xref: /freebsd/contrib/dialog/textbox.c (revision e14ddd1f16e7e5788392c50de21ea7c927e0690c)
1 /*
2  *  $Id: textbox.c,v 1.101 2011/06/29 09:53:03 tom Exp $
3  *
4  *  textbox.c -- implements the text box
5  *
6  *  Copyright 2000-2010,2011	Thomas E.  Dickey
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU Lesser General Public License, version 2.1
10  *  as published by the Free Software Foundation.
11  *
12  *  This program is distributed in the hope that it will be useful, but
13  *  WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  *  Lesser General Public License for more details.
16  *
17  *  You should have received a copy of the GNU Lesser General Public
18  *  License along with this program; if not, write to
19  *	Free Software Foundation, Inc.
20  *	51 Franklin St., Fifth Floor
21  *	Boston, MA 02110, USA.
22  *
23  *  An earlier version of this program lists as authors:
24  *	Savio Lam (lam836@cs.cuhk.hk)
25  */
26 
27 #include <dialog.h>
28 #include <dlg_keys.h>
29 
30 #define PAGE_LENGTH	(height - 4)
31 #define PAGE_WIDTH	(width - 2)
32 
33 typedef struct {
34     DIALOG_CALLBACK obj;
35     WINDOW *text;
36     const char **buttons;
37     int hscroll;
38     char line[MAX_LEN + 1];
39     int fd;
40     long file_size;
41     long fd_bytes_read;
42     long bytes_read;
43     long buffer_len;
44     bool begin_reached;
45     bool buffer_first;
46     bool end_reached;
47     long page_length;		/* lines on the page which is shown */
48     long in_buf;		/* ending index into buf[] for page */
49     char *buf;
50 } MY_OBJ;
51 
52 static long
53 lseek_obj(MY_OBJ * obj, long offset, int mode)
54 {
55     long fpos;
56     if ((fpos = (long) lseek(obj->fd, (off_t) offset, mode)) == -1) {
57 	switch (mode) {
58 	case SEEK_CUR:
59 	    dlg_exiterr("Cannot get file position");
60 	    break;
61 	case SEEK_END:
62 	    dlg_exiterr("Cannot seek to end of file");
63 	    break;
64 	case SEEK_SET:
65 	    dlg_exiterr("Cannot set file position to %ld", offset);
66 	    break;
67 	}
68     }
69     return fpos;
70 }
71 
72 static long
73 ftell_obj(MY_OBJ * obj)
74 {
75     return lseek_obj(obj, 0L, SEEK_CUR);
76 }
77 
78 static char *
79 xalloc(size_t size)
80 {
81     char *result = dlg_malloc(char, size);
82     assert_ptr(result, "xalloc");
83     return result;
84 }
85 
86 /*
87  * read_high() substitutes read() for tab->spaces conversion
88  *
89  * buffer_len, fd_bytes_read, bytes_read are modified
90  * buf is allocated
91  *
92  * fd_bytes_read is the effective number of bytes read from file
93  * bytes_read is the length of buf, that can be different if tab_correct
94  */
95 static void
96 read_high(MY_OBJ * obj, size_t size_read)
97 {
98     char *buftab, ch;
99     int i = 0, j, n, tmpint;
100     long begin_line;
101 
102     /* Allocate space for read buffer */
103     buftab = xalloc(size_read + 1);
104 
105     if ((obj->fd_bytes_read = read(obj->fd, buftab, size_read)) != -1) {
106 
107 	buftab[obj->fd_bytes_read] = '\0';	/* mark end of valid data */
108 
109 	if (dialog_vars.tab_correct) {
110 
111 	    /* calculate bytes_read by buftab and fd_bytes_read */
112 	    obj->bytes_read = begin_line = 0;
113 	    for (j = 0; j < obj->fd_bytes_read; j++)
114 		if (buftab[j] == TAB)
115 		    obj->bytes_read += dialog_state.tab_len
116 			- ((obj->bytes_read - begin_line)
117 			   % dialog_state.tab_len);
118 		else if (buftab[j] == '\n') {
119 		    obj->bytes_read++;
120 		    begin_line = obj->bytes_read;
121 		} else
122 		    obj->bytes_read++;
123 
124 	    if (obj->bytes_read > obj->buffer_len) {
125 		if (obj->buffer_first)
126 		    obj->buffer_first = FALSE;	/* disp = 0 */
127 		else {
128 		    free(obj->buf);
129 		}
130 
131 		obj->buffer_len = obj->bytes_read;
132 
133 		/* Allocate space for read buffer */
