source: menu/lxdialog/textbox.c@ 7a82194

ablfs-more legacy trunk
Last change on this file since 7a82194 was 2ce3688, checked in by Pierre Labastie <pierre@…>, 9 years ago

Adapt menu to ncurses ABI 6, and clear a warning
  • Property mode set to 100644
File size: 15.2 KB
Line 
1/*
2 * textbox.c -- implements the text box
3 *
4 * ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
5 * MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include "dialog.h"
23
24static void back_lines (int n);
25static void print_page (WINDOW * win, int height, int width);
26static void print_line (WINDOW * win, int row, int width);
27static char *get_line (void);
28static void print_position (WINDOW * win, int height, int width);
29
30static int hscroll, fd, file_size, bytes_read;
31static int begin_reached = 1, end_reached, page_length;
32static char *buf, *page;
33
34/*
35 * Display text from a file in a dialog box.
36 */
37int
38dialog_textbox (const char *title, const char *file, int height, int width)
39{
40 int i, x, y, cur_x, cur_y, fpos, key = 0;
41 int passed_end;
42 WINDOW *dialog, *text;
43
44 /* Open input file for reading */
45 if ((fd = open (file, O_RDONLY)) == -1) {
46 endwin ();
47 fprintf (stderr,
48 "\nCan't open input file in dialog_textbox().\n");
49 exit (-1);
50 }
51 /* Get file size. Actually, 'file_size' is the real file size - 1,
52 since it's only the last byte offset from the beginning */
53 if ((file_size = lseek (fd, 0, SEEK_END)) == -1) {
54 endwin ();
55 fprintf (stderr, "\nError getting file size in dialog_textbox().\n");
56 exit (-1);
57 }
58 /* Restore file pointer to beginning of file after getting file size */
59 if (lseek (fd, 0, SEEK_SET) == -1) {
60 endwin ();
61 fprintf (stderr, "\nError moving file pointer in dialog_textbox().\n");
62 exit (-1);
63 }
64 /* Allocate space for read buffer */
65 if ((buf = malloc (BUF_SIZE + 1)) == NULL) {
66 endwin ();
67 fprintf (stderr, "\nCan't allocate memory in dialog_textbox().\n");
68 exit (-1);
69 }
70 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
71 endwin ();
72 fprintf (stderr, "\nError reading file in dialog_textbox().\n");
73 exit (-1);
74 }
75 buf[bytes_read] = '\0'; /* mark end of valid data */
76 page = buf; /* page is pointer to start of page to be displayed */
77
78 /* center dialog box on screen */
79 x = (COLS - width) / 2;
80 y = (LINES - height) / 2;
81
82
83 draw_shadow (stdscr, y, x, height, width);
84
85 dialog = newwin (height, width, y, x);
86 keypad (dialog, TRUE);
87
88 /* Create window for text region, used for scrolling text */
89 text = subwin (dialog, height - 4, width - 2, y + 1, x + 1);
90 wattrset (text, dialog_attr);
91 wbkgdset (text, dialog_attr & A_COLOR);
92
93 keypad (text, TRUE);
94
95 /* register the new window, along with its borders */
96 draw_box (dialog, 0, 0, height, width, dialog_attr, border_attr);
97
98 wattrset (dialog, border_attr);
99 mvwaddch (dialog, height-3, 0, ACS_LTEE);
100 for (i = 0; i < width - 2; i++)
101 waddch (dialog, ACS_HLINE);
102 wattrset (dialog, dialog_attr);
103 wbkgdset (dialog, dialog_attr & A_COLOR);
104 waddch (dialog, ACS_RTEE);
105
106 if (title != NULL && strlen(title) >= width-2 ) {
107 /* truncate long title -- mec */
108 char * title2 = malloc(width-2+1);
109 memcpy( title2, title, width-2 );
110 title2[width-2] = '\0';
111 title = title2;
112 }
113
114 if (title != NULL) {
115 wattrset (dialog, title_attr);
116 mvwaddch (dialog, 0, (width - strlen(title))/2 - 1, ' ');
117 waddstr (dialog, (char *)title);
118 waddch (dialog, ' ');
119 }
120 wbkgdset (dialog, 0);
121 print_button (dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
122 wbkgdset (dialog, dialog_attr & A_COLOR);
123 wnoutrefresh (dialog);
124 getyx (dialog, cur_y, cur_x); /* Save cursor position */
125
126 /* Print first page of text */
127 attr_clear (text, height - 4, width - 2, dialog_attr);
128 print_page (text, height - 4, width - 2);
129 print_position (dialog, height, width);
130 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
131 wrefresh (dialog);
132
133 while ((key != ESC) && (key != '\n')) {
134 key = wgetch (dialog);
135 switch (key) {
136 case 'E': /* Exit */
