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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, |
f0fa15c5 | 4 | ;; 2005, 2006, 2007 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 | |
14 | ;; the Free Software Foundation; either version 2, or (at your option) | |
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 |
522f9216 | 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 | |
522f9216 | 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 |
522f9216 RS |
126 | "*If non-nil, in free cursor mode backward-char (left-arrow) works |
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 | ||
135 | (defvar tpu-cursor-free nil | |
136 | "If non-nil, let the cursor roam free.") | |
137 | ||
138 | ||
139 | ;;; Hooks -- Set cursor free in picture mode. | |
140 | ;;; Clean up when writing a file from cursor free mode. | |
141 | ||
158a958d | 142 | (add-hook 'picture-mode-hook 'tpu-set-cursor-free) |
522f9216 RS |
143 | |
144 | (defun tpu-write-file-hook nil | |
145 | "Eliminate whitespace at ends of lines, if the cursor is free." | |
918b0076 | 146 | (if (and (buffer-modified-p) tpu-cursor-free) (tpu-trim-line-ends))) |
522f9216 | 147 | |
90d5ea04 RS |
148 | (or (memq 'tpu-write-file-hook write-file-functions) |
149 | (setq write-file-functions | |
150 | (cons 'tpu-write-file-hook write-file-functions))) | |
522f9216 RS |
151 | |
152 | ||
153 | ;;; Utility routines for implementing scroll margins | |
154 | ||
155 | (defun tpu-top-check (beg lines) | |
156 | "Enforce scroll margin at the top of screen." | |
157 | (let ((margin (/ (* (window-height) tpu-top-scroll-margin) 100))) | |
158 | (cond ((< beg margin) (recenter beg)) | |
159 | ((< (- beg lines) margin) (recenter margin))))) | |
160 | ||
161 | (defun tpu-bottom-check (beg lines) | |
162 | "Enforce scroll margin at the bottom of screen." | |
163 | (let* ((height (window-height)) | |
164 | (margin (+ 1 (/ (* height tpu-bottom-scroll-margin) 100))) | |
165 | ;; subtract 1 from height because it includes mode line | |
166 | (difference (- height margin 1))) | |
167 | (cond ((> beg difference) (recenter beg)) | |
168 | ((> (+ beg lines) difference) (recenter (- margin)))))) | |
169 | ||
170 | ||
171 | ;;; Movement by character | |
172 | ||
173 | (defun tpu-forward-char (num) | |
174 | "Move right ARG characters (left if ARG is negative)." | |
175 | (interactive "p") | |
176 | (if tpu-cursor-free (picture-forward-column num) (forward-char num))) | |
177 | ||
178 | (defun tpu-backward-char (num) | |
179 | "Move left ARG characters (right if ARG is negative)." | |
180 | (interactive "p") | |
181 | (cond ((not tpu-cursor-free) | |
182 | (backward-char num)) | |
183 | (tpu-backward-char-like-tpu | |
184 | (picture-backward-column num)) | |
185 | ((bolp) | |
186 | (backward-char 1) | |
187 | (picture-end-of-line) | |
188 | (picture-backward-column (1- num))) | |
189 | (t | |
190 | (picture-backward-column num)))) | |
191 | ||
192 | ||
193 | ;;; Movement by line | |
194 | ||
195 | (defun tpu-next-line (num) | |
196 | "Move to next line. | |
197 | Prefix argument serves as a repeat count." | |
198 | (interactive "p") | |
199 | (let ((beg (tpu-current-line))) | |
200 | (if tpu-cursor-free (or (eobp) (picture-move-down num)) | |
201 | (next-line-internal num)) | |
202 | (tpu-bottom-check beg num) | |
203 | (setq this-command 'next-line))) | |
204 | ||
205 | (defun tpu-previous-line (num) | |
206 | "Move to previous line. | |
207 | Prefix argument serves as a repeat count." | |
208 | (interactive "p") | |
209 | (let ((beg (tpu-current-line))) | |
210 | (if tpu-cursor-free (picture-move-up num) (next-line-internal (- num))) | |
211 | (tpu-top-check beg num) | |
212 | (setq this-command 'previous-line))) | |
