File: /usr/src/linux/scripts/lxdialog/textbox.c
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
24 static void back_lines (int n);
25 static void print_page (WINDOW * win, int height, int width);
26 static void print_line (WINDOW * win, int row, int width);
27 static char *get_line (void);
28 static void print_position (WINDOW * win, int height, int width);
29
30 static int hscroll = 0, fd, file_size, bytes_read;
31 static int begin_reached = 1, end_reached = 0, page_length;
32 static char *buf, *page;
33
34 /*
35 * Display text from a file in a dialog box.
36 */
37 int
38 dialog_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 char search_term[MAX_LEN + 1];
43 WINDOW *dialog, *text;
44
45 search_term[0] = '\0'; /* no search term entered yet */
46
47 /* Open input file for reading */
48 if ((fd = open (file, O_RDONLY)) == -1) {
49 endwin ();
50 fprintf (stderr,
51 "\nCan't open input file in dialog_textbox().\n");
52 exit (-1);
53 }
54 /* Get file size. Actually, 'file_size' is the real file size - 1,
55 since it's only the last byte offset from the beginning */
56 if ((file_size = lseek (fd, 0, SEEK_END)) == -1) {
57 endwin ();
58 fprintf (stderr, "\nError getting file size in dialog_textbox().\n");
59 exit (-1);
60 }
61 /* Restore file pointer to beginning of file after getting file size */
62 if (lseek (fd, 0, SEEK_SET) == -1) {
63 endwin ();
64 fprintf (stderr, "\nError moving file pointer in dialog_textbox().\n");
65 exit (-1);
66 }
67 /* Allocate space for read buffer */
68 if ((buf = malloc (BUF_SIZE + 1)) == NULL) {
69 endwin ();
70 fprintf (stderr, "\nCan't allocate memory in dialog_textbox().\n");
71 exit (-1);
72 }
73 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
74 endwin ();
75 fprintf (stderr, "\nError reading file in dialog_textbox().\n");
76 exit (-1);
77 }
78 buf[bytes_read] = '\0'; /* mark end of valid data */
79 page = buf; /* page is pointer to start of page to be displayed */
80
81 /* center dialog box on screen */
82 x = (COLS - width) / 2;
83 y = (LINES - height) / 2;
84
85
86 draw_shadow (stdscr, y, x, height, width);
87
88 dialog = newwin (height, width, y, x);
89 keypad (dialog, TRUE);
90
91 /* Create window for text region, used for scrolling text */
92 text = subwin (dialog, height - 4, width - 2, y + 1, x + 1);
93 wattrset (text, dialog_attr);
94 wbkgdset (text, dialog_attr & A_COLOR);
95
96 keypad (text, TRUE);
97
98 /* register the new window, along with its borders */
99 draw_box (dialog, 0, 0, height, width, dialog_attr, border_attr);
100
101 wattrset (dialog, border_attr);
102 mvwaddch (dialog, height-3, 0, ACS_LTEE);
103 for (i = 0; i < width - 2; i++)
104 waddch (dialog, ACS_HLINE);
105 wattrset (dialog, dialog_attr);
106 wbkgdset (dialog, dialog_attr & A_COLOR);
107 waddch (dialog, ACS_RTEE);
108
109 if (title != NULL && strlen(title) >= width-2 ) {
110 /* truncate long title -- mec */
111 char * title2 = malloc(width-2+1);
112 memcpy( title2, title, width-2 );
113 title2[width-2] = '\0';
114 title = title2;
115 }
116
117 if (title != NULL) {
118 wattrset (dialog, title_attr);
119 mvwaddch (dialog, 0, (width - strlen(title))/2 - 1, ' ');
120 waddstr (dialog, (char *)title);
121 waddch (dialog, ' ');
122 }
123 print_button (dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
124 wnoutrefresh (dialog);
125 getyx (dialog, cur_y, cur_x); /* Save cursor position */
126
127 /* Print first page of text */
128 attr_clear (text, height - 4, width - 2, dialog_attr);
129 print_page (text, height - 4, width - 2);
130 print_position (dialog, height, width);
131 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
132 wrefresh (dialog);
133
134 while ((key != ESC) && (key != '\n')) {
135 key = wgetch (dialog);
136 switch (key) {
137 case 'E': /* Exit */
138 case 'e':
139 case 'X':
140 case 'x':
141 delwin (dialog);
142 free (buf);
143 close (fd);
144 return 0;
145 case 'g': /* First page */
146 case KEY_HOME:
147 if (!begin_reached) {
148 begin_reached = 1;
149 /* First page not in buffer? */
150 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
