keys.h

FritzOS - 简单的C++开发OS的实例// 英文

/* keys.h : FritzOS Key Board I/O Header File For The FritzOS C++ Kernel
   Copyright (C) 2002 Tom Fritz

 * This program is a part of the FritzOS kernel, and may be freely
 * copied under the terms of the GNU General Public License (GPL),
 * version 2, or at your option any later version.

   For more info, look at the COPYING file.
*/

// defines:

#ifndef KEYS_H
#define KEYS_H

// Check to see if types.h is not included - keys.h needs it
#ifndef TYPES_H
#error keys.h needs types.h		// ERROR, file not included.
#endif

// Check to see if x86.h is not included - keys.h needs it
#ifndef X86_H
#error keys.h needs x86.h		// ERROR, file not included.
#endif

// If someone likes using lower-case functions, define GetRawKey to getrawkey, and others
#define getrawkey GetRawKey
#define getrawkeynow GetRawKeyNow

// Includes:
#include "keydefs.h"		// Keyboard defines

// voids:
// For getting keys from the keyboard.
UCHAR const getch();

// For getting raw keyboard scancodes
UINT GetRawKey();

// For getting raw keyboard scancodes without waiting for a key.
UINT GetRawKeyNow();

// data:
// For keeping track if the shift key is down or up
int shift;

// Create a typedef for getting keys, to hold the correct value:
typedef UCHAR KEY;

// Create a raw scancode data type for getting scancodes:
typedef UINT RAWKEY;

// It converts scancode to ASCII, too...
// Example:
// KEY KeyGot = getch();
KEY const getch()
{
	RAWKEY scan;			// For holding the scancode from the keyboard
	KEY retchar;			// The chararacter that returns the Scancode to ASCII code

	// Get the scancode
	scan = getrawkey();

	// Check to see if the shift key is down
	if ( shift ) 				// same as if ( shift == TRUE )
		retchar = asciiShift[ scan ];	// It is, use the upper shift codes

	// Not down
	else if ( !shift )			// same as else if ( shift == FALSE )
		retchar = asciiNonSh[ scan ];	// Not down - use lower shift codes

	// Return the ASCII version of the scancode...i.e the converted code
	return retchar;				
}

//************************************************************************************************************
//

// Example: int thekey = getrawkey(); 		// you can also use getrawkey instead of GetRawKey
UINT GetRawKey()
{
	RAWKEY scancode;				// For getting the keyboard raw scancode

	// Loop untill a key to be pressed
	while ( TRUE )
	{
		// Wait for the key, need this.
		while ( ( inportb( 0x64 ) & 1 ) == FALSE ) // 0x64 is for reading the 8042 status register
			;

		scancode = getrawkeynow();		// KEYPORT is the keyboard port for getting keys

		// Check to see if a key is up
		if ( scancode & KEYPRESS )
		{
			// Key is up, need to do this:
			scancode &= 0x7F;

			// A key is up, check to see if the shift key is up
			if ( scancode == KRLEFT_SHIFT || scancode == KRRIGHT_SHIFT )
				shift = FALSE;		// it's up - don't use shifted characters

			continue;			// Loop again
		}

		// Check to see if the shift key is down
		if ( scancode == KRLEFT_SHIFT || scancode == KRRIGHT_SHIFT )
		{
			shift = TRUE;				// It is down, use upper shift characters.

			continue;				// Restart, so it doesn't return a shift
		}

		// Return the key.
		return scancode;
	}
}

//************************************************************************************************************
//

// Example: int thekey = GetRawKeyNow();		// could also use getrawkeynow.
UINT GetRawKeyNow()
{
	int rawkey;	// For getting the raw scancode

	rawkey = inportb( KEYPORT );		// KEYPORT is 0x60 - the keyboard's keys port

	// Return the keyboard scancode value:
	return rawkey;
}

#endif

// End of keys.h