File: | src/gnu/usr.bin/texinfo/info/display.c |
Warning: | line 388, column 15 Value stored to 'begin' is never read |
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1 | /* display.c -- How to display Info windows. |
2 | $Id: display.c,v 1.4 2006/07/17 16:12:36 espie Exp $ |
3 | |
4 | Copyright (C) 1993, 1997, 2003, 2004 Free Software Foundation, Inc. |
5 | |
6 | This program is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by |
8 | the Free Software Foundation; either version 2, or (at your option) |
9 | any later version. |
10 | |
11 | This program is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | GNU General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with this program; if not, write to the Free Software |
18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
19 | |
20 | Originally written by Brian Fox (bfox@ai.mit.edu). */ |
21 | |
22 | #include "info.h" |
23 | #include "display.h" |
24 | |
25 | extern int info_any_buffered_input_p (void); /* Found in session.c. */ |
26 | |
27 | static void free_display (DISPLAY_LINE **display); |
28 | static DISPLAY_LINE **make_display (int width, int height); |
29 | |
30 | void handle_tag (char *tag); |
31 | void handle_tag_start (char *tag); |
32 | void handle_tag_end (char *tag); |
33 | |
34 | /* An array of display lines which tell us what is currently visible on |
35 | the display. */ |
36 | DISPLAY_LINE **the_display = (DISPLAY_LINE **)NULL((void *)0); |
37 | |
38 | /* Non-zero means do no output. */ |
39 | int display_inhibited = 0; |
40 | |
41 | /* Initialize THE_DISPLAY to WIDTH and HEIGHT, with nothing in it. */ |
42 | void |
43 | display_initialize_display (int width, int height) |
44 | { |
45 | free_display (the_display); |
46 | the_display = make_display (width, height); |
47 | display_clear_display (the_display); |
48 | } |
49 | |
50 | /* Clear all of the lines in DISPLAY making the screen blank. */ |
51 | void |
52 | display_clear_display (DISPLAY_LINE **display) |
53 | { |
54 | register int i; |
55 | |
56 | for (i = 0; display[i]; i++) |
57 | { |
58 | display[i]->text[0] = '\0'; |
59 | display[i]->textlen = 0; |
60 | display[i]->inverse = 0; |
61 | } |
62 | } |
63 | |
64 | /* Non-zero if we didn't completely redisplay a window. */ |
65 | int display_was_interrupted_p = 0; |
66 | |
67 | /* Update the windows pointed to by WINDOW in the_display. This actually |
68 | writes the text on the screen. */ |
69 | void |
70 | display_update_display (WINDOW *window) |
71 | { |
72 | register WINDOW *win; |
73 | |
74 | display_was_interrupted_p = 0; |
75 | |
76 | /* For every window in the list, check contents against the display. */ |
77 | for (win = window; win; win = win->next) |
78 | { |
79 | /* Only re-display visible windows which need updating. */ |
80 | if (((win->flags & W_WindowVisible0x04) == 0) || |
81 | ((win->flags & W_UpdateWindow0x01) == 0) || |
82 | (win->height == 0)) |
83 | continue; |
84 | |
85 | display_update_one_window (win); |
86 | if (display_was_interrupted_p) |
87 | break; |
88 | } |
89 | |
90 | /* Always update the echo area. */ |
91 | display_update_one_window (the_echo_area); |
92 | } |
93 | |
94 | void |
95 | handle_tag_start (char *tag) |
96 | { |
97 | /* TODO really handle this tag. */ |
98 | return; |
99 | } |
100 | |
101 | void |
102 | handle_tag_end (char *tag) |
103 | { |
104 | /* TODO really handle this tag. */ |
105 | return; |
106 | } |
107 | |
108 | void |
109 | handle_tag (char *tag) |
110 | { |
111 | if (tag[0] == '/') |
112 | { |
113 | tag++; |
114 | handle_tag_end (tag); |
115 | } |
116 | else |
117 | handle_tag_start (tag); |
118 | } |
119 | |
120 | /* Display WIN on the_display. Unlike display_update_display (), this |
