The Atari Compendium/The Atari Compendium (Toad Computers) (1994).iso/files/umich/music/eked-m1.zoo/src/gm/key_man.c

C/C++ Source or Header | 1995-02-19 | 5KB | 183 lines

/*
 *  EKED-M1 : Editor for Korg M1 synth; key_man.c : keyboard equivalents
 *  Copyright (C) 1995 Steven M. Eker ([e-mail])
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stddef.h>
#include <string.h>
#include <ctype.h>
#include <osbind.h>
#include <gemfast.h>
#include "gem_man.h"

/*
 *    shift_code =    00000000 0000ACLR    (alt, ctrl, left, right)
 *    scan_code =    00000000 0sssssss
 *    lookup code =    000000ss sssssACS    where S = L|R
 */
#define KE_CODE(s, r)    (((s) >> 1) | ((s) & 1) | ((r) << 3))
#define KE_HASH(c)    (((unsigned) (c)) % MAX_EQUIV)

typedef struct {
  char *name;            /* Key name as it appears in menu */
  char code;            /* scancode */
} NAMED_KEY;

static KEY_EQUIV ke_table[MAX_EQUIV];

static void check_for_equiv(int title, int item, char *string);
static int ascii2key(char c);

KEY_EQUIV *km_get_equiv(int shift_code, int scan_code)
{
  int c = KE_CODE(shift_code, scan_code);
  KEY_EQUIV *start = ke_table + KE_HASH(c), *k = start;

  do{
    if(k->code == c)
      return k;
    if(k->code == 0)    /* most key combinations won't be equivalents! */
      break;
    if(++k == ke_table + MAX_EQUIV)
      k = ke_table;
  }while(k != start);
  return NULL;
}

void km_set_equiv(int shift_code, int scan_code, int title, int item)
{
  int c = KE_CODE(shift_code, scan_code);
  KEY_EQUIV *start = ke_table + KE_HASH(c), *k = start;

  do{
    if(k->code == c || k->code == 0){
      k->code = c;
      k->title = title;
      k->item = item;
      return;
    }
    if(++k == ke_table + MAX_EQUIV)
      k = ke_table;
  }while(k != start);
}

void km_scan_menu(OBJECT *menu)
{
  int active = menu[menu[0].ob_head].ob_head, dropdown = menu[0].ob_tail;
  int t, b, i;

  for(t = menu[menu[active].ob_head].ob_next,
      b = menu[menu[dropdown].ob_head].ob_next;
      t != active && b != dropdown; t = menu[t].ob_next, b = menu[b].ob_next){
    for(i = menu[b].ob_head; i != b; i = menu[i].ob_next)
      check_for_equiv(t, i, (char *) menu[i].ob_spec);
  }
}

static void check_for_equiv(int title, int item, char *string)
{
  static NAMED_KEY misc[] = {
    {"Tab", 0x0F},    {"Esc", 0x01},    {"ClrHome", 0x47},    {"Del", 0x53},
    {"Undo", 0x61},    {"Bksp", 0x0E},    {"Help", 0x62},        {"Enter", 0x72},
    {"Ins", 0x52},    {"Ret", 0x1C},    {NULL, 0x00}
  };
  int i, c, n, start, end, seeking_space, shift_code, scan_code;
  size_t l;
  NAMED_KEY *p;

  n = 0;
  seeking_space = 0;
  for(i = 0; string[i]; i++){
    if(isspace(string[i])){
      if(seeking_space){
        end = i - 1;
        seeking_space = 0;
      }
    }
    else{
      if(!seeking_space){
        n++;
        start = i;
        seeking_space = 1;
      }
    }
  }
  if(n < 2)
    return;
  if(seeking_space)
    end = i - 1;
/*
 *    More than two words; last word is string[start]...string[end]
 *    Check for modifiers
 */
  shift_code = 0;
  for(i = start; i < end; i++){
    c = string[i];
    if(c == 0x01)
      shift_code |= 1;    /* shift */
    else if(c == '^')
      shift_code |= 4;    /* control */
    else if(c == 0x07)
      shift_code |= 8;    /* alternate */
    else
      break;
  }
/*
 *    Check for a valid key name
 */
  scan_code = -1;
  if(i == end)    /* one character - assume ASCII */
    scan_code = ascii2key(string[i]);
  else if(string[i] == 'F' && isdigit(string[i + 1]) && i + 2 <= end){
    n = string[i + 1] - '0';
    if(i + 2 == end)
      n = isdigit(string[i + 2]) ? 10 * n + string[i + 2] - '0' : 0;
    if(n >= 1){
      if(n <= 10)
        scan_code = (0x3B - 1) + n;
      else if(n <= 20)
        scan_code = (0x54 - 11) + n;
    }
  }
  else{
    for(p = misc; p->code; p++){
      l = strlen(p->name);
      if(end - i + 1 == l && strncmp(string + i, p->name, l) == 0){
        scan_code = p->code;
        break;
      }
    }
  }
  if(scan_code > 0)
    km_set_equiv(shift_code, scan_code, title, item);
}

static int ascii2key(char c)
{
  _KEYTAB *p = Keytbl((char *) -1, (char *) -1, (char *) -1);
  char *unshift = p->unshift, *shift = p->shift, *caps = p->caps;
  int i;

  for(i = 0; i <= 127; i++){
    if(unshift[i] == c || shift[i] == c || caps[i] == c)
      return i;
  }
  return -1;
}