1 /*
2  * Copyright (C) 2018 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 
17 package com.android.settings.accessibility;
18 
19 import android.content.Context;
20 import android.os.Vibrator;
21 
22 import androidx.preference.Preference;
23 import androidx.preference.PreferenceScreen;
24 
25 import com.android.settings.R;
26 import com.android.settings.core.SliderPreferenceController;
27 import com.android.settings.widget.SeekBarPreference;
28 import com.android.settingslib.core.lifecycle.LifecycleObserver;
29 import com.android.settingslib.core.lifecycle.events.OnStart;
30 import com.android.settingslib.core.lifecycle.events.OnStop;
31 
32 /**
33  * Abstract preference controller for a vibration intensity setting, that displays multiple
34  * intensity levels to the user as a slider.
35  */
36 public abstract class VibrationIntensityPreferenceController extends SliderPreferenceController
37         implements LifecycleObserver, OnStart, OnStop {
38 
39     protected final VibrationPreferenceConfig mPreferenceConfig;
40     private final VibrationPreferenceConfig.SettingObserver mSettingsContentObserver;
41     private final int mMaxIntensity;
42 
VibrationIntensityPreferenceController(Context context, String prefkey, VibrationPreferenceConfig preferenceConfig)43     protected VibrationIntensityPreferenceController(Context context, String prefkey,
44             VibrationPreferenceConfig preferenceConfig) {
45         this(context, prefkey, preferenceConfig,
46                 context.getResources().getInteger(
47                         R.integer.config_vibration_supported_intensity_levels));
48     }
49 
VibrationIntensityPreferenceController(Context context, String prefkey, VibrationPreferenceConfig preferenceConfig, int supportedIntensityLevels)50     protected VibrationIntensityPreferenceController(Context context, String prefkey,
51             VibrationPreferenceConfig preferenceConfig, int supportedIntensityLevels) {
52         super(context, prefkey);
53         mPreferenceConfig = preferenceConfig;
54         mSettingsContentObserver = new VibrationPreferenceConfig.SettingObserver(
55                 preferenceConfig);
56         mMaxIntensity = Math.min(Vibrator.VIBRATION_INTENSITY_HIGH, supportedIntensityLevels);
57     }
58 
59     @Override
onStart()60     public void onStart() {
61         mSettingsContentObserver.register(mContext);
62     }
63 
64     @Override
onStop()65     public void onStop() {
66         mSettingsContentObserver.unregister(mContext);
67     }
68 
69     @Override
displayPreference(PreferenceScreen screen)70     public void displayPreference(PreferenceScreen screen) {
71         super.displayPreference(screen);
72         final SeekBarPreference preference = screen.findPreference(getPreferenceKey());
73         mSettingsContentObserver.onDisplayPreference(this, preference);
74         preference.setEnabled(mPreferenceConfig.isPreferenceEnabled());
75         preference.setSummaryProvider(unused -> mPreferenceConfig.getSummary());
76         preference.setMin(getMin());
77         preference.setMax(getMax());
78         // Haptics previews played by the Settings app don't bypass user settings to be played.
79         // The sliders continuously updates the intensity value so the previews can apply them.
80         preference.setContinuousUpdates(true);
81     }
82 
83     @Override
updateState(Preference preference)84     public void updateState(Preference preference) {
85         super.updateState(preference);
86         if (preference != null) {
87             preference.setEnabled(mPreferenceConfig.isPreferenceEnabled());
88         }
89     }
90 
91     @Override
getMin()92     public int getMin() {
93         return Vibrator.VIBRATION_INTENSITY_OFF;
94     }
95 
96     @Override
getMax()97     public int getMax() {
98         return mMaxIntensity;
99     }
100 
101     @Override
getSliderPosition()102     public int getSliderPosition() {
103         if (!mPreferenceConfig.isPreferenceEnabled()) {
104             return getMin();
105         }
106         final int position = mPreferenceConfig.readIntensity();
107         return Math.min(position, getMax());
108     }
109 
110     @Override
setSliderPosition(int position)111     public boolean setSliderPosition(int position) {
112         if (!mPreferenceConfig.isPreferenceEnabled()) {
113             // Ignore slider updates when the preference is disabled.
114             return false;
115         }
116         final int intensity = calculateVibrationIntensity(position);
117         final boolean success = mPreferenceConfig.updateIntensity(intensity);
118 
119         if (success && (position != Vibrator.VIBRATION_INTENSITY_OFF)) {
120             mPreferenceConfig.playVibrationPreview();
121         }
122 
123         return success;
124     }
125 
calculateVibrationIntensity(int position)126     private int calculateVibrationIntensity(int position) {
127         int maxPosition = getMax();
128         if (position >= maxPosition) {
129             if (maxPosition == 1) {
130                 // If there is only one intensity available besides OFF, then use the device default
131                 // intensity to ensure no scaling will ever happen in the platform.
132                 return mPreferenceConfig.getDefaultIntensity();
133             }
134             // If the settings granularity is lower than the platform's then map the max position to
135             // the highest vibration intensity, skipping intermediate values in the scale.
136             return Vibrator.VIBRATION_INTENSITY_HIGH;
137         }
138         return position;
139     }
140 }
141