scripts/kconfig/lxdialog/textbox.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  textbox.c -- implements the text box
   4  *
   5  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
   6  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
   7  */
   8
   9 #include "dialog.h"
  10
  11 static int hscroll;
  12 static int begin_reached, end_reached, page_length;
  13 static char *buf;
  14 static char *page;
  15
  16 /*
  17  * Go back 'n' lines in text. Called by dialog_textbox().
  18  * 'page' will be updated to point to the desired line in 'buf'.
  19  */
  20 static void back_lines(int n)
  21 {
  22         int i;
  23
  24         begin_reached = 0;
  25         /* Go back 'n' lines */
  26         for (i = 0; i < n; i++) {
  27                 if (*page == '\0') {
  28                         if (end_reached) {
  29                                 end_reached = 0;
  30                                 continue;
  31                         }
  32                 }
  33                 if (page == buf) {
  34                         begin_reached = 1;
  35                         return;
  36                 }
  37                 page--;
  38                 do {
  39                         if (page == buf) {
  40                                 begin_reached = 1;
  41                                 return;
  42                         }
  43                         page--;
  44                 } while (*page != '\n');
  45                 page++;
  46         }
  47 }
  48
  49 /*
  50  * Return current line of text. Called by dialog_textbox() and print_line().
  51  * 'page' should point to start of current line before calling, and will be
  52  * updated to point to start of next line.
  53  */
  54 static char *get_line(void)
  55 {
  56         int i = 0;
  57         static char line[MAX_LEN + 1];
  58
  59         end_reached = 0;
  60         while (*page != '\n') {
  61                 if (*page == '\0') {
  62                         end_reached = 1;
  63                         break;
  64                 } else if (i < MAX_LEN)
  65                         line[i++] = *(page++);
  66                 else {
  67                         /* Truncate lines longer than MAX_LEN characters */
  68                         if (i == MAX_LEN)
  69                                 line[i++] = '\0';
  70                         page++;
  71                 }
  72         }
  73         if (i <= MAX_LEN)
  74                 line[i] = '\0';
  75         if (!end_reached)
  76                 page++;         /* move past '\n' */
  77
  78         return line;
  79 }
  80
  81 /*
  82  * Print a new line of text.
  83  */
  84 static void print_line(WINDOW *win, int row, int width)
  85 {
  86         char *line;
  87
  88         line = get_line();
  89         line += MIN(strlen(line), hscroll);     /* Scroll horizontally */
  90         wmove(win, row, 0);     /* move cursor to correct line */
  91         waddch(win, ' ');
  92         waddnstr(win, line, MIN(strlen(line), width - 2));
  93
  94         /* Clear 'residue' of previous line */
  95         wclrtoeol(win);
  96 }
  97
  98 /*
  99  * Print a new page of text.
 100  */
 101 static void print_page(WINDOW *win, int height, int width, update_text_fn
 102                        update_text, void *data)
 103 {
 104         int i, passed_end = 0;
 105
 106         if (update_text) {
 107                 char *end;
 108
 109                 for (i = 0; i < height; i++)
 110                         get_line();
 111                 end = page;
 112                 back_lines(height);
 113                 update_text(buf, page - buf, end - buf, data);
 114         }
 115
 116         page_length = 0;
 117         for (i = 0; i < height; i++) {
 118                 print_line(win, i, width);
 119                 if (!passed_end)
 120                         page_length++;
 121                 if (end_reached && !passed_end)
 122                         passed_end = 1;
 123         }
 124         wnoutrefresh(win);
 125 }
 126
 127 /*
 128  * Print current position
 129  */
 130 static void print_position(WINDOW *win)
 131 {
 132         int percent;
 133
 134         wattrset(win, dlg.position_indicator.atr);
 135         wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
 136         percent = (page - buf) * 100 / strlen(buf);
 137         wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
 138         wprintw(win, "(%3d%%)", percent);
 139 }
 140
 141 /*
 142  * refresh window content
 143  */
 144 static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
 145                              int cur_y, int cur_x, update_text_fn update_text,
 146                              void *data)
 147 {
 148         print_page(box, boxh, boxw, update_text, data);
 149         print_position(dialog);
 150         wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
 151         wrefresh(dialog);
 152 }
 153
 154 /*
 155  * Display text from a file in a dialog box.
