follow-mode (waiting-for-user-input-p) win) | |
545 | (let ((windows (follow-all-followers win))) | |
546 | (unless (eq (window-buffer selected) buffer) | |
547 | (setq win (car windows)) | |
548 | (select-window win)) | |
549 | (follow-redisplay windows win t) | |
550 | (setq follow-windows-start-end-cache nil) | |
551 | (unless (eq selected win) | |
552 | (select-window selected) | |
553 | (set-buffer buffer)))))) | |
554 | ||
c93b886f | 555 | ;;; Buffer |
e79016aa KH |
556 | |
557 | ;;;###autoload | |
558 | (defun follow-delete-other-windows-and-split (&optional arg) | |
17f6d002 | 559 | "Create two side by side windows and enter Follow mode. |
e79016aa KH |
560 | |
561 | Execute this command to display as much as possible of the text | |
cb02be17 | 562 | in the selected window. All other windows, in the current |
e79016aa | 563 | frame, are deleted and the selected window is split in two |
17f6d002 | 564 | side-by-side windows. Follow mode is activated, hence the |
e79016aa KH |
565 | two windows always will display two successive pages. |
566 | \(If one window is moved, the other one will follow.) | |
567 | ||
8cd3480b | 568 | If ARG is positive, the leftmost window is selected. If negative, |
e79016aa | 569 | the rightmost is selected. If ARG is nil, the leftmost window is |
782fbf2a | 570 | selected if the original window is the first one in the frame." |
e79016aa | 571 | (interactive "P") |
cb02be17 | 572 | (let ((other (or (and (null arg) |
e79016aa KH |
573 | (not (eq (selected-window) |
574 | (frame-first-window (selected-frame))))) | |
575 | (and arg | |
576 | (< (prefix-numeric-value arg) 0)))) | |
577 | (start (window-start))) | |
578 | (delete-other-windows) | |
2d197ffb | 579 | (split-window-right) |
cb02be17 | 580 | (if other |
e79016aa KH |
581 | (progn |
582 | (other-window 1) | |
583 | (set-window-start (selected-window) start) | |
584 | (setq follow-internal-force-redisplay t))) | |
585 | (follow-mode 1))) | |
586 | ||
587 | (defun follow-switch-to-buffer (buffer) | |
17f6d002 | 588 | "Show BUFFER in all windows in the current Follow mode window chain." |
e79016aa KH |
589 | (interactive "BSwitch to Buffer: ") |
590 | (let ((orig-window (selected-window)) | |
591 | (windows (follow-all-followers))) | |
592 | (while windows | |
593 | (select-window (car windows)) | |
594 | (switch-to-buffer buffer) | |
595 | (setq windows (cdr windows))) | |
596 | (select-window orig-window))) | |
597 | ||
598 | ||
599 | (defun follow-switch-to-buffer-all (&optional buffer) | |
600 | "Show BUFFER in all windows on this frame. | |
601 | Defaults to current buffer." | |
cb02be17 | 602 | (interactive (list (read-buffer "Switch to Buffer: " |
e79016aa KH |
603 | (current-buffer)))) |
604 | (or buffer (setq buffer (current-buffer))) | |
605 | (let ((orig-window (selected-window))) | |
782fbf2a CY |
606 | (walk-windows (lambda (win) |
607 | (select-window win) | |
608 | (switch-to-buffer buffer)) | |
609 | 'no-minibuf) | |
e79016aa KH |
610 | (select-window orig-window) |
611 | (follow-redisplay))) | |
612 | ||
613 | ||
614 | (defun follow-switch-to-current-buffer-all () | |
782fbf2a | 615 | "Show current buffer in all windows on this frame, and enter Follow mode." |
e79016aa | 616 | (interactive) |
782fbf2a CY |
617 | (unless follow-mode |
618 | (follow-mode 1)) | |
e79016aa KH |
619 | (follow-switch-to-buffer-all)) |
620 | ||
c93b886f | 621 | ;;; Movement |
e79016aa | 622 | |
fc779383 | 623 | ;; Note, these functions are not very useful, at least not unless you |
e79016aa KH |
624 | ;; rebind the rather cumbersome key sequence `C-c . p'. |
625 | ||
626 | (defun follow-next-window () | |
627 | "Select the next window showing the same buffer." | |
628 | (interactive) | |
629 | (let ((succ (cdr (follow-split-followers (follow-all-followers))))) | |
630 | (if succ | |
631 | (select-window (car succ)) | |
632 | (error "%s" "No more windows")))) | |
633 | ||
634 | ||
635 | (defun follow-previous-window () | |
636 | "Select the previous window showing the same buffer." | |
637 | (interactive) | |
638 | (let ((pred (car (follow-split-followers (follow-all-followers))))) | |
639 | (if pred | |
640 | (select-window (car pred)) | |
641 | (error "%s" "No more windows")))) | |
642 | ||
643 | ||
644 | (defun follow-first-window () | |
645 | "Select the first window in the frame showing the same buffer." | |
646 | (interactive) | |
647 | (select-window (car (follow-all-followers)))) | |
648 | ||
649 | ||
650 | (defun follow-last-window () | |
651 | "Select the last window in the frame showing the same buffer." | |
652 | (interactive) | |
653 | (select-window (car (reverse (follow-all-followers))))) | |
654 | ||
c93b886f | 655 | ;;; Redraw |
e79016aa KH |
656 | |
657 | (defun follow-recenter (&optional arg) | |
cb02be17 KH |
658 | "Recenter the middle window around point. |
659 | Rearrange all other windows around the middle window. | |
e79016aa KH |
660 | |
661 | With a positive argument, place the current line ARG lines | |
8cd3480b JB |
662 | from the top. With a negative argument, place it -ARG lines |
663 | from the bottom." | |
