kconfig: move lxdialog to scripts/kconfig/lxdialog
[linux-2.6] / scripts / kconfig / 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, 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  */
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         char search_term[MAX_LEN + 1];
42         WINDOW *dialog, *text;
43
44         search_term[0] = '\0';  /* no search term entered yet */
45
46         /* Open input file for reading */
47         if ((fd = open(file, O_RDONLY)) == -1) {
48                 endwin();
49                 fprintf(stderr, "\nCan't open input file in dialog_textbox().\n");
50                 exit(-1);
51         }
52         /* Get file size. Actually, 'file_size' is the real file size - 1,
53            since it's only the last byte offset from the beginning */
54         if ((file_size = lseek(fd, 0, SEEK_END)) == -1) {
55                 endwin();
56                 fprintf(stderr, "\nError getting file size in dialog_textbox().\n");
57                 exit(-1);
58         }
59         /* Restore file pointer to beginning of file after getting file size */
60         if (lseek(fd, 0, SEEK_SET) == -1) {
61                 endwin();
62                 fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
63                 exit(-1);
64         }
65         /* Allocate space for read buffer */
66         if ((buf = malloc(BUF_SIZE + 1)) == NULL) {
67                 endwin();
68                 fprintf(stderr, "\nCan't allocate memory in dialog_textbox().\n");
69                 exit(-1);
70         }
71         if ((bytes_read = read(fd, buf, BUF_SIZE)) == -1) {
72                 endwin();
73                 fprintf(stderr, "\nError reading file in dialog_textbox().\n");
74                 exit(-1);
75         }
76         buf[bytes_read] = '\0'; /* mark end of valid data */
77         page = buf;             /* page is pointer to start of page to be displayed */
78
79         /* center dialog box on screen */
80         x = (COLS - width) / 2;
81         y = (LINES - height) / 2;
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         print_title(dialog, title, width);
107
108         print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
109         wnoutrefresh(dialog);
110         getyx(dialog, cur_y, cur_x);    /* Save cursor position */
111
112         /* Print first page of text */
113         attr_clear(text, height - 4, width - 2, dialog_attr);
114         print_page(text, height - 4, width - 2);
115         print_position(dialog, height, width);
116         wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
117         wrefresh(dialog);
118
119         while ((key != ESC) && (key != '\n')) {
120                 key = wgetch(dialog);
121                 switch (key) {
122                 case 'E':       /* Exit */
123                 case 'e':
124                 case 'X':
125                 case 'x':
126                         delwin(dialog);
127                         free(buf);
128                         close(fd);
129                         return 0;
130                 case 'g':       /* First page */
131                 case KEY_HOME:
132                         if (!begin_reached) {
133                                 begin_reached = 1;
134                                 /* First page not in buffer? */
135                                 if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
136                                         endwin();
137                                         fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
138                                         exit(-1);
139                                 }
140                                 if (fpos > bytes_read) {        /* Yes, we have to read it in */
141                                         if (lseek(fd, 0, SEEK_SET) == -1) {
142                                                 endwin();
143                                                 fprintf(stderr, "\nError moving file pointer in "
144                                                                 "dialog_textbox().\n");
145                                                 exit(-1);
146                                         }
147                                         if ((bytes_read =
148                                              read(fd, buf, BUF_SIZE)) == -1) {
149                                                 endwin();
150                                                 fprintf(stderr, "\nError reading file in dialog_textbox().\n");
151                                                 exit(-1);
152                                         }
153                                         buf[bytes_read] = '\0';
154                                 }
155                                 page = buf;
156                                 print_page(text, height - 4, width - 2);
157                                 print_position(dialog, height, width);
158                                 wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
159                                 wrefresh(dialog);
160                         }
161                         break;
162                 case 'G':       /* Last page */
163                 case KEY_END:
164
165                         end_reached = 1;
166                         /* Last page not in buffer? */
167                         if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
168                                 endwin();
169                                 fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
170                                 exit(-1);
171                         }
172                         if (fpos < file_size) { /* Yes, we have to read it in */
173                                 if (lseek(fd, -BUF_SIZE, SEEK_END) == -1) {
174                                         endwin();
175                                         fprintf(stderr, "\nError moving file pointer in dialog_textbox().\n");
176                                         exit(-1);
177                                 }
178                                 if ((bytes_read =
179                                      read(fd, buf, BUF_SIZE)) == -1) {
180                                         endwin();
181                                         fprintf(stderr, "\nError reading file in dialog_textbox().\n");