 156  *
 157  * keys is a null-terminated array
 158  * update_text() may not add or remove any '\n' or '\0' in tbuf
 159  */
 160 int dialog_textbox(const char *title, char *tbuf, int initial_height,
 161                    int initial_width, int *keys, int *_vscroll, int *_hscroll,
 162                    update_text_fn update_text, void *data)
 163 {
 164         int i, x, y, cur_x, cur_y, key = 0;
 165         int height, width, boxh, boxw;
 166         WINDOW *dialog, *box;
 167         bool done = false;
 168
 169         begin_reached = 1;
 170         end_reached = 0;
 171         page_length = 0;
 172         hscroll = 0;
 173         buf = tbuf;
 174         page = buf;     /* page is pointer to start of page to be displayed */
 175
 176         if (_vscroll && *_vscroll) {
 177                 begin_reached = 0;
 178
 179                 for (i = 0; i < *_vscroll; i++)
 180                         get_line();
 181         }
 182         if (_hscroll)
 183                 hscroll = *_hscroll;
 184
 185 do_resize:
 186         getmaxyx(stdscr, height, width);
 187         if (height < TEXTBOX_HEIGTH_MIN || width < TEXTBOX_WIDTH_MIN)
 188                 return -ERRDISPLAYTOOSMALL;
 189         if (initial_height != 0)
 190                 height = initial_height;
 191         else
 192                 if (height > 4)
 193                         height -= 4;
 194                 else
 195                         height = 0;
 196         if (initial_width != 0)
 197                 width = initial_width;
 198         else
 199                 if (width > 5)
 200                         width -= 5;
 201                 else
 202                         width = 0;
 203
 204         /* center dialog box on screen */
 205         x = (getmaxx(stdscr) - width) / 2;
 206         y = (getmaxy(stdscr) - height) / 2;
 207
 208         draw_shadow(stdscr, y, x, height, width);
 209
 210         dialog = newwin(height, width, y, x);
 211         keypad(dialog, TRUE);
 212
 213         /* Create window for box region, used for scrolling text */
 214         boxh = height - 4;
 215         boxw = width - 2;
 216         box = subwin(dialog, boxh, boxw, y + 1, x + 1);
 217         wattrset(box, dlg.dialog.atr);
 218         wbkgdset(box, dlg.dialog.atr & A_COLOR);
 219
 220         keypad(box, TRUE);
 221
 222         /* register the new window, along with its borders */
 223         draw_box(dialog, 0, 0, height, width,
 224                  dlg.dialog.atr, dlg.border.atr);
 225
 226         wattrset(dialog, dlg.border.atr);
 227         mvwaddch(dialog, height - 3, 0, ACS_LTEE);
 228         for (i = 0; i < width - 2; i++)
 229                 waddch(dialog, ACS_HLINE);
 230         wattrset(dialog, dlg.dialog.atr);
 231         wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
 232         waddch(dialog, ACS_RTEE);
 233
 234         print_title(dialog, title, width);
 235
 236         print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
 237         wnoutrefresh(dialog);
 238         getyx(dialog, cur_y, cur_x);    /* Save cursor position */
 239
 240         /* Print first page of text */
 241         attr_clear(box, boxh, boxw, dlg.dialog.atr);
 242         refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x, update_text,
 243                          data);
 244
 245         while (!done) {
 246                 key = wgetch(dialog);
 247                 switch (key) {
 248                 case 'E':       /* Exit */
 249                 case 'e':
 250                 case 'X':
 251                 case 'x':
 252                 case 'q':
 253                 case '\n':
 254                         done = true;
 255                         break;
 256                 case 'g':       /* First page */
 257                 case KEY_HOME:
 258                         if (!begin_reached) {
 259                                 begin_reached = 1;
 260                                 page = buf;
 261                                 refresh_text_box(dialog, box, boxh, boxw,
 262                                                  cur_y, cur_x, update_text,
 263                                                  data);
 264                         }
 265                         break;
 266                 case 'G':       /* Last page */
 267                 case KEY_END:
 268
 269                         end_reached = 1;
 270                         /* point to last char in buf */
 271                         page = buf + strlen(buf);
 272                         back_lines(boxh);