e79016aa KH |
664 | (interactive "P") |
665 | (if arg | |
666 | (let ((p (point)) | |
667 | (arg (prefix-numeric-value arg))) | |
668 | (if (>= arg 0) | |
669 | ;; Recenter relative to the top. | |
670 | (progn | |
671 | (follow-first-window) | |
672 | (goto-char p) | |
673 | (recenter arg)) | |
674 | ;; Recenter relative to the bottom. | |
675 | (follow-last-window) | |
676 | (goto-char p) | |
677 | (recenter arg) | |
678 | ;; Otherwise, our post-command-hook will move the window | |
679 | ;; right back. | |
680 | (setq follow-internal-force-redisplay t))) | |
681 | ;; Recenter in the middle. | |
682 | (let* ((dest (point)) | |
683 | (windows (follow-all-followers)) | |
684 | (win (nth (/ (- (length windows) 1) 2) windows))) | |
685 | (select-window win) | |
686 | (goto-char dest) | |
782fbf2a | 687 | (recenter)))) |
e79016aa KH |
688 | |
689 | ||
690 | (defun follow-redraw () | |
691 | "Arrange windows displaying the same buffer in successor order. | |
692 | This function can be called even if the buffer is not in Follow mode. | |
693 | ||
694 | Hopefully, there should be no reason to call this function when in | |
695 | Follow mode since the windows should always be aligned." | |
696 | (interactive) | |
697 | (sit-for 0) | |
698 | (follow-redisplay)) | |
699 | ||
c93b886f | 700 | ;;; End of buffer |
e79016aa KH |
701 | |
702 | (defun follow-end-of-buffer (&optional arg) | |
17f6d002 | 703 | "Move point to the end of the buffer, Follow mode style. |
e79016aa KH |
704 | |
705 | If the end is not visible, it will be displayed in the last possible | |
17f6d002 | 706 | window in the Follow mode window chain. |
e79016aa | 707 | |
cb02be17 | 708 | The mark is left at the previous position. With arg N, put point N/10 |
e79016aa KH |
709 | of the way from the true end." |
710 | (interactive "P") | |
711 | (let ((followers (follow-all-followers)) | |
712 | (pos (point))) | |
713 | (cond (arg | |
714 | (select-window (car (reverse followers)))) | |
cb02be17 | 715 | ((follow-select-if-end-visible |
e79016aa KH |
716 | (follow-windows-start-end followers))) |
717 | (t | |
718 | (select-window (car (reverse followers))))) | |
719 | (goto-char pos) | |
2a4b9211 RS |
720 | (with-no-warnings |
721 | (end-of-buffer arg)))) | |
e79016aa | 722 | |
c93b886f | 723 | ;;; Display |
e79016aa | 724 | |
782fbf2a CY |
725 | (defun follow--window-sorter (w1 w2) |
726 | "Sorting function for W1 and W2 based on their positions. | |
727 | Return non-nil if W1 is above W2; if their top-lines | |
728 | are at the same position, return non-nil if W1 is to the | |
729 | left of W2." | |
730 | (let* ((edge-1 (window-pixel-edges w1)) | |
731 | (edge-2 (window-pixel-edges w2)) | |
732 | (y1 (nth 1 edge-1)) | |
733 | (y2 (nth 1 edge-2))) | |
734 | (if (= y1 y2) | |
735 | (< (car edge-1) (car edge-2)) | |
736 | (< y1 y2)))) | |
737 | ||
738 | (defun follow-all-followers (&optional win) | |
739 | "Return all windows displaying the same buffer as the WIN. | |
740 | The list is sorted with topmost and leftmost windows first, and | |
741 | contains only windows in the same frame as WIN. If WIN is nil, | |
742 | it defaults to the selected window." | |
743 | (unless (window-live-p win) | |
744 | (setq win (selected-window))) | |
745 | (let ((buffer (window-buffer win)) | |
746 | windows) | |
747 | (dolist (w (window-list (window-frame win) 'no-minibuf win)) | |
748 | (if (eq (window-buffer w) buffer) | |
749 | (push w windows))) | |
750 | (sort windows 'follow--window-sorter))) | |
e79016aa KH |
751 | |
752 | (defun follow-split-followers (windows &optional win) | |
782fbf2a | 753 | "Split WINDOWS into two sets: predecessors and successors. |
cb02be17 | 754 | Return `(PRED . SUCC)' where `PRED' and `SUCC' are ordered starting |
e79016aa | 755 | from the selected window." |
cb02be17 | 756 | (or win |
e79016aa KH |
757 | (setq win (selected-window))) |
758 | (let ((pred '())) | |
759 | (while (not (eq (car windows) win)) | |
760 | (setq pred (cons (car windows) pred)) | |
761 | (setq windows (cdr windows))) | |
762 | (cons pred (cdr windows)))) | |
763 | ||
e79016aa | 764 | (defun follow-calc-win-end (&optional win) |
c93b886f CY |
765 | "Calculate the end position for window WIN. |
766 | Return (END-POS END-OF-BUFFER). | |
767 | ||
768 | Actually, the position returned is the start of the line after | |
769 | the last fully-visible line in WIN. If WIN is nil, the selected | |
770 | window is used." | |
771 | (let* ((win (or win (selected-window))) | |
772 | (edges (window-inside-pixel-edges win)) | |
773 | (ht (- (nth 3 edges) (nth 1 edges))) | |
774 | (last-line-pos (posn-point (posn-at-x-y 0 (1- ht) win)))) | |
775 | (if (pos-visible-in-window-p last-line-pos win) | |
776 | (let ((end (window-end win t))) | |
777 | (list end (= end (point-max)))) | |
778 | (list last-line-pos nil)))) | |
e79016aa | 779 | |
e79016aa | 780 | (defun follow-calc-win-start (windows pos win) |
782fbf2a CY |
781 | "Determine the start of window WIN in a Follow mode window chain. |
782 | WINDOWS is a list of chained windows, and POS is the starting | |
783 | position for the first window in the list. If WIN is nil, return | |
