src/help.c

   1 /* Hypertext file browser.
   2    Copyright (C) 1994, 1995 Miguel de Icaza.
   3    Copyright (C) 1994, 1995 Janne Kukonlehto
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19    Implements the hypertext file viewer.
  20    The hypertext file is a file that may have one or more nodes.  Each
  21    node ends with a ^D character and starts with a bracket, then the
  22    name of the node and then a closing bracket.
  23
  24    Links in the hypertext file are specified like this: the text that
  25    will be highlighted should have a leading ^A, then it comes the
  26    text, then a ^B indicating that highlighting is done, then the name
  27    of the node you want to link to and then a ^C.
  28
  29    The file must contain a ^D at the beginning and at the end of the
  30    file or the program will not be able to detect the end of file.
  31
  32    Lazyness/widgeting attack: This file does use the dialog manager
  33    and uses mainly the dialog to achieve the help work.  there is only
  34    one specialized widget and it's only used to forward the mouse messages
  35    to the appropiate routine.
  36
  37 */
  38
  39 #include <config.h>
  40 #include <stdio.h>
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <errno.h>
  44
  45 #include "global.h"
  46 #include "tty.h"
  47 #include "color.h"
  48 #include "dialog.h"
  49 #include "win.h"
  50 #include "mouse.h"
  51 #include "key.h"        /* For mi_getch() */
  52 #include "help.h"
  53 #include "dlg.h"                /* For Dlg_head */
  54 #include "widget.h"             /* For Widget */
  55
  56 #define MAXLINKNAME 80
  57 #define HISTORY_SIZE 20
  58 #define HELP_WINDOW_WIDTH 62
  59
  60 /* "$Id$" */
  61
  62 static char *data;              /* Pointer to the loaded data file */
  63 static int help_lines = 18;     /* Lines in help viewer */
  64 static int  history_ptr;        /* For the history queue */
  65 static char *main_node;         /* The main node */
  66 static char *last_shown = 0;    /* Last byte shown in a screen */
  67 static int end_of_node = 0;     /* Flag: the last character of the node shown? */
  68 static char *currentpoint, *startpoint;
  69 static char *selected_item;
  70
  71 /* The widget variables */
  72 static Dlg_head *whelp;
  73
  74 static struct {
  75     char *page;                 /* Pointer to the selected page */
  76     char *link;                 /* Pointer to the selected link */
  77 } history [HISTORY_SIZE];
  78
  79 /* Link areas for the mouse */
  80 typedef struct Link_Area {
  81     int x1, y1, x2, y2;
  82     char *link_name;
  83     struct Link_Area *next;
  84 } Link_Area;
  85
  86 static Link_Area *link_area = NULL;
  87 static int inside_link_area = 0;
  88
  89 static int help_callback (struct Dlg_head *h, int id, int msg);
  90
  91 #ifdef HAS_ACS_AS_PCCHARS
  92 static const struct {
  93     int acscode;
  94     int pccode;
  95 } acs2pc_table [] = {
  96     { 'q',  0xC4 },
  97     { 'x',  0xB3 },
  98     { 'l',  0xDA },
  99     { 'k',  0xBF },
 100     { 'm',  0xC0 },
 101     { 'j',  0xD9 },
 102     { 'a',  0xB0 },
 103     { 'u',  0xB4 },
 104     { 't',  0xC3 },
 105     { 'w',  0xC2 },
 106     { 'v',  0xC1 },
 107     { 'n',  0xC5 },
 108     { 0, 0 } };
 109
 110 static int acs2pc (int acscode)
 111 {
 112     int i;
 113
 114     for (i = 0; acs2pc_table[i].acscode != 0; i++)
 115         if (acscode == acs2pc_table[i].acscode) {
 116             return acs2pc_table[i].pccode;
 117         }
 118     return 0;
 119 }
 120 #endif
 121
 122 /* returns the position where text was found in the start buffer */
 123 /* or 0 if not found */
 124 static char *
 125 search_string (char *start, char *text)
 126 {
