aboutsummaryrefslogtreecommitdiff
path: root/scripts/lxdialog/textbox.c
blob: fa8d92ea02b6efbc1b7980f38a46534f4f477caa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
/*
 *  textbox.c -- implements the text box
 *
 *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "dialog.h"

static void back_lines(int n);
static void print_page(WINDOW * win, int height, int width);
static void print_line(WINDOW * win, int row, int width);
static char *get_line(void);
static void print_position(WINDOW * win, int height, int width);

static int hscroll, fd, file_size, bytes_read;
static int begin_reached = 1, end_reached, page_length;
static char *buf, *page;

/*
 * Display text from a file in a dialog box.
 */
int dialog_textbox(const char *title, const char *file, int height, int width)
{
	int i, x, y, cur_x, cur_y, fpos, key = 0;
	int passed_end;
	char search_term[MAX_LEN + 1];
	WINDOW *dialog, *text;

	search_term[0] = '\0';	/* no search term entered yet */

	/* Open input file for reading */
	if ((fd = open(file, O_RDONLY)) == -1) {
		endwin();
		fprintf(stderr, "\nCan't open input file in dialog_textbox().\n");
		exit(-1);
	}
	/* Get file size. Actually, 'file_size' is the real file size - 1,
	   since it's only the last byte offset from the beginning */
	if ((file_size = lseek(fd, 0, SEEK_END)) == -1) {
		endwin();
		fprintf(stderr, "\nError getting file size in dialog_textbox().\n");
		exit(-1);
	}
	/* Restore file pointer to beginning of file after getting file size */
	if (lseek(fd, 0, SEEK_SET) == -1) {
		endwin();
		fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
		exit(-1);
	}
	/* Allocate space for read buffer */
	if ((buf = malloc(BUF_SIZE + 1)) == NULL) {
		endwin();
		fprintf(stderr, "\nCan't allocate memory in dialog_textbox().\n");
		exit(-1);
	}
	if ((bytes_read = read(fd, buf, BUF_SIZE)) == -1) {
		endwin();
		fprintf(stderr, "\nError reading file in dialog_textbox().\n");
		exit(-1);
	}
	buf[bytes_read] = '\0';	/* mark end of valid data */
	page = buf;		/* page is pointer to start of page to be displayed */

	/* center dialog box on screen */
	x = (COLS - width) / 2;
	y = (LINES - height) / 2;

	draw_shadow(stdscr, y, x, height, width);

	dialog = newwin(height, width, y, x);
	keypad(dialog, TRUE);

	/* Create window for text region, used for scrolling text */
	text = subwin(dialog, height - 4, width - 2, y + 1, x + 1);
	wattrset(text, dialog_attr);
	wbkgdset(text, dialog_attr & A_COLOR);

	keypad(text, TRUE);

	/* register the new window, along with its borders */
	draw_box(dialog, 0, 0, height, width, dialog_attr, border_attr);

	wattrset(dialog, border_attr);
	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
	for (i = 0; i < width - 2; i++)
		waddch(dialog, ACS_HLINE);
	wattrset(dialog, dialog_attr);
	wbkgdset(dialog, dialog_attr & A_COLOR);
	waddch(dialog, ACS_RTEE);

	if (title != NULL && strlen(title) >= width - 2) {
		/* truncate long title -- mec */
		char *title2 = malloc(width - 2 + 1);
		memcpy(title2, title, width - 2);
		title2[width - 2] = '\0';
		title = title2;
	}

	if (title != NULL) {
		wattrset(dialog, title_attr);
		mvwaddch(dialog, 0, (width - strlen(title)) / 2 - 1, ' ');
		waddstr(dialog, (char *)title);
		waddch(dialog, ' ');
	}
	print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
	wnoutrefresh(dialog);
	getyx(dialog, cur_y, cur_x);	/* Save cursor position */

