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e8af40ee | 1 | ;;; tpu-extras.el --- scroll margins and free cursor mode for TPU-edt |
b4196a99 | 2 | |
d59c3137 | 3 | ;; Copyright (C) 1993, 1994, 1995, 2000, 2001, 2002, 2003, 2004, |
8b72699e | 4 | ;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc. |
522f9216 RS |
5 | |
6 | ;; Author: Rob Riepel <riepel@networking.stanford.edu> | |
7 | ;; Maintainer: Rob Riepel <riepel@networking.stanford.edu> | |
b7f66977 | 8 | ;; Keywords: emulations |
522f9216 | 9 | |
75993094 RS |
10 | ;; This file is part of GNU Emacs. |
11 | ||
12 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
13 | ;; it under the terms of the GNU General Public License as published by | |
e0085d62 | 14 | ;; the Free Software Foundation; either version 3, or (at your option) |
75993094 RS |
15 | ;; any later version. |
16 | ||
522f9216 | 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
75993094 RS |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
b578f267 | 23 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
3a35cf56 LK |
24 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
25 | ;; Boston, MA 02110-1301, USA. | |
522f9216 | 26 | |
522f9216 RS |
27 | ;;; Commentary: |
28 | ||
84299083 RS |
29 | ;; Use the functions defined here to customize TPU-edt to your tastes by |
30 | ;; setting scroll margins and/or turning on free cursor mode. Here's an | |
31 | ;; example for your .emacs file. | |
32 | ||
33 | ;; (tpu-set-cursor-free) ; Set cursor free. | |
34 | ;; (tpu-set-scroll-margins "10%" "15%") ; Set scroll margins. | |
35 | ||
36 | ;; Scroll margins and cursor binding can be changed from within emacs using | |
37 | ;; the following commands: | |
38 | ||
39 | ;; tpu-set-scroll-margins or set scroll margins | |
40 | ;; tpu-set-cursor-bound or set cursor bound | |
41 | ;; tpu-set-cursor-free or set cursor free | |
42 | ||
43 | ;; Additionally, Gold-F toggles between bound and free cursor modes. | |
44 | ||
45 | ;; Note that switching out of free cursor mode or exiting TPU-edt while in | |
46 | ;; free cursor mode strips trailing whitespace from every line in the file. | |
47 | ||
48 | ||
49 | ;;; Details: | |
50 | ||
522f9216 RS |
51 | ;; The functions contained in this file implement scroll margins and free |
52 | ;; cursor mode. The following keys and commands are affected. | |
53 | ||
54 | ;; key/command function scroll cursor | |
55 | ||
56 | ;; Up-Arrow previous line x x | |
57 | ;; Down-Arrow next line x x | |
58 | ;; Right-Arrow next character x | |
59 | ;; Left-Arrow previous character x | |
60 | ;; KP0 next or previous line x | |
61 | ;; KP7 next or previous page x | |
62 | ;; KP8 next or previous screen x | |
63 | ;; KP2 next or previous end-of-line x x | |
64 | ;; Control-e current end-of-line x | |
65 | ;; Control-h previous beginning-of-line x | |
66 | ;; Next Scr next screen x | |
67 | ;; Prev Scr previous screen x | |
68 | ;; Search find a string x | |
69 | ;; Replace find and replace a string x | |
70 | ;; Newline insert a newline x | |
71 | ;; Paragraph next or previous paragraph x | |
72 | ;; Auto-Fill break lines on spaces x | |
73 | ||
74 | ;; These functions are not part of the base TPU-edt for the following | |
75 | ;; reasons: | |
76 | ||
77 | ;; Free cursor mode is implemented with the emacs picture-mode functions. | |
78 | ;; These functions support moving the cursor all over the screen, however, | |
79 | ;; when the cursor is moved past the end of a line, spaces or tabs are | |
80 | ;; appended to the line - even if no text is entered in that area. In | |
81 | ;; order for a free cursor mode to work exactly like TPU/edt, this trailing | |
82 | ;; whitespace needs to be dealt with in every function that might encounter | |
83 | ;; it. Such global changes are impractical, however, free cursor mode is | |
84 | ;; too valuable to abandon completely, so it has been implemented in those | |
85 | ;; functions where it serves best. | |
86 | ||
87 | ;; The implementation of scroll margins adds overhead to previously | |
