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