134 		obj->buf = xalloc((size_t) obj->buffer_len + 1);
135 	    }
136 
137 	} else {
138 	    if (obj->buffer_first) {
139 		obj->buffer_first = FALSE;
140 
141 		/* Allocate space for read buffer */
142 		obj->buf = xalloc(size_read + 1);
143 	    }
144 
145 	    obj->bytes_read = obj->fd_bytes_read;
146 	}
147 
148 	j = 0;
149 	begin_line = 0;
150 	while (j < obj->fd_bytes_read)
151 	    if (((ch = buftab[j++]) == TAB) && (dialog_vars.tab_correct != 0)) {
152 		tmpint = (dialog_state.tab_len
153 			  - ((int) ((long) i - begin_line) % dialog_state.tab_len));
154 		for (n = 0; n < tmpint; n++)
155 		    obj->buf[i++] = ' ';
156 	    } else {
157 		if (ch == '\n')
158 		    begin_line = i + 1;
159 		obj->buf[i++] = ch;
160 	    }
161 
162 	obj->buf[i] = '\0';	/* mark end of valid data */
163 
164     }
165     if (obj->bytes_read == -1)
166 	dlg_exiterr("Error reading file");
167     free(buftab);
168 }
169 
170 static long
171 find_first(MY_OBJ * obj, char *buffer, long length)
172 {
173     long recount = obj->page_length;
174     long result = 0;
175 
176     while (length > 0) {
177 	if (buffer[length] == '\n') {
178 	    if (--recount < 0) {
179 		result = length;
180 		break;
181 	    }
182 	}
183 	--length;
184     }
185     return result;
186 }
187 
188 static long
189 tabize(MY_OBJ * obj, long val, long *first_pos)
190 {
191     long fpos;
192     long i, count, begin_line;
193     char *buftab;
194 
195     if (!dialog_vars.tab_correct)
196 	return val;
197 
198     fpos = ftell_obj(obj);
199 
200     lseek_obj(obj, fpos - obj->fd_bytes_read, SEEK_SET);
201 
202     /* Allocate space for read buffer */
203     buftab = xalloc((size_t) val + 1);
204 
205     if ((read(obj->fd, buftab, (size_t) val)) == -1)
206 	dlg_exiterr("Error reading file in tabize().");
207 
208     begin_line = count = 0;
209     if (first_pos != 0)
210 	*first_pos = 0;
211 
212     for (i = 0; i < val; i++) {
213 	if ((first_pos != 0) && (count >= val)) {
214 	    *first_pos = find_first(obj, buftab, i);
215 	    break;
216 	}
217 	if (buftab[i] == TAB)
218 	    count += dialog_state.tab_len
219 		- ((count - begin_line) % dialog_state.tab_len);
220 	else if (buftab[i] == '\n') {
221 	    count++;
222 	    begin_line = count;
223 	} else
224 	    count++;
225     }
226 
227     lseek_obj(obj, fpos, SEEK_SET);
228     free(buftab);
229     return count;
230 }
231 /*
232  * Return current line of text.
233  * 'page' should point to start of current line before calling, and will be
234  * updated to point to start of next line.
235  */
236 static char *
237 get_line(MY_OBJ * obj)
238 {
239     int i = 0;
240     long fpos;
241 
242     obj->end_reached = FALSE;
243     while (obj->buf[obj->in_buf] != '\n') {
244 	if (obj->buf[obj->in_buf] == '\0') {	/* Either end of file or end of buffer reached */
245 	    fpos = ftell_obj(obj);
246 
247 	    if (fpos < obj->file_size) {	/* Not end of file yet */
248 		/* We've reached end of buffer, but not end of file yet, so
249 		 * read next part of file into buffer
250 		 */
251 		read_high(obj, BUF_SIZE);
252 		obj->in_buf = 0;
253 	    } else {
254 		if (!obj->end_reached)
255 		    obj->end_reached = TRUE;
256 		break;
257 	    }
258 	} else if (i < MAX_LEN)
259 	    obj->line[i++] = obj->buf[obj->in_buf++];
260 	else {
261 	    if (i == MAX_LEN)	/* Truncate lines longer than MAX_LEN characters */
262 		obj->line[i++] = '\0';
263 	    obj->in_buf++;
264 	}
265     }
266     if (i <= MAX_LEN)
267 	obj->line[i] = '\0';
268     if (!obj->end_reached)
269 	obj->in_buf++;		/* move past '\n' */
270 
271     return obj->line;
272 }
273 
274 static bool
275 match_string(MY_OBJ * obj, char *string)
276 {
277     char *match = get_line(obj);
278     return strstr(match, string) != 0;
279 }
280 
281 /*
282  * Go back 'n' lines in text file. Called by dialog_textbox().