 127     char *d = text;
 128     char *e = start;
 129
 130     /* fmt sometimes replaces a space with a newline in the help file */
 131     /* Replace the newlines in the link name with spaces to correct the situation */
 132     while (*d){
 133         if (*d == '\n')
 134             *d = ' ';
 135         d++;
 136     }
 137     /* Do search */
 138     for (d = text; *e; e++){
 139         if (*d == *e)
 140             d++;
 141         else
 142             d = text;
 143         if (!*d)
 144             return e+1;
 145     }
 146     return 0;
 147 }
 148
 149 /* Searches text in the buffer pointed by start.  Search ends */
 150 /* if the CHAR_NODE_END is found in the text.  Returns 0 on failure */
 151 static char *search_string_node (char *start, char *text)
 152 {
 153     char *d = text;
 154     char *e = start;
 155
 156     if (!start)
 157         return 0;
 158
 159     for (; *e && *e != CHAR_NODE_END; e++){
 160         if (*d == *e)
 161             d++;
 162         else
 163             d = text;
 164         if (!*d)
 165             return e+1;
 166     }
 167     return 0;
 168 }
 169
 170 /* Searches the_char in the buffer pointer by start and searches */
 171 /* it can search forward (direction = 1) or backward (direction = -1) */
 172 static char *search_char_node (char *start, char the_char, int direction)
 173 {
 174     char *e;
 175
 176     e = start;
 177
 178     for (; *e && (*e != CHAR_NODE_END); e += direction){
 179         if (*e == the_char)
 180             return e;
 181     }
 182     return 0;
 183 }
 184
 185 /* Returns the new current pointer when moved lines lines */
 186 static char *move_forward2 (char *c, int lines)
 187 {
 188     char *p;
 189     int  line;
 190
 191     currentpoint = c;
 192     for (line = 0, p = currentpoint; *p && *p != CHAR_NODE_END; p++){
 193         if (line == lines)
 194             return currentpoint = p;
 195         if (*p == '\n')
 196             line++;
 197     }
 198     return currentpoint = c;
 199 }
 200
 201 static char *move_backward2 (char *c, int lines)
 202 {
 203     char *p;
 204     int line;
 205
 206     currentpoint = c;
 207     for (line = 0, p = currentpoint; *p && p >= data; p--){
 208         if (*p == CHAR_NODE_END)
 209         {
 210             /* We reached the beginning of the node */
 211             /* Skip the node headers */
 212             while (*p != ']') p++;
 213             return currentpoint = p + 2;
 214         }
 215         if (*(p - 1) == '\n')
 216             line++;
 217         if (line == lines)
 218             return currentpoint = p;
 219     }
 220     return currentpoint = c;
 221 }
 222
 223 static void move_forward (int i)
 224 {
 225     if (end_of_node)
 226         return;
 227     currentpoint = move_forward2 (currentpoint, i);
 228 }
 229
 230 static void move_backward (int i)
 231 {
 232     currentpoint = move_backward2 (currentpoint, ++i);
 233 }
 234
 235 static void move_to_top (int dummy)
 236 {
 237     while (currentpoint > data && *currentpoint != CHAR_NODE_END)
 238         currentpoint--;
 239     while (*currentpoint != ']')
 240         currentpoint++;
 241     currentpoint = currentpoint + 1;
 242     selected_item = NULL;
 243 }
 244
 245 static void move_to_bottom (int dummy)
 246 {
 247     while (*currentpoint && *currentpoint != CHAR_NODE_END)
 248         currentpoint++;
 249     currentpoint--;
 250     move_backward (help_lines - 1);
 251 }
 252
 253 static char *help_follow_link (char *start, char *selected_item)
 254 {
 255     char link_name [MAXLINKNAME];
 256     char *p;
 257     int  i = 0;
 258
 259     if (!selected_item)
 260         return start;
 261