182                                         exit(-1);
183                                 }
184                                 buf[bytes_read] = '\0';
185                         }
186                         page = buf + bytes_read;
187                         back_lines(height - 4);
188                         print_page(text, height - 4, width - 2);
189                         print_position(dialog, height, width);
190                         wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
191                         wrefresh(dialog);
192                         break;
193                 case 'K':       /* Previous line */
194                 case 'k':
195                 case KEY_UP:
196                         if (!begin_reached) {
197                                 back_lines(page_length + 1);
198
199                                 /* We don't call print_page() here but use scrolling to ensure
200                                    faster screen update. However, 'end_reached' and
201                                    'page_length' should still be updated, and 'page' should
202                                    point to start of next page. This is done by calling
203                                    get_line() in the following 'for' loop. */
204                                 scrollok(text, TRUE);
205                                 wscrl(text, -1);        /* Scroll text region down one line */
206                                 scrollok(text, FALSE);
207                                 page_length = 0;
208                                 passed_end = 0;
209                                 for (i = 0; i < height - 4; i++) {
210                                         if (!i) {
211                                                 /* print first line of page */
212                                                 print_line(text, 0, width - 2);
213                                                 wnoutrefresh(text);
214                                         } else
215                                                 /* Called to update 'end_reached' and 'page' */
216                                                 get_line();
217                                         if (!passed_end)
218                                                 page_length++;
219                                         if (end_reached && !passed_end)
220                                                 passed_end = 1;
221                                 }
222
223                                 print_position(dialog, height, width);
224                                 wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
225                                 wrefresh(dialog);
226                         }
227                         break;
228                 case 'B':       /* Previous page */
229                 case 'b':
230                 case KEY_PPAGE:
231                         if (begin_reached)
232                                 break;
233                         back_lines(page_length + height - 4);
234                         print_page(text, height - 4, width - 2);
235                         print_position(dialog, height, width);
236                         wmove(dialog, cur_y, cur_x);
237                         wrefresh(dialog);
238                         break;
239                 case 'J':       /* Next line */
240                 case 'j':
241                 case KEY_DOWN:
242                         if (!end_reached) {
243                                 begin_reached = 0;
244                                 scrollok(text, TRUE);
245                                 scroll(text);   /* Scroll text region up one line */
246                                 scrollok(text, FALSE);
247                                 print_line(text, height - 5, width - 2);
248                                 wnoutrefresh(text);
249                                 print_position(dialog, height, width);
250                                 wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
251                                 wrefresh(dialog);
252                         }
253                         break;
254                 case KEY_NPAGE: /* Next page */
255                 case ' ':
256                         if (end_reached)
257                                 break;
258
259                         begin_reached = 0;
260                         print_page(text, height - 4, width - 2);
261                         print_position(dialog, height, width);
262                         wmove(dialog, cur_y, cur_x);
263                         wrefresh(dialog);
264                         break;
265                 case '0':       /* Beginning of line */
266                 case 'H':       /* Scroll left */
267                 case 'h':
268                 case KEY_LEFT:
269                         if (hscroll <= 0)
270                                 break;
271
272                         if (key == '0')
273                                 hscroll = 0;
274                         else
275                                 hscroll--;
276                         /* Reprint current page to scroll horizontally */
277                         back_lines(page_length);
278                         print_page(text, height - 4, width - 2);
279                         wmove(dialog, cur_y, cur_x);
280                         wrefresh(dialog);
281                         break;
282                 case 'L':       /* Scroll right */
283                 case 'l':
284                 case KEY_RIGHT:
285                         if (hscroll >= MAX_LEN)
286                                 break;
287                         hscroll++;
288                         /* Reprint current page to scroll horizontally */
289                         back_lines(page_length);
290                         print_page(text, height - 4, width - 2);
291                         wmove(dialog, cur_y, cur_x);
292                         wrefresh(dialog);
293                         break;
294                 case ESC:
295                         break;
296                 }
297         }
298
299         delwin(dialog);
300         free(buf);
301         close(fd);
302         return -1;              /* ESC pressed */
303 }
304
305 /*
306  * Go back 'n' lines in text file. Called by dialog_textbox().
