com/android/server/biometrics/sensors/fingerprint/GestureAvailabilityDispatcher.java

/*
 * Copyright (C) 2020 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.server.biometrics.sensors.fingerprint;

import android.hardware.fingerprint.IFingerprintClientActiveCallback;
import android.os.RemoteException;
import android.util.Slog;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * Keeps track of sensor gesture availability (e.g. swipe), and notifies clients when its
 * availability changes
 */
public class GestureAvailabilityDispatcher {
    private static final String TAG = "GestureAvailabilityTracker";

    private final CopyOnWriteArrayList<IFingerprintClientActiveCallback> mClientActiveCallbacks;
    private final Map<Integer, Boolean> mActiveSensors;

    private boolean mIsActive;

    GestureAvailabilityDispatcher() {
        mClientActiveCallbacks = new CopyOnWriteArrayList<>();
        mActiveSensors = new HashMap<>();
    }

    /**
     * @return true if any sensor is active.
     */
    public boolean isAnySensorActive() {
        return mIsActive;
    }

    public void markSensorActive(int sensorId, boolean active) {
        mActiveSensors.put(sensorId, active);

        final boolean wasActive = mIsActive;
        boolean isActive = false;
        for (Boolean b : mActiveSensors.values()) {
            if (b) {
                isActive = true;
                break;
            }
        }

        if (wasActive != isActive) {
            Slog.d(TAG, "Notifying gesture availability, active=" + mIsActive);
            mIsActive = isActive;
            notifyClientActiveCallbacks(mIsActive);
        }
    }

    void registerCallback(IFingerprintClientActiveCallback callback) {
        mClientActiveCallbacks.add(callback);
    }

    void removeCallback(IFingerprintClientActiveCallback callback) {
        mClientActiveCallbacks.remove(callback);
    }

    private void notifyClientActiveCallbacks(boolean isActive) {
        for (IFingerprintClientActiveCallback callback : mClientActiveCallbacks) {
            try {
                callback.onClientActiveChanged(isActive);
            } catch (RemoteException re) {
                // If the remote is dead, stop notifying it
                mClientActiveCallbacks.remove(callback);
            }
        }
    }
}