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