151 endwin ();
152 fprintf (stderr,
153 "\nError moving file pointer in dialog_textbox().\n");
154 exit (-1);
155 }
156 if (fpos > bytes_read) { /* Yes, we have to read it in */
157 if (lseek (fd, 0, SEEK_SET) == -1) {
158 endwin ();
159 fprintf (stderr, "\nError moving file pointer in "
160 "dialog_textbox().\n");
161 exit (-1);
162 }
163 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
164 endwin ();
165 fprintf (stderr,
166 "\nError reading file in dialog_textbox().\n");
167 exit (-1);
168 }
169 buf[bytes_read] = '\0';
170 }
171 page = buf;
172 print_page (text, height - 4, width - 2);
173 print_position (dialog, height, width);
174 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
175 wrefresh (dialog);
176 }
177 break;
178 case 'G': /* Last page */
179 case KEY_END:
180
181 end_reached = 1;
182 /* Last page not in buffer? */
183 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
184 endwin ();
185 fprintf (stderr,
186 "\nError moving file pointer in dialog_textbox().\n");
187 exit (-1);
188 }
189 if (fpos < file_size) { /* Yes, we have to read it in */
190 if (lseek (fd, -BUF_SIZE, SEEK_END) == -1) {
191 endwin ();
192 fprintf (stderr,
193 "\nError moving file pointer in dialog_textbox().\n");
194 exit (-1);
195 }
196 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
197 endwin ();
198 fprintf (stderr,
199 "\nError reading file in dialog_textbox().\n");
200 exit (-1);
201 }
202 buf[bytes_read] = '\0';
203 }
204 page = buf + bytes_read;
205 back_lines (height - 4);
206 print_page (text, height - 4, width - 2);
207 print_position (dialog, height, width);
208 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
209 wrefresh (dialog);
210 break;
211 case 'K': /* Previous line */
212 case 'k':
213 case KEY_UP:
214 if (!begin_reached) {
215 back_lines (page_length + 1);
216
217 /* We don't call print_page() here but use scrolling to ensure
218 faster screen update. However, 'end_reached' and
219 'page_length' should still be updated, and 'page' should
220 point to start of next page. This is done by calling
221 get_line() in the following 'for' loop. */
222 scrollok (text, TRUE);
223 wscrl (text, -1); /* Scroll text region down one line */
224 scrollok (text, FALSE);
225 page_length = 0;
226 passed_end = 0;
227 for (i = 0; i < height - 4; i++) {
228 if (!i) {
229 /* print first line of page */
230 print_line (text, 0, width - 2);
231 wnoutrefresh (text);
232 } else
233 /* Called to update 'end_reached' and 'page' */
234 get_line ();
235 if (!passed_end)
236 page_length++;
237 if (end_reached && !passed_end)
238 passed_end = 1;
239 }
240
241 print_position (dialog, height, width);
242 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
243 wrefresh (dialog);
244 }
245 break;
246 case 'B': /* Previous page */
247 case 'b':
248 case KEY_PPAGE:
249 if (begin_reached)
250 break;
251 back_lines (page_length + height - 4);
252 print_page (text, height - 4, width - 2);
253 print_position (dialog, height, width);
254 wmove (dialog, cur_y, cur_x);
255 wrefresh (dialog);
256 break;
257 case 'J': /* Next line */
258 case 'j':
259 case KEY_DOWN:
260 if (!end_reached) {
261 begin_reached = 0;
262 scrollok (text, TRUE);
263 scroll (text); /* Scroll text region up one line */
264 scrollok (text, FALSE);
265 print_line (text, height - 5, width - 2);
266 wnoutrefresh (text);
267 print_position (dialog, height, width);
268 wmove (dialog, cur_y, cur_x); /* Restore cursor position */
269 wrefresh (dialog);
270 }
271 break;
272 case KEY_NPAGE: /* Next page */
273 case ' ':
274 if (end_reached)
275 break;
276
277 begin_reached = 0;
278 print_page (text, height - 4, width - 2);
279 print_position (dialog, height, width);
280 wmove (dialog, cur_y, cur_x);
281 wrefresh (dialog);
282 break;
283 case '0': /* Beginning of line */
284 case 'H': /* Scroll left */
285 case 'h':
286 case KEY_LEFT:
287 if (hscroll <= 0)
288 break;
289
290 if (key == '0')
291 hscroll = 0;
292 else
293 hscroll--;
294 /* Reprint current page to scroll horizontally */
