1/* Copyright (c) 1985 Ceriel J.H. Jacobs */
  2
  3#include "help.h"
  4#include "commands.h"
  5#include "display.h"
  6#include "in_all.h"
  7#include "keys.h"
  8#include "machine.h"
  9#include "main.h"
 10#include "options.h"
 11#include "output.h"
 12#include "prompt.h"
 13#include "term.h"
 14
 15static int           h_cnt;  /* Count # of lines */
 16static struct state *origin; /* Keep track of startstate */
 17
 18/*
 19 * Print a key sequence.
 20 * We arrived at an endstate. The s_next link in the state structure now
 21 * leads us from "origin" to the current state, so that we can print the key
 22 * sequence easily.
 23 */
 24
 25static void
 26pr_comm()
 27{
 28  struct state *p = origin;
 29  char         *pb;
 30  int           c;
 31  char          buf[30];
 32  int           i = 0; /* How many characters printed? */
 33
 34  pb = buf;
 35  for (;;) {
 36    c = p->s_char & 0177;
 37    if (c < ' ' || c == 0177) {
 38      /*
 39       * Will take an extra position
 40       */
 41      i++;
 42    }
 43    *pb++ = c;
 44    i++;
 45    if (!p->s_match)
 46      break;
 47    p = p->s_next;
 48  }
 49  do {
 50    *pb++ = ' ';
 51  } while (++i < 12);
 52  *pb = 0;
 53  cputline(buf);
 54}
 55
 56/*
 57 * Print out a description of the keymap. This is done, by temporarily using
 58 * the s_next field in the state structure indicate the state matching the
 59 * next character, so that we can walk from "origin" to an endstate.
 60 */
 61
 62static void
 63pr_mach(struct state *currstate, struct state *back)
 64{
 65  struct state *save;
 66
 67  while (currstate) {
 68    if (interrupt)
 69      break;
 70    if (back) {
 71      save         = back->s_next; /* Save original link */
 72      back->s_next = currstate;
 73    }
 74    if (!currstate->s_match) {
 75      /*
 76       * End state, print command
 77       */
 78      pr_comm();
 79      putline(commands[currstate->s_cnt].c_descr);
 80      putline("\r\n");
 81      if (++h_cnt >= maxpagesize) {
 82        ret_to_continue();
 83        h_cnt = 0;
 84      }
 85    } else
 86      pr_mach(currstate->s_match, currstate);
 87    currstate = currstate->s_next;
 88    if (back)
 89      back->s_next = save; /* restore */
 90    else
 91      origin = currstate;
 92  }
 93}
 94
 95/*ARGSUSED*/
 96int
 97do_help(long i)
 98{ /* The help command */
 99  (void)i;
100
101  startcomm = 0;
102  h_cnt     = 2;
103  putline("\r\nSummary of yap commands:\r\n");
104  origin = currmap->k_mach;
105  pr_mach(currmap->k_mach, (struct state *)0);
106  if (h_cnt) {
107    ret_to_continue();
108  }
109  if (!hardcopy && scr_info.currentpos)
110    redraw(1);
111  return 0;
112}