784 | the point below all windows." | |
785 | (while (and windows (not (eq (car windows) win))) | |
786 | (let ((old-start (window-start (car windows)))) | |
787 | ;; Can't use `save-window-excursion' since it triggers a redraw. | |
e79016aa | 788 | (set-window-start (car windows) pos 'noforce) |
4484b97d | 789 | (setq pos (car (follow-calc-win-end (car windows)))) |
782fbf2a CY |
790 | (set-window-start (car windows) old-start 'noforce) |
791 | (setq windows (cdr windows)))) | |
792 | pos) | |
e79016aa | 793 | |
f3bfa025 KH |
794 | ;; The result from `follow-windows-start-end' is cached when using |
795 | ;; a handful simple commands, like cursor movement commands. | |
796 | ||
797 | (defsubst follow-cache-valid-p (windows) | |
798 | "Test if the cached value of `follow-windows-start-end' can be used. | |
799 | Note that this handles the case when the cache has been set to nil." | |
800 | (let ((res t) | |
801 | (cache follow-windows-start-end-cache)) | |
802 | (while (and res windows cache) | |
803 | (setq res (and (eq (car windows) | |
804 | (car (car cache))) | |
805 | (eq (window-start (car windows)) | |
806 | (car (cdr (car cache)))))) | |
807 | (setq windows (cdr windows)) | |
808 | (setq cache (cdr cache))) | |
809 | (and res (null windows) (null cache)))) | |
810 | ||
e79016aa | 811 | (defun follow-windows-start-end (windows) |
782fbf2a | 812 | "Return a list of (WIN START END BUFFER-END-P) for window list WINDOWS." |
f3bfa025 KH |
813 | (if (follow-cache-valid-p windows) |
814 | follow-windows-start-end-cache | |
30bf4750 CY |
815 | (let ((orig-win (selected-window)) |
816 | win-start-end) | |
817 | (dolist (w windows) | |
818 | (select-window w) | |
819 | (push (cons w (cons (window-start) (follow-calc-win-end))) | |
820 | win-start-end)) | |
f3bfa025 | 821 | (select-window orig-win) |
30bf4750 | 822 | (setq follow-windows-start-end-cache (nreverse win-start-end))))) |
f3bfa025 | 823 | |
f3bfa025 | 824 | (defsubst follow-pos-visible (pos win win-start-end) |
e79016aa KH |
825 | "Non-nil when POS is visible in WIN." |
826 | (let ((wstart-wend-bend (cdr (assq win win-start-end)))) | |
827 | (and (>= pos (car wstart-wend-bend)) | |
30bf4750 | 828 | (or (< pos (cadr wstart-wend-bend)) |
e79016aa KH |
829 | (nth 2 wstart-wend-bend))))) |
830 | ||
831 | ||
30bf4750 | 832 | ;; By `aligned' we mean that for all adjacent windows, the end of the |
e79016aa KH |
833 | ;; first is equal with the start of the successor. The first window |
834 | ;; should start at a full screen line. | |
835 | ||
f3bfa025 | 836 | (defsubst follow-windows-aligned-p (win-start-end) |
782fbf2a CY |
837 | "Non-nil if the follower windows are aligned. |
838 | The argument, WIN-START-END, should be a list of the form | |
839 | returned by `follow-windows-start-end'." | |
840 | (let ((result t)) | |
841 | (while (and win-start-end result) | |
842 | (if (cdr win-start-end) | |
843 | (setq result (eq (nth 2 (car win-start-end)) | |
844 | (nth 1 (cadr win-start-end))))) | |
e79016aa | 845 | (setq win-start-end (cdr win-start-end))) |
782fbf2a | 846 | result)) |
e79016aa KH |
847 | |
848 | ;; Check if the point is visible in all windows. (So that | |
849 | ;; no one will be recentered.) | |
850 | ||
851 | (defun follow-point-visible-all-windows-p (win-start-end) | |
8cd3480b | 852 | "Non-nil when the `window-point' is visible in all windows." |
e79016aa KH |
853 | (let ((res t)) |
854 | (while (and res win-start-end) | |
f3bfa025 KH |
855 | (setq res (follow-pos-visible (window-point (car (car win-start-end))) |
856 | (car (car win-start-end)) | |
857 | win-start-end)) | |
e79016aa KH |
858 | (setq win-start-end (cdr win-start-end))) |
859 | res)) | |
860 | ||
861 | ||
5eba16a3 | 862 | ;; Make sure WIN always starts at the beginning of a whole screen |
e79016aa KH |
863 | ;; line. If WIN is not aligned the start is updated which probably |
864 | ;; will lead to a redisplay of the screen later on. | |
865 | ;; | |
866 | ;; This is used with the first window in a follow chain. The reason | |
867 | ;; is that we want to detect that the point is outside the window. | |
868 | ;; (Without the update, the start of the window will move as the | |
869 | ;; user presses BackSpace, and the other window redisplay routines | |
870 | ;; will move the start of the window in the wrong direction.) | |
871 | ||
872 | (defun follow-update-window-start (win) | |
873 | "Make sure that the start of WIN starts at a full screen line." | |
874 | (save-excursion | |
875 | (goto-char (window-start win)) | |
4484b97d | 876 | (unless (bolp) |
e79016aa | 877 | (vertical-motion 0 win) |
4484b97d | 878 | (unless (eq (point) (window-start win)) |
e79016aa KH |
879 | (vertical-motion 1 win) |
880 | (set-window-start win (point) 'noforce))))) | |
881 | ||
e79016aa KH |
882 | (defun follow-select-if-visible (dest win-start-end) |
883 | "Select and return a window, if DEST is visible in it. | |
884 | Return the selected window." | |
782fbf2a | 885 | (let (win win-end wse) |
e79016aa | 886 | (while (and (not win) win-start-end) |