88 | ;; simple and often used commands. These commands are now responsible | |
89 | ;; for their normal operation and part of the display function. There | |
90 | ;; is a possibility that this display overhead could adversely affect the | |
91 | ;; performance of TPU-edt on slower computers. In order to support the | |
92 | ;; widest range of computers, scroll margin support is optional. | |
93 | ||
84299083 RS |
94 | ;; It's actually not known whether the overhead associated with scroll |
95 | ;; margin support is significant. If you find that it is, please send | |
522f9216 RS |
96 | ;; a note describing the extent of the performance degradation. Be sure |
97 | ;; to include a description of the platform where you're running TPU-edt. | |
98 | ;; Send your note to the address provided by Gold-V. | |
99 | ||
100 | ;; Even with these differences and limitations, these functions implement | |
101 | ;; important aspects of the real TPU/edt. Those who miss free cursor mode | |
102 | ;; and/or scroll margins will appreciate these implementations. | |
103 | ||
522f9216 RS |
104 | ;;; Code: |
105 | ||
106 | ||
2582e468 | 107 | ;;; Gotta have tpu-edt |
522f9216 | 108 | |
2582e468 | 109 | (require 'tpu-edt) |
522f9216 RS |
110 | |
111 | ||
112 | ;;; Customization variables | |
113 | ||
786b07e8 | 114 | (defcustom tpu-top-scroll-margin 0 |
944a8b1d | 115 | "Scroll margin at the top of the screen. |
786b07e8 SE |
116 | Interpreted as a percent of the current window size." |
117 | :type 'integer | |
118 | :group 'tpu) | |
119 | (defcustom tpu-bottom-scroll-margin 0 | |
944a8b1d | 120 | "Scroll margin at the bottom of the screen. |
786b07e8 SE |
121 | Interpreted as a percent of the current window size." |
122 | :type 'integer | |
123 | :group 'tpu) | |
522f9216 | 124 | |
786b07e8 | 125 | (defcustom tpu-backward-char-like-tpu t |
944a8b1d | 126 | "If non-nil, in free cursor mode backward-char (left-arrow) works |
522f9216 | 127 | just like TPU/edt. Otherwise, backward-char will move to the end of |
786b07e8 SE |
128 | the previous line when starting from a line beginning." |
129 | :type 'boolean | |
130 | :group 'tpu) | |
522f9216 RS |
131 | |
132 | ||
133 | ;;; Global variables | |
134 | ||
944a8b1d SM |
135 | ;;;###autoload |
136 | (define-minor-mode tpu-cursor-free-mode | |
137 | "Minor mode to allow the cursor to move freely about the screen." | |
138 | :init-value nil | |
139 | (if (not tpu-cursor-free-mode) | |
140 | (tpu-trim-line-ends))) | |
522f9216 RS |
141 | |
142 | ||
143 | ;;; Hooks -- Set cursor free in picture mode. | |
144 | ;;; Clean up when writing a file from cursor free mode. | |
145 | ||
158a958d | 146 | (add-hook 'picture-mode-hook 'tpu-set-cursor-free) |
522f9216 | 147 | |
944a8b1d | 148 | (defun tpu-trim-line-ends-if-needed () |
522f9216 | 149 | "Eliminate whitespace at ends of lines, if the cursor is free." |
944a8b1d SM |
150 | (if (and (buffer-modified-p) tpu-cursor-free-mode) (tpu-trim-line-ends))) |
151 | (add-hook 'before-save-hook 'tpu-trim-line-ends-if-needed) | |
522f9216 RS |
152 | |
153 | ||
154 | ;;; Utility routines for implementing scroll margins | |
155 | ||
156 | (defun tpu-top-check (beg lines) | |
157 | "Enforce scroll margin at the top of screen." | |
158 | (let ((margin (/ (* (window-height) tpu-top-scroll-margin) 100))) | |
159 | (cond ((< beg margin) (recenter beg)) | |
160 | ((< (- beg lines) margin) (recenter margin))))) | |
161 | ||
162 | (defun tpu-bottom-check (beg lines) | |
163 | "Enforce scroll margin at the bottom of screen." | |
164 | (let* ((height (window-height)) | |
165 | (margin (+ 1 (/ (* height tpu-bottom-scroll-margin) 100))) | |
166 | ;; subtract 1 from height because it includes mode line | |
167 | (difference (- height margin 1))) | |
168 | (cond ((> beg difference) (recenter beg)) | |
169 | ((> (+ beg lines) difference) (recenter (- margin)))))) | |
170 | ||
171 | ||
172 | ;;; Movement by character | |
173 | ||
174 | (defun tpu-forward-char (num) | |
175 | "Move right ARG characters (left if ARG is negative)." | |
