content: /*
   * Copyright (C) 2019 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.launcher3.util;
  
  import static android.os.VibrationEffect.createPredefined;
  import static android.provider.Settings.System.HAPTIC_FEEDBACK_ENABLED;
  
  import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
  import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
  
  import android.annotation.TargetApi;
  import android.content.ContentResolver;
  import android.content.Context;
  import android.database.ContentObserver;
  import android.os.Build;
  import android.os.VibrationEffect;
  import android.os.Vibrator;
  import android.provider.Settings;
  
  /**
   * Wrapper around {@link Vibrator} to easily perform haptic feedback where necessary.
   */
  @TargetApi(Build.VERSION_CODES.Q)
  public class VibratorWrapper {
  
      public static final MainThreadInitializedObject<VibratorWrapper> INSTANCE =
              new MainThreadInitializedObject<>(VibratorWrapper::new);
  
      private static final VibrationEffect EFFECT_CLICK =
              createPredefined(VibrationEffect.EFFECT_CLICK);
  
      /**
       * Haptic when entering overview.
       */
      public static final VibrationEffect OVERVIEW_HAPTIC = EFFECT_CLICK;
  
      private final Vibrator mVibrator;
      private final boolean mHasVibrator;
  
      private boolean mIsHapticFeedbackEnabled;
  
      public VibratorWrapper(Context context) {
          mVibrator = context.getSystemService(Vibrator.class);
          mHasVibrator = mVibrator.hasVibrator();
          if (mHasVibrator) {
              final ContentResolver resolver = context.getContentResolver();
              mIsHapticFeedbackEnabled = isHapticFeedbackEnabled(resolver);
              final ContentObserver observer = new ContentObserver(MAIN_EXECUTOR.getHandler()) {
                  @Override
                  public void onChange(boolean selfChange) {
                      mIsHapticFeedbackEnabled = isHapticFeedbackEnabled(resolver);
                  }
              };
              resolver.registerContentObserver(Settings.System.getUriFor(HAPTIC_FEEDBACK_ENABLED),
                      false /* notifyForDescendents */, observer);
          } else {
              mIsHapticFeedbackEnabled = false;
          }
      }
  
      private boolean isHapticFeedbackEnabled(ContentResolver resolver) {
          return Settings.System.getInt(resolver, HAPTIC_FEEDBACK_ENABLED, 0) == 1;
      }
  
      /** Vibrates with the given effect if haptic feedback is available and enabled. */
      public void vibrate(VibrationEffect vibrationEffect) {
          if (mHasVibrator && mIsHapticFeedbackEnabled) {
              UI_HELPER_EXECUTOR.execute(() -> mVibrator.vibrate(vibrationEffect));
          }
      }
  }
  