307  * 'page' will be updated to point to the desired line in 'buf'.
308  */
309 static void back_lines(int n)
310 {
311         int i, fpos;
312
313         begin_reached = 0;
314         /* We have to distinguish between end_reached and !end_reached
315            since at end of file, the line is not ended by a '\n'.
316            The code inside 'if' basically does a '--page' to move one
317            character backward so as to skip '\n' of the previous line */
318         if (!end_reached) {
319                 /* Either beginning of buffer or beginning of file reached? */
320                 if (page == buf) {
321                         if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
322                                 endwin();
323                                 fprintf(stderr, "\nError moving file pointer in "
324                                                 "back_lines().\n");
325                                 exit(-1);
326                         }
327                         if (fpos > bytes_read) {        /* Not beginning of file yet */
328                                 /* We've reached beginning of buffer, but not beginning of
329                                    file yet, so read previous part of file into buffer.
330                                    Note that we only move backward for BUF_SIZE/2 bytes,
331                                    but not BUF_SIZE bytes to avoid re-reading again in
332                                    print_page() later */
333                                 /* Really possible to move backward BUF_SIZE/2 bytes? */
334                                 if (fpos < BUF_SIZE / 2 + bytes_read) {
335                                         /* No, move less then */
336                                         if (lseek(fd, 0, SEEK_SET) == -1) {
337                                                 endwin();
338                                                 fprintf(stderr, "\nError moving file pointer in "
339                                                                 "back_lines().\n");
340                                                 exit(-1);
341                                         }
342                                         page = buf + fpos - bytes_read;
343                                 } else {        /* Move backward BUF_SIZE/2 bytes */
344                                         if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
345                                                 endwin();
346                                                 fprintf(stderr, "\nError moving file pointer "
347                                                                 "in back_lines().\n");
348                                                 exit(-1);
349                                         }
350                                         page = buf + BUF_SIZE / 2;
351                                 }
352                                 if ((bytes_read =
353                                      read(fd, buf, BUF_SIZE)) == -1) {
354                                         endwin();
355                                         fprintf(stderr, "\nError reading file in back_lines().\n");
356                                         exit(-1);
357                                 }
358                                 buf[bytes_read] = '\0';
359                         } else {        /* Beginning of file reached */
360                                 begin_reached = 1;
361                                 return;
362                         }
363                 }
364                 if (*(--page) != '\n') {        /* '--page' here */
365                         /* Something's wrong... */
366                         endwin();
367                         fprintf(stderr, "\nInternal error in back_lines().\n");
368                         exit(-1);
369                 }
370         }
371         /* Go back 'n' lines */
372         for (i = 0; i < n; i++)
373                 do {
374                         if (page == buf) {
375                                 if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
376                                         endwin();
377                                         fprintf(stderr, "\nError moving file pointer in back_lines().\n");
378                                         exit(-1);
379                                 }
380                                 if (fpos > bytes_read) {
381                                         /* Really possible to move backward BUF_SIZE/2 bytes? */
382                                         if (fpos < BUF_SIZE / 2 + bytes_read) {
383                                                 /* No, move less then */
384                                                 if (lseek(fd, 0, SEEK_SET) == -1) {
385                                                         endwin();
386                                                         fprintf(stderr, "\nError moving file pointer "
387                                                                         "in back_lines().\n");
388                                                         exit(-1);
389                                                 }
390                                                 page = buf + fpos - bytes_read;
391                                         } else {        /* Move backward BUF_SIZE/2 bytes */
392                                                 if (lseek (fd, -(BUF_SIZE / 2 + bytes_read), SEEK_CUR) == -1) {
393                                                         endwin();
394                                                         fprintf(stderr, "\nError moving file pointer"
395                                                                         " in back_lines().\n");
396                                                         exit(-1);
397                                                 }
398                                                 page = buf + BUF_SIZE / 2;
399                                         }
400                                         if ((bytes_read =
401                                              read(fd, buf, BUF_SIZE)) == -1) {
402                                                 endwin();
403                                                 fprintf(stderr, "\nError reading file in "
404                                                                 "back_lines().\n");
405                                                 exit(-1);
406                                         }
407                                         buf[bytes_read] = '\0';
408                                 } else {        /* Beginning of file reached */
409                                         begin_reached = 1;
410                                         return;
411                                 }
412                         }
413                 } while (*(--page) != '\n');
414         page++;
415 }
416
417 /*
418  * Print a new page of text. Called by dialog_textbox().