121 | function only does one window. */ |
122 | void |
123 | display_update_one_window (WINDOW *win) |
124 | { |
125 | register char *nodetext; /* Current character to display. */ |
126 | register char *last_node_char; /* Position of the last character in node. */ |
127 | register int i; /* General use index. */ |
128 | char *printed_line; /* Buffer for a printed line. */ |
129 | int pl_index = 0; /* Index into PRINTED_LINE. */ |
130 | int line_index = 0; /* Number of lines done so far. */ |
131 | int pl_ignore = 0; /* How many chars use zero width on screen. */ |
132 | int allocated_win_width; |
133 | DISPLAY_LINE **display = the_display; |
134 | |
135 | /* If display is inhibited, that counts as an interrupted display. */ |
136 | if (display_inhibited) |
137 | display_was_interrupted_p = 1; |
138 | |
139 | /* If the window has no height, or display is inhibited, quit now. */ |
140 | if (!win->height || display_inhibited) |
141 | return; |
142 | |
143 | /* If the window's first row doesn't appear in the_screen, then it |
144 | cannot be displayed. This can happen when the_echo_area is the |
145 | window to be displayed, and the screen has shrunk to less than one |
146 | line. */ |
147 | if ((win->first_row < 0) || (win->first_row > the_screen->height)) |
148 | return; |
149 | |
150 | /* Print each line in the window into our local buffer, and then |
151 | check the contents of that buffer against the display. If they |
152 | differ, update the display. */ |
153 | allocated_win_width = win->width + 1; |
154 | printed_line = (char *)xmalloc (allocated_win_width); |
155 | |
156 | if (!win->node || !win->line_starts) |
157 | goto done_with_node_display; |
158 | |
159 | nodetext = win->line_starts[win->pagetop]; |
160 | last_node_char = win->node->contents + win->node->nodelen; |
161 | |
162 | for (; nodetext < last_node_char; nodetext++) |
163 | { |
164 | char *rep = NULL((void *)0), *rep_carried_over, rep_temp[2]; |
165 | int replen; |
166 | |
167 | if (isprint (*nodetext)) |
168 | { |
169 | rep_temp[0] = *nodetext; |
170 | replen = 1; |
171 | rep_temp[1] = '\0'; |
172 | rep = rep_temp; |
173 | } |
174 | else |
175 | { |
176 | if (*nodetext == '\r' || *nodetext == '\n') |
177 | { |
178 | replen = win->width - pl_index + pl_ignore; |
179 | } |
180 | else if (*nodetext == '\0' |
181 | && (nodetext + 2) < last_node_char |
182 | && *(nodetext + 1) == '\b' |
183 | && *(nodetext + 2) == '[') |
184 | { |
185 | /* Found new style tag/cookie \0\b[ |
186 | Read until the closing tag \0\b] */ |
187 | int element_len = 0; |
188 | char *element; |
189 | |
190 | /* Skip the escapes. */ |
191 | nodetext += 3; |
192 | |
193 | while (!(*nodetext == '\0' |
194 | && *(nodetext + 1) == '\b' |
195 | && *(nodetext + 2) == ']')) |
196 | { |
197 | nodetext++; |
198 | element_len++; |
199 | } |
200 | |
201 | element = (char *) malloc (element_len + 1); |
202 | strncpy (element, nodetext - element_len, element_len); |
203 | |
204 | /* Skip the escapes. */ |
205 | nodetext += 2; |
206 | pl_ignore += element_len + 5; |
207 | /* Append string terminator. */ |
208 | element[element_len] = '\0'; |
209 | |
210 | handle_tag (element); |
211 | |
212 | /* Over and out */ |
213 | free (element); |
214 | |
215 | continue; |
216 | } |
217 | else |
218 | { |
219 | rep = printed_representation (*nodetext, pl_index); |
220 | replen = strlen (rep); |
221 | } |
222 | } |
223 | |
224 | /* Support ANSI escape sequences under -R. */ |
225 | if (raw_escapes_p |
226 | && *nodetext == '\033' |
227 | && nodetext[1] == '[' |
228 | && isdigit (nodetext[2])) |
229 | { |
230 | if (nodetext[3] == 'm') |
231 | pl_ignore += 4; |