	/* Print first page of text */
	attr_clear(text, height - 4, width - 2, dialog_attr);
	print_page(text, height - 4, width - 2);
	print_position(dialog, height, width);
	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
	wrefresh(dialog);

	while ((key != ESC) && (key != '\n')) {
		key = wgetch(dialog);
		switch (key) {
		case 'E':	/* Exit */
		case 'e':
		case 'X':
		case 'x':
			delwin(dialog);
			free(buf);
			close(fd);
			return 0;
		case 'g':	/* First page */
		case KEY_HOME:
			if (!begin_reached) {
				begin_reached = 1;
				/* First page not in buffer? */
				if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
					endwin();
					fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
					exit(-1);
				}
				if (fpos > bytes_read) {	/* Yes, we have to read it in */
					if (lseek(fd, 0, SEEK_SET) == -1) {
						endwin();
						fprintf(stderr, "\nError moving file pointer in "
							        "dialog_textbox().\n");
						exit(-1);
					}
					if ((bytes_read =
					     read(fd, buf, BUF_SIZE)) == -1) {
						endwin();
						fprintf(stderr, "\nError reading file in dialog_textbox().\n");
						exit(-1);
					}
					buf[bytes_read] = '\0';
				}
				page = buf;
				print_page(text, height - 4, width - 2);
				print_position(dialog, height, width);
				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
				wrefresh(dialog);
			}
			break;
		case 'G':	/* Last page */
		case KEY_END:

			end_reached = 1;
			/* Last page not in buffer? */
			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
				endwin();
				fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
				exit(-1);
			}
			if (fpos < file_size) {	/* Yes, we have to read it in */
				if (lseek(fd, -BUF_SIZE, SEEK_END) == -1) {
					endwin();
					fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
					exit(-1);
				}
				if ((bytes_read =
				     read(fd, buf, BUF_SIZE)) == -1) {
					endwin();
					fprintf(stderr, "\nError reading file in dialog_textbox().\n");
					exit(-1);
				}
				buf[bytes_read] = '\0';
			}
			page = buf + bytes_read;
			back_lines(height - 4);
			print_page(text, height - 4, width - 2);
			print_position(dialog, height, width);
			wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
			wrefresh(dialog);
			break;
		case 'K':	/* Previous line */
		case 'k':
		case KEY_UP:
			if (!begin_reached) {
				back_lines(page_length + 1);

				/* We don't call print_page() here but use scrolling to ensure
				   faster screen update. However, 'end_reached' and
				   'page_length' should still be updated, and 'page' should
				   point to start of next page. This is done by calling
				   get_line() in the following 'for' loop. */
				scrollok(text, TRUE);
				wscrl(text, -1);	/* Scroll text region down one line */
				scrollok(text, FALSE);
				page_length = 0;
				passed_end = 0;
				for (i = 0; i < height - 4; i++) {
					if (!i) {
						/* print first line of page */
						print_line(text, 0, width - 2);
						wnoutrefresh(text);
					} else
						/* Called to update 'end_reached' and 'page' */
						get_line();
					if (!passed_end)
						page_length++;
					if (end_reached && !passed_end)
						passed_end = 1;
				}

				print_position(dialog, height, width);
				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
				wrefresh(dialog);
			}
			break;
		case 'B':	/* Previous page */
		case 'b':
		case KEY_PPAGE:
			if (begin_reached)
				break;
			back_lines(page_length + height - 4);
			print_page(text, height - 4, width - 2);
			print_position(dialog, height, width);
			wmove(dialog, cur_y, cur_x);
			wrefresh(dialog);
			break;
		case 'J':	/* Next line */
		case 'j':
		case KEY_DOWN:
			if (!end_reached) {
				begin_reached = 0;
				scrollok(text, TRUE);
				scroll(text);	/* Scroll text region up one line */
				scrollok(text, FALSE);
				print_line(text, height - 5, width - 2);
				wnoutrefresh(text);
				print_position(dialog, height, width);
				wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
				wrefresh(dialog);
			}
			break;
		case KEY_NPAGE:	/* Next page */
		case ' ':
			if (end_reached)
				break;