ff753438 | 887 | ;; Don't select a window that was just moved. This makes it |
782fbf2a CY |
888 | ;; possible to later select the last window after a |
889 | ;; `end-of-buffer' command. | |
890 | (setq wse (car win-start-end)) | |
891 | (when (follow-pos-visible dest (car wse) win-start-end) | |
892 | (setq win (car wse) | |
893 | win-end (nth 2 wse)) | |
4484b97d | 894 | (select-window win)) |
e79016aa KH |
895 | (setq win-start-end (cdr win-start-end))) |
896 | win)) | |
897 | ||
5eba16a3 JB |
898 | ;; Lets select a window showing the end. Make sure we only select it if |
899 | ;; it wasn't just moved here. (I.e. M-> shall not unconditionally place | |
e79016aa KH |
900 | ;; the point in the selected window.) |
901 | ;; | |
da6062e6 | 902 | ;; (Compatibility kludge: in Emacs `window-end' is equal to `point-max'; |
e79016aa | 903 | ;; in XEmacs, it is equal to `point-max + 1'. Should I really bother |
cb02be17 | 904 | ;; checking `window-end' now when I check `end-of-buffer' explicitly?) |
e79016aa KH |
905 | |
906 | (defun follow-select-if-end-visible (win-start-end) | |
907 | "Select and return a window, if end is visible in it." | |
908 | (let ((win nil)) | |
909 | (while (and (not win) win-start-end) | |
ff753438 | 910 | ;; Don't select a window that was just moved. This makes it |
e79016aa KH |
911 | ;; possible to later select the last window after a `end-of-buffer' |
912 | ;; command. | |
913 | (if (and (eq (point-max) (nth 2 (car win-start-end))) | |
914 | (nth 3 (car win-start-end)) | |
ff753438 RS |
915 | ;; `window-end' might return nil. |
916 | (let ((end (window-end (car (car win-start-end))))) | |
917 | (and end | |
918 | (eq (point-max) (min (point-max) end))))) | |
e79016aa KH |
919 | (progn |
920 | (setq win (car (car win-start-end))) | |
921 | (select-window win))) | |
922 | (setq win-start-end (cdr win-start-end))) | |
923 | win)) | |
924 | ||
925 | ||
ff753438 | 926 | ;; Select a window that will display the point if the windows would |
e79016aa KH |
927 | ;; be redisplayed with the first window fixed. This is useful for |
928 | ;; example when the user has pressed return at the bottom of a window | |
929 | ;; as the point is not visible in any window. | |
930 | ||
931 | (defun follow-select-if-visible-from-first (dest windows) | |
30bf4750 CY |
932 | "Try to select one of WINDOWS without repositioning the topmost window. |
933 | If one of the windows in WINDOWS contains DEST, select it, call | |
934 | `follow-redisplay', move point to DEST, and return that window. | |
935 | Otherwise, return nil." | |
936 | (let (win end-pos-end-p) | |
e79016aa KH |
937 | (save-excursion |
938 | (goto-char (window-start (car windows))) | |
939 | ;; Make sure the line start in the beginning of a real screen | |
940 | ;; line. | |
cb02be17 | 941 | (vertical-motion 0 (car windows)) |
30bf4750 | 942 | (when (>= dest (point)) |
e79016aa KH |
943 | ;; At or below the start. Check the windows. |
944 | (save-window-excursion | |
30bf4750 CY |
945 | (let ((windows windows)) |
946 | (while (and (not win) windows) | |
947 | (set-window-start (car windows) (point) 'noforce) | |
948 | (setq end-pos-end-p (follow-calc-win-end (car windows))) | |
949 | (goto-char (car end-pos-end-p)) | |
c93b886f CY |
950 | ;; Visible, if dest above end, or if eob is visible |
951 | ;; inside the window. | |
30bf4750 CY |
952 | (if (or (car (cdr end-pos-end-p)) |
953 | (< dest (point))) | |
e79016aa | 954 | (setq win (car windows)) |
30bf4750 CY |
955 | (setq windows (cdr windows)))))))) |
956 | (when win | |
957 | (select-window win) | |
958 | (follow-redisplay windows (car windows)) | |
959 | (goto-char dest)) | |
e79016aa KH |
960 | win)) |
961 | ||
c93b886f | 962 | ;;; Redisplay |
e79016aa KH |
963 | |
964 | ;; Redraw all the windows on the screen, starting with the top window. | |
c80e3b4a | 965 | ;; The window used as as marker is WIN, or the selected window if WIN |
4484b97d CY |
966 | ;; is nil. Start every window directly after the end of the previous |
967 | ;; window, to make sure long lines are displayed correctly. | |
e79016aa | 968 | |
30bf4750 | 969 | (defun follow-redisplay (&optional windows win preserve-win) |
e79016aa KH |
970 | "Reposition the WINDOWS around WIN. |
971 | Should the point be too close to the roof we redisplay everything | |
8cd3480b | 972 | from the top. WINDOWS should contain a list of windows to |
5eba16a3 | 973 | redisplay; it is assumed that WIN is a member of the list. |
e79016aa KH |
974 | Should WINDOWS be nil, the windows displaying the |
975 | same buffer as WIN, in the current frame, are used. | |
30bf4750 CY |
976 | Should WIN be nil, the selected window is used. |
977 | If PRESERVE-WIN is non-nil, keep WIN itself unchanged while | |
978 | repositioning the other windows." | |
4484b97d CY |
979 | (or win (setq win (selected-window))) |
980 | (or windows (setq windows (follow-all-followers win))) | |
981 | ;; Calculate the start of the first window. | |
982 | (let* ((old-win-start (window-start win)) | |
983 | (try-first-start (follow-estimate-first-window-start | |
984 | windows win old-win-start)) | |
