| /* |
| * Copyright (C) 2017 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 and |
| * limitations under the License. |
| */ |
| |
| package com.android.car; |
| |
| import android.car.hardware.CarSensorManager; |
| import android.os.IBinder; |
| import java.util.LinkedList; |
| |
| /** |
| * This class wraps a set of listeners of a given type of event, grouped by event-transmission rate. |
| * This is logic that is common to different services that need to receive and rebroadcast events. |
| * @param <ClientType> The type of event listener. |
| */ |
| public class Listeners<ClientType extends com.android.car.Listeners.IListener> { |
| public interface IListener extends IBinder.DeathRecipient { |
| void release(); |
| } |
| |
| public static class ClientWithRate<ClientType extends IListener> { |
| private final ClientType mClient; |
| /** rate requested from client */ |
| private int mRate; |
| |
| ClientWithRate(ClientType client, int rate) { |
| mClient = client; |
| mRate = rate; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| //TODO(egranata): is this truly necessary? |
| if (o instanceof ClientWithRate && |
| mClient == ((ClientWithRate) o).mClient) { |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| return mClient.hashCode(); |
| } |
| |
| int getRate() { |
| return mRate; |
| } |
| |
| void setRate(int rate) { |
| mRate = rate; |
| } |
| |
| ClientType getClient() { |
| return mClient; |
| } |
| } |
| |
| private final LinkedList<ClientWithRate<ClientType>> mClients = new LinkedList<>(); |
| /** rate sent to car */ |
| private int mRate; |
| |
| Listeners(int rate) { |
| mRate = rate; |
| } |
| |
| int getRate() { |
| return mRate; |
| } |
| |
| void setRate(int rate) { |
| mRate = rate; |
| } |
| |
| /** update rate from existing clients and return true if rate is changed. */ |
| boolean updateRate() { |
| //TODO(egranata): we might need to support other rate ranges |
| int fastestRate = CarSensorManager.SENSOR_RATE_NORMAL; |
| for (ClientWithRate<ClientType> clientWithRate: mClients) { |
| int clientRate = clientWithRate.getRate(); |
| if (clientRate < fastestRate) { |
| fastestRate = clientRate; |
| } |
| } |
| if (mRate != fastestRate) { |
| mRate = fastestRate; |
| return true; |
| } |
| return false; |
| } |
| |
| void addClientWithRate(ClientWithRate<ClientType> clientWithRate) { |
| mClients.add(clientWithRate); |
| } |
| |
| void removeClientWithRate(ClientWithRate<ClientType> clientWithRate) { |
| mClients.remove(clientWithRate); |
| } |
| |
| int getNumberOfClients() { |
| return mClients.size(); |
| } |
| |
| Iterable<ClientWithRate<ClientType>> getClients() { |
| return mClients; |
| } |
| |
| ClientWithRate<ClientType> findClientWithRate(ClientType client) { |
| for (ClientWithRate<ClientType> clientWithRate: mClients) { |
| if (clientWithRate.getClient() == client) { |
| return clientWithRate; |
| } |
| } |
| return null; |
| } |
| |
| void release() { |
| for (ClientWithRate<ClientType> clientWithRate: mClients) { |
| clientWithRate.getClient().release(); |
| } |
| mClients.clear(); |
| } |
| } |