283  * 'in_buf' will be updated to point to the desired line in 'buf'.
284  */
285 static void
286 back_lines(MY_OBJ * obj, long n)
287 {
288     int i;
289     long fpos;
290     long val_to_tabize;
291 
292     obj->begin_reached = FALSE;
293     /* We have to distinguish between end_reached and !end_reached since at end
294        * of file, the line is not ended by a '\n'.  The code inside 'if'
295        * basically does a '--in_buf' to move one character backward so as to
296        * skip '\n' of the previous line */
297     if (!obj->end_reached) {
298 	/* Either beginning of buffer or beginning of file reached? */
299 
300 	if (obj->in_buf == 0) {
301 	    fpos = ftell_obj(obj);
302 
303 	    if (fpos > obj->fd_bytes_read) {	/* Not beginning of file yet */
304 		/* We've reached beginning of buffer, but not beginning of file
305 		 * yet, so read previous part of file into buffer.  Note that
306 		 * we only move backward for BUF_SIZE/2 bytes, but not BUF_SIZE
307 		 * bytes to avoid re-reading again in print_page() later
308 		 */
309 		/* Really possible to move backward BUF_SIZE/2 bytes? */
310 		if (fpos < BUF_SIZE / 2 + obj->fd_bytes_read) {
311 		    /* No, move less than */
312 		    lseek_obj(obj, 0L, SEEK_SET);
313 		    val_to_tabize = fpos - obj->fd_bytes_read;
314 		} else {	/* Move backward BUF_SIZE/2 bytes */
315 		    lseek_obj(obj, -(BUF_SIZE / 2 + obj->fd_bytes_read), SEEK_CUR);
316 		    val_to_tabize = BUF_SIZE / 2;
317 		}
318 		read_high(obj, BUF_SIZE);
319 
320 		obj->in_buf = tabize(obj, val_to_tabize, (long *) 0);
321 
322 	    } else {		/* Beginning of file reached */
323 		obj->begin_reached = TRUE;
324 		return;
325 	    }
326 	}
327 	obj->in_buf--;
328 	if (obj->buf[obj->in_buf] != '\n')
329 	    /* Something's wrong... */
330 	    dlg_exiterr("Internal error in back_lines().");
331     }
332 
333     /* Go back 'n' lines */
334     for (i = 0; i < n; i++) {
335 	do {
336 	    if (obj->in_buf == 0) {
337 		fpos = ftell_obj(obj);
338 
339 		if (fpos > obj->fd_bytes_read) {
340 		    /* Really possible to move backward BUF_SIZE/2 bytes? */
341 		    if (fpos < BUF_SIZE / 2 + obj->fd_bytes_read) {
342 			/* No, move less than */
343 			lseek_obj(obj, 0L, SEEK_SET);
344 			val_to_tabize = fpos - obj->fd_bytes_read;
345 		    } else {	/* Move backward BUF_SIZE/2 bytes */
346 			lseek_obj(obj, -(BUF_SIZE / 2 + obj->fd_bytes_read), SEEK_CUR);
347 			val_to_tabize = BUF_SIZE / 2;
348 		    }
349 		    read_high(obj, BUF_SIZE);
350 
351 		    obj->in_buf = tabize(obj, val_to_tabize, (long *) 0);
352 
353 		} else {	/* Beginning of file reached */
354 		    obj->begin_reached = TRUE;
355 		    return;
356 		}
357 	    }
358 	} while (obj->buf[--(obj->in_buf)] != '\n');
359     }
360     obj->in_buf++;
361 }
362 
363 /*
364  * Print a new line of text.