232 | else if (isdigit (nodetext[3]) && nodetext[4] == 'm') |
233 | pl_ignore += 5; |
234 | } |
235 | while (pl_index + 2 >= allocated_win_width - 1) |
236 | { |
237 | allocated_win_width *= 2; |
238 | printed_line = (char *)xrealloc (printed_line, allocated_win_width); |
239 | } |
240 | |
241 | /* If this character can be printed without passing the width of |
242 | the line, then stuff it into the line. */ |
243 | if (replen + pl_index < win->width + pl_ignore) |
244 | { |
245 | /* Optimize if possible. */ |
246 | if (replen == 1) |
247 | { |
248 | printed_line[pl_index++] = *rep; |
249 | } |
250 | else |
251 | { |
252 | for (i = 0; i < replen; i++) |
253 | printed_line[pl_index++] = rep[i]; |
254 | } |
255 | } |
256 | else |
257 | { |
258 | DISPLAY_LINE *entry; |
259 | |
260 | /* If this character cannot be printed in this line, we have |
261 | found the end of this line as it would appear on the screen. |
262 | Carefully print the end of the line, and then compare. */ |
263 | if (*nodetext == '\n' || *nodetext == '\r' || *nodetext == '\t') |
264 | { |
265 | printed_line[pl_index] = '\0'; |
266 | rep_carried_over = (char *)NULL((void *)0); |
267 | } |
268 | else |
269 | { |
270 | /* The printed representation of this character extends into |
271 | the next line. Remember the offset of the last character |
272 | printed out of REP so that we can carry the character over |
273 | to the next line. */ |
274 | for (i = 0; pl_index < (win->width + pl_ignore - 1);) |
275 | printed_line[pl_index++] = rep[i++]; |
276 | |
277 | rep_carried_over = rep + i; |
278 | |
279 | /* If printing the last character in this window couldn't |
280 | possibly cause the screen to scroll, place a backslash |
281 | in the rightmost column. */ |
282 | if (1 + line_index + win->first_row < the_screen->height) |
283 | { |
284 | if (win->flags & W_NoWrap0x10) |
285 | printed_line[pl_index++] = '$'; |
286 | else |
287 | printed_line[pl_index++] = '\\'; |
288 | } |
289 | printed_line[pl_index] = '\0'; |
290 | } |
291 | |
292 | /* We have the exact line as it should appear on the screen. |
293 | Check to see if this line matches the one already appearing |
294 | on the screen. */ |
295 | entry = display[line_index + win->first_row]; |
296 | |
297 | /* If the screen line is inversed, then we have to clear |
298 | the line from the screen first. Why, I don't know. |
299 | (But don't do this if we have no visible entries, as can |
300 | happen if the window is shrunk very small.) */ |
301 | if ((entry && entry->inverse) |
302 | /* Need to erase the line if it has escape sequences. */ |
303 | || (raw_escapes_p && strchr (entry->text, '\033') != 0)) |
304 | { |
305 | terminal_goto_xy (0, line_index + win->first_row); |
306 | terminal_clear_to_eol (); |
307 | entry->inverse = 0; |
308 | entry->text[0] = '\0'; |
309 | entry->textlen = 0; |
310 | } |
311 | |
312 | /* Find the offset where these lines differ. */ |
313 | for (i = 0; i < pl_index; i++) |
314 | if (printed_line[i] != entry->text[i]) |
315 | break; |
316 | |
317 | /* If the lines are not the same length, or if they differed |
318 | at all, we must do some redrawing. */ |
319 | if ((i != pl_index) || (pl_index != entry->textlen)) |
320 | { |
321 | /* Move to the proper point on the terminal. */ |
322 | terminal_goto_xy (i, line_index + win->first_row); |
323 | |
324 | /* If there is any text to print, print it. */ |
325 | if (i != pl_index) |
326 | terminal_put_text (printed_line + i); |
327 | |
328 | /* If the printed text didn't extend all the way to the edge |
329 | of the window, and text was appearing between here and the |
330 | edge of the window, clear from here to the end of the line. */ |
