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 }