365  */
366 static void
367 print_line(MY_OBJ * obj, int row, int width)
368 {
369     if (wmove(obj->text, row, 0) != ERR) {
370 	int i, y, x;
371 	char *line = get_line(obj);
372 	const int *cols = dlg_index_columns(line);
373 	const int *indx = dlg_index_wchars(line);
374 	int limit = dlg_count_wchars(line);
375 	int first = 0;
376 	int last = limit;
377 
378 	if (width > getmaxx(obj->text))
379 	    width = getmaxx(obj->text);
380 	--width;		/* for the leading ' ' */
381 
382 	for (i = 0; i <= limit && cols[i] < obj->hscroll; ++i)
383 	    first = i;
384 
385 	for (i = first; (i <= limit) && ((cols[i] - cols[first]) < width); ++i)
386 	    last = i;
387 
388 	(void) waddch(obj->text, ' ');
389 	(void) waddnstr(obj->text, line + indx[first], indx[last] - indx[first]);
390 
391 	getyx(obj->text, y, x);
392 	if (y == row) {		/* Clear 'residue' of previous line */
393 	    for (i = 0; i <= width - x; i++) {
394 		(void) waddch(obj->text, ' ');
395 	    }
396 	}
397     }
398 }
399 
400 /*
401  * Print a new page of text.
402  */
403 static void
404 print_page(MY_OBJ * obj, int height, int width)
405 {
406     int i, passed_end = 0;
407 
408     obj->page_length = 0;
409     for (i = 0; i < height; i++) {
410 	print_line(obj, i, width);
411 	if (!passed_end)
412 	    obj->page_length++;
413 	if (obj->end_reached && !passed_end)
414 	    passed_end = 1;
415     }
416     (void) wnoutrefresh(obj->text);
417 }
418 
419 /*
420  * Print current position
421  */
422 static void
423 print_position(MY_OBJ * obj, WINDOW *win, int height, int width)
424 {
425     long fpos;
426     long size;
427     long first = -1;
428 
429     fpos = ftell_obj(obj);
430     if (dialog_vars.tab_correct)
431 	size = tabize(obj, obj->in_buf, &first);
432     else
433 	first = find_first(obj, obj->buf, size = obj->in_buf);
434 
435     dlg_draw_scrollbar(win,
436 		       first,
437 		       fpos - obj->fd_bytes_read + size,
438 		       fpos - obj->fd_bytes_read + size,
439 		       obj->file_size,
440 		       0, PAGE_WIDTH,
441 		       0, PAGE_LENGTH + 1,
442 		       border_attr,
443 		       border_attr);
444 }
445 
446 /*
447  * Display a dialog box and get the search term from user.
448  */
449 static int
450 get_search_term(WINDOW *dialog, char *input, int height, int width)
451 {
452     /* *INDENT-OFF* */
453     static DLG_KEYS_BINDING binding[] = {
454 	INPUTSTR_BINDINGS,
455 	HELPKEY_BINDINGS,
456 	ENTERKEY_BINDINGS,
457 	END_KEYS_BINDING
458     };
459     /* *INDENT-ON* */
460 
461     int old_x, old_y;
462     int box_x, box_y;
463     int box_height, box_width;
464     int offset = 0;
465     int key = 0;
466     int fkey = 0;
467     bool first = TRUE;
468     int result = DLG_EXIT_UNKNOWN;
469     const char *caption = _("Search");
470     int len_caption = dlg_count_columns(caption);
471     const int *indx;
472     int limit;
473     WINDOW *widget;
474 
475     getbegyx(dialog, old_y, old_x);
476 
477     box_height = 1 + (2 * MARGIN);
478     box_width = len_caption + (2 * (MARGIN + 2));
479     box_width = MAX(box_width, 30);
480     box_width = MIN(box_width, getmaxx(dialog) - 2 * MARGIN);
481     len_caption = MIN(len_caption, box_width - (2 * (MARGIN + 1)));
482 
483     box_x = (width - box_width) / 2;
484     box_y = (height - box_height) / 2;
485     widget = dlg_new_modal_window(dialog,
486 				  box_height, box_width,
487 				  old_y + box_y, old_x + box_x);
488     keypad(widget, TRUE);
489     dlg_register_window(widget, "searchbox", binding);
490 
491     dlg_draw_box(widget, 0, 0, box_height, box_width,
492 		 searchbox_attr,
493 		 searchbox_border_attr);
494     wattrset(widget, searchbox_title_attr);
495     (void) wmove(widget, 0, (box_width - len_caption) / 2);
496 
497     indx = dlg_index_wchars(caption);