 273                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 274                                          cur_x, update_text, data);
 275                         break;
 276                 case 'K':       /* Previous line */
 277                 case 'k':
 278                 case KEY_UP:
 279                         if (begin_reached)
 280                                 break;
 281
 282                         back_lines(page_length + 1);
 283                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 284                                          cur_x, update_text, data);
 285                         break;
 286                 case 'B':       /* Previous page */
 287                 case 'b':
 288                 case 'u':
 289                 case KEY_PPAGE:
 290                         if (begin_reached)
 291                                 break;
 292                         back_lines(page_length + boxh);
 293                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 294                                          cur_x, update_text, data);
 295                         break;
 296                 case 'J':       /* Next line */
 297                 case 'j':
 298                 case KEY_DOWN:
 299                         if (end_reached)
 300                                 break;
 301
 302                         back_lines(page_length - 1);
 303                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 304                                          cur_x, update_text, data);
 305                         break;
 306                 case KEY_NPAGE: /* Next page */
 307                 case ' ':
 308                 case 'd':
 309                         if (end_reached)
 310                                 break;
 311
 312                         begin_reached = 0;
 313                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 314                                          cur_x, update_text, data);
 315                         break;
 316                 case '0':       /* Beginning of line */
 317                 case 'H':       /* Scroll left */
 318                 case 'h':
 319                 case KEY_LEFT:
 320                         if (hscroll <= 0)
 321                                 break;
 322
 323                         if (key == '0')
 324                                 hscroll = 0;
 325                         else
 326                                 hscroll--;
 327                         /* Reprint current page to scroll horizontally */
 328                         back_lines(page_length);
 329                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 330                                          cur_x, update_text, data);
 331                         break;
 332                 case 'L':       /* Scroll right */
 333                 case 'l':
 334                 case KEY_RIGHT:
 335                         if (hscroll >= MAX_LEN)
 336                                 break;
 337                         hscroll++;
 338                         /* Reprint current page to scroll horizontally */
 339                         back_lines(page_length);
 340                         refresh_text_box(dialog, box, boxh, boxw, cur_y,
 341                                          cur_x, update_text, data);
 342                         break;
 343                 case KEY_ESC:
 344                         if (on_key_esc(dialog) == KEY_ESC)
 345                                 done = true;
 346                         break;
 347                 case KEY_RESIZE:
 348                         back_lines(height);
 349                         delwin(box);
 350                         delwin(dialog);
 351                         on_key_resize();
 352                         goto do_resize;
 353                 default:
 354                         for (i = 0; keys[i]; i++) {
 355                                 if (key == keys[i]) {
 356                                         done = true;
 357                                         break;
 358                                 }
 359                         }
 360                 }
 361         }
 362         delwin(box);
 363         delwin(dialog);
 364         if (_vscroll) {
 365                 const char *s;
 366
 367                 s = buf;
 368                 *_vscroll = 0;
 369                 back_lines(page_length);
 370                 while (s < page && (s = strchr(s, '\n'))) {
 371                         (*_vscroll)++;
 372                         s++;
 373                 }
 374         }
 375         if (_hscroll)
 376                 *_hscroll = hscroll;
 377         return key;
 378 }