419  */
420 static void print_page(WINDOW * win, int height, int width)
421 {
422         int i, passed_end = 0;
423
424         page_length = 0;
425         for (i = 0; i < height; i++) {
426                 print_line(win, i, width);
427                 if (!passed_end)
428                         page_length++;
429                 if (end_reached && !passed_end)
430                         passed_end = 1;
431         }
432         wnoutrefresh(win);
433 }
434
435 /*
436  * Print a new line of text. Called by dialog_textbox() and print_page().
437  */
438 static void print_line(WINDOW * win, int row, int width)
439 {
440         int y, x;
441         char *line;
442
443         line = get_line();
444         line += MIN(strlen(line), hscroll);     /* Scroll horizontally */
445         wmove(win, row, 0);     /* move cursor to correct line */
446         waddch(win, ' ');
447         waddnstr(win, line, MIN(strlen(line), width - 2));
448
449         getyx(win, y, x);
450         /* Clear 'residue' of previous line */
451 #if OLD_NCURSES
452         {
453                 int i;
454                 for (i = 0; i < width - x; i++)
455                         waddch(win, ' ');
456         }
457 #else
458         wclrtoeol(win);
459 #endif
460 }
461
462 /*
463  * Return current line of text. Called by dialog_textbox() and print_line().
464  * 'page' should point to start of current line before calling, and will be
465  * updated to point to start of next line.
466  */
467 static char *get_line(void)
468 {
469         int i = 0, fpos;
470         static char line[MAX_LEN + 1];
471
472         end_reached = 0;
473         while (*page != '\n') {
474                 if (*page == '\0') {
475                         /* Either end of file or end of buffer reached */
476                         if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
477                                 endwin();
478                                 fprintf(stderr, "\nError moving file pointer in "
479                                                 "get_line().\n");
480                                 exit(-1);
481                         }
482                         if (fpos < file_size) { /* Not end of file yet */
483                                 /* We've reached end of buffer, but not end of file yet,
484                                    so read next part of file into buffer */
485                                 if ((bytes_read =
486                                      read(fd, buf, BUF_SIZE)) == -1) {
487                                         endwin();
488                                         fprintf(stderr, "\nError reading file in get_line().\n");
489                                         exit(-1);
490                                 }
491                                 buf[bytes_read] = '\0';
492                                 page = buf;
493                         } else {
494                                 if (!end_reached)
495                                         end_reached = 1;
496                                 break;
497                         }
498                 } else if (i < MAX_LEN)
499                         line[i++] = *(page++);
500                 else {
501                         /* Truncate lines longer than MAX_LEN characters */
502                         if (i == MAX_LEN)
503                                 line[i++] = '\0';
504                         page++;
505                 }
506         }
507         if (i <= MAX_LEN)
508                 line[i] = '\0';
509         if (!end_reached)
510                 page++;         /* move pass '\n' */
511
512         return line;
513 }
514
515 /*
516  * Print current position
517  */
518 static void print_position(WINDOW * win, int height, int width)
519 {
520         int fpos, percent;
521
522         if ((fpos = lseek(fd, 0, SEEK_CUR)) == -1) {
523                 endwin();
524                 fprintf(stderr, "\nError moving file pointer in print_position().\n");
525                 exit(-1);
526         }
527         wattrset(win, position_indicator_attr);
528         wbkgdset(win, position_indicator_attr & A_COLOR);
529         percent = !file_size ?
530             100 : ((fpos - bytes_read + page - buf) * 100) / file_size;
531         wmove(win, height - 3, width - 9);
532         wprintw(win, "(%3d%%)", percent);
533 }