213 | ||
214 | (defun tpu-next-beginning-of-line (num) | |
215 | "Move to beginning of line; if at beginning, move to beginning of next line. | |
216 | Accepts a prefix argument for the number of lines to move." | |
217 | (interactive "p") | |
218 | (let ((beg (tpu-current-line))) | |
219 | (backward-char 1) | |
1bb45f86 | 220 | (forward-visible-line (- 1 num)) |
522f9216 RS |
221 | (tpu-top-check beg num))) |
222 | ||
223 | (defun tpu-next-end-of-line (num) | |
224 | "Move to end of line; if at end, move to end of next line. | |
225 | Accepts a prefix argument for the number of lines to move." | |
226 | (interactive "p") | |
227 | (let ((beg (tpu-current-line))) | |
228 | (cond (tpu-cursor-free | |
229 | (let ((beg (point))) | |
230 | (if (< 1 num) (forward-line num)) | |
231 | (picture-end-of-line) | |
232 | (if (<= (point) beg) (progn (forward-line) (picture-end-of-line))))) | |
233 | (t | |
234 | (forward-char) | |
235 | (end-of-line num))) | |
236 | (tpu-bottom-check beg num))) | |
237 | ||
238 | (defun tpu-previous-end-of-line (num) | |
239 | "Move EOL upward. | |
240 | Accepts a prefix argument for the number of lines to move." | |
241 | (interactive "p") | |
242 | (let ((beg (tpu-current-line))) | |
243 | (cond (tpu-cursor-free | |
244 | (picture-end-of-line (- 1 num))) | |
245 | (t | |
246 | (end-of-line (- 1 num)))) | |
247 | (tpu-top-check beg num))) | |
248 | ||
249 | (defun tpu-current-end-of-line nil | |
250 | "Move point to end of current line." | |
251 | (interactive) | |
252 | (let ((beg (point))) | |
253 | (if tpu-cursor-free (picture-end-of-line) (end-of-line)) | |
254 | (if (= beg (point)) (message "You are already at the end of a line.")))) | |
255 | ||
256 | (defun tpu-forward-line (num) | |
257 | "Move to beginning of next line. | |
258 | Prefix argument serves as a repeat count." | |
259 | (interactive "p") | |
260 | (let ((beg (tpu-current-line))) | |
261 | (next-line-internal num) | |
262 | (tpu-bottom-check beg num) | |
263 | (beginning-of-line))) | |
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))) |
522f9216 RS |
271 | (next-line-internal (- num)) |
272 | (tpu-top-check beg num) | |
273 | (beginning-of-line))) | |
274 | ||
275 | ||
276 | ;;; Movement by paragraph | |
277 | ||
278 | (defun tpu-paragraph (num) | |
279 | "Move to the next paragraph in the current direction. | |
280 | A repeat count means move that many paragraphs." | |
281 | (interactive "p") | |
282 | (let* ((left nil) | |
283 | (beg (tpu-current-line)) | |
284 | (height (window-height)) | |
285 | (top-percent | |
286 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
287 | (bottom-percent | |
288 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
289 | (top-margin (/ (* height top-percent) 100)) | |
290 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
291 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
292 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
293 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
294 | (far (save-excursion | |
295 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
296 | (cond (tpu-advance | |
297 | (tpu-next-paragraph num) | |
298 | (cond((> (point) far) | |
299 | (setq left (save-excursion (forward-line height))) | |
300 | (if (= 0 left) (recenter top-margin) | |
301 | (recenter (- left bottom-up-margin)))) | |
302 | (t | |
303 | (and (> (point) bottom) (recenter bottom-margin))))) | |
304 | (t | |
305 | (tpu-previous-paragraph num) | |
306 | (and (< (point) top) (recenter (min beg top-margin))))))) | |
307 | ||
308 | ||
309 | ;;; Movement by page | |
310 | ||
311 | (defun tpu-page (num) | |
312 | "Move to the next page in the current direction. | |
313 | A repeat count means move that many pages." | |
