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  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include "dialog.h"
  11
  12 static void back_lines(int n);
  13 static void print_page(WINDOW *win, int height, int width, update_text_fn
  14                        update_text, void *data);
  15 static void print_line(WINDOW *win, int row, int width);
  16 static char *get_line(void);
  17 static void print_position(WINDOW * win);
  18
  19 static int hscroll;
  20 static int begin_reached, end_reached, page_length;
  21 static char *buf;
  22 static char *page;
  23
  24 /*
  25  * refresh window content
  26  */
  27 static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
  28                              int cur_y, int cur_x, update_text_fn update_text,
  29                              void *data)
  30 {
  31         print_page(box, boxh, boxw, update_text, data);
  32         print_position(dialog);
  33         wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
  34         wrefresh(dialog);
  35 }
  36
  37
  38 /*
  39  * Display text from a file in a dialog box.
  40  *
  41  * keys is a null-terminated array
  42  * update_text() may not add or remove any '\n' or '\0' in tbuf
  43  */
  44 int dialog_textbox(const char *title, char *tbuf, int initial_height,
  45                    int initial_width, int *keys, int *_vscroll, int *_hscroll,
  46                    update_text_fn update_text, void *data)
  47 {
  48         int i, x, y, cur_x, cur_y, key = 0;
  49         int height, width, boxh, boxw;
  50         WINDOW *dialog, *box;
  51         bool done = false;
  52
  53         begin_reached = 1;
  54         end_reached = 0;
  55         page_length = 0;
  56         hscroll = 0;
  57         buf = tbuf;
  58         page = buf;     /* page is pointer to start of page to be displayed */
  59
  60         if (_vscroll && *_vscroll) {
  61                 begin_reached = 0;
  62
  63                 for (i = 0; i < *_vscroll; i++)
  64                         get_line();
  65         }
  66         if (_hscroll)
  67                 hscroll = *_hscroll;
  68
  69 do_resize:
  70         getmaxyx(stdscr, height, width);
  71         if (height < TEXTBOX_HEIGTH_MIN || width < TEXTBOX_WIDTH_MIN)
  72                 return -ERRDISPLAYTOOSMALL;
  73         if (initial_height != 0)
  74                 height = initial_height;
  75         else
  76                 if (height > 4)
  77                         height -= 4;
  78                 else
  79                         height = 0;
  80         if (initial_width != 0)
  81                 width = initial_width;
  82         else
  83                 if (width > 5)
  84                         width -= 5;
  85                 else
  86                         width = 0;
  87
  88         /* center dialog box on screen */
  89         x = (getmaxx(stdscr) - width) / 2;
  90         y = (getmaxy(stdscr) - height) / 2;
  91
  92         draw_shadow(stdscr, y, x, height, width);
  93
  94         dialog = newwin(height, width, y, x);
  95         keypad(dialog, TRUE);
  96
  97         /* Create window for box region, used for scrolling text */
  98         boxh = height - 4;
  99         boxw = width - 2;
 100         box = subwin(dialog, boxh, boxw, y + 1, x + 1);
 101         wattrset(box, dlg.dialog.atr);
 102         wbkgdset(box, dlg.dialog.atr & A_COLOR);
 103
 104         keypad(box, TRUE);
 105
 106         /* register the new window, along with its borders */
 107         draw_box(dialog, 0, 0, height, width,
 108                  dlg.dialog.atr, dlg.border.atr);
 109
 110         wattrset(dialog, dlg.border.atr);
 111         mvwaddch(dialog, height - 3, 0, ACS_LTEE);
 112         for (i = 0; i < width - 2; i++)
 113                 waddch(dialog, ACS_HLINE);
 114         wattrset(dialog, dlg.dialog.atr);
 115         wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
 116         waddch(dialog, ACS_RTEE);
 117
 118         print_title(dialog, title, width);
 119
 120         print_button(dialog, gettext(" Exit "), height - 2, width / 2 - 4, TRUE);
 121         wnoutrefresh(dialog);
 122         getyx(dialog, cur_y, cur_x);    /* Save cursor position */
 123
 124         /* Print first page of text */
 125         attr_clear(box, boxh, boxw, dlg.dialog.atr);
 126         refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x, update_text,
 127                          data);
 128
 129         while (!done) {
 130                 key = wgetch(dialog);
 131                 switch (key) {
 132                 case 'E':       /* Exit */
 133                 case 'e':
 134                 case 'X':
 135                 case 'x':
 136                 case 'q':
 137                 case '\n':
 138                         done = true;
 139                         break;
 140                 case 'g':       /* First page */
 141                 case KEY_HOME:
 142                         if (!begin_reached) {
 143                                 begin_reached = 1;
 144                                 page = buf;
 145                                 refresh_text_box(dialog, box, boxh, boxw,
 146                                                  cur_y, cur_x, update_text,