985 | (try-win-start (follow-calc-win-start | |
986 | windows try-first-start win)) | |
987 | (start (cond ((= try-win-start old-win-start) | |
988 | (follow-debug-message "exact") | |
989 | try-first-start) | |
990 | ((< try-win-start old-win-start) | |
991 | (follow-debug-message "above") | |
992 | (follow-calculate-first-window-start-from-above | |
993 | windows try-first-start win old-win-start)) | |
994 | (t | |
995 | (follow-debug-message "below") | |
996 | (follow-calculate-first-window-start-from-below | |
997 | windows try-first-start win old-win-start))))) | |
998 | (dolist (w windows) | |
30bf4750 CY |
999 | (unless (and preserve-win (eq w win)) |
1000 | (set-window-start w start)) | |
4484b97d | 1001 | (setq start (car (follow-calc-win-end w)))))) |
e79016aa | 1002 | |
e79016aa KH |
1003 | (defun follow-estimate-first-window-start (windows win start) |
1004 | "Estimate the position of the first window. | |
4484b97d CY |
1005 | The estimate is computed by assuming that the window WIN, which |
1006 | should be a member of WINDOWS, starts at position START." | |
1007 | (let ((windows-before (car (follow-split-followers windows win)))) | |
e79016aa KH |
1008 | (save-excursion |
1009 | (goto-char start) | |
e79016aa | 1010 | (vertical-motion 0 win) |
4484b97d CY |
1011 | (dolist (w windows-before) |
1012 | (vertical-motion (- 1 (window-text-height w)) w)) | |
1013 | (point)))) | |
e79016aa KH |
1014 | |
1015 | ||
1016 | ;; Find the starting point, start at GUESS and search downward. | |
1017 | ;; The returned point is always a point below GUESS. | |
1018 | ||
cb02be17 | 1019 | (defun follow-calculate-first-window-start-from-above |
e79016aa KH |
1020 | (windows guess win start) |
1021 | (save-excursion | |
1022 | (let ((done nil) | |
1023 | win-start | |
1024 | res) | |
1025 | (goto-char guess) | |
1026 | (while (not done) | |
1027 | (if (not (= (vertical-motion 1 (car windows)) 1)) | |
1028 | ;; Hit bottom! (Can we really do this?) | |
1029 | ;; We'll keep it, since it ensures termination. | |
1030 | (progn | |
1031 | (setq done t) | |
1032 | (setq res (point-max))) | |
1033 | (setq win-start (follow-calc-win-start windows (point) win)) | |
1034 | (if (>= win-start start) | |
4484b97d | 1035 | (setq done t res (point))))) |
e79016aa KH |
1036 | res))) |
1037 | ||
1038 | ||
1039 | ;; Find the starting point, start at GUESS and search upward. Return | |
1040 | ;; a point on the same line as GUESS, or above. | |
e79016aa KH |
1041 | |
1042 | (defun follow-calculate-first-window-start-from-below | |
1043 | (windows guess &optional win start) | |
1044 | (setq win (or win (selected-window))) | |
1045 | (setq start (or start (window-start win))) | |
1046 | (save-excursion | |
13d5c73f | 1047 | (let (done win-start res opoint) |
fc779383 | 1048 | ;; Always calculate what happens when no line is displayed in the first |
e79016aa KH |
1049 | ;; window. (The `previous' res is needed below!) |
1050 | (goto-char guess) | |
1051 | (vertical-motion 0 (car windows)) | |
1052 | (setq res (point)) | |
1053 | (while (not done) | |
13d5c73f | 1054 | (setq opoint (point)) |
e79016aa KH |
1055 | (if (not (= (vertical-motion -1 (car windows)) -1)) |
1056 | ;; Hit roof! | |
4484b97d | 1057 | (setq done t res (point-min)) |
e79016aa | 1058 | (setq win-start (follow-calc-win-start windows (point) win)) |
13d5c73f CY |
1059 | (cond ((>= (point) opoint) |
1060 | ;; In some pathological cases, vertical-motion may | |
1061 | ;; return -1 even though point has not decreased. In | |
1062 | ;; that case, avoid looping forever. | |
1063 | (setq done t res (point))) | |
1064 | ((= win-start start) ; Perfect match, use this value | |
1065 | (setq done t res (point))) | |
5eba16a3 | 1066 | ((< win-start start) ; Walked to far, use previous result |
e79016aa KH |
1067 | (setq done t)) |
1068 | (t ; Store result for next iteration | |
1069 | (setq res (point)))))) | |
1070 | res))) | |
1071 | ||
c93b886f | 1072 | ;;; Avoid tail recenter |
e79016aa | 1073 | |
782fbf2a CY |
1074 | ;; This sets the window internal flag `force_start'. The effect is |
1075 | ;; that windows only displaying the tail aren't recentered. | |
e79016aa | 1076 | ;; |
782fbf2a CY |
1077 | ;; A window displaying only the tail, is a window whose window-start |
1078 | ;; position is equal to (point-max) of the buffer it displays. | |
e79016aa | 1079 | |
06b60517 | 1080 | (defun follow-avoid-tail-recenter (&rest _rest) |
e79016aa | 1081 | "Make sure windows displaying the end of a buffer aren't recentered. |
7194219d | 1082 | This is done by reading and rewriting the start position of |
17f6d002 | 1083 | non-first windows in Follow mode." |
782fbf2a CY |
1084 | (let* ((orig-buffer (current-buffer)) |
1085 | (top (frame-first-window (selected-frame))) | |
1086 | (win top) | |
1087 | who) ; list of (buffer . frame) | |
1088 | ;; If the only window in the frame is a minibuffer | |
1089 | ;; window, `next-window' will never find it again... | |
1090 | (unless (window-minibuffer-p top) | |
1091 | (while ;; look, no body! | |
1092 | (let ((start (window-start win)) | |
1093 | (pair (cons (window-buffer win) (window-frame win)))) | |