314 | (interactive "p") | |
315 | (let* ((left nil) | |
316 | (beg (tpu-current-line)) | |
317 | (height (window-height)) | |
318 | (top-percent | |
319 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
320 | (bottom-percent | |
321 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
322 | (top-margin (/ (* height top-percent) 100)) | |
323 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
324 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
325 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
326 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
327 | (far (save-excursion | |
328 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
329 | (cond (tpu-advance | |
330 | (forward-page num) | |
331 | (cond((> (point) far) | |
332 | (setq left (save-excursion (forward-line height))) | |
333 | (if (= 0 left) (recenter top-margin) | |
334 | (recenter (- left bottom-up-margin)))) | |
335 | (t | |
336 | (and (> (point) bottom) (recenter bottom-margin))))) | |
337 | (t | |
338 | (backward-page num) | |
339 | (and (< (point) top) (recenter (min beg top-margin))))))) | |
340 | ||
341 | ||
342 | ;;; Scrolling | |
343 | ||
344 | (defun tpu-scroll-window-down (num) | |
345 | "Scroll the display down to the next section. | |
346 | A repeat count means scroll that many sections." | |
347 | (interactive "p") | |
348 | (let* ((beg (tpu-current-line)) | |
349 | (height (1- (window-height))) | |
350 | (lines (* num (/ (* height tpu-percent-scroll) 100)))) | |
351 | (next-line-internal (- lines)) | |
352 | (tpu-top-check beg lines))) | |
353 | ||
354 | (defun tpu-scroll-window-up (num) | |
355 | "Scroll the display up to the next section. | |
356 | A repeat count means scroll that many sections." | |
357 | (interactive "p") | |
358 | (let* ((beg (tpu-current-line)) | |
359 | (height (1- (window-height))) | |
360 | (lines (* num (/ (* height tpu-percent-scroll) 100)))) | |
361 | (next-line-internal lines) | |
362 | (tpu-bottom-check beg lines))) | |
363 | ||
364 | ||
365 | ;;; Replace the TPU-edt internal search function | |
366 | ||
367 | (defun tpu-search-internal (pat &optional quiet) | |
368 | "Search for a string or regular expression." | |
369 | (let* ((left nil) | |
370 | (beg (tpu-current-line)) | |
371 | (height (window-height)) | |
372 | (top-percent | |
373 | (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin)) | |
374 | (bottom-percent | |
375 | (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin)) | |
376 | (top-margin (/ (* height top-percent) 100)) | |
377 | (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100))) | |
378 | (bottom-margin (max beg (- height bottom-up-margin 1))) | |
379 | (top (save-excursion (move-to-window-line top-margin) (point))) | |
380 | (bottom (save-excursion (move-to-window-line bottom-margin) (point))) | |
381 | (far (save-excursion | |
382 | (goto-char bottom) (forward-line (- height 2)) (point)))) | |
383 | (tpu-search-internal-core pat quiet) | |
b4196a99 | 384 | (if tpu-searching-forward |
522f9216 RS |
385 | (cond((> (point) far) |
386 | (setq left (save-excursion (forward-line height))) | |
387 | (if (= 0 left) (recenter top-margin) | |
388 | (recenter (- left bottom-up-margin)))) | |
389 | (t | |
390 | (and (> (point) bottom) (recenter bottom-margin)))) | |
391 | (and (< (point) top) (recenter (min beg top-margin)))))) | |
392 | ||
393 | ||
394 | ||
395 | ;;; Replace the newline, newline-and-indent, and do-auto-fill functions | |
396 | ||
397 | (or (fboundp 'tpu-old-newline) | |
398 | (fset 'tpu-old-newline (symbol-function 'newline))) | |
399 | (or (fboundp 'tpu-old-do-auto-fill) | |
400 | (fset 'tpu-old-do-auto-fill (symbol-function 'do-auto-fill))) | |
401 | (or (fboundp 'tpu-old-newline-and-indent) | |