 147                                                  data);
 148                         }
 149                         break;
 150                 case 'G':       /* Last page */
 151                 case KEY_END:
 152
 153                         end_reached = 1;
 154                         /* point to last char in buf */
 155                         page = buf + strlen(buf);
 156                         back_lines(boxh);
 157                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 158                                          cur_x, update_text, data);
 159                         break;
 160                 case 'K':       /* Previous line */
 161                 case 'k':
 162                 case KEY_UP:
 163                         if (begin_reached)
 164                                 break;
 165
 166                         back_lines(page_length + 1);
 167                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 168                                          cur_x, update_text, data);
 169                         break;
 170                 case 'B':       /* Previous page */
 171                 case 'b':
 172                 case 'u':
 173                 case KEY_PPAGE:
 174                         if (begin_reached)
 175                                 break;
 176                         back_lines(page_length + boxh);
 177                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 178                                          cur_x, update_text, data);
 179                         break;
 180                 case 'J':       /* Next line */
 181                 case 'j':
 182                 case KEY_DOWN:
 183                         if (end_reached)
 184                                 break;
 185
 186                         back_lines(page_length - 1);
 187                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 188                                          cur_x, update_text, data);
 189                         break;
 190                 case KEY_NPAGE: /* Next page */
 191                 case ' ':
 192                 case 'd':
 193                         if (end_reached)
 194                                 break;
 195
 196                         begin_reached = 0;
 197                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 198                                          cur_x, update_text, data);
 199                         break;
 200                 case '0':       /* Beginning of line */
 201                 case 'H':       /* Scroll left */
 202                 case 'h':
 203                 case KEY_LEFT:
 204                         if (hscroll <= 0)
 205                                 break;
 206
 207                         if (key == '0')
 208                                 hscroll = 0;
 209                         else
 210                                 hscroll--;
 211                         /* Reprint current page to scroll horizontally */
 212                         back_lines(page_length);
 213                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 214                                          cur_x, update_text, data);
 215                         break;
 216                 case 'L':       /* Scroll right */
 217                 case 'l':
 218                 case KEY_RIGHT:
 219                         if (hscroll >= MAX_LEN)
 220                                 break;
 221                         hscroll++;
 222                         /* Reprint current page to scroll horizontally */
 223                         back_lines(page_length);
 224                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 225                                          cur_x, update_text, data);
 226                         break;
 227                 case KEY_ESC:
 228                         if (on_key_esc(dialog) == KEY_ESC)
 229                                 done = true;
 230                         break;
 231                 case KEY_RESIZE:
 232                         back_lines(height);
 233                         delwin(box);
 234                         delwin(dialog);
 235                         on_key_resize();
 236                         goto do_resize;
 237                 default:
 238                         for (i = 0; keys[i]; i++) {
 239                                 if (key == keys[i]) {
 240                                         done = true;
 241                                         break;
 242                                 }
 243                         }
 244                 }
 245         }
 246         delwin(box);
 247         delwin(dialog);
 248         if (_vscroll) {
 249                 const char *s;
 250
 251                 s = buf;
 252                 *_vscroll = 0;
 253                 back_lines(page_length);
 254                 while (s < page && (s = strchr(s, '\n'))) {
 255                         (*_vscroll)++;
 256                         s++;
 257                 }
 258         }
 259         if (_hscroll)
 260                 *_hscroll = hscroll;
 261         return key;
 262 }
 263
 264 /*
 265  * Go back 'n' lines in text. Called by dialog_textbox().
