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