content: /**
   * 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.server.biometrics.face;
  
  import android.content.Context;
  import android.hardware.biometrics.BiometricAuthenticator;
  import android.hardware.face.Face;
  import android.text.TextUtils;
  import android.util.SparseArray;
  
  import com.android.internal.annotations.GuardedBy;
  import com.android.server.biometrics.BiometricUtils;
  
  import java.util.List;
  
  /**
   * Utility class for dealing with faces and face settings.
   */
  public class FaceUtils implements BiometricUtils {
  
      private static final Object sInstanceLock = new Object();
      private static FaceUtils sInstance;
  
      @GuardedBy("this")
      private final SparseArray<FaceUserState> mUsers = new SparseArray<>();
  
      public static FaceUtils getInstance() {
          synchronized (sInstanceLock) {
              if (sInstance == null) {
                  sInstance = new FaceUtils();
              }
          }
          return sInstance;
      }
  
      private FaceUtils() {
      }
  
      @Override
      public List<Face> getBiometricsForUser(Context ctx, int userId) {
          return getStateForUser(ctx, userId).getBiometrics();
      }
  
      @Override
      public void addBiometricForUser(Context ctx, int userId,
              BiometricAuthenticator.Identifier identifier) {
          getStateForUser(ctx, userId).addBiometric(identifier);
      }
  
      @Override
      public void removeBiometricForUser(Context ctx, int userId, int faceId) {
          getStateForUser(ctx, userId).removeBiometric(faceId);
      }
  
      @Override
      public void renameBiometricForUser(Context ctx, int userId, int faceId, CharSequence name) {
          if (TextUtils.isEmpty(name)) {
              // Don't do the rename if it's empty
              return;
          }
          getStateForUser(ctx, userId).renameBiometric(faceId, name);
      }
  
      @Override
      public CharSequence getUniqueName(Context context, int userId) {
          return getStateForUser(context, userId).getUniqueName();
      }
  
      private FaceUserState getStateForUser(Context ctx, int userId) {
          synchronized (this) {
              FaceUserState state = mUsers.get(userId);
              if (state == null) {
                  state = new FaceUserState(ctx, userId);
                  mUsers.put(userId, state);
              }
              return state;
          }
      }
  }
  
  