1094 | (set-buffer (window-buffer win)) | |
1095 | (cond ((null (member pair who)) | |
1096 | (setq who (cons pair who))) | |
1097 | ((and follow-mode (eq (point-max) start)) | |
1098 | ;; Write the same window start back, but don't | |
1099 | ;; set the NOFORCE flag. | |
1100 | (set-window-start win start))) | |
1101 | (setq win (next-window win 'not t)) | |
1102 | (not (eq win top)))) ;; Loop while this is true. | |
1103 | (set-buffer orig-buffer)))) | |
e79016aa | 1104 | |
c93b886f | 1105 | ;;; Post Command Hook |
e79016aa | 1106 | |
08a1dbe6 | 1107 | ;; The magic little box. This function is called after every command. |
e79016aa KH |
1108 | |
1109 | ;; This is not as complicated as it seems. It is simply a list of common | |
1110 | ;; display situations and the actions to take, plus commands for redrawing | |
1111 | ;; the screen if it should be unaligned. | |
1112 | ;; | |
1113 | ;; We divide the check into two parts; whether we are at the end or not. | |
99dfcc0d | 1114 | ;; This is due to the fact that the end can actually be visible |
e79016aa KH |
1115 | ;; in several window even though they are aligned. |
1116 | ||
1117 | (defun follow-post-command-hook () | |
cb02be17 | 1118 | "Ensure that the windows in Follow mode are adjacent after each command." |
4484b97d CY |
1119 | (unless (input-pending-p) |
1120 | (let ((follow-inside-post-command-hook t) | |
1121 | (win (selected-window))) | |
e79016aa | 1122 | ;; Work in the selected window, not in the current buffer. |
4484b97d CY |
1123 | (with-current-buffer (window-buffer win) |
1124 | (unless (and (symbolp this-command) | |
1125 | (get this-command 'follow-mode-use-cache)) | |
782fbf2a CY |
1126 | (setq follow-windows-start-end-cache nil))) |
1127 | (follow-adjust-window win (point))))) | |
1128 | ||
1129 | (defun follow-adjust-window (win dest) | |
1130 | ;; Adjust the window WIN and its followers. | |
1131 | (with-current-buffer (window-buffer win) | |
1132 | (when (and follow-mode | |
1133 | (not (window-minibuffer-p win))) | |
1134 | (let* ((windows (follow-all-followers win)) | |
1135 | (win-start-end (progn | |
1136 | (follow-update-window-start (car windows)) | |
1137 | (follow-windows-start-end windows))) | |
1138 | (aligned (follow-windows-aligned-p win-start-end)) | |
1139 | (visible (follow-pos-visible dest win win-start-end)) | |
1140 | selected-window-up-to-date) | |
1141 | (unless (and aligned visible) | |
1142 | (setq follow-windows-start-end-cache nil)) | |
1143 | ||
1144 | ;; Select a window to display point. | |
1145 | (unless follow-internal-force-redisplay | |
1146 | (if (eq dest (point-max)) | |
1147 | ;; Be careful at point-max: the display can be aligned | |
1148 | ;; while DEST can be visible in several windows. | |
1149 | (cond | |
1150 | ;; Select the current window, but only when the display | |
1151 | ;; is correct. (When inserting characters in a tail | |
1152 | ;; window, the display is not correct, as they are | |
1153 | ;; shown twice.) | |
1154 | ;; | |
1155 | ;; Never stick to the current window after a deletion. | |
1156 | ;; Otherwise, when typing `DEL' in a window showing | |
1157 | ;; only the end of the file, a character would be | |
1158 | ;; removed from the window above, which is very | |
1159 | ;; unintuitive. | |
1160 | ((and visible | |
1161 | aligned | |
1162 | (not (memq this-command | |
1163 | '(backward-delete-char | |
1164 | delete-backward-char | |
1165 | backward-delete-char-untabify | |
1166 | kill-region)))) | |
1167 | (follow-debug-message "Max: same")) | |
1168 | ;; If the end is visible, and the window doesn't | |
1169 | ;; seems like it just has been moved, select it. | |
1170 | ((follow-select-if-end-visible win-start-end) | |
1171 | (follow-debug-message "Max: end visible") | |
1172 | (setq visible t aligned nil) | |
1173 | (goto-char dest)) | |
1174 | ;; Just show the end... | |
1175 | (t | |
1176 | (follow-debug-message "Max: default") | |
1177 | (select-window (car (last windows))) | |
1178 | (goto-char dest) | |
1179 | (setq visible nil aligned nil))) | |
1180 | ||
1181 | ;; We're not at the end, here life is much simpler. | |
1182 | (cond | |
1183 | ;; This is the normal case! | |
1184 | ;; It should be optimized for speed. | |
1185 | ((and visible aligned) | |
1186 | (follow-debug-message "same")) | |
1187 | ;; Pick a position in any window. If the display is ok, | |
1188 | ;; this picks the `correct' window. | |
1189 | ((follow-select-if-visible dest win-start-end) | |
1190 | (follow-debug-message "visible") | |
1191 | (goto-char dest) | |
1192 | ;; Perform redisplay, in case line is partially visible. | |
1193 | (setq visible nil)) | |
1194 | ;; Not visible anywhere else, lets pick this one. | |
1195 | (visible | |
1196 | (follow-debug-message "visible in selected.")) | |
1197 | ;; If DEST is before the first window start, select the | |
1198 | ;; first window. | |
1199 | ((< dest (nth 1 (car win-start-end))) | |
1200 | (follow-debug-message "before first") | |
1201 | (select-window (car windows)) | |
1202 | (goto-char dest) | |
1203 | (setq visible nil aligned nil)) | |