331 | if ((pl_index < win->width + pl_ignore |
332 | && pl_index < entry->textlen) |
333 | || (entry->inverse)) |
334 | terminal_clear_to_eol (); |
335 | |
336 | fflush (stdout(&__sF[1])); |
337 | |
338 | /* Update the display text buffer. */ |
339 | if (strlen (printed_line) > (unsigned int) screenwidth) |
340 | /* printed_line[] can include more than screenwidth |
341 | characters if we are under -R and there are escape |
342 | sequences in it. However, entry->text was |
343 | allocated (in display_initialize_display) for |
344 | screenwidth characters only. */ |
345 | entry->text = xrealloc (entry->text, strlen (printed_line)+1); |
346 | strcpy (entry->text + i, printed_line + i); |
347 | entry->textlen = pl_index; |
348 | |
349 | /* Lines showing node text are not in inverse. Only modelines |
350 | have that distinction. */ |
351 | entry->inverse = 0; |
352 | } |
353 | |
354 | /* We have done at least one line. Increment our screen line |
355 | index, and check against the bottom of the window. */ |
356 | if (++line_index == win->height) |
357 | break; |
358 | |
359 | /* A line has been displayed, and the screen reflects that state. |
360 | If there is typeahead pending, then let that typeahead be read |
361 | now, instead of continuing with the display. */ |
362 | if (info_any_buffered_input_p ()) |
363 | { |
364 | free (printed_line); |
365 | display_was_interrupted_p = 1; |
366 | return; |
367 | } |
368 | |
369 | /* Reset PL_INDEX to the start of the line. */ |
370 | pl_index = 0; |
371 | pl_ignore = 0; /* this is computed per line */ |
372 | |
373 | /* If there are characters from REP left to print, stuff them |
374 | into the buffer now. */ |
375 | if (rep_carried_over) |
376 | for (; rep[pl_index]; pl_index++) |
377 | printed_line[pl_index] = rep[pl_index]; |
378 | |
379 | /* If this window has chosen not to wrap lines, skip to the end |
380 | of the physical line in the buffer, and start a new line here. */ |
381 | if (pl_index && (win->flags & W_NoWrap0x10)) |
382 | { |
383 | char *begin; |
384 | |
385 | pl_index = 0; |
386 | printed_line[0] = '\0'; |
387 | |
388 | begin = nodetext; |
Value stored to 'begin' is never read | |
389 | |
390 | while ((nodetext < last_node_char) && (*nodetext != '\n')) |
391 | nodetext++; |
392 | } |
393 | } |
394 | } |
395 | |
396 | done_with_node_display: |
397 | /* We have reached the end of the node or the end of the window. If it |
398 | is the end of the node, then clear the lines of the window from here |
399 | to the end of the window. */ |
400 | for (; line_index < win->height; line_index++) |
401 | { |
402 | DISPLAY_LINE *entry = display[line_index + win->first_row]; |
403 | |
404 | /* If this line has text on it then make it go away. */ |
405 | if (entry && entry->textlen) |
406 | { |
407 | entry->textlen = 0; |
408 | entry->text[0] = '\0'; |
409 | |
410 | terminal_goto_xy (0, line_index + win->first_row); |
411 | terminal_clear_to_eol (); |
412 | } |
413 | } |
414 | |
415 | /* Finally, if this window has a modeline it might need to be redisplayed. |
416 | Check the window's modeline against the one in the display, and update |
417 | if necessary. */ |
418 | if ((win->flags & W_InhibitMode0x08) == 0) |
419 | { |
420 | window_make_modeline (win); |
421 | line_index = win->first_row + win->height; |
422 | |
423 | /* This display line must both be in inverse, and have the same |
424 | contents. */ |
425 | if ((!display[line_index]->inverse) || |
426 | (strcmp (display[line_index]->text, win->modeline) != 0)) |
427 | { |
428 | terminal_goto_xy (0, line_index); |
429 | terminal_begin_inverse (); |
430 | terminal_put_text (win->modeline); |
431 | terminal_end_inverse (); |
