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