498     limit = dlg_limit_columns(caption, len_caption, 0);
499     (void) waddnstr(widget, caption + indx[0], indx[limit] - indx[0]);
500 
501     box_y++;
502     box_x++;
503     box_width -= 2;
504     offset = dlg_count_columns(input);
505 
506     while (result == DLG_EXIT_UNKNOWN) {
507 	if (!first) {
508 	    key = dlg_getc(widget, &fkey);
509 	    if (fkey) {
510 		switch (fkey) {
511 #ifdef KEY_RESIZE
512 		case KEY_RESIZE:
513 		    result = DLG_EXIT_CANCEL;
514 		    continue;
515 #endif
516 		case DLGK_ENTER:
517 		    result = DLG_EXIT_OK;
518 		    continue;
519 		}
520 	    } else if (key == ESC) {
521 		result = DLG_EXIT_ESC;
522 		continue;
523 	    } else if (key == ERR) {
524 		napms(50);
525 		continue;
526 	    }
527 	}
528 	if (dlg_edit_string(input, &offset, key, fkey, first)) {
529 	    dlg_show_string(widget, input, offset, searchbox_attr,
530 			    1, 1, box_width, FALSE, first);
531 	    first = FALSE;
532 	}
533     }
534     dlg_del_window(widget);
535     return result;
536 }
537 
538 static bool
539 perform_search(MY_OBJ * obj, int height, int width, int key, char *search_term)
540 {
541     int dir;
542     long tempinx;
543     long fpos;
544     int result;
545     bool found;
546     bool temp, temp1;
547     bool moved = FALSE;
548 
549     /* set search direction */
550     dir = (key == '/' || key == 'n') ? 1 : 0;
551     if (dir ? !obj->end_reached : !obj->begin_reached) {
552 	if (key == 'n' || key == 'N') {
553 	    if (search_term[0] == '\0') {	/* No search term yet */
554 		(void) beep();
555 		return FALSE;
556 	    }
557 	    /* Get search term from user */
558 	} else if ((result = get_search_term(obj->text, search_term,
559 					     PAGE_LENGTH,
560 					     PAGE_WIDTH)) != DLG_EXIT_OK
561 		   || search_term[0] == '\0') {
562 #ifdef KEY_RESIZE
563 	    if (result == DLG_EXIT_CANCEL) {
564 		ungetch(key);
565 		ungetch(KEY_RESIZE);
566 		/* FALLTHRU */
567 	    }
568 #endif
569 	    /* ESC pressed, or no search term, reprint page to clear box */
570 	    wattrset(obj->text, dialog_attr);
571 	    back_lines(obj, obj->page_length);
572 	    return TRUE;
573 	}
574 	/* Save variables for restoring in case search term can't be found */
575 	tempinx = obj->in_buf;
576 	temp = obj->begin_reached;
577 	temp1 = obj->end_reached;
578 	fpos = ftell_obj(obj) - obj->fd_bytes_read;
579 	/* update 'in_buf' to point to next (previous) line before
580 	   forward (backward) searching */
581 	back_lines(obj, (dir
582 			 ? obj->page_length - 1
583 			 : obj->page_length + 1));
584 	found = FALSE;
585 	if (dir) {		/* Forward search */
586 	    while ((found = match_string(obj, search_term)) == FALSE) {
587 		if (obj->end_reached)
588 		    break;
589 	    }
590 	} else {		/* Backward search */
591 	    while ((found = match_string(obj, search_term)) == FALSE) {
592 		if (obj->begin_reached)
593 		    break;
594 		back_lines(obj, 2L);
595 	    }
596 	}
597 	if (found == FALSE) {	/* not found */
598 	    (void) beep();
599 	    /* Restore program state to that before searching */
600 	    lseek_obj(obj, fpos, SEEK_SET);
601 
602 	    read_high(obj, BUF_SIZE);
603 
604 	    obj->in_buf = tempinx;
605 	    obj->begin_reached = temp;
606 	    obj->end_reached = temp1;
607 	    /* move 'in_buf' to point to start of current page to
608 	     * re-print current page.  Note that 'in_buf' always points
609 	     * to start of next page, so this is necessary
610 	     */
611 	    back_lines(obj, obj->page_length);
612 	} else {		/* Search term found */
613 	    back_lines(obj, 1L);
614 	}
615 	/* Reprint page */
616 	wattrset(obj->text, dialog_attr);
617 	moved = TRUE;
618     } else {			/* no need to find */
619 	(void) beep();
620     }
621     return moved;
622 }
623 
624 /*
625  * Display text from a file in a dialog box.