 262     for (p = selected_item; *p && *p != CHAR_NODE_END && *p != CHAR_LINK_POINTER; p++)
 263         ;
 264     if (*p == CHAR_LINK_POINTER){
 265         link_name [0] = '[';
 266         for (i = 1; *p != CHAR_LINK_END && *p && *p != CHAR_NODE_END && i < MAXLINKNAME-3; )
 267             link_name [i++] = *++p;
 268         link_name [i-1] = ']';
 269         link_name [i] = 0;
 270         p = search_string (data, link_name);
 271         if (p)
 272             return p;
 273     }
 274     return _(" Help file format error\n\x4");   /*  */
 275 }
 276
 277 static char *select_next_link (char *start, char *current_link)
 278 {
 279     char *p;
 280
 281     if (!current_link)
 282         return 0;
 283
 284     p = search_string_node (current_link, STRING_LINK_END);
 285     if (!p)
 286         return NULL;
 287     p = search_string_node (p, STRING_LINK_START);
 288     if (!p)
 289         return NULL;
 290     return p - 1;
 291 }
 292
 293 static char *select_prev_link (char *start, char *current_link)
 294 {
 295     char *p;
 296
 297     if (!current_link)
 298         return 0;
 299
 300     p = current_link - 1;
 301     if (p <= start)
 302         return 0;
 303
 304     p = search_char_node (p, CHAR_LINK_START, -1);
 305     return p;
 306 }
 307
 308 static void start_link_area (int x, int y, char *link_name)
 309 {
 310     Link_Area *new;
 311
 312     if (inside_link_area)
 313         message (0, _(" Warning "), _(" Internal bug: Double start of link area "));
 314
 315     /* Allocate memory for a new link area */
 316     new = g_new (Link_Area, 1);
 317     new->next = link_area;
 318     link_area = new;
 319
 320     /* Save the beginning coordinates of the link area */
 321     link_area->x1 = x;
 322     link_area->y1 = y;
 323
 324     /* Save the name of the destination anchor */
 325     link_area->link_name = link_name;
 326
 327     inside_link_area = 1;
 328 }
 329
 330 static void end_link_area (int x, int y)
 331 {
 332     if (inside_link_area){
 333         /* Save the end coordinates of the link area */
 334         link_area->x2 = x;
 335         link_area->y2 = y;
 336
 337         inside_link_area = 0;
 338     }
 339 }
 340
 341 static void clear_link_areas (void)
 342 {
 343     Link_Area *current;
 344
 345     while (link_area){
 346         current = link_area;
 347         link_area = current -> next;
 348         g_free (current);
 349     }
 350     inside_link_area = 0;
 351 }
 352
 353 static void show (Dlg_head *h, char *paint_start)
 354 {
 355     char *p;
 356     int  col, line, c;
 357     int  painting = 1;
 358     int acs;                    /* Flag: Alternate character set active? */
 359     int repeat_paint;
 360     int active_col, active_line;/* Active link position */
 361
 362     do {
 363
 364         line = col = acs = active_col = active_line = repeat_paint = 0;
 365
 366         clear_link_areas ();
 367         if (selected_item < paint_start)
 368             selected_item = NULL;
 369
 370         for (p = paint_start; *p != CHAR_NODE_END && line < help_lines; p++){
 371             c = (unsigned char)*p;
 372             switch (c){
 373             case CHAR_LINK_START:
 374                 if (selected_item == NULL)
 375                     selected_item = p;
 376                 if (p == selected_item){
 377                     attrset (HELP_SLINK_COLOR);
 378
 379                     /* Store the coordinates of the link */
 380                     active_col = col + 2;
 381                     active_line = line + 2;
 382                 }
 383                 else
 384                     attrset (HELP_LINK_COLOR);
 385                 start_link_area (col, line, p);
 386                 break;
 387             case CHAR_LINK_POINTER:
