getxch.c

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/*  CXL - Copyright (c) 1987-1990 by Mike Smedley - All Rights Reserved  */
/*  GETXCH.C    - gets a key (ASCII code/extended ASCII code) from keyboard  */

#include <conio.h>
#include <dos.h>
#include <stdlib.h>
#include "cxldef.h"
#include "cxlkey.h"
#include "cxlmou.h"
#include "cxlvid.h"
#include "cxlwin.h"

#if     defined(_M_IX86)
#define bioskey(a)  _bios_keybrd(a)
#endif

static void call_func(void (*func)(void));
static struct _item_t *find_hotkey(struct _menu_t *wmenu,unsigned xch);

unsigned getxch(void)
{
    register unsigned int xch;
    int bstat,mrow,mcol,bcount;
    struct _onkey_t *onkey;
    struct _kbuf_t *kbuf;
    struct _item_t *item;

    /* check for any keys in the CXL keyboard "buffer" */
    if(_kbinfo.kbuf==NULL) {

        /* reset mouse position, left button, and right button */
        if((_mouse&MS_KEYS)&&!kbhit()) {
            msgotoxy(12,40);
            msbclear();
        }

        /* loop until a key has no match in the defined onkey linked list */
        for(;;) {

Continue:
            /* if mouse installed, translate movements/button presses */
            if((_mouse&MS_KEYS)&&!kbhit()) {

                /* set keypress source to default to mouse.  if a key */
                /* is actually pressed, then it will be changed.      */
                _kbinfo.source=2;

                for(;;) {

                    /* check CXL's keyboard buffer for keystrokes */
                    if(_kbinfo.kbuf!=NULL) goto keybuf;

                    /* process keyboard loop handler */
                    if(_kbinfo.kbloop!=NULL) (*_kbinfo.kbloop) ();

                    /* check keyboard for activity.  if a key has   */
                    /* been pressed, leave keyboard/mouse wait loop */
                    if(kbhit()) {
                        xch=bioskey(0);
                        _kbinfo.source=0;
                        break;
                    }

                    /* check left button for activity.  if it has   */
                    /* been pressed, translate it to the Enter key, */
                    /* and leave keyboard/mouse wait loop           */
                    msbreles(0,&bstat,&bcount,&mrow,&mcol);
                    if(bcount) {
                        xch=0x1c0d; /* Enter */
                        break;
                    }

                    /* check right button for activity.  if it has */
                    /* been pressed, translate it to the Esc key,  */
                    /* and leave keyboard/mouse wait loop.         */
                    msbreles(1,&bstat,&bcount,&mrow,&mcol);
                    if(bcount) {
                        xch=0x011b; /* Esc */
                        break;
                    }

                    /* read mouse status.  check direction */
                    /* of mouse movement and translate it  */
                    /* into one of the arrow keys.         */
                    msstatus(&bstat,&mrow,&mcol);
                    xch=0;
                    if(mrow<11)      xch=0x4800;  /* Up */
                    else if(mrow>13) xch=0x5000;  /* Down */
                    else if(mcol<37) xch=0x4b00;  /* Left */
                    else if(mcol>43) xch=0x4d00;  /* Right */
                    if(xch) break;
                }
            }
            else {

                /* check CXL's keyboard buffer for keystrokes */
                if(_kbinfo.kbuf!=NULL) goto keybuf;

                /* process keyboard loop handler */
                if(_kbinfo.kbloop!=NULL) while(!kbhit()) (*_kbinfo.kbloop) ();

                /* get key from keyboard */
                xch=bioskey(0);
                _kbinfo.source=0;
            }

            /* search through onkey linked list for a         */
            /* matching defined onkey.  if one is found,      */
            /* then save the current environment, call the    */
            /* onkey's function, and restore the environment. */
            onkey=_kbinfo.onkey;
            while(onkey!=NULL) {
                if( onkey->keycode == xch ) {
                    call_func(onkey->func);
                    if(_kbinfo.inmenu&&(_mouse&MS_CURS)) return(0);
                    break;
                }
                onkey=onkey->prev;
            }
            if(onkey!=NULL) {
                if(!onkey->pass) continue;
                xch=onkey->pass;
                break;
            }

            /* search for a menu hot key.  if one is found,    */
            /* then save the current environment, call the     */
            /* hotkey's function, and restore the environment. */
            if(_winfo.menu!=NULL&&xch) {
                item=find_hotkey(_winfo.menu,xch);
                if(item!=NULL) {
                    call_func(item->select);
                    if(_kbinfo.inmenu&&(_mouse&MS_CURS)) return(0);
                    goto Continue;
                }
            }

            break;
        }
    }
    else {

keybuf:

        /* return key from top of buffer */
        xch=_kbinfo.kbuf->xch;

        /* set variable to indicate that key came from buffer */
        _kbinfo.source=1;

        /* free keypress record and update linked list */
        kbuf=_kbinfo.kbuf->next;
        free(_kbinfo.kbuf);
        _kbinfo.kbuf=kbuf;
        if(_kbinfo.kbuf!=NULL) _kbinfo.kbuf->prev=NULL;
    }

    /* return keypress */
    return(xch);
}

/*---------------------------------------------------------------------------*/

static void call_func(void (*func)(void))
{
    struct _menu_t *menu;
    int sline,eline,row,col;

    getcursz(&sline,&eline);
    readcur(&row,&col);
    menu=_winfo.cmenu;
    (*func)();
    _winfo.cmenu=menu;
    gotoxy_(row,col);
    setcursz(sline,eline);
}

/*---------------------------------------------------------------------------*/

static struct _item_t *find_hotkey(struct _menu_t *wmenu,unsigned xch)
{
    struct _item_t *witem,*item;

    /* do while more items in this menu */
    for(witem=wmenu->item;witem!=NULL;witem=witem->prev) {

        /* if hot key matches keypress, return its item address */
        if(witem->hotkey==xch&&(!(witem->fmask&M_NOSEL))&&witem->select!=NULL)
            return(witem);

        /* if current item has a child menu, process it */
        if(witem->child!=NULL) {
            item=find_hotkey(witem->child,xch);
            if(item!=NULL) return(item);
        }
    }

    /* return address of item found */
    return(witem);
}