176 | (interactive "p") | |
944a8b1d | 177 | (if tpu-cursor-free-mode (picture-forward-column num) (forward-char num))) |
522f9216 RS |
178 | |
179 | (defun tpu-backward-char (num) | |
180 | "Move left ARG characters (right if ARG is negative)." | |
181 | (interactive "p") | |
944a8b1d | 182 | (cond ((not tpu-cursor-free-mode) |
522f9216 RS |
183 | (backward-char num)) |
184 | (tpu-backward-char-like-tpu | |
185 | (picture-backward-column num)) | |
186 | ((bolp) | |
187 | (backward-char 1) | |
188 | (picture-end-of-line) | |
189 | (picture-backward-column (1- num))) | |
190 | (t | |
191 | (picture-backward-column num)))) | |
192 | ||
193 | ||
194 | ;;; Movement by line | |
195 | ||
196 | (defun tpu-next-line (num) | |
197 | "Move to next line. | |
198 | Prefix argument serves as a repeat count." | |
199 | (interactive "p") | |
200 | (let ((beg (tpu-current-line))) | |
944a8b1d SM |
201 | (if tpu-cursor-free-mode (or (eobp) (picture-move-down num)) |
202 | (line-move num)) | |
522f9216 RS |
203 | (tpu-bottom-check beg num) |
204 | (setq this-command 'next-line))) | |
205 | ||
206 | (defun tpu-previous-line (num) | |
207 | "Move to previous line. | |
208 | Prefix argument serves as a repeat count." | |
209 | (interactive "p") | |
210 | (let ((beg (tpu-current-line))) | |
944a8b1d | 211 | (if tpu-cursor-free-mode (picture-move-up num) (line-move (- num))) |
522f9216 RS |
212 | (tpu-top-check beg num) |
213 | (setq this-command 'previous-line))) | |
214 | ||
215 | (defun tpu-next-beginning-of-line (num) | |
216 | "Move to beginning of line; if at beginning, move to beginning of next line. | |
217 | Accepts a prefix argument for the number of lines to move." | |
218 | (interactive "p") | |
219 | (let ((beg (tpu-current-line))) | |
220 | (backward-char 1) | |
1bb45f86 | 221 | (forward-visible-line (- 1 num)) |
522f9216 RS |
222 | (tpu-top-check beg num))) |
223 | ||
224 | (defun tpu-next-end-of-line (num) | |
225 | "Move to end of line; if at end, move to end of next line. | |
226 | Accepts a prefix argument for the number of lines to move." | |
227 | (interactive "p") | |
228 | (let ((beg (tpu-current-line))) | |
944a8b1d | 229 | (cond (tpu-cursor-free-mode |
522f9216 RS |
230 | (let ((beg (point))) |
231 | (if (< 1 num) (forward-line num)) | |
232 | (picture-end-of-line) | |
233 | (if (<= (point) beg) (progn (forward-line) (picture-end-of-line))))) | |
234 | (t | |
235 | (forward-char) | |
236 | (end-of-line num))) | |
237 | (tpu-bottom-check beg num))) | |
238 | ||
239 | (defun tpu-previous-end-of-line (num) | |
240 | "Move EOL upward. | |
241 | Accepts a prefix argument for the number of lines to move." | |
242 | (interactive "p") | |
243 | (let ((beg (tpu-current-line))) | |
944a8b1d | 244 | (cond (tpu-cursor-free-mode |
522f9216 RS |
245 | (picture-end-of-line (- 1 num))) |
246 | (t | |
247 | (end-of-line (- 1 num)))) | |
248 | (tpu-top-check beg num))) | |
249 | ||
f2b18979 | 250 | (defun tpu-current-end-of-line () |
522f9216 RS |
251 | "Move point to end of current line." |
252 | (interactive) | |
253 | (let ((beg (point))) | |
944a8b1d | 254 | (if tpu-cursor-free-mode (picture-end-of-line) (end-of-line)) |
522f9216 RS |
255 | (if (= beg (point)) (message "You are already at the end of a line.")))) |
256 | ||
257 | (defun tpu-forward-line (num) | |
258 | "Move to beginning of next line. | |
259 | Prefix argument serves as a repeat count." | |
260 | (interactive "p") | |
261 | (let ((beg (tpu-current-line))) | |
944a8b1d SM |
262 | (forward-line num) |
263 | (tpu-bottom-check beg num))) | |
522f9216 RS |
264 | |
265 | (defun tpu-backward-line (num) | |
266 | "Move to beginning of previous line. | |
267 | Prefix argument serves as repeat count." | |
268 | (interactive "p") | |
269 | (let ((beg (tpu-current-line))) | |
84299083 | 270 | (or (bolp) (>= 0 num) (setq num (- num 1))) |
944a8b1d SM |
271 | (forward-line (- num)) |
272 | (tpu-top-check beg num))) | |
522f9216 RS |
273 | |
274 | ||
275 | ;;; Movement by paragraph | |
276 | ||
277 | (defun tpu-paragraph (num) | |