 388                 painting = 0;
 389                 end_link_area (col - 1, line);
 390                 break;
 391             case CHAR_LINK_END:
 392                 painting = 1;
 393                 attrset (HELP_NORMAL_COLOR);
 394                 break;
 395             case CHAR_ALTERNATE:
 396                 acs = 1;
 397                 break;
 398             case CHAR_NORMAL:
 399                 acs = 0;
 400                 break;
 401             case CHAR_VERSION:
 402                 dlg_move (h, line+2, col+2);
 403                 addstr (VERSION);
 404                 col += strlen (VERSION);
 405                 break;
 406             case CHAR_BOLD_ON:
 407                 attrset (HELP_BOLD_COLOR);
 408                 break;
 409             case CHAR_ITALIC_ON:
 410                 attrset (HELP_ITALIC_COLOR);
 411                 break;
 412             case CHAR_BOLD_OFF:
 413                 attrset (HELP_NORMAL_COLOR);
 414                 break;
 415             case '\n':
 416                 line++;
 417                 col = 0;
 418                 break;
 419             case '\t':
 420                 col = (col/8 + 1) * 8;
 421                 break;
 422             case CHAR_MCLOGO:
 423             case CHAR_TEXTONLY_START:
 424             case CHAR_TEXTONLY_END:
 425                 break;
 426             case CHAR_XONLY_START:
 427                 while (*p && *p != CHAR_NODE_END && *p != CHAR_XONLY_END)
 428                     p++;
 429                 if (*p == CHAR_NODE_END || !*p)
 430                     p--;
 431                 break;
 432             default:
 433                 if (!painting)
 434                     continue;
 435                 if (col > HELP_WINDOW_WIDTH-1)
 436                     continue;
 437
 438                 dlg_move (h, line+2, col+2);
 439                 if (acs){
 440                     if (c == ' ' || c == '.')
 441                         addch (c);
 442                     else
 443 #ifndef OS2_NT
 444 #ifndef HAVE_SLANG
 445                         addch (acs_map [c]);
 446 #else
 447                         SLsmg_draw_object (h->y + line + 2, h->x + col + 2, c);
 448 #endif
 449 #else
 450                         addch (acs2pc (c));
 451 #endif /* OS2_NT */
 452                 } else
 453                     addch (c);
 454                 col++;
 455                 break;
 456             }
 457         }
 458         last_shown = p;
 459         end_of_node = line < help_lines;
 460         attrset (HELP_NORMAL_COLOR);
 461         if (selected_item >= last_shown){
 462             if (link_area != NULL){
 463                 selected_item = link_area->link_name;
 464                 repeat_paint = 1;
 465             }
 466             else
 467                 selected_item = NULL;
 468         }
 469     } while (repeat_paint);
 470
 471     /* Position the cursor over a nice link */
 472     if (active_col)
 473         dlg_move (h, active_line, active_col);
 474 }
 475
 476 static int help_event (Gpm_Event *event, Widget *w)
 477 {
 478     Link_Area *current_area;
 479
 480     if (! (event->type & GPM_UP))
 481         return 0;
 482
 483     /* The event is relative to the dialog window, adjust it: */
 484     event->y -= 2;
 485
 486     if (event->buttons & GPM_B_RIGHT){
 487         currentpoint = startpoint = history [history_ptr].page;
 488         selected_item = history [history_ptr].link;
 489         history_ptr--;
 490         if (history_ptr < 0)
 491             history_ptr = HISTORY_SIZE-1;
 492
 493         help_callback (w->parent, 0, DLG_DRAW);
 494         return 0;
 495     }
 496
 497     /* Test whether the mouse click is inside one of the link areas */