626  */
627 int
628 dialog_textbox(const char *title, const char *file, int height, int width)
629 {
630     /* *INDENT-OFF* */
631     static DLG_KEYS_BINDING binding[] = {
632 	HELPKEY_BINDINGS,
633 	ENTERKEY_BINDINGS,
634 	DLG_KEYS_DATA( DLGK_GRID_DOWN,  'J' ),
635 	DLG_KEYS_DATA( DLGK_GRID_DOWN,  'j' ),
636 	DLG_KEYS_DATA( DLGK_GRID_DOWN,  KEY_DOWN ),
637 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'H' ),
638 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
639 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
640 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'L' ),
641 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
642 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
643 	DLG_KEYS_DATA( DLGK_GRID_UP,    'K' ),
644 	DLG_KEYS_DATA( DLGK_GRID_UP,    'k' ),
645 	DLG_KEYS_DATA( DLGK_GRID_UP,    KEY_UP ),
646 	DLG_KEYS_DATA( DLGK_PAGE_FIRST, 'g' ),
647 	DLG_KEYS_DATA( DLGK_PAGE_FIRST, KEY_HOME ),
648 	DLG_KEYS_DATA( DLGK_PAGE_LAST,  'G' ),
649 	DLG_KEYS_DATA( DLGK_PAGE_LAST,  KEY_END ),
650 	DLG_KEYS_DATA( DLGK_PAGE_LAST,  KEY_LL ),
651 	DLG_KEYS_DATA( DLGK_PAGE_NEXT,  ' ' ),
652 	DLG_KEYS_DATA( DLGK_PAGE_NEXT,  KEY_NPAGE ),
653 	DLG_KEYS_DATA( DLGK_PAGE_PREV,  'B' ),
654 	DLG_KEYS_DATA( DLGK_PAGE_PREV,  'b' ),
655 	DLG_KEYS_DATA( DLGK_PAGE_PREV,  KEY_PPAGE ),
656 	DLG_KEYS_DATA( DLGK_BEGIN,	'0' ),
657 	DLG_KEYS_DATA( DLGK_BEGIN,	KEY_BEG ),
658 	DLG_KEYS_DATA( DLGK_FIELD_NEXT, TAB ),
659 	DLG_KEYS_DATA( DLGK_FIELD_PREV, KEY_BTAB ),
660 	END_KEYS_BINDING
661     };
662     /* *INDENT-ON* */
663 
664 #ifdef KEY_RESIZE
665     int old_height = height;
666     int old_width = width;
667 #endif
668     long fpos;
669     int x, y, cur_x, cur_y;
670     int key = 0, fkey;
671     int next = 0;
672     int i, code, passed_end;
673     char search_term[MAX_LEN + 1];
674     MY_OBJ obj;
675     WINDOW *dialog;
676     bool moved;
677     int result = DLG_EXIT_UNKNOWN;
678     int button = dialog_vars.extra_button ? dlg_defaultno_button() : 0;
679     int min_width = 12;
680 
681     search_term[0] = '\0';	/* no search term entered yet */
682 
683     memset(&obj, 0, sizeof(obj));
684 
685     obj.begin_reached = TRUE;
686     obj.buffer_first = TRUE;
687     obj.end_reached = FALSE;
688     obj.buttons = dlg_exit_label();
689 
690     /* Open input file for reading */
691     if ((obj.fd = open(file, O_RDONLY)) == -1)
692 	dlg_exiterr("Can't open input file %s", file);
693 
694     /* Get file size. Actually, 'file_size' is the real file size - 1,
695        since it's only the last byte offset from the beginning */
696     obj.file_size = lseek_obj(&obj, 0L, SEEK_END);
697 
698     /* Restore file pointer to beginning of file after getting file size */
699     lseek_obj(&obj, 0L, SEEK_SET);
700 
701     read_high(&obj, BUF_SIZE);
702 
703     dlg_button_layout(obj.buttons, &min_width);
704 
705 #ifdef KEY_RESIZE
706   retry:
707 #endif
708     moved = TRUE;
709 
710     dlg_auto_sizefile(title, file, &height, &width, 2, min_width);
711     dlg_print_size(height, width);
712     dlg_ctl_size(height, width);
713 
714     x = dlg_box_x_ordinate(width);
715     y = dlg_box_y_ordinate(height);
716 
717     dialog = dlg_new_window(height, width, y, x);
718     dlg_register_window(dialog, "textbox", binding);
719     dlg_register_buttons(dialog, "textbox", obj.buttons);
720 
721     dlg_mouse_setbase(x, y);
722 
723     /* Create window for text region, used for scrolling text */
724     obj.text = dlg_sub_window(dialog, PAGE_LENGTH, PAGE_WIDTH, y + 1, x + 1);
725 
726     /* register the new window, along with its borders */
727     dlg_mouse_mkbigregion(0, 0, PAGE_LENGTH + 2, width, KEY_MAX, 1, 1, 1 /* lines */ );
728     dlg_draw_box(dialog, 0, 0, height, width, dialog_attr, border_attr);
729     dlg_draw_bottom_box(dialog);
730     dlg_draw_title(dialog, title);
731 
732     dlg_draw_buttons(dialog, PAGE_LENGTH + 2, 0, obj.buttons, button, FALSE, width);
733     (void) wnoutrefresh(dialog);
734     getyx(dialog, cur_y, cur_x);	/* Save cursor position */
735 
736     dlg_attr_clear(obj.text, PAGE_LENGTH, PAGE_WIDTH, dialog_attr);
737 
738     while (result == DLG_EXIT_UNKNOWN) {
739 
740 	/*
741 	 * Update the screen according to whether we shifted up/down by a line
742 	 * or not.