137 case 'e':
138 case 'X':
139 case 'x':
140 delwin (dialog);
141 free (buf);
142 close (fd);
143 return 0;
144 case 'g': /* First page */
145 case KEY_HOME:
146 if (!begin_reached) {
147 begin_reached = 1;
148 /* First page not in buffer? */
149 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
150 endwin ();
151 fprintf (stderr,
152 "\nError moving file pointer in dialog_textbox().\n");
153 exit (-1);
154 }
155 if (fpos > bytes_read) { /* Yes, we have to read it in */
156 if (lseek (fd, 0, SEEK_SET) == -1) {
157 endwin ();
158 fprintf (stderr, "\nError moving file pointer in "
159 "dialog_textbox().\n");
160 exit (-1);
161 }
162 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
163 endwin ();
164 fprintf (stderr,
165 "\nError reading file in dialog_textbox().\n");
166 exit (-1);
167 }
168 buf[bytes_read] = '\0';
169 }
170 page = buf;
171 print_page (text, height - 4, width - 2);
172 print_position (dialog, height, width);
173 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
174 wrefresh (dialog);
175 }
176 break;
177 case 'G': /* Last page */
178 case KEY_END:
179
180 end_reached = 1;
181 /* Last page not in buffer? */
182 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
183 endwin ();
184 fprintf (stderr,
185 "\nError moving file pointer in dialog_textbox().\n");
186 exit (-1);
187 }
188 if (fpos < file_size) { /* Yes, we have to read it in */
189 if (lseek (fd, -BUF_SIZE, SEEK_END) == -1) {
190 endwin ();
191 fprintf (stderr,
192 "\nError moving file pointer in dialog_textbox().\n");
193 exit (-1);
194 }
195 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
196 endwin ();
197 fprintf (stderr,
198 "\nError reading file in dialog_textbox().\n");
199 exit (-1);
200 }
201 buf[bytes_read] = '\0';
202 }
203 page = buf + bytes_read;
204 back_lines (height - 4);
205 print_page (text, height - 4, width - 2);
206 print_position (dialog, height, width);
207 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
208 wrefresh (dialog);
209 break;
210 case 'K': /* Previous line */
211 case 'k':
212 case KEY_UP:
213 if (!begin_reached) {
214 back_lines (page_length + 1);
215
216 /* We don't call print_page() here but use scrolling to ensure
217 faster screen update. However, 'end_reached' and
218 'page_length' should still be updated, and 'page' should
219 point to start of next page. This is done by calling
220 get_line() in the following 'for' loop. */
221 scrollok (text, TRUE);
222 wscrl (text, -1); /* Scroll text region down one line */
223 scrollok (text, FALSE);
224 page_length = 0;
225 passed_end = 0;
226 for (i = 0; i < height - 4; i++) {
227 if (!i) {
228 /* print first line of page */
229 print_line (text, 0, width - 2);
230 wnoutrefresh (text);
231 } else
232 /* Called to update 'end_reached' and 'page' */
233 get_line ();
234 if (!passed_end)
235 page_length++;
236 if (end_reached && !passed_end)
237 passed_end = 1;
238 }
239
240 print_position (dialog, height, width);
241 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
242 wrefresh (dialog);
243 }
244 break;
245 case 'B': /* Previous page */
246 case 'b':
247 case KEY_PPAGE:
248 if (begin_reached)
249 break;
250 back_lines (page_length + height - 4);
251 print_page (text, height - 4, width - 2);
252 print_position (dialog, height, width);
253 wmove (dialog, cur_y, cur_x);
254 wrefresh (dialog);
255 break;
256 case 'J': /* Next line */
257 case 'j':
258 case KEY_DOWN:
259 if (!end_reached) {
260 begin_reached = 0;
261 scrollok (text, TRUE);
262 scroll (text); /* Scroll text region up one line */
263 scrollok (text, FALSE);
264 print_line (text, height - 5, width - 2);
265 wnoutrefresh (text);
266 print_position (dialog, height, width);
267 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
268 wrefresh (dialog);
269 }
270 break;
271 case KEY_NPAGE: /* Next page */
272 case ' ':
273 if (end_reached)
274 break;
275
276 begin_reached = 0;
277 print_page (text, height - 4, width - 2);
278 print_position (dialog, height, width);
279 wmove (dialog, cur_y, cur_x);
280 wrefresh (dialog);
281 break;
282 case '0': /* Beginning of line */
283 case 'H': /* Scroll left */
284 case 'h':
285 case KEY_LEFT:
286 if (hscroll <= 0)
287 break;