278 | "Move to the next paragraph in the current direction. | |
279 | A repeat count means move that many paragraphs." | |
280 | (interactive "p") | |
281 | (let* ((left nil) | |
282 | (beg (tpu-current-line)) | |
283 | (height (window-height)) | |
284 | (top-percent | |
285 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
286 | (bottom-percent | |
287 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
288 | (top-margin (/ (* height top-percent) 100)) | |
289 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
290 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
291 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
292 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
293 | (far (save-excursion | |
294 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
295 | (cond (tpu-advance | |
296 | (tpu-next-paragraph num) | |
297 | (cond((> (point) far) | |
298 | (setq left (save-excursion (forward-line height))) | |
299 | (if (= 0 left) (recenter top-margin) | |
300 | (recenter (- left bottom-up-margin)))) | |
301 | (t | |
302 | (and (> (point) bottom) (recenter bottom-margin))))) | |
303 | (t | |
304 | (tpu-previous-paragraph num) | |
305 | (and (< (point) top) (recenter (min beg top-margin))))))) | |
306 | ||
307 | ||
308 | ;;; Movement by page | |
309 | ||
310 | (defun tpu-page (num) | |
311 | "Move to the next page in the current direction. | |
312 | A repeat count means move that many pages." | |
313 | (interactive "p") | |
314 | (let* ((left nil) | |
315 | (beg (tpu-current-line)) | |
316 | (height (window-height)) | |
317 | (top-percent | |
318 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
319 | (bottom-percent | |
320 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
321 | (top-margin (/ (* height top-percent) 100)) | |
322 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
323 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
324 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
325 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
326 | (far (save-excursion | |
327 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
328 | (cond (tpu-advance | |
329 | (forward-page num) | |
330 | (cond((> (point) far) | |
331 | (setq left (save-excursion (forward-line height))) | |
332 | (if (= 0 left) (recenter top-margin) | |
333 | (recenter (- left bottom-up-margin)))) | |
334 | (t | |
335 | (and (> (point) bottom) (recenter bottom-margin))))) | |
336 | (t | |
337 | (backward-page num) | |
338 | (and (< (point) top) (recenter (min beg top-margin))))))) | |
339 | ||
340 | ||
341 | ;;; Scrolling | |
342 | ||
343 | (defun tpu-scroll-window-down (num) | |
344 | "Scroll the display down to the next section. | |
345 | A repeat count means scroll that many sections." | |
346 | (interactive "p") | |
347 | (let* ((beg (tpu-current-line)) | |
348 | (height (1- (window-height))) | |
349 | (lines (* num (/ (* height tpu-percent-scroll) 100)))) | |
944a8b1d | 350 | (line-move (- lines)) |
522f9216 RS |
351 | (tpu-top-check beg lines))) |
352 | ||
353 | (defun tpu-scroll-window-up (num) | |
354 | "Scroll the display up to the next section. | |
355 | A repeat count means scroll that many sections." | |
356 | (interactive "p") | |
357 | (let* ((beg (tpu-current-line)) | |
358 | (height (1- (window-height))) | |
359 | (lines (* num (/ (* height tpu-percent-scroll) 100)))) | |
944a8b1d | 360 | (line-move lines) |
522f9216 RS |
361 | (tpu-bottom-check beg lines))) |
362 | ||
363 | ||
364 | ;;; Replace the TPU-edt internal search function | |
365 | ||
366 | (defun tpu-search-internal (pat &optional quiet) | |
367 | "Search for a string or regular expression." | |
368 | (let* ((left nil) | |
369 | (beg (tpu-current-line)) | |
370 | (height (window-height)) | |
371 | (top-percent | |
372 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
373 | (bottom-percent | |
374 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
375 | (top-margin (/ (* height top-percent) 100)) | |
376 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
377 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