 266  * 'page' will be updated to point to the desired line in 'buf'.
 267  */
 268 static void back_lines(int n)
 269 {
 270         int i;
 271
 272         begin_reached = 0;
 273         /* Go back 'n' lines */
 274         for (i = 0; i < n; i++) {
 275                 if (*page == '\0') {
 276                         if (end_reached) {
 277                                 end_reached = 0;
 278                                 continue;
 279                         }
 280                 }
 281                 if (page == buf) {
 282                         begin_reached = 1;
 283                         return;
 284                 }
 285                 page--;
 286                 do {
 287                         if (page == buf) {
 288                                 begin_reached = 1;
 289                                 return;
 290                         }
 291                         page--;
 292                 } while (*page != '\n');
 293                 page++;
 294         }
 295 }
 296
 297 /*
 298  * Print a new page of text.
 299  */
 300 static void print_page(WINDOW *win, int height, int width, update_text_fn
 301                        update_text, void *data)
 302 {
 303         int i, passed_end = 0;
 304
 305         if (update_text) {
 306                 char *end;
 307
 308                 for (i = 0; i < height; i++)
 309                         get_line();
 310                 end = page;
 311                 back_lines(height);
 312                 update_text(buf, page - buf, end - buf, data);
 313         }
 314
 315         page_length = 0;
 316         for (i = 0; i < height; i++) {
 317                 print_line(win, i, width);
 318                 if (!passed_end)
 319                         page_length++;
 320                 if (end_reached && !passed_end)
 321                         passed_end = 1;
 322         }
 323         wnoutrefresh(win);
 324 }
 325
 326 /*
 327  * Print a new line of text.
 328  */
 329 static void print_line(WINDOW * win, int row, int width)
 330 {
 331         char *line;
 332
 333         line = get_line();
 334         line += MIN(strlen(line), hscroll);     /* Scroll horizontally */
 335         wmove(win, row, 0);     /* move cursor to correct line */
 336         waddch(win, ' ');
 337         waddnstr(win, line, MIN(strlen(line), width - 2));
 338
 339         /* Clear 'residue' of previous line */
 340 #if OLD_NCURSES
 341         {
 342                 int x = getcurx(win);
 343                 int i;
 344                 for (i = 0; i < width - x; i++)
 345                         waddch(win, ' ');
 346         }
 347 #else
 348         wclrtoeol(win);
 349 #endif
 350 }
 351
 352 /*
 353  * Return current line of text. Called by dialog_textbox() and print_line().
 354  * 'page' should point to start of current line before calling, and will be
 355  * updated to point to start of next line.
 356  */
 357 static char *get_line(void)
 358 {
 359         int i = 0;
 360         static char line[MAX_LEN + 1];
 361
 362         end_reached = 0;
 363         while (*page != '\n') {
 364                 if (*page == '\0') {
 365                         end_reached = 1;
 366                         break;
 367                 } else if (i < MAX_LEN)
 368                         line[i++] = *(page++);
 369                 else {
 370                         /* Truncate lines longer than MAX_LEN characters */
 371                         if (i == MAX_LEN)
 372                                 line[i++] = '\0';
 373                         page++;
 374                 }
 375         }
 376         if (i <= MAX_LEN)
 377                 line[i] = '\0';
 378         if (!end_reached)
 379                 page++;         /* move past '\n' */
 380
 381         return line;
 382 }
 383
 384 /*
 385  * Print current position
 386  */
 387 static void print_position(WINDOW * win)
 388 {
 389         int percent;
 390
 391         wattrset(win, dlg.position_indicator.atr);
 392         wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
 393         percent = (page - buf) * 100 / strlen(buf);
 394         wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
 395         wprintw(win, "(%3d%%)", percent);
 396 }