 498     current_area = link_area;
 499     while (current_area)
 500     {
 501         /* Test one line link area */
 502         if (event->y == current_area->y1 && event->x >= current_area->x1 &&
 503             event->y == current_area->y2 && event->x <= current_area->x2)
 504             break;
 505         /* Test two line link area */
 506         if (current_area->y1 + 1 == current_area->y2){
 507             /* The first line */
 508             if (event->y == current_area->y1 && event->x >= current_area->x1)
 509                 break;
 510             /* The second line */
 511             if (event->y == current_area->y2 && event->x <= current_area->x2)
 512                 break;
 513         }
 514         /* Mouse will not work with link areas of more than two lines */
 515
 516         current_area = current_area -> next;
 517     }
 518
 519     /* Test whether a link area was found */
 520     if (current_area){
 521         /* The click was inside a link area -> follow the link */
 522         history_ptr = (history_ptr+1) % HISTORY_SIZE;
 523         history [history_ptr].page = currentpoint;
 524         history [history_ptr].link = current_area->link_name;
 525         currentpoint = startpoint = help_follow_link (currentpoint, current_area->link_name);
 526         selected_item = NULL;
 527     } else{
 528         if (event->y < 0)
 529             move_backward (help_lines - 1);
 530         else if (event->y >= help_lines)
 531             move_forward (help_lines - 1);
 532         else if (event->y < help_lines/2)
 533             move_backward (1);
 534         else
 535             move_forward (1);
 536     }
 537
 538     /* Show the new node */
 539     help_callback (w->parent, 0, DLG_DRAW);
 540
 541     return 0;
 542 }
 543
 544 /* show help */
 545 static void
 546 help_help_cmd (Dlg_head *h)
 547 {
 548     history_ptr = (history_ptr+1) % HISTORY_SIZE;
 549     history [history_ptr].page = currentpoint;
 550     history [history_ptr].link = selected_item;
 551     currentpoint = startpoint = search_string (data, "[How to use help]") + 1;
 552     selected_item = NULL;
 553     help_callback (h, 0, DLG_DRAW);
 554 }
 555
 556 static void
 557 help_index_cmd (Dlg_head *h)
 558 {
 559     char *new_item;
 560
 561     history_ptr = (history_ptr+1) % HISTORY_SIZE;
 562     history [history_ptr].page = currentpoint;
 563     history [history_ptr].link = selected_item;
 564     currentpoint = startpoint = search_string (data, "[Help]") + 1;
 565
 566     if (!(new_item = search_string (data, "[Contents]")))
 567         message (1, MSG_ERROR, _(" Cannot find node [Contents] in help file "));
 568     else
 569         currentpoint = startpoint = new_item + 1;
 570     selected_item = NULL;
 571     help_callback (h, 0, DLG_DRAW);
 572 }
 573
 574 static void quit_cmd (void *x)
 575 {
 576     dlg_stop ((Dlg_head *)x);
 577 }
 578
 579 static void prev_node_cmd (Dlg_head *h)
 580 {
 581     currentpoint = startpoint = history [history_ptr].page;
 582     selected_item = history [history_ptr].link;
 583     history_ptr--;
 584     if (history_ptr < 0)
 585         history_ptr = HISTORY_SIZE-1;
 586
 587     help_callback (h, 0, DLG_DRAW);
 588 }
 589
 590 static int md_callback (Dlg_head *h, Widget *w, int msg, int par)
 591 {
 592     return default_proc (h, msg, par);
 593 }
 594
 595 static Widget *mousedispatch_new (int y, int x, int yl, int xl)
 596 {
 597     Widget *w = g_new (Widget, 1);
 598
 599     init_widget (w, y, x, yl, xl,
 600                  (callback_fn) md_callback, 0, (mouse_h)  help_event, NULL);
 601
 602     return w;
 603 }
 604
 605 static int help_handle_key (struct Dlg_head *h, int c)
 606 {