432 | strcpy (display[line_index]->text, win->modeline); |
433 | display[line_index]->inverse = 1; |
434 | display[line_index]->textlen = strlen (win->modeline); |
435 | fflush (stdout(&__sF[1])); |
436 | } |
437 | } |
438 | |
439 | /* Okay, this window doesn't need updating anymore. */ |
440 | win->flags &= ~W_UpdateWindow0x01; |
441 | free (printed_line); |
442 | fflush (stdout(&__sF[1])); |
443 | } |
444 | |
445 | /* Scroll the region of the_display starting at START, ending at END, and |
446 | moving the lines AMOUNT lines. If AMOUNT is less than zero, the lines |
447 | are moved up in the screen, otherwise down. Actually, it is possible |
448 | for no scrolling to take place in the case that the terminal doesn't |
449 | support it. This doesn't matter to us. */ |
450 | void |
451 | display_scroll_display (int start, int end, int amount) |
452 | { |
453 | register int i, last; |
454 | DISPLAY_LINE *temp; |
455 | |
456 | /* If this terminal cannot do scrolling, give up now. */ |
457 | if (!terminal_can_scroll) |
458 | return; |
459 | |
460 | /* If there isn't anything displayed on the screen because it is too |
461 | small, quit now. */ |
462 | if (!the_display[0]) |
463 | return; |
464 | |
465 | /* If there is typeahead pending, then don't actually do any scrolling. */ |
466 | if (info_any_buffered_input_p ()) |
467 | return; |
468 | |
469 | /* Do it on the screen. */ |
470 | terminal_scroll_terminal (start, end, amount); |
471 | |
472 | /* Now do it in the display buffer so our contents match the screen. */ |
473 | if (amount > 0) |
474 | { |
475 | last = end + amount; |
476 | |
477 | /* Shift the lines to scroll right into place. */ |
478 | for (i = 0; i < (end - start); i++) |
479 | { |
480 | temp = the_display[last - i]; |
481 | the_display[last - i] = the_display[end - i]; |
482 | the_display[end - i] = temp; |
483 | } |
484 | |
485 | /* The lines have been shifted down in the buffer. Clear all of the |
486 | lines that were vacated. */ |
487 | for (i = start; i != (start + amount); i++) |
488 | { |
489 | the_display[i]->text[0] = '\0'; |
490 | the_display[i]->textlen = 0; |
491 | the_display[i]->inverse = 0; |
492 | } |
493 | } |
494 | |
495 | if (amount < 0) |
496 | { |
497 | last = start + amount; |
498 | for (i = 0; i < (end - start); i++) |
499 | { |
500 | temp = the_display[last + i]; |
501 | the_display[last + i] = the_display[start + i]; |
502 | the_display[start + i] = temp; |
503 | } |
504 | |
505 | /* The lines have been shifted up in the buffer. Clear all of the |
506 | lines that are left over. */ |
507 | for (i = end + amount; i != end; i++) |
508 | { |
509 | the_display[i]->text[0] = '\0'; |
510 | the_display[i]->textlen = 0; |
511 | the_display[i]->inverse = 0; |
512 | } |
513 | } |
514 | } |
515 | |
516 | /* Try to scroll lines in WINDOW. OLD_PAGETOP is the pagetop of WINDOW before |
517 | having had its line starts recalculated. OLD_STARTS is the list of line |
518 | starts that used to appear in this window. OLD_COUNT is the number of lines |
519 | that appear in the OLD_STARTS array. */ |
520 | void |
521 | display_scroll_line_starts (WINDOW *window, int old_pagetop, |
522 | char **old_starts, int old_count) |
523 | { |
524 | register int i, old, new; /* Indices into the line starts arrays. */ |
525 | int last_new, last_old; /* Index of the last visible line. */ |
526 | int old_first, new_first; /* Index of the first changed line. */ |
527 | int unchanged_at_top = 0; |
528 | int already_scrolled = 0; |
529 | |
530 | /* Locate the first line which was displayed on the old window. */ |
531 | old_first = old_pagetop; |
532 | new_first = window->pagetop; |
533 | |
534 | /* Find the last line currently visible in this window. */ |