402 | (fset 'tpu-old-newline-and-indent (symbol-function 'newline-and-indent))) | |
403 | ||
404 | (defun newline (&optional num) | |
405 | "Insert a newline. With arg, insert that many newlines. | |
406 | In Auto Fill mode, can break the preceding line if no numeric arg. | |
407 | This is the TPU-edt version that respects the bottom scroll margin." | |
408 | (interactive "p") | |
409 | (let ((beg (tpu-current-line))) | |
410 | (or num (setq num 1)) | |
411 | (tpu-old-newline num) | |
412 | (tpu-bottom-check beg num))) | |
413 | ||
414 | (defun newline-and-indent nil | |
415 | "Insert a newline, then indent according to major mode. | |
416 | Indentation is done using the current indent-line-function. | |
417 | In programming language modes, this is the same as TAB. | |
418 | In some text modes, where TAB inserts a tab, this indents | |
419 | to the specified left-margin column. This is the TPU-edt | |
420 | version that respects the bottom scroll margin." | |
421 | (interactive) | |
422 | (let ((beg (tpu-current-line))) | |
423 | (tpu-old-newline-and-indent) | |
424 | (tpu-bottom-check beg 1))) | |
425 | ||
426 | (defun do-auto-fill nil | |
427 | "TPU-edt version that respects the bottom scroll margin." | |
428 | (let ((beg (tpu-current-line))) | |
429 | (tpu-old-do-auto-fill) | |
430 | (tpu-bottom-check beg 1))) | |
431 | ||
432 | ||
433 | ;;; Function to set scroll margins | |
434 | ||
83ba7a93 | 435 | ;;;###autoload |
522f9216 RS |
436 | (defun tpu-set-scroll-margins (top bottom) |
437 | "Set scroll margins." | |
438 | (interactive | |
439 | "sEnter top scroll margin (N lines or N%% or RETURN for current value): \ | |
440 | \nsEnter bottom scroll margin (N lines or N%% or RETURN for current value): ") | |
441 | ;; set top scroll margin | |
442 | (or (string= top "") | |
443 | (if (string= "%" (substring top -1)) | |
027a4b6b | 444 | (setq tpu-top-scroll-margin (string-to-number top)) |
522f9216 | 445 | (setq tpu-top-scroll-margin |
027a4b6b | 446 | (/ (1- (+ (* (string-to-number top) 100) (window-height))) |
522f9216 RS |
447 | (window-height))))) |
448 | ;; set bottom scroll margin | |
449 | (or (string= bottom "") | |
450 | (if (string= "%" (substring bottom -1)) | |
027a4b6b | 451 | (setq tpu-bottom-scroll-margin (string-to-number bottom)) |
522f9216 | 452 | (setq tpu-bottom-scroll-margin |
027a4b6b | 453 | (/ (1- (+ (* (string-to-number bottom) 100) (window-height))) |
522f9216 RS |
454 | (window-height))))) |
455 | ;; report scroll margin settings if running interactively | |
456 | (and (interactive-p) | |
457 | (message "Scroll margins set. Top = %s%%, Bottom = %s%%" | |
458 | tpu-top-scroll-margin tpu-bottom-scroll-margin))) | |
459 | ||
522f9216 RS |
460 | |
461 | ;;; Functions to set cursor bound or free | |
462 | ||
83ba7a93 | 463 | ;;;###autoload |
522f9216 RS |
464 | (defun tpu-set-cursor-free nil |
465 | "Allow the cursor to move freely about the screen." | |
466 | (interactive) | |
467 | (setq tpu-cursor-free t) | |
468 | (substitute-key-definition 'tpu-set-cursor-free | |
469 | 'tpu-set-cursor-bound | |
470 | GOLD-map) | |
471 | (message "The cursor will now move freely about the screen.")) | |
472 | ||
83ba7a93 | 473 | ;;;###autoload |
522f9216 RS |
474 | (defun tpu-set-cursor-bound nil |
475 | "Constrain the cursor to the flow of the text." | |
476 | (interactive) | |
918b0076 | 477 | (tpu-trim-line-ends) |
522f9216 RS |
478 | (setq tpu-cursor-free nil) |
479 | (substitute-key-definition 'tpu-set-cursor-bound | |
480 | 'tpu-set-cursor-free | |
481 | GOLD-map) | |
482 | (message "The cursor is now bound to the flow of your text.")) | |
483 | ||
ab5796a9 | 484 | ;;; arch-tag: 89676fa4-33ec-48cb-9135-6f3bf230ab1a |
522f9216 | 485 | ;;; tpu-extras.el ends here |