git.sur5r.net Git - kconfig-frontends/blob - libs/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, gettext(" 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                 case 'q':
 133                         delwin(box);
 134                         delwin(dialog);
 135                         return 0;
 136                 case 'g':       /* First page */
 137                 case KEY_HOME:
 138                         if (!begin_reached) {
 139                                 begin_reached = 1;
 140                                 page = buf;
 141                                 refresh_text_box(dialog, box, boxh, boxw,
 142                                                  cur_y, cur_x);
 143                         }
 144                         break;
 145                 case 'G':       /* Last page */
 146                 case KEY_END:
 147
 148                         end_reached = 1;
 149                         /* point to last char in buf */
 150                         page = buf + strlen(buf);
 151                         back_lines(boxh);
 152                         refresh_text_box(dialog, box, boxh, boxw,
 153                                          cur_y, cur_x);
 154                         break;
 155                 case 'K':       /* Previous line */
 156                 case 'k':
 157                 case KEY_UP:
 158                         if (!begin_reached) {
 159                                 back_lines(page_length + 1);
 160
 161                                 /* We don't call print_page() here but use
 162                                  * scrolling to ensure faster screen update.
 163                                  * However, 'end_reached' and 'page_length'
 164                                  * should still be updated, and 'page' should
 165                                  * point to start of next page. This is done
 166                                  * by calling get_line() in the following
 167                                  * 'for' loop. */
 168                                 scrollok(box, TRUE);
 169                                 wscrl(box, -1); /* Scroll box region down one line */
 170                                 scrollok(box, FALSE);
 171                                 page_length = 0;
 172                                 passed_end = 0;
 173                                 for (i = 0; i < boxh; i++) {
 174                                         if (!i) {
 175                                                 /* print first line of page */
 176                                                 print_line(box, 0, boxw);
 177                                                 wnoutrefresh(box);
 178                                         } else
 179                                                 /* Called to update 'end_reached' and 'page' */
 180                                                 get_line();
 181                                         if (!passed_end)
 182                                                 page_length++;
 183                                         if (end_reached && !passed_end)
 184                                                 passed_end = 1;
 185                                 }
 186
 187                                 print_position(dialog);
 188                                 wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
 189                                 wrefresh(dialog);
 190                         }
 191                         break;
 192                 case 'B':       /* Previous page */
 193                 case 'b':
 194                 case 'u':
 195                 case KEY_PPAGE:
 196                         if (begin_reached)
 197                                 break;
 198                         back_lines(page_length + boxh);
 199                         refresh_text_box(dialog, box, boxh, boxw,
 200                                          cur_y, cur_x);
 201                         break;
 202                 case 'J':       /* Next line */
 203                 case 'j':
 204                 case KEY_DOWN:
 205                         if (!end_reached) {
 206                                 begin_reached = 0;
 207                                 scrollok(box, TRUE);
 208                                 scroll(box);    /* Scroll box region up one line */
 209                                 scrollok(box, FALSE);
 210                                 print_line(box, boxh - 1, boxw);
 211                                 wnoutrefresh(box);
 212                                 print_position(dialog);
 213                                 wmove(dialog, cur_y, cur_x);    /* Restore cursor position */
 214                                 wrefresh(dialog);
 215                         }
 216                         break;
 217                 case KEY_NPAGE: /* Next page */
 218                 case ' ':
 219                 case 'd':
 220                         if (end_reached)
 221                                 break;
 222
 223                         begin_reached = 0;
 224                         refresh_text_box(dialog, box, boxh, boxw,
 225                                          cur_y, cur_x);
 226                         break;
 227                 case '0':       /* Beginning of line */
 228                 case 'H':       /* Scroll left */
 229                 case 'h':
 230                 case KEY_LEFT:
 231                         if (hscroll <= 0)
 232                                 break;
 233
 234                         if (key == '0')
 235                                 hscroll = 0;
 236                         else
 237                                 hscroll--;
 238                         /* Reprint current page to scroll horizontally */
 239                         back_lines(page_length);
 240                         refresh_text_box(dialog, box, boxh, boxw,
 241                                          cur_y, cur_x);
 242                         break;
 243                 case 'L':       /* Scroll right */
 244                 case 'l':
 245                 case KEY_RIGHT:
 246                         if (hscroll >= MAX_LEN)
 247                                 break;
 248                         hscroll++;
 249                         /* Reprint current page to scroll horizontally */
 250                         back_lines(page_length);
 251                         refresh_text_box(dialog, box, boxh, boxw,
 252                                          cur_y, cur_x);
 253                         break;
 254                 case KEY_ESC:
 255                         key = on_key_esc(dialog);
 256                         break;
 257                 case KEY_RESIZE:
 258                         back_lines(height);
 259                         delwin(box);
 260                         delwin(dialog);
 261                         on_key_resize();
 262                         goto do_resize;
 263                 }
 264         }
 265         delwin(box);
 266         delwin(dialog);
 267         return key;             /* ESC pressed */
 268 }
 269
 270 /*
 271  * Go back 'n' lines in text. Called by dialog_textbox().
