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