295 back_lines (page_length);
296 print_page (text, height - 4, width - 2);
297 wmove (dialog, cur_y, cur_x);
298 wrefresh (dialog);
299 break;
300 case 'L': /* Scroll right */
301 case 'l':
302 case KEY_RIGHT:
303 if (hscroll >= MAX_LEN)
304 break;
305 hscroll++;
306 /* Reprint current page to scroll horizontally */
307 back_lines (page_length);
308 print_page (text, height - 4, width - 2);
309 wmove (dialog, cur_y, cur_x);
310 wrefresh (dialog);
311 break;
312 case ESC:
313 break;
314 }
315 }
316
317 delwin (dialog);
318 free (buf);
319 close (fd);
320 return -1; /* ESC pressed */
321 }
322
323 /*
324 * Go back 'n' lines in text file. Called by dialog_textbox().
325 * 'page' will be updated to point to the desired line in 'buf'.
326 */
327 static void
328 back_lines (int n)
329 {
330 int i, fpos;
331
332 begin_reached = 0;
333 /* We have to distinguish between end_reached and !end_reached
334 since at end of file, the line is not ended by a '\n'.
335 The code inside 'if' basically does a '--page' to move one
336 character backward so as to skip '\n' of the previous line */
337 if (!end_reached) {
338 /* Either beginning of buffer or beginning of file reached? */
339 if (page == buf) {
340 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
341 endwin ();
342 fprintf (stderr, "\nError moving file pointer in "
343 "back_lines().\n");
344 exit (-1);
345 }
346 if (fpos > bytes_read) { /* Not beginning of file yet */
347 /* We've reached beginning of buffer, but not beginning of
348 file yet, so read previous part of file into buffer.
349 Note that we only move backward for BUF_SIZE/2 bytes,
350 but not BUF_SIZE bytes to avoid re-reading again in
351 print_page() later */
352 /* Really possible to move backward BUF_SIZE/2 bytes? */
353 if (fpos < BUF_SIZE / 2 + bytes_read) {
354 /* No, move less then */
355 if (lseek (fd, 0, SEEK_SET) == -1) {
356 endwin ();
357 fprintf (stderr, "\nError moving file pointer in "
358 "back_lines().\n");
359 exit (-1);
360 }
361 page = buf + fpos - bytes_read;
362 } else { /* Move backward BUF_SIZE/2 bytes */
363 if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR)
364 == -1) {
365 endwin ();
366 fprintf (stderr, "\nError moving file pointer "
367 "in back_lines().\n");
368 exit (-1);
369 }
370 page = buf + BUF_SIZE / 2;
371 }
372 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
373 endwin ();
374 fprintf (stderr, "\nError reading file in back_lines().\n");
375 exit (-1);
376 }
377 buf[bytes_read] = '\0';
378 } else { /* Beginning of file reached */
379 begin_reached = 1;
380 return;
381 }
382 }
383 if (*(--page) != '\n') { /* '--page' here */
384 /* Something's wrong... */
385 endwin ();
386 fprintf (stderr, "\nInternal error in back_lines().\n");
387 exit (-1);
388 }
389 }
390 /* Go back 'n' lines */
391 for (i = 0; i < n; i++)
392 do {
393 if (page == buf) {
394 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
395 endwin ();
396 fprintf (stderr,
397 "\nError moving file pointer in back_lines().\n");
398 exit (-1);
399 }
400 if (fpos > bytes_read) {
401 /* Really possible to move backward BUF_SIZE/2 bytes? */
402 if (fpos < BUF_SIZE / 2 + bytes_read) {
403 /* No, move less then */
404 if (lseek (fd, 0, SEEK_SET) == -1) {
405 endwin ();
406 fprintf (stderr, "\nError moving file pointer "
407 "in back_lines().\n");
408 exit (-1);
409 }
410 page = buf + fpos - bytes_read;
411 } else { /* Move backward BUF_SIZE/2 bytes */
412 if (lseek (fd, -(BUF_SIZE / 2 + bytes_read),
413 SEEK_CUR) == -1) {
414 endwin ();
415 fprintf (stderr, "\nError moving file pointer"
416 " in back_lines().\n");
417 exit (-1);
418 }
419 page = buf + BUF_SIZE / 2;
420 }
421 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
422 endwin ();
423 fprintf (stderr, "\nError reading file in "
424 "back_lines().\n");
425 exit (-1);
426 }
427 buf[bytes_read] = '\0';
428 } else { /* Beginning of file reached */
429 begin_reached = 1;
430 return;
431 }
432 }
433 } while (*(--page) != '\n');
434 page++;
435 }
436
437 /*
438 * Print a new page of text. Called by dialog_textbox().