 272  * 'page' will be updated to point to the desired line in 'buf'.
 273  */
 274 static void back_lines(int n)
 275 {
 276         int i;
 277
 278         begin_reached = 0;
 279         /* Go back 'n' lines */
 280         for (i = 0; i < n; i++) {
 281                 if (*page == '\0') {
 282                         if (end_reached) {
 283                                 end_reached = 0;
 284                                 continue;
 285                         }
 286                 }
 287                 if (page == buf) {
 288                         begin_reached = 1;
 289                         return;
 290                 }
 291                 page--;
 292                 do {
 293                         if (page == buf) {
 294                                 begin_reached = 1;
 295                                 return;
 296                         }
 297                         page--;
 298                 } while (*page != '\n');
 299                 page++;
 300         }
 301 }
 302
 303 /*
 304  * Print a new page of text. Called by dialog_textbox().
 305  */
 306 static void print_page(WINDOW * win, int height, int width)
 307 {
 308         int i, passed_end = 0;
 309
 310         page_length = 0;
 311         for (i = 0; i < height; i++) {
 312                 print_line(win, i, width);
 313                 if (!passed_end)
 314                         page_length++;
 315                 if (end_reached && !passed_end)
 316                         passed_end = 1;
 317         }
 318         wnoutrefresh(win);
 319 }
 320
 321 /*
 322  * Print a new line of text. Called by dialog_textbox() and print_page().
 323  */
 324 static void print_line(WINDOW * win, int row, int width)
 325 {
 326         char *line;
 327
 328         line = get_line();
 329         line += MIN(strlen(line), hscroll);     /* Scroll horizontally */
 330         wmove(win, row, 0);     /* move cursor to correct line */
 331         waddch(win, ' ');
 332         waddnstr(win, line, MIN(strlen(line), width - 2));
 333
 334         /* Clear 'residue' of previous line */
 335 #if OLD_NCURSES
 336         {
 337                 int x = getcurx(win);
 338                 int i;
 339                 for (i = 0; i < width - x; i++)
 340                         waddch(win, ' ');
 341         }
 342 #else
 343         wclrtoeol(win);
 344 #endif
 345 }
 346
 347 /*
 348  * Return current line of text. Called by dialog_textbox() and print_line().
 349  * 'page' should point to start of current line before calling, and will be
 350  * updated to point to start of next line.
 351  */
 352 static char *get_line(void)
 353 {
 354         int i = 0;
 355         static char line[MAX_LEN + 1];
 356
 357         end_reached = 0;
 358         while (*page != '\n') {
 359                 if (*page == '\0') {
 360                         if (!end_reached) {
 361                                 end_reached = 1;
 362                                 break;
 363                         }
 364                 } else if (i < MAX_LEN)
 365                         line[i++] = *(page++);
 366                 else {
 367                         /* Truncate lines longer than MAX_LEN characters */
 368                         if (i == MAX_LEN)
 369                                 line[i++] = '\0';
 370                         page++;
 371                 }
 372         }
 373         if (i <= MAX_LEN)
 374                 line[i] = '\0';
 375         if (!end_reached)
 376                 page++;         /* move pass '\n' */
 377
 378         return line;
 379 }
 380
 381 /*
 382  * Print current position
 383  */
 384 static void print_position(WINDOW * win)
 385 {
 386         int percent;
 387
 388         wattrset(win, dlg.position_indicator.atr);
 389         wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
 390         percent = (page - buf) * 100 / strlen(buf);
 391         wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
 392         wprintw(win, "(%3d%%)", percent);
 393 }