1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.midi; 18 19 import android.media.midi.MidiReceiver; 20 import android.media.midi.MidiSender; 21 22 import java.io.IOException; 23 import java.util.concurrent.CopyOnWriteArrayList; 24 25 /** 26 * Utility class for dispatching MIDI data to a list of {@link android.media.midi.MidiReceiver}s. 27 * This class subclasses {@link android.media.midi.MidiReceiver} and dispatches any data it receives 28 * to its receiver list. Any receivers that throw an exception upon receiving data will 29 * be automatically removed from the receiver list, but no IOException will be returned 30 * from the dispatcher's {@link android.media.midi.MidiReceiver#onSend} in that case. 31 */ 32 public final class MidiDispatcher extends MidiReceiver { 33 34 private final CopyOnWriteArrayList<MidiReceiver> mReceivers 35 = new CopyOnWriteArrayList<MidiReceiver>(); 36 37 private final MidiSender mSender = new MidiSender() { 38 @Override 39 public void onConnect(MidiReceiver receiver) { 40 mReceivers.add(receiver); 41 } 42 43 @Override 44 public void onDisconnect(MidiReceiver receiver) { 45 mReceivers.remove(receiver); 46 } 47 }; 48 49 /** 50 * Returns the number of {@link android.media.midi.MidiReceiver}s this dispatcher contains. 51 * @return the number of receivers 52 */ getReceiverCount()53 public int getReceiverCount() { 54 return mReceivers.size(); 55 } 56 57 /** 58 * Returns a {@link android.media.midi.MidiSender} which is used to add and remove 59 * {@link android.media.midi.MidiReceiver}s 60 * to the dispatcher's receiver list. 61 * @return the dispatcher's MidiSender 62 */ getSender()63 public MidiSender getSender() { 64 return mSender; 65 } 66 67 @Override onSend(byte[] msg, int offset, int count, long timestamp)68 public void onSend(byte[] msg, int offset, int count, long timestamp) throws IOException { 69 for (MidiReceiver receiver : mReceivers) { 70 try { 71 receiver.send(msg, offset, count, timestamp); 72 } catch (IOException e) { 73 // if the receiver fails we remove the receiver but do not propagate the exception 74 mReceivers.remove(receiver); 75 } 76 } 77 } 78 79 @Override onFlush()80 public void onFlush() throws IOException { 81 for (MidiReceiver receiver : mReceivers) { 82 receiver.flush(); 83 } 84 } 85 } 86