535 | last_new = window->pagetop + (window->height - 1); |
536 | if (last_new > window->line_count) |
537 | last_new = window->line_count - 1; |
538 | |
539 | /* Find the last line which used to be currently visible in this window. */ |
540 | last_old = old_pagetop + (window->height - 1); |
541 | if (last_old > old_count) |
542 | last_old = old_count - 1; |
543 | |
544 | for (old = old_first, new = new_first; |
545 | old < last_old && new < last_new; |
546 | old++, new++) |
547 | if (old_starts[old] != window->line_starts[new]) |
548 | break; |
549 | else |
550 | unchanged_at_top++; |
551 | |
552 | /* Loop through the old lines looking for a match in the new lines. */ |
553 | for (old = old_first + unchanged_at_top; old < last_old; old++) |
554 | { |
555 | for (new = new_first; new < last_new; new++) |
556 | if (old_starts[old] == window->line_starts[new]) |
557 | { |
558 | /* Find the extent of the matching lines. */ |
559 | for (i = 0; (old + i) < last_old; i++) |
560 | if (old_starts[old + i] != window->line_starts[new + i]) |
561 | break; |
562 | |
563 | /* Scroll these lines if there are enough of them. */ |
564 | { |
565 | int start, end, amount; |
566 | |
567 | start = (window->first_row |
568 | + ((old + already_scrolled) - old_pagetop)); |
569 | amount = new - (old + already_scrolled); |
570 | end = window->first_row + window->height; |
571 | |
572 | /* If we are shifting the block of lines down, then the last |
573 | AMOUNT lines will become invisible. Thus, don't bother |
574 | scrolling them. */ |
575 | if (amount > 0) |
576 | end -= amount; |
577 | |
578 | if ((end - start) > 0) |
579 | { |
580 | display_scroll_display (start, end, amount); |
581 | |
582 | /* Some lines have been scrolled. Simulate the scrolling |
583 | by offsetting the value of the old index. */ |
584 | old += i; |
585 | already_scrolled += amount; |
586 | } |
587 | } |
588 | } |
589 | } |
590 | } |
591 | |
592 | /* Move the screen cursor to directly over the current character in WINDOW. */ |
593 | void |
594 | display_cursor_at_point (WINDOW *window) |
595 | { |
596 | int vpos, hpos; |
597 | |
598 | vpos = window_line_of_point (window) - window->pagetop + window->first_row; |
599 | hpos = window_get_cursor_column (window); |
600 | terminal_goto_xy (hpos, vpos); |
601 | fflush (stdout(&__sF[1])); |
602 | } |
603 | |
604 | /* **************************************************************** */ |
605 | /* */ |
606 | /* Functions Static to this File */ |
607 | /* */ |
608 | /* **************************************************************** */ |
609 | |
610 | /* Make a DISPLAY_LINE ** with width and height. */ |
611 | static DISPLAY_LINE ** |
612 | make_display (int width, int height) |
613 | { |
614 | register int i; |
615 | DISPLAY_LINE **display; |
616 | |
617 | display = (DISPLAY_LINE **)xmalloc ((1 + height) * sizeof (DISPLAY_LINE *)); |
618 | |
619 | for (i = 0; i < height; i++) |
620 | { |
621 | display[i] = (DISPLAY_LINE *)xmalloc (sizeof (DISPLAY_LINE)); |
622 | display[i]->text = (char *)xmalloc (1 + width); |
623 | display[i]->textlen = 0; |
624 | display[i]->inverse = 0; |
625 | } |
626 | display[i] = (DISPLAY_LINE *)NULL((void *)0); |
627 | return (display); |
628 | } |
629 | |
630 | /* Free the storage allocated to DISPLAY. */ |
631 | static void |
632 | free_display (DISPLAY_LINE **display) |
633 | { |
634 | register int i; |
635 | register DISPLAY_LINE *display_line; |
636 | |
637 | if (!display) |
638 | return; |
639 | |
640 | for (i = 0; (display_line = display[i]); i++) |
641 | { |
642 | free (display_line->text); |
643 | free (display_line); |
644 | } |
645 | free (display); |
646 | } |