 607     char *new_item;
 608
 609     if (c != KEY_UP && c != KEY_DOWN &&
 610         check_movement_keys (c, 1, help_lines, currentpoint,
 611                              (movefn) move_backward2,
 612                              (movefn) move_forward2,
 613                              (movefn) move_to_top,
 614                              (movefn) move_to_bottom))
 615         /* Nothing */;
 616     else switch (c){
 617     case 'l':
 618     case KEY_LEFT:
 619         prev_node_cmd (h);
 620         break;
 621
 622     case '\n':
 623     case KEY_RIGHT:
 624         /* follow link */
 625         if (!selected_item){
 626 #ifdef WE_WANT_TO_GO_BACKWARD_ON_KEY_RIGHT
 627             /* Is there any reason why the right key would take us
 628              * backward if there are no links selected?, I agree
 629              * with Torben than doing nothing in this case is better
 630              */
 631             /* If there are no links, go backward in history */
 632             history_ptr--;
 633             if (history_ptr < 0)
 634                 history_ptr = HISTORY_SIZE-1;
 635
 636             currentpoint = startpoint = history [history_ptr].page;
 637             selected_item   = history [history_ptr].link;
 638 #endif
 639         } else {
 640             history_ptr = (history_ptr+1) % HISTORY_SIZE;
 641             history [history_ptr].page = currentpoint;
 642             history [history_ptr].link = selected_item;
 643             currentpoint = startpoint = help_follow_link (currentpoint, selected_item) + 1;
 644         }
 645         selected_item = NULL;
 646         break;
 647
 648     case KEY_DOWN:
 649     case '\t':
 650         /* select next link */
 651         new_item = select_next_link (startpoint, selected_item);
 652         if (new_item){
 653             selected_item = new_item;
 654             if (selected_item >= last_shown){
 655                 if (c == KEY_DOWN)
 656                     move_forward (1);
 657                 else
 658                     selected_item = NULL;
 659             }
 660         } else if (c == KEY_DOWN)
 661             move_forward (1);
 662         else
 663             selected_item = NULL;
 664         break;
 665
 666     case KEY_UP:
 667     case ALT ('\t'):
 668         /* select previous link */
 669         new_item = select_prev_link (startpoint, selected_item);
 670         selected_item = new_item;
 671         if (selected_item < currentpoint || selected_item >= last_shown){
 672             if (c == KEY_UP)
 673                 move_backward (1);
 674             else{
 675                 if (link_area != NULL)
 676                     selected_item = link_area->link_name;
 677                 else
 678                     selected_item = NULL;
 679             }
 680         }
 681         break;
 682
 683     case 'n':
 684         /* Next node */
 685         new_item = currentpoint;
 686         while (*new_item && *new_item != CHAR_NODE_END)
 687             new_item++;
 688         if (*++new_item == '['){
 689             while (*new_item != ']')
 690                 new_item++;
 691             currentpoint = new_item + 2;
 692             selected_item = NULL;
 693         }
 694         break;
 695
 696     case 'p':
 697         /* Previous node */
 698         new_item = currentpoint;
 699         while (new_item > data + 1 && *new_item != CHAR_NODE_END)
 700             new_item--;
 701         new_item--;
 702         while (new_item > data && *new_item != CHAR_NODE_END)
 703             new_item--;
 704         while (*new_item != ']')
 705             new_item++;
 706         currentpoint = new_item + 2;
 707         selected_item = NULL;
 708         break;
