1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.android.launcher3.util;
17 
18 import static android.os.VibrationEffect.createPredefined;
19 import static android.provider.Settings.System.HAPTIC_FEEDBACK_ENABLED;
20 
21 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
22 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
23 
24 import android.annotation.TargetApi;
25 import android.content.ContentResolver;
26 import android.content.Context;
27 import android.database.ContentObserver;
28 import android.os.Build;
29 import android.os.VibrationEffect;
30 import android.os.Vibrator;
31 import android.provider.Settings;
32 
33 /**
34  * Wrapper around {@link Vibrator} to easily perform haptic feedback where necessary.
35  */
36 @TargetApi(Build.VERSION_CODES.Q)
37 public class VibratorWrapper {
38 
39     public static final MainThreadInitializedObject<VibratorWrapper> INSTANCE =
40             new MainThreadInitializedObject<>(VibratorWrapper::new);
41 
42     private static final VibrationEffect EFFECT_CLICK =
43             createPredefined(VibrationEffect.EFFECT_CLICK);
44 
45     /**
46      * Haptic when entering overview.
47      */
48     public static final VibrationEffect OVERVIEW_HAPTIC = EFFECT_CLICK;
49 
50     private final Vibrator mVibrator;
51     private final boolean mHasVibrator;
52 
53     private boolean mIsHapticFeedbackEnabled;
54 
VibratorWrapper(Context context)55     public VibratorWrapper(Context context) {
56         mVibrator = context.getSystemService(Vibrator.class);
57         mHasVibrator = mVibrator.hasVibrator();
58         if (mHasVibrator) {
59             final ContentResolver resolver = context.getContentResolver();
60             mIsHapticFeedbackEnabled = isHapticFeedbackEnabled(resolver);
61             final ContentObserver observer = new ContentObserver(MAIN_EXECUTOR.getHandler()) {
62                 @Override
63                 public void onChange(boolean selfChange) {
64                     mIsHapticFeedbackEnabled = isHapticFeedbackEnabled(resolver);
65                 }
66             };
67             resolver.registerContentObserver(Settings.System.getUriFor(HAPTIC_FEEDBACK_ENABLED),
68                     false /* notifyForDescendents */, observer);
69         } else {
70             mIsHapticFeedbackEnabled = false;
71         }
72     }
73 
isHapticFeedbackEnabled(ContentResolver resolver)74     private boolean isHapticFeedbackEnabled(ContentResolver resolver) {
75         return Settings.System.getInt(resolver, HAPTIC_FEEDBACK_ENABLED, 0) == 1;
76     }
77 
78     /** Vibrates with the given effect if haptic feedback is available and enabled. */
vibrate(VibrationEffect vibrationEffect)79     public void vibrate(VibrationEffect vibrationEffect) {
80         if (mHasVibrator && mIsHapticFeedbackEnabled) {
81             UI_HELPER_EXECUTOR.execute(() -> mVibrator.vibrate(vibrationEffect));
82         }
83     }
84 }
85