			begin_reached = 0;
			print_page(text, height - 4, width - 2);
			print_position(dialog, height, width);
			wmove(dialog, cur_y, cur_x);
			wrefresh(dialog);
			break;
		case '0':	/* Beginning of line */
		case 'H':	/* Scroll left */
		case 'h':
		case KEY_LEFT:
			if (hscroll <= 0)
				break;

			if (key == '0')
				hscroll = 0;
			else
				hscroll--;
			/* Reprint current page to scroll horizontally */
			back_lines(page_length);
			print_page(text, height - 4, width - 2);
			wmove(dialog, cur_y, cur_x);
			wrefresh(dialog);
			break;
		case 'L':	/* Scroll right */
		case 'l':
		case KEY_RIGHT:
			if (hscroll >= MAX_LEN)
				break;
			hscroll++;
			/* Reprint current page to scroll horizontally */
			back_lines(page_length);
			print_page(text, height - 4, width - 2);
			wmove(dialog, cur_y, cur_x);
			wrefresh(dialog);
			break;
		case ESC:
			break;
		}
	}

	delwin(dialog);
	free(buf);
	close(fd);
	return -1;		/* ESC pressed */
}

/*
 * Go back 'n' lines in text file. Called by dialog_textbox().
 * 'page' will be updated to point to the desired line in 'buf'.
 */
static void back_lines(int n)
{
	int i, fpos;

	begin_reached = 0;
	/* We have to distinguish between end_reached and !end_reached
	   since at end of file, the line is not ended by a '\n'.
	   The code inside 'if' basically does a '--page' to move one
	   character backward so as to skip '\n' of the previous line */
	if (!end_reached) {
		/* Either beginning of buffer or beginning of file reached? */
		if (page == buf) {
			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
				endwin();
				fprintf(stderr, "\nError moving file pointer in "
					        "back_lines().\n");
				exit(-1);
			}
			if (fpos > bytes_read) {	/* Not beginning of file yet */
				/* We've reached beginning of buffer, but not beginning of
				   file yet, so read previous part of file into buffer.
				   Note that we only move backward for BUF_SIZE/2 bytes,
				   but not BUF_SIZE bytes to avoid re-reading again in
				   print_page() later */
				/* Really possible to move backward BUF_SIZE/2 bytes? */
				if (fpos < BUF_SIZE / 2 + bytes_read) {
					/* No, move less then */
					if (lseek(fd, 0, SEEK_SET) == -1) {
						endwin();
						fprintf(stderr, "\nError moving file pointer in "
						                "back_lines().\n");
						exit(-1);
					}
					page = buf + fpos - bytes_read;
				} else {	/* Move backward BUF_SIZE/2 bytes */
					if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
						endwin();
						fprintf(stderr, "\nError moving file pointer "
						                "in back_lines().\n");
						exit(-1);
					}
					page = buf + BUF_SIZE / 2;
				}
				if ((bytes_read =
				     read(fd, buf, BUF_SIZE)) == -1) {
					endwin();
					fprintf(stderr, "\nError reading file in back_lines().\n");
					exit(-1);
				}
				buf[bytes_read] = '\0';
			} else {	/* Beginning of file reached */
				begin_reached = 1;
				return;
			}
		}
		if (*(--page) != '\n') {	/* '--page' here */
			/* Something's wrong... */
			endwin();
			fprintf(stderr, "\nInternal error in back_lines().\n");
			exit(-1);
		}
	}
	/* Go back 'n' lines */
	for (i = 0; i < n; i++)
		do {
			if (page == buf) {
				if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
					endwin();
					fprintf(stderr, "\nError moving file pointer in back_lines().\n");
					exit(-1);
				}
				if (fpos > bytes_read) {
					/* Really possible to move backward BUF_SIZE/2 bytes? */
					if (fpos < BUF_SIZE / 2 + bytes_read) {
						/* No, move less then */
						if (lseek(fd, 0, SEEK_SET) == -1) {
							endwin();
							fprintf(stderr, "\nError moving file pointer "
							                "in back_lines().\n");
							exit(-1);
						}
						page = buf + fpos - bytes_read;
					} else {	/* Move backward BUF_SIZE/2 bytes */
						if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
							endwin();
							fprintf(stderr, "\nError moving file pointer"
							                " in back_lines().\n");
							exit(-1);
						}
						page = buf + BUF_SIZE / 2;
					}
					if ((bytes_read =
					     read(fd, buf, BUF_SIZE)) == -1) {
						endwin();
						fprintf(stderr, "\nError reading file in "
						                "back_lines().\n");
						exit(-1);
					}
					buf[bytes_read] = '\0';
				} else {	/* Beginning of file reached */
					begin_reached = 1;
					return;
				}
			}
		} while (*(--page) != '\n');
	page++;
}