743 	 */
744 	if (moved) {
745 	    if (next < 0) {
746 		(void) scrollok(obj.text, TRUE);
747 		(void) scroll(obj.text);	/* Scroll text region up one line */
748 		(void) scrollok(obj.text, FALSE);
749 		print_line(&obj, PAGE_LENGTH - 1, PAGE_WIDTH);
750 		(void) wnoutrefresh(obj.text);
751 	    } else if (next > 0) {
752 		/*
753 		 * We don't call print_page() here but use scrolling to ensure
754 		 * faster screen update.  However, 'end_reached' and
755 		 * 'page_length' should still be updated, and 'in_buf' should
756 		 * point to start of next page.  This is done by calling
757 		 * get_line() in the following 'for' loop.
758 		 */
759 		(void) scrollok(obj.text, TRUE);
760 		(void) wscrl(obj.text, -1);	/* Scroll text region down one line */
761 		(void) scrollok(obj.text, FALSE);
762 		obj.page_length = 0;
763 		passed_end = 0;
764 		for (i = 0; i < PAGE_LENGTH; i++) {
765 		    if (!i) {
766 			print_line(&obj, 0, PAGE_WIDTH);	/* print first line of page */
767 			(void) wnoutrefresh(obj.text);
768 		    } else
769 			(void) get_line(&obj);	/* Called to update 'end_reached' and 'in_buf' */
770 		    if (!passed_end)
771 			obj.page_length++;
772 		    if (obj.end_reached && !passed_end)
773 			passed_end = 1;
774 		}
775 	    } else {
776 		print_page(&obj, PAGE_LENGTH, PAGE_WIDTH);
777 	    }
778 	    print_position(&obj, dialog, height, width);
779 	    (void) wmove(dialog, cur_y, cur_x);		/* Restore cursor position */
780 	    wrefresh(dialog);
781 	}
782 	moved = FALSE;		/* assume we'll not move */
783 	next = 0;		/* ...but not scroll by a line */
784 
785 	key = dlg_mouse_wgetch(dialog, &fkey);
786 	if (dlg_result_key(key, fkey, &result))
787 	    break;
788 
789 	if (!fkey && (code = dlg_char_to_button(key, obj.buttons)) >= 0) {
790 	    result = dlg_ok_buttoncode(code);
791 	    break;
792 	}
793 
794 	if (fkey) {
795 	    switch (key) {
796 	    default:
797 		if (is_DLGK_MOUSE(key)) {
798 		    result = dlg_exit_buttoncode(key - M_EVENT);
799 		    if (result < 0)
800 			result = DLG_EXIT_OK;
801 		} else {
802 		    beep();
803 		}
804 		break;
805 	    case DLGK_FIELD_NEXT:
806 		button = dlg_next_button(obj.buttons, button);
807 		if (button < 0)
808 		    button = 0;
809 		dlg_draw_buttons(dialog,
810 				 height - 2, 0,
811 				 obj.buttons, button,
812 				 FALSE, width);
813 		break;
814 	    case DLGK_FIELD_PREV:
815 		button = dlg_prev_button(obj.buttons, button);
816 		if (button < 0)
817 		    button = 0;
818 		dlg_draw_buttons(dialog,
819 				 height - 2, 0,
820 				 obj.buttons, button,
821 				 FALSE, width);
822 		break;
823 	    case DLGK_ENTER:
824 		if (dialog_vars.nook)
825 		    result = DLG_EXIT_OK;
826 		else
827 		    result = dlg_exit_buttoncode(button);
828 		break;
829 	    case DLGK_PAGE_FIRST:
830 		if (!obj.begin_reached) {
831 		    obj.begin_reached = 1;
832 		    /* First page not in buffer? */
833 		    fpos = ftell_obj(&obj);
834 
835 		    if (fpos > obj.fd_bytes_read) {
836 			/* Yes, we have to read it in */