439 */
440 static void
441 print_page (WINDOW * win, int height, int width)
442 {
443 int i, passed_end = 0;
444
445 page_length = 0;
446 for (i = 0; i < height; i++) {
447 print_line (win, i, width);
448 if (!passed_end)
449 page_length++;
450 if (end_reached && !passed_end)
451 passed_end = 1;
452 }
453 wnoutrefresh (win);
454 }
455
456 /*
457 * Print a new line of text. Called by dialog_textbox() and print_page().
458 */
459 static void
460 print_line (WINDOW * win, int row, int width)
461 {
462 int y, x;
463 char *line;
464
465 line = get_line ();
466 line += MIN (strlen (line), hscroll); /* Scroll horizontally */
467 wmove (win, row, 0); /* move cursor to correct line */
468 waddch (win, ' ');
469 waddnstr (win, line, MIN (strlen (line), width - 2));
470
471 getyx (win, y, x);
472 /* Clear 'residue' of previous line */
473 #if OLD_NCURSES
474 {
475 int i;
476 for (i = 0; i < width - x; i++)
477 waddch (win, ' ');
478 }
479 #else
480 wclrtoeol(win);
481 #endif
482 }
483
484 /*
485 * Return current line of text. Called by dialog_textbox() and print_line().
486 * 'page' should point to start of current line before calling, and will be
487 * updated to point to start of next line.
488 */
489 static char *
490 get_line (void)
491 {
492 int i = 0, fpos;
493 static char line[MAX_LEN + 1];
494
495 end_reached = 0;
496 while (*page != '\n') {
497 if (*page == '\0') {
498 /* Either end of file or end of buffer reached */
499 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
500 endwin ();
501 fprintf (stderr, "\nError moving file pointer in "
502 "get_line().\n");
503 exit (-1);
504 }
505 if (fpos < file_size) { /* Not end of file yet */
506 /* We've reached end of buffer, but not end of file yet,
507 so read next part of file into buffer */
508 if ((bytes_read = read (fd, buf, BUF_SIZE)) == -1) {
509 endwin ();
510 fprintf (stderr, "\nError reading file in get_line().\n");
511 exit (-1);
512 }
513 buf[bytes_read] = '\0';
514 page = buf;
515 } else {
516 if (!end_reached)
517 end_reached = 1;
518 break;
519 }
520 } else if (i < MAX_LEN)
521 line[i++] = *(page++);
522 else {
523 /* Truncate lines longer than MAX_LEN characters */
524 if (i == MAX_LEN)
525 line[i++] = '\0';
526 page++;
527 }
528 }
529 if (i <= MAX_LEN)
530 line[i] = '\0';
531 if (!end_reached)
532 page++; /* move pass '\n' */
533
534 return line;
535 }
536
537 /*
538 * Print current position
539 */
540 static void
541 print_position (WINDOW * win, int height, int width)
542 {
543 int fpos, percent;
544
545 if ((fpos = lseek (fd, 0, SEEK_CUR)) == -1) {
546 endwin ();
547 fprintf (stderr, "\nError moving file pointer in print_position().\n");
548 exit (-1);
549 }
550 wattrset (win, position_indicator_attr);
551 wbkgdset (win, position_indicator_attr & A_COLOR);
552 percent = !file_size ?
553 100 : ((fpos - bytes_read + page - buf) * 100) / file_size;
554 wmove (win, height - 3, width - 9);
555 wprintw (win, "(%3d%%)", percent);
556 }
557