/*
 * Print a new page of text. Called by dialog_textbox().
 */
static void print_page(WINDOW * win, int height, int width)
{
	int i, passed_end = 0;

	page_length = 0;
	for (i = 0; i < height; i++) {
		print_line(win, i, width);
		if (!passed_end)
			page_length++;
		if (end_reached && !passed_end)
			passed_end = 1;
	}
	wnoutrefresh(win);
}

/*
 * Print a new line of text. Called by dialog_textbox() and print_page().
 */
static void print_line(WINDOW * win, int row, int width)
{
	int y, x;
	char *line;

	line = get_line();
	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */
	wmove(win, row, 0);	/* move cursor to correct line */
	waddch(win, ' ');
	waddnstr(win, line, MIN(strlen(line), width - 2));

	getyx(win, y, x);
	/* Clear 'residue' of previous line */
#if OLD_NCURSES
	{
		int i;
		for (i = 0; i < width - x; i++)
			waddch(win, ' ');
	}
#else
	wclrtoeol(win);
#endif
}

/*
 * Return current line of text. Called by dialog_textbox() and print_line().
 * 'page' should point to start of current line before calling, and will be
 * updated to point to start of next line.
 */
static char *get_line(void)
{
	int i = 0, fpos;
	static char line[MAX_LEN + 1];

	end_reached = 0;
	while (*page != '\n') {
		if (*page == '\0') {
			/* Either end of file or end of buffer reached */
			if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
				endwin();
				fprintf(stderr, "\nError moving file pointer in "
				                "get_line().\n");
				exit(-1);
			}
			if (fpos < file_size) {	/* Not end of file yet */
				/* We've reached end of buffer, but not end of file yet,
				   so read next part of file into buffer */
				if ((bytes_read =
				     read(fd, buf, BUF_SIZE)) == -1) {
					endwin();
					fprintf(stderr, "\nError reading file in get_line().\n");
					exit(-1);
				}
				buf[bytes_read] = '\0';
				page = buf;
			} else {
				if (!end_reached)
					end_reached = 1;
				break;
			}
		} else if (i < MAX_LEN)
			line[i++] = *(page++);
		else {
			/* Truncate lines longer than MAX_LEN characters */
			if (i == MAX_LEN)
				line[i++] = '\0';
			page++;
		}
	}
	if (i <= MAX_LEN)
		line[i] = '\0';
	if (!end_reached)
		page++;		/* move pass '\n' */

	return line;
}

/*
 * Print current position
 */
static void print_position(WINDOW * win, int height, int width)
{
	int fpos, percent;

	if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
		endwin();
		fprintf(stderr, "\nError moving file pointer in print_position().\n");
		exit(-1);
	}
	wattrset(win, position_indicator_attr);
	wbkgdset(win, position_indicator_attr & A_COLOR);
	percent = !file_size ?
	    100 : ((fpos - bytes_read + page - buf) * 100) / file_size;
	wmove(win, height - 3, width - 9);
	wprintw(win, "(%3d%%)", percent);
}