1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
5  * except in compliance with the License. You may obtain a copy of the License at
6  *
7  *      http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software distributed under the
10  * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
11  * KIND, either express or implied. See the License for the specific language governing
12  * permissions and limitations under the License.
13  */
14 package com.android.settings.display;
15 
16 import android.app.ActivityManager;
17 import android.content.ContentResolver;
18 import android.content.Context;
19 import android.database.ContentObserver;
20 import android.hardware.display.ColorDisplayManager;
21 import android.net.Uri;
22 import android.os.Handler;
23 import android.os.Looper;
24 import android.os.UserHandle;
25 import android.provider.Settings.Secure;
26 import android.provider.Settings.System;
27 import androidx.annotation.VisibleForTesting;
28 import androidx.preference.Preference;
29 import androidx.preference.PreferenceScreen;
30 
31 import com.android.settingslib.core.lifecycle.LifecycleObserver;
32 import com.android.settingslib.core.lifecycle.events.OnStart;
33 import com.android.settingslib.core.lifecycle.events.OnStop;
34 
35 import com.android.settings.core.TogglePreferenceController;
36 
37 public class DisplayWhiteBalancePreferenceController extends TogglePreferenceController
38     implements LifecycleObserver, OnStart, OnStop {
39 
40     private ColorDisplayManager mColorDisplayManager;
41     @VisibleForTesting
42     ContentObserver mContentObserver;
43     private Preference mPreference;
44 
DisplayWhiteBalancePreferenceController(Context context, String key)45     public DisplayWhiteBalancePreferenceController(Context context, String key) {
46         super(context, key);
47     }
48 
49     @Override
getAvailabilityStatus()50     public int getAvailabilityStatus() {
51         return getColorDisplayManager().isDisplayWhiteBalanceAvailable(mContext) ?
52             AVAILABLE : DISABLED_FOR_USER;
53     }
54 
55     @Override
isChecked()56     public boolean isChecked() {
57         return getColorDisplayManager().isDisplayWhiteBalanceEnabled();
58     }
59 
60     @Override
setChecked(boolean isChecked)61     public boolean setChecked(boolean isChecked) {
62         return getColorDisplayManager().setDisplayWhiteBalanceEnabled(isChecked);
63     }
64 
65     @Override
onStart()66     public void onStart() {
67         if (!isAvailable()) {
68             return;
69         }
70 
71         final ContentResolver cr = mContext.getContentResolver();
72         mContentObserver = new ContentObserver(new Handler(Looper.getMainLooper())) {
73             @Override
74             public void onChange(boolean selfChange, Uri uri) {
75                 super.onChange(selfChange, uri);
76                 updateVisibility();
77             }
78         };
79         cr.registerContentObserver(
80                 Secure.getUriFor(Secure.ACCESSIBILITY_DISPLAY_INVERSION_ENABLED),
81                 false /* notifyForDescendants */, mContentObserver,
82                 ActivityManager.getCurrentUser());
83         cr.registerContentObserver(
84                 Secure.getUriFor(Secure.ACCESSIBILITY_DISPLAY_DALTONIZER_ENABLED),
85                 false /* notifyForDescendants */, mContentObserver,
86                 ActivityManager.getCurrentUser());
87         cr.registerContentObserver(
88                 System.getUriFor(System.DISPLAY_COLOR_MODE),
89                 false /* notifyForDescendants */, mContentObserver,
90                 ActivityManager.getCurrentUser());
91 
92         updateVisibility();
93     }
94 
95     @Override
onStop()96     public void onStop() {
97         if (mContentObserver != null) {
98             mContext.getContentResolver().unregisterContentObserver(mContentObserver);
99             mContentObserver = null;
100         }
101     }
102 
103     @Override
displayPreference(PreferenceScreen screen)104     public void displayPreference(PreferenceScreen screen) {
105         super.displayPreference(screen);
106         mPreference = screen.findPreference(getPreferenceKey());
107     }
108 
109     @VisibleForTesting
getColorDisplayManager()110     ColorDisplayManager getColorDisplayManager() {
111         if (mColorDisplayManager == null) {
112             mColorDisplayManager = mContext.getSystemService(ColorDisplayManager.class);
113         }
114         return mColorDisplayManager;
115     }
116 
117     @VisibleForTesting
updateVisibility()118     void updateVisibility() {
119         if (mPreference != null) {
120             ColorDisplayManager cdm = getColorDisplayManager();
121 
122             // Display white balance is only valid in linear light space. COLOR_MODE_SATURATED
123             // implies unmanaged color mode, and hence unknown color processing conditions.
124             // We also disallow display white balance when color accessibility features are enabled.
125             mPreference.setVisible(cdm.getColorMode() != ColorDisplayManager.COLOR_MODE_SATURATED &&
126                     !cdm.areAccessibilityTransformsEnabled(mContext));
127         }
128     }
129 }
130