837 			lseek_obj(&obj, 0L, SEEK_SET);
838 
839 			read_high(&obj, BUF_SIZE);
840 		    }
841 		    obj.in_buf = 0;
842 		    moved = TRUE;
843 		}
844 		break;
845 	    case DLGK_PAGE_LAST:
846 		obj.end_reached = TRUE;
847 		/* Last page not in buffer? */
848 		fpos = ftell_obj(&obj);
849 
850 		if (fpos < obj.file_size) {
851 		    /* Yes, we have to read it in */
852 		    lseek_obj(&obj, -BUF_SIZE, SEEK_END);
853 
854 		    read_high(&obj, BUF_SIZE);
855 		}
856 		obj.in_buf = obj.bytes_read;
857 		back_lines(&obj, (long) PAGE_LENGTH);
858 		moved = TRUE;
859 		break;
860 	    case DLGK_GRID_UP:	/* Previous line */
861 		if (!obj.begin_reached) {
862 		    back_lines(&obj, obj.page_length + 1);
863 		    next = 1;
864 		    moved = TRUE;
865 		}
866 		break;
867 	    case DLGK_PAGE_PREV:	/* Previous page */
868 	    case DLGK_MOUSE(KEY_PPAGE):
869 		if (!obj.begin_reached) {
870 		    back_lines(&obj, obj.page_length + PAGE_LENGTH);
871 		    moved = TRUE;
872 		}
873 		break;
874 	    case DLGK_GRID_DOWN:	/* Next line */
875 		if (!obj.end_reached) {
876 		    obj.begin_reached = 0;
877 		    next = -1;
878 		    moved = TRUE;
879 		}
880 		break;
881 	    case DLGK_PAGE_NEXT:	/* Next page */
882 	    case DLGK_MOUSE(KEY_NPAGE):
883 		if (!obj.end_reached) {
884 		    obj.begin_reached = 0;
885 		    moved = TRUE;
886 		}
887 		break;
888 	    case DLGK_BEGIN:	/* Beginning of line */
889 		if (obj.hscroll > 0) {
890 		    obj.hscroll = 0;
891 		    /* Reprint current page to scroll horizontally */
892 		    back_lines(&obj, obj.page_length);
893 		    moved = TRUE;
894 		}
895 		break;
896 	    case DLGK_GRID_LEFT:	/* Scroll left */
897 		if (obj.hscroll > 0) {
898 		    obj.hscroll--;
899 		    /* Reprint current page to scroll horizontally */
900 		    back_lines(&obj, obj.page_length);
901 		    moved = TRUE;
902 		}
903 		break;
904 	    case DLGK_GRID_RIGHT:	/* Scroll right */
905 		if (obj.hscroll < MAX_LEN) {
906 		    obj.hscroll++;
907 		    /* Reprint current page to scroll horizontally */
908 		    back_lines(&obj, obj.page_length);
909 		    moved = TRUE;
910 		}
911 		break;
912 #ifdef KEY_RESIZE
913 	    case KEY_RESIZE:
914 		/* reset data */
915 		height = old_height;
916 		width = old_width;
917 		back_lines(&obj, obj.page_length);
918 		moved = TRUE;
919 		/* repaint */
920 		dlg_clear();
921 		dlg_del_window(dialog);
922 		refresh();
923 		dlg_mouse_free_regions();
924 		goto retry;
925 #endif
926 	    }
927 	} else {
928 	    switch (key) {
929 	    case '/':		/* Forward search */
930 	    case 'n':		/* Repeat forward search */
931 	    case '?':		/* Backward search */
932 	    case 'N':		/* Repeat backward search */
933 		moved = perform_search(&obj, height, width, key, search_term);
934 		fkey = FALSE;
935 		break;
936 	    default:
937 		beep();
938 		break;
939 	    }
940 	}
941     }
942 
943     dlg_del_window(dialog);
944     free(obj.buf);
945     (void) close(obj.fd);
946     dlg_mouse_free_regions();
947     return result;
948 }
949