| /* |
| * Copyright (C) 2018 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.internal; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * Represent listeners for a property grouped by their rate. |
| * T is a type of EventListener such as CarPropertyEventListener |
| * in {@link android.car.hardware.property.CarPropertyManager} |
| * @param <T> |
| * @hide |
| */ |
| public class CarRatedFloatListeners<T> { |
| private final Map<T, Float> mListenersToRate = new HashMap<>(4); |
| |
| private float mUpdateRate; |
| |
| protected long mLastUpdateTime = -1; |
| |
| protected CarRatedFloatListeners(float rate) { |
| mUpdateRate = rate; |
| } |
| |
| /** Check listener */ |
| public boolean contains(T listener) { |
| return mListenersToRate.containsKey(listener); |
| } |
| /** Return current rate after updating */ |
| public float getRate() { |
| return mUpdateRate; |
| } |
| |
| /** |
| * Remove given listener from the list and update rate if necessary. |
| * |
| * @param listener |
| * @return true if rate was updated. Otherwise, returns false. |
| */ |
| public boolean remove(T listener) { |
| mListenersToRate.remove(listener); |
| if (mListenersToRate.isEmpty()) { |
| return false; |
| } |
| Float updateRate = Collections.max(mListenersToRate.values()); |
| if (updateRate != mUpdateRate) { |
| mUpdateRate = updateRate; |
| return true; |
| } |
| return false; |
| } |
| |
| public boolean isEmpty() { |
| return mListenersToRate.isEmpty(); |
| } |
| |
| /** |
| * Add given listener to the list and update rate if necessary. |
| * |
| * @param listener if null, add part is skipped. |
| * @param updateRate |
| * @return true if rate was updated. Otherwise, returns false. |
| */ |
| public boolean addAndUpdateRate(T listener, float updateRate) { |
| Float oldUpdateRate = mListenersToRate.put(listener, updateRate); |
| if (mUpdateRate < updateRate) { |
| mUpdateRate = updateRate; |
| return true; |
| } else if (oldUpdateRate != null && oldUpdateRate == mUpdateRate) { |
| mUpdateRate = Collections.max(mListenersToRate.values()); |
| } |
| return false; |
| } |
| |
| public Collection<T> getListeners() { |
| return mListenersToRate.keySet(); |
| } |
| } |
| |