 709
 710     case 'c':
 711         help_index_cmd (h);
 712         break;
 713
 714     case ESC_CHAR:
 715     case XCTRL('g'):
 716         dlg_stop (h);
 717         break;
 718
 719     default:
 720         return 0;
 721
 722     }
 723     help_callback (h, 0, DLG_DRAW);
 724     return 1;
 725 }
 726
 727 static int help_callback (struct Dlg_head *h, int id, int msg)
 728 {
 729     switch (msg){
 730     case DLG_DRAW:
 731         attrset (HELP_NORMAL_COLOR);
 732         dlg_erase (h);
 733         draw_box (h, 1, 1, help_lines+2, HELP_WINDOW_WIDTH+2);
 734         attrset (COLOR_HOT_NORMAL);
 735         dlg_move (h, 1, (HELP_WINDOW_WIDTH - 1) / 2);
 736         addstr (_(" Help "));
 737         attrset (HELP_NORMAL_COLOR);
 738         show (h, currentpoint);
 739         break;
 740
 741     case DLG_KEY:
 742         return help_handle_key (h, id);
 743     }
 744     return 0;
 745 }
 746
 747 static void
 748 interactive_display_finish (void)
 749 {
 750     clear_link_areas ();
 751     g_free (data);
 752 }
 753
 754 void
 755 interactive_display (char *filename, char *node)
 756 {
 757     WButtonBar  *help_bar;
 758     Widget      *md;
 759     char        *hlpfile = filename;
 760
 761     if (filename)
 762         data = load_file (filename);
 763     else
 764         data = load_mc_home_file ("mc.hlp", &hlpfile);
 765
 766     if (data == NULL){
 767         message (1, MSG_ERROR, _(" Cannot open file %s \n %s "),
 768                  hlpfile, unix_error_string (errno));
 769     }
 770
 771     if (!filename)
 772         g_free (hlpfile);
 773
 774     if (!data)
 775         return;
 776
 777     if (!(main_node = search_string (data, node))){
 778         message (1, MSG_ERROR, _(" Cannot find node %s in help file "), node);
 779         interactive_display_finish ();
 780         return;
 781     }
 782
 783     if (help_lines > LINES - 4)
 784         help_lines = LINES - 4;
 785
 786     whelp = create_dlg (0, 0, help_lines+4, HELP_WINDOW_WIDTH+4, dialog_colors,
 787                         help_callback, "[Help]", "help",
 788                         DLG_TRYUP | DLG_CENTER | DLG_WANT_TAB);
 789
 790     selected_item = search_string_node (main_node, STRING_LINK_START) - 1;
 791     currentpoint = startpoint = main_node + 1;
 792
 793     for (history_ptr = HISTORY_SIZE; history_ptr;){
 794         history_ptr--;
 795         history [history_ptr].page = currentpoint;
 796         history [history_ptr].link = selected_item;
 797     }
 798
 799     help_bar = buttonbar_new (1);
 800     help_bar->widget.y -= whelp->y;
 801     help_bar->widget.x -= whelp->x;
 802
 803     md       = mousedispatch_new (1, 1, help_lines, HELP_WINDOW_WIDTH-2);
 804
 805     add_widget (whelp, help_bar);
 806     add_widget (whelp, md);
 807
 808     define_label_data (whelp, (Widget *)NULL, 1, _("Help"),
 809                        (buttonbarfn) help_help_cmd, whelp);
 810     define_label_data (whelp, (Widget *)NULL, 2, _("Index"),
 811                        (buttonbarfn) help_index_cmd,whelp);
 812     define_label_data (whelp, (Widget *)NULL, 3, _("Prev"),
 813                        (buttonbarfn) prev_node_cmd, whelp);
 814     define_label (whelp, (Widget *) NULL, 4, "", 0);
 815     define_label (whelp, (Widget *) NULL, 5, "", 0);
 816     define_label (whelp, (Widget *) NULL, 6, "", 0);
 817     define_label (whelp, (Widget *) NULL, 7, "", 0);
 818     define_label (whelp, (Widget *) NULL, 8, "", 0);
 819     define_label (whelp, (Widget *) NULL, 9, "", 0);
 820     define_label_data (whelp, (Widget *) NULL, 10, _("Quit"), quit_cmd, whelp);
 821
 822     run_dlg (whelp);
 823     interactive_display_finish ();
 824     destroy_dlg (whelp);
 825 }
 826