288
289 if (key == '0')
290 hscroll = 0;
291 else
292 hscroll--;
293 /* Reprint current page to scroll horizontally */
294 back_lines (page_length);
295 print_page (text, height - 4, width - 2);
296 wmove (dialog, cur_y, cur_x);
297 wrefresh (dialog);
298 break;
299 case 'L': /* Scroll right */
300 case 'l':
301 case KEY_RIGHT:
302 if (hscroll >= MAX_LEN)
303 break;
304 hscroll++;
305 /* Reprint current page to scroll horizontally */
306 back_lines (page_length);
307 print_page (text, height - 4, width - 2);
308 wmove (dialog, cur_y, cur_x);
309 wrefresh (dialog);
310 break;
311 case ESC:
312 break;
313 }
314 }
315
316 delwin (dialog);
317 free (buf);
318 close (fd);
319 return 1; /* ESC pressed */
320}
321
322/*
323 * Go back 'n' lines in text file. Called by dialog_textbox().
324 * 'page' will be updated to point to the desired line in 'buf'.
325 */
326static void
327back_lines (int n)
328{
329 int i, fpos;
330
331 begin_reached = 0;
332 /* We have to distinguish between end_reached and !end_reached
333 since at end of file, the line is not ended by a '\n'.
334 The code inside 'if' basically does a '--page' to move one
335 character backward so as to skip '\n' of the previous line */
336 if (!end_reached) {
337 /* Either beginning of buffer or beginning of file reached? */
338 if (page == buf) {
339 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
340 endwin ();
341 fprintf (stderr, "\nError moving file pointer in "
342 "back_lines().\n");
343 exit (-1);
344 }
345 if (fpos > bytes_read) { /* Not beginning of file yet */
346 /* We've reached beginning of buffer, but not beginning of
347 file yet, so read previous part of file into buffer.
348 Note that we only move backward for BUF_SIZE/2 bytes,
349 but not BUF_SIZE bytes to avoid re-reading again in
350 print_page() later */
351 /* Really possible to move backward BUF_SIZE/2 bytes? */
352 if (fpos < BUF_SIZE / 2 + bytes_read) {
353 /* No, move less then */
354 if (lseek (fd, 0, SEEK_SET) == -1) {
355 endwin ();
356 fprintf (stderr, "\nError moving file pointer in "
357 "back_lines().\n");
358 exit (-1);
359 }
360 page = buf + fpos - bytes_read;
361 } else { /* Move backward BUF_SIZE/2 bytes */
362 if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR)
363 == -1) {
364 endwin ();
365 fprintf (stderr, "\nError moving file pointer "
366 "in back_lines().\n");
367 exit (-1);
368 }
369 page = buf + BUF_SIZE / 2;
370 }
371 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
372 endwin ();
373 fprintf (stderr, "\nError reading file in back_lines().\n");
374 exit (-1);
375 }
376 buf[bytes_read] = '\0';
377 } else { /* Beginning of file reached */
378 begin_reached = 1;
379 return;
380 }
381 }
382 if (*(--page) != '\n') { /* '--page' here */
383 /* Something's wrong... */
384 endwin ();
385 fprintf (stderr, "\nInternal error in back_lines().\n");
386 exit (-1);
387 }
388 }
389 /* Go back 'n' lines */
390 for (i = 0; i < n; i++)
391 do {
392 if (page == buf) {
393 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
394 endwin ();
395 fprintf (stderr,
396 "\nError moving file pointer in back_lines().\n");
397 exit (-1);
398 }
399 if (fpos > bytes_read) {
400 /* Really possible to move backward BUF_SIZE/2 bytes? */
401 if (fpos < BUF_SIZE / 2 + bytes_read) {
402 /* No, move less then */
403 if (lseek (fd, 0, SEEK_SET) == -1) {
404 endwin ();
405 fprintf (stderr, "\nError moving file pointer "
406 "in back_lines().\n");
407 exit (-1);
408 }
409 page = buf + fpos - bytes_read;
410 } else { /* Move backward BUF_SIZE/2 bytes */
411 if (lseek (fd, -(BUF_SIZE / 2 + bytes_read),
412 SEEK_CUR) == -1) {
413 endwin ();
414 fprintf (stderr, "\nError moving file pointer"
415 " in back_lines().\n");
416 exit (-1);
417 }
418 page = buf + BUF_SIZE / 2;
419 }
420 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
421 endwin ();
422 fprintf (stderr, "\nError reading file in "
423 "back_lines().\n");
424 exit (-1);
425 }
426 buf[bytes_read] = '\0';
427 } else { /* Beginning of file reached */
428 begin_reached = 1;
429 return;
430 }
431 }
432 } while (*(--page) != '\n');
433 page++;
434}
435
436/*
437 * Print a new page of text. Called by dialog_textbox().