378 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
379 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
380 | (far (save-excursion | |
381 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
382 | (tpu-search-internal-core pat quiet) | |
b4196a99 | 383 | (if tpu-searching-forward |
522f9216 RS |
384 | (cond((> (point) far) |
385 | (setq left (save-excursion (forward-line height))) | |
386 | (if (= 0 left) (recenter top-margin) | |
387 | (recenter (- left bottom-up-margin)))) | |
388 | (t | |
389 | (and (> (point) bottom) (recenter bottom-margin)))) | |
390 | (and (< (point) top) (recenter (min beg top-margin)))))) | |
391 | ||
392 | ||
393 | ||
f2b18979 SM |
394 | ;; Advise the newline, newline-and-indent, and do-auto-fill functions. |
395 | (defadvice newline (around tpu-respect-bottom-scroll-margin activate disable) | |
396 | "Respect `tpu-bottom-scroll-margin'." | |
397 | (let ((beg (tpu-current-line)) | |
398 | (num (prefix-numeric-value (ad-get-arg 0)))) | |
399 | ad-do-it | |
522f9216 RS |
400 | (tpu-bottom-check beg num))) |
401 | ||
f2b18979 SM |
402 | (defadvice newline-and-indent (around tpu-respect-bottom-scroll-margin) |
403 | "Respect `tpu-bottom-scroll-margin'." | |
522f9216 | 404 | (let ((beg (tpu-current-line))) |
f2b18979 | 405 | ad-do-it |
522f9216 RS |
406 | (tpu-bottom-check beg 1))) |
407 | ||
f2b18979 SM |
408 | (defadvice do-auto-fill (around tpu-respect-bottom-scroll-margin) |
409 | "Respect `tpu-bottom-scroll-margin'." | |
522f9216 | 410 | (let ((beg (tpu-current-line))) |
f2b18979 | 411 | ad-do-it |
522f9216 RS |
412 | (tpu-bottom-check beg 1))) |
413 | ||
414 | ||
415 | ;;; Function to set scroll margins | |
416 | ||
83ba7a93 | 417 | ;;;###autoload |
522f9216 RS |
418 | (defun tpu-set-scroll-margins (top bottom) |
419 | "Set scroll margins." | |
420 | (interactive | |
421 | "sEnter top scroll margin (N lines or N%% or RETURN for current value): \ | |
422 | \nsEnter bottom scroll margin (N lines or N%% or RETURN for current value): ") | |
423 | ;; set top scroll margin | |
424 | (or (string= top "") | |
f2b18979 SM |
425 | (setq tpu-top-scroll-margin |
426 | (if (string= "%" (substring top -1)) | |
427 | (string-to-number top) | |
027a4b6b | 428 | (/ (1- (+ (* (string-to-number top) 100) (window-height))) |
522f9216 RS |
429 | (window-height))))) |
430 | ;; set bottom scroll margin | |
431 | (or (string= bottom "") | |
f2b18979 SM |
432 | (setq tpu-bottom-scroll-margin |
433 | (if (string= "%" (substring bottom -1)) | |
434 | (string-to-number bottom) | |
027a4b6b | 435 | (/ (1- (+ (* (string-to-number bottom) 100) (window-height))) |
522f9216 | 436 | (window-height))))) |
f2b18979 SM |
437 | (dolist (f '(newline newline-and-indent do-auto-fill)) |
438 | (ad-enable-advice f 'around 'tpu-respect-bottom-scroll-margin) | |
439 | (ad-activate f)) | |
522f9216 RS |
440 | ;; report scroll margin settings if running interactively |
441 | (and (interactive-p) | |
442 | (message "Scroll margins set. Top = %s%%, Bottom = %s%%" | |
443 | tpu-top-scroll-margin tpu-bottom-scroll-margin))) | |
444 | ||
522f9216 RS |
445 | |
446 | ;;; Functions to set cursor bound or free | |
447 | ||
83ba7a93 | 448 | ;;;###autoload |
f2b18979 | 449 | (defun tpu-set-cursor-free () |
522f9216 RS |
450 | "Allow the cursor to move freely about the screen." |
451 | (interactive) | |
944a8b1d | 452 | (tpu-cursor-free-mode 1) |
522f9216 RS |
453 | (message "The cursor will now move freely about the screen.")) |
454 | ||
83ba7a93 | 455 | ;;;###autoload |
f2b18979 | 456 | (defun tpu-set-cursor-bound () |
522f9216 RS |
457 | "Constrain the cursor to the flow of the text." |
458 | (interactive) | |
944a8b1d | 459 | (tpu-cursor-free-mode -1) |
522f9216 RS |
460 | (message "The cursor is now bound to the flow of your text.")) |
461 | ||
944a8b1d SM |
462 | ;; Local Variables: |
463 | ;; generated-autoload-file: "tpu-edt.el" | |
464 | ;; End: | |
465 | ||
f2b18979 | 466 | ;; arch-tag: 89676fa4-33ec-48cb-9135-6f3bf230ab1a |
522f9216 | 467 | ;;; tpu-extras.el ends here |