blob: 5b3904583880dff1f84a20c954835063029b0098 [file] [log] [blame]
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions an
* limitations under the License.
*/
package com.android.server.midi;
import android.midi.MidiDevice;
import android.midi.MidiDeviceInfo;
import android.os.ParcelFileDescriptor;
import android.system.OsConstants;
import android.util.Log;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
// Our subclass of MidiDeviceBase to implement a virtual MIDI device
class VirtualMidiDevice extends MidiDeviceBase {
private static final String TAG = "VirtualMidiDevice";
private ParcelFileDescriptor[] mFileDescriptors;
private FileInputStream mInputStream;
private FileOutputStream mOutputStream;
public VirtualMidiDevice(MidiDeviceInfo info) {
super(info);
}
public boolean open() {
if (mInputStream != null && mOutputStream != null) {
// already open
return true;
}
try {
mFileDescriptors = ParcelFileDescriptor.createSocketPair(
OsConstants.SOCK_SEQPACKET);
FileDescriptor fd = mFileDescriptors[0].getFileDescriptor();
mInputStream = new FileInputStream(fd);
mOutputStream = new FileOutputStream(fd);
return true;
} catch (IOException e) {
Log.e(TAG, "failed to create ParcelFileDescriptor pair");
return false;
}
}
void close() {
super.close();
try {
if (mInputStream != null) {
mInputStream.close();
}
if (mOutputStream != null) {
mOutputStream.close();
}
if (mFileDescriptors != null && mFileDescriptors[0] != null) {
mFileDescriptors[0].close();
// file descriptor 1 is passed to client process
}
} catch (IOException e) {
}
}
MidiDevice getProxy() {
return new MidiDevice(mDeviceInfo, mFileDescriptors[1]);
}
int readMessage(byte[] buffer) throws IOException {
int ret = mInputStream.read(buffer);
// for now, throw away the timestamp
return ret - 8;
}
void writeMessage(byte[] buffer, int count) throws IOException {
mOutputStream.write(buffer, 0, count);
}
}