438 */
439static void
440print_page (WINDOW * win, int height, int width)
441{
442 int i, passed_end = 0;
443
444 page_length = 0;
445 for (i = 0; i < height; i++) {
446 print_line (win, i, width);
447 if (!passed_end)
448 page_length++;
449 if (end_reached && !passed_end)
450 passed_end = 1;
451 }
452 wnoutrefresh (win);
453}
454
455/*
456 * Print a new line of text. Called by dialog_textbox() and print_page().
457 */
458static void
459print_line (WINDOW * win, int row, int width)
460{
461 char *line;
462
463 line = get_line ();
464 line += MIN (strlen (line), hscroll); /* Scroll horizontally */
465 wmove (win, row, 0); /* move cursor to correct line */
466 waddch (win, ' ');
467 waddnstr (win, line, MIN (strlen (line), width - 2));
468
469 /* Clear 'residue' of previous line */
470#if OLD_NCURSES
471 {
472 int y, x;
473 int i;
474 getyx (win, y, x);
475 for (i = 0; i < width - x; i++)
476 waddch (win, ' ');
477 }
478#else
479 wclrtoeol(win);
480#endif
481}
482
483/*
484 * Return current line of text. Called by dialog_textbox() and print_line().
485 * 'page' should point to start of current line before calling, and will be
486 * updated to point to start of next line.
487 */
488static char *
489get_line (void)
490{
491 int i = 0, fpos;
492 static char line[MAX_LEN + 1];
493
494 end_reached = 0;
495 while (*page != '\n') {
496 if (*page == '\0') {
497 /* Either end of file or end of buffer reached */
498 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
499 endwin ();
500 fprintf (stderr, "\nError moving file pointer in "
501 "get_line().\n");
502 exit (-1);
503 }
504 if (fpos < file_size) { /* Not end of file yet */
505 /* We've reached end of buffer, but not end of file yet,
506 so read next part of file into buffer */
507 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
508 endwin ();
509 fprintf (stderr, "\nError reading file in get_line().\n");
510 exit (-1);
511 }
512 buf[bytes_read] = '\0';
513 page = buf;
514 } else {
515 if (!end_reached)
516 end_reached = 1;
517 break;
518 }
519 } else if (i < MAX_LEN)
520 line[i++] = *(page++);
521 else {
522 /* Truncate lines longer than MAX_LEN characters */
523 if (i == MAX_LEN)
524 line[i++] = '\0';
525 page++;
526 }
527 }
528 if (i <= MAX_LEN)
529 line[i] = '\0';
530 if (!end_reached)
531 page++; /* move pass '\n' */
532
533 return line;
534}
535
536/*
537 * Print current position
538 */
539static void
540print_position (WINDOW * win, int height, int width)
541{
542 int fpos, percent;
543
544 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
545 endwin ();
546 fprintf (stderr, "\nError moving file pointer in print_position().\n");
547 exit (-1);
548 }
549 wattrset (win, position_indicator_attr);
550 wbkgdset (win, position_indicator_attr & A_COLOR);
551 percent = !file_size ?
552 100 : ((fpos - bytes_read + page - buf) * 100) / file_size;
553 wmove (win, height - 3, width - 9);
554 wprintw (win, "(%3d%%)", percent);
555}
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