1204 | ;; If we can position the cursor without moving the first | |
1205 | ;; window, do it. This is the case that catches `RET' at | |
1206 | ;; the bottom of a window. | |
1207 | ((follow-select-if-visible-from-first dest windows) | |
1208 | (follow-debug-message "Below first") | |
1209 | (setq visible t aligned t)) | |
1210 | ;; None of the above. Stick to the selected window. | |
1211 | (t | |
1212 | (follow-debug-message "None") | |
1213 | (setq visible nil aligned nil)))) | |
1214 | ||
1215 | ;; If a new window was selected, make sure that the old is | |
1216 | ;; not scrolled when the point is outside the window. | |
1217 | (unless (eq win (selected-window)) | |
1218 | (let ((p (window-point win))) | |
1219 | (set-window-start win (window-start win) nil) | |
1220 | (set-window-point win p)))) | |
1221 | ||
1222 | (unless visible | |
1223 | ;; If point may not be visible in the selected window, | |
1224 | ;; perform a redisplay; this ensures scrolling. | |
1225 | (let ((opoint (point))) | |
1226 | (redisplay) | |
1227 | ;; If this `redisplay' moved point, we got clobbered by a | |
1228 | ;; previous call to `set-window-start'. Try again. | |
1229 | (when (/= (point) opoint) | |
1230 | (goto-char opoint) | |
1231 | (redisplay))) | |
1232 | ||
1233 | (setq selected-window-up-to-date t) | |
1234 | (follow-avoid-tail-recenter) | |
1235 | (setq win-start-end (follow-windows-start-end windows) | |
1236 | follow-windows-start-end-cache nil | |
1237 | aligned nil)) | |
1238 | ||
1239 | ;; Now redraw the windows around the selected window. | |
1240 | (unless (and (not follow-internal-force-redisplay) | |
1241 | (or aligned | |
1242 | (follow-windows-aligned-p win-start-end)) | |
1243 | (follow-point-visible-all-windows-p win-start-end)) | |
1244 | (setq follow-internal-force-redisplay nil) | |
1245 | (follow-redisplay windows (selected-window) | |
1246 | selected-window-up-to-date) | |
1247 | (setq win-start-end (follow-windows-start-end windows) | |
1248 | follow-windows-start-end-cache nil) | |
1249 | ;; The point can ends up in another window when DEST is at | |
1250 | ;; the beginning of the buffer and the selected window is | |
1251 | ;; not the first. It can also happen when long lines are | |
1252 | ;; used and there is a big difference between the width of | |
1253 | ;; the windows. (When scrolling one line in a wide window | |
1254 | ;; which will cause a move larger that an entire small | |
1255 | ;; window.) | |
1256 | (unless (follow-pos-visible dest win win-start-end) | |
1257 | (follow-select-if-visible dest win-start-end) | |
1258 | (goto-char dest))) | |
1259 | ||
1260 | ;; If the region is visible, make it look good when spanning | |
1261 | ;; multiple windows. | |
1262 | (when (region-active-p) | |
1263 | (follow-maximize-region | |
1264 | (selected-window) windows win-start-end))) | |
1265 | ||
1266 | ;; Whether or not the buffer was in follow mode, update windows | |
1267 | ;; displaying the tail so that Emacs won't recenter them. | |
1268 | (follow-avoid-tail-recenter)))) | |
e79016aa | 1269 | |
c93b886f | 1270 | ;;; The region |
e79016aa KH |
1271 | |
1272 | ;; Tries to make the highlighted area representing the region look | |
cb02be17 | 1273 | ;; good when spanning several windows. |
e79016aa KH |
1274 | ;; |
1275 | ;; Not perfect, as the point can't be placed at window end, only at | |
cb02be17 | 1276 | ;; end-1. This will highlight a little bit in windows above |
e79016aa KH |
1277 | ;; the current. |
1278 | ||
1279 | (defun follow-maximize-region (win windows win-start-end) | |
cb02be17 | 1280 | "Make a highlighted region stretching multiple windows look good." |
e79016aa KH |
1281 | (let* ((all (follow-split-followers windows win)) |
1282 | (pred (car all)) | |
1283 | (succ (cdr all)) | |
1284 | data) | |
1285 | (while pred | |
1286 | (setq data (assq (car pred) win-start-end)) | |
1287 | (set-window-point (car pred) (max (nth 1 data) (- (nth 2 data) 1))) | |
1288 | (setq pred (cdr pred))) | |
1289 | (while succ | |
1290 | (set-window-point (car succ) (nth 1 (assq (car succ) win-start-end))) | |
1291 | (setq succ (cdr succ))))) | |
1292 | ||
c93b886f | 1293 | ;;; Scroll bar |
e79016aa KH |
1294 | |
1295 | ;;;; Scroll-bar support code. | |
1296 | ||
782fbf2a CY |
1297 | ;; This handles the case where the user drags the scroll bar of a |
1298 | ;; non-selected window whose buffer is in Follow mode. | |
1299 | ||
1300 | (defun follow-scroll-bar-toolkit-scroll (event) | |
1301 | (interactive "e") | |
1302 | (scroll-bar-toolkit-scroll event) | |
1303 | (follow-redraw-after-event event)) | |
1304 | ||
1305 | (defun follow-scroll-bar-drag (event) | |
1306 | (interactive "e") | |
1307 | (scroll-bar-drag event) | |
1308 | (follow-redraw-after-event event)) | |
1309 | ||
1310 | (defun follow-scroll-bar-scroll-up (event) | |
1311 | (interactive "e") | |
1312 | (scroll-bar-scroll-up event) | |
1313 | (follow-redraw-after-event event)) | |
1314 | ||
1315 | (defun follow-scroll-bar-scroll-down (event) | |
1316 | (interactive "e") | |
1317 | (scroll-bar-scroll-down event) | |
1318 | (follow-redraw-after-event event)) | |
