mididevice.java

java编程的一些Applets例子。值得深入研究一下。

/*
 * MidiDevice.java
 */

package midi;

/** Base class for MIDI in, out, and sync devices */
public abstract class MidiDevice {

	/*--------------- Constant Values ------------------*/

	/* MIDI status byte definitions */
	public static final int MidiNoteOff				=  0x80;
	public static final int MidiNoteOn				=  0x90;
	public static final int MidiKeyAftertouch		=  0xA0;
	public static final int MidiControlChange		=  0xB0;
	public static final int MidiProgramChange		=  0xC0;
	public static final int MidiChannelAftertouch	=  0xD0;
	public static final int MidiPitchBend			=  0xE0;
	public static final int MidiSysEx				=  0xF0;
	public static final int MidiMTCQuarterFrame		=  0xF1;
	public static final int MidiSongPositionPtr		=  0xF2;
	public static final int MidiSongSelect			=  0xF3;
	/* 0xF4, 0xF5 undefined */
	public static final int MidiTuneRequest			=  0xF6;
	public static final int MidiEndSysEx			=  0xF7;
	public static final int MidiTimingClock			=  0xF8;
	/* 0xF9 undefined */
	public static final int MidiStart				=  0xFA;
	public static final int MidiContinue			=  0xFB;
	public static final int MidiStop				=  0xFC;
	/* 0xFD undefined */
	public static final int MidiActiveSense			=  0xFE;
	public static final int MidiSystemReset			=  0xFF;

	/* mask for system messages */
	public static final int MidiSystemMessage		=  0xF0;

	/*--- Windows MIDI Mapper device index (from MMSYSTEM.H) ---*/
	public static final int MIDI_MAPPER = -1;

	/*--- ERROR RETURN CODES (from MMSYSTEM.H) ---*/

	/* General device error return values */
	public static final int MMSYSERR_NOERROR	 = 0;  /* no error */
	public static final int MMSYSERR_ERROR       = 1;  /* unspecified error */
	public static final int MMSYSERR_BADDEVICEID = 2;  /* device ID out of range */
	public static final int MMSYSERR_NOTENABLED  = 3;  /* driver failed enable */
	public static final int MMSYSERR_ALLOCATED   = 4;  /* device already allocated */
	public static final int MMSYSERR_INVALHANDLE = 5;  /* device handle is invalid */
	public static final int MMSYSERR_NODRIVER    = 6;  /* no device driver present */
	public static final int MMSYSERR_NOMEM       = 7;  /* memory allocation error */
	public static final int MMSYSERR_NOTSUPPORTED= 8;  /* function isn't supported */
	public static final int MMSYSERR_BADERRNUM   = 9;  /* error value out of range */
	public static final int MMSYSERR_INVALFLAG   = 10; /* invalid flag passed */
	public static final int MMSYSERR_INVALPARAM  = 11; /* invalid parameter passed */
	public static final int MMSYSERR_HANDLEBUSY  = 12; /* handle being used */

	/* MIDI error return values */
	public static final int MIDIERR_UNPREPARED   = 64; /* header not prepared */
	public static final int MIDIERR_STILLPLAYING = 65; /* still something playing */
	public static final int MIDIERR_NOMAP        = 66; /* no configured instruments */
	public static final int MIDIERR_NOTREADY     = 67; /* hardware is still busy */
	public static final int MIDIERR_NODEVICE     = 68; /* port no longer connected */
	public static final int MIDIERR_INVALIDSETUP = 69; /* invalid MIF */
	public static final int MIDIERR_BADOPENMODE  = 70; /* operation unsupported w/ open mode */
	public static final int MIDIERR_DONT_CONTINUE= 71; /* thru device 'eating' a message */

	/*------------ End of Constant Values --------------*/


	/** MIDI device index
	    This number is valid and unchanging whether device is open or closed.
    */
	protected int deviceId;

	/** MIDI device handle
		This number is valid only when the device is open, and may change
		if the device is closed and then reopened
	*/
	protected int deviceHandle = 0;

	/** Empty constructor not allowed */
	private MidiDevice() throws MidiBadDeviceException {
		throw new MidiBadDeviceException("Device ID not specified");
	}
		
	/** Construct a MidiDevice with a particular ID */
	protected MidiDevice(int id) throws MidiBadDeviceException {
		
		// MIDI_MAPPER is a Windows-defined MIDI filter used for performing MIDI
		// message translation on the fly.
		if (id < 0 && id != MIDI_MAPPER) {
			throw new MidiBadDeviceException(id);
		}
		deviceId = id;
	}

	/** Open the device; initialize deviceHandle if successful */
	public abstract void Open() throws MidiException;

	/** Close the device */
	public abstract void Close() throws MidiException;
}