1319 | ||
87233a14 CY |
1320 | (defun follow-mwheel-scroll (event) |
1321 | (interactive "e") | |
1322 | (mwheel-scroll event) | |
1323 | (follow-redraw-after-event event)) | |
1324 | ||
782fbf2a | 1325 | (defun follow-redraw-after-event (event) |
87233a14 CY |
1326 | "Re-align the Follow mode windows affected by EVENT." |
1327 | (let* ((window (nth 0 (event-end event))) | |
1328 | (buffer (window-buffer window)) | |
1329 | (orig-win (selected-window))) | |
1330 | (when (and (buffer-local-value 'follow-mode buffer) | |
782fbf2a CY |
1331 | ;; Ignore the case where we scroll the selected window; |
1332 | ;; that is handled by the post-command hook function. | |
1333 | (not (eq window (selected-window)))) | |
1334 | (select-window window) | |
1335 | (follow-redisplay) | |
87233a14 CY |
1336 | (unless (eq (window-buffer orig-win) buffer) |
1337 | (select-window orig-win))))) | |
e79016aa | 1338 | |
c93b886f | 1339 | ;;; Window size change |
e79016aa | 1340 | |
782fbf2a CY |
1341 | ;; The functions in `window-size-change-functions' are called every |
1342 | ;; time a window in a frame changes size, most notably after the frame | |
1343 | ;; has been resized. We call `follow-post-command-hook' for every | |
1344 | ;; Follow mode buffer visible in any window in the resized frame. | |
e79016aa | 1345 | ;; |
782fbf2a CY |
1346 | ;; Since `follow-window-size-change' can be called indirectly from |
1347 | ;; `follow-post-command-hook' we have a potential infinite loop. To | |
1348 | ;; avoid this, we simply do not do anything in this situation. The | |
1349 | ;; variable `follow-inside-post-command-hook' contains information | |
1350 | ;; about whether the execution actually is inside the | |
e79016aa KH |
1351 | ;; post-command-hook or not. |
1352 | ||
e79016aa KH |
1353 | (defun follow-window-size-change (frame) |
1354 | "Redraw all windows in FRAME, when in Follow mode." | |
782fbf2a CY |
1355 | ;; Below, we call `post-command-hook'. Avoid an infloop. |
1356 | (unless follow-inside-post-command-hook | |
e79016aa KH |
1357 | (let ((buffers '()) |
1358 | (orig-window (selected-window)) | |
1359 | (orig-buffer (current-buffer)) | |
1360 | (orig-frame (selected-frame)) | |
1361 | windows | |
1362 | buf) | |
1363 | (select-frame frame) | |
1364 | (unwind-protect | |
cb02be17 | 1365 | (walk-windows |
782fbf2a CY |
1366 | (lambda (win) |
1367 | (setq buf (window-buffer win)) | |
1368 | (unless (memq buf buffers) | |
1369 | (set-buffer buf) | |
1370 | (when follow-mode | |
1371 | (setq windows (follow-all-followers win)) | |
1372 | (if (not (memq orig-window windows)) | |
1373 | (follow-redisplay windows win) | |
1374 | ;; Make sure we're redrawing around the selected | |
1375 | ;; window. | |
1376 | (select-window orig-window) | |
1377 | (follow-post-command-hook) | |
1378 | (setq orig-window (selected-window))) | |
1379 | (setq buffers (cons buf buffers))))) | |
1380 | 'no-minibuf) | |
e79016aa KH |
1381 | (select-frame orig-frame) |
1382 | (set-buffer orig-buffer) | |
1383 | (select-window orig-window))))) | |
1384 | ||
782fbf2a | 1385 | (add-hook 'window-scroll-functions 'follow-avoid-tail-recenter t) |
e79016aa | 1386 | |
c93b886f | 1387 | ;;; Profile support |
e79016aa KH |
1388 | |
1389 | ;; The following (non-evaluated) section can be used to | |
1390 | ;; profile this package using `elp'. | |
1391 | ;; | |
1392 | ;; Invalid indentation on purpose! | |
1393 | ||
782fbf2a CY |
1394 | ;; (setq elp-function-list |
1395 | ;; '(window-end | |
1396 | ;; vertical-motion | |
1397 | ;; follow-mode | |
1398 | ;; follow-all-followers | |
1399 | ;; follow-split-followers | |
1400 | ;; follow-redisplay | |
1401 | ;; follow-estimate-first-window-start | |
1402 | ;; follow-calculate-first-window-start-from-above | |
1403 | ;; follow-calculate-first-window-start-from-below | |
1404 | ;; follow-calc-win-end | |
1405 | ;; follow-calc-win-start | |
1406 | ;; follow-pos-visible | |
1407 | ;; follow-windows-start-end | |
1408 | ;; follow-cache-valid-p | |
1409 | ;; follow-select-if-visible | |
1410 | ;; follow-select-if-visible-from-first | |
1411 | ;; follow-windows-aligned-p | |
1412 | ;; follow-point-visible-all-windows-p | |
1413 | ;; follow-avoid-tail-recenter | |
1414 | ;; follow-update-window-start | |
1415 | ;; follow-post-command-hook)) | |
fc779383 | 1416 | |
e79016aa KH |
1417 | (provide 'follow) |
1418 | ||
e79016aa KH |
1419 | ;; /------------------------------------------------------------------------\ |
1420 | ;; | "I [..] am rarely happier then when spending an entire day programming | | |
1421 | ;; | my computer to perform automatically a task that it would otherwise | | |
1422 | ;; | take me a good ten seconds to do by hand. Ten seconds, I tell myself, | | |
1423 | ;; | is ten seconds. Time is valuable and ten seconds' worth of it is well | | |
1424 | ;; | worth the investment of a day's happy activity working out a way to | | |
1425 | ;; | save it". -- Douglas Adams, "Last Chance to See" | | |
1426 | ;; \------------------------------------------------------------------------/ | |
1427 | ||
1428 | ;;; follow.el ends here |