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.car.developeroptions.nfc;
17 
18 import android.content.BroadcastReceiver;
19 import android.content.Context;
20 import android.content.Intent;
21 import android.content.IntentFilter;
22 import android.net.Uri;
23 import android.nfc.NfcAdapter;
24 import android.provider.Settings;
25 import android.util.Log;
26 import androidx.annotation.VisibleForTesting;
27 import androidx.preference.PreferenceScreen;
28 import androidx.preference.SwitchPreference;
29 
30 import com.android.car.developeroptions.core.TogglePreferenceController;
31 import com.android.car.developeroptions.slices.SliceBackgroundWorker;
32 import com.android.settingslib.core.lifecycle.LifecycleObserver;
33 import com.android.settingslib.core.lifecycle.events.OnPause;
34 import com.android.settingslib.core.lifecycle.events.OnResume;
35 
36 import java.io.IOException;
37 
38 public class NfcPreferenceController extends TogglePreferenceController
39         implements LifecycleObserver, OnResume, OnPause {
40 
41     public static final String KEY_TOGGLE_NFC = "toggle_nfc";
42     private final NfcAdapter mNfcAdapter;
43     private NfcEnabler mNfcEnabler;
44     @VisibleForTesting
45     NfcAirplaneModeObserver mAirplaneModeObserver;
46 
NfcPreferenceController(Context context, String key)47     public NfcPreferenceController(Context context, String key) {
48         super(context, key);
49         mNfcAdapter = NfcAdapter.getDefaultAdapter(context);
50     }
51 
52     @Override
displayPreference(PreferenceScreen screen)53     public void displayPreference(PreferenceScreen screen) {
54         super.displayPreference(screen);
55         if (!isAvailable()) {
56             mNfcEnabler = null;
57             return;
58         }
59 
60         final SwitchPreference switchPreference = screen.findPreference(getPreferenceKey());
61 
62         mNfcEnabler = new NfcEnabler(mContext, switchPreference);
63 
64         // Listen to airplane mode updates if NFC should be turned off when airplane mode is on
65         if (shouldTurnOffNFCInAirplaneMode(mContext) || isToggleableInAirplaneMode(mContext)) {
66             mAirplaneModeObserver =
67                     new NfcAirplaneModeObserver(mContext, mNfcAdapter, switchPreference);
68         }
69     }
70 
71     @Override
isChecked()72     public boolean isChecked() {
73         return mNfcAdapter.isEnabled();
74     }
75 
76     @Override
setChecked(boolean isChecked)77     public boolean setChecked(boolean isChecked) {
78         if (isChecked) {
79             mNfcAdapter.enable();
80         } else {
81             mNfcAdapter.disable();
82         }
83         return true;
84     }
85 
86     @Override
87     @AvailabilityStatus
getAvailabilityStatus()88     public int getAvailabilityStatus() {
89         return mNfcAdapter != null
90                 ? AVAILABLE
91                 : UNSUPPORTED_ON_DEVICE;
92     }
93 
94     @Override
hasAsyncUpdate()95     public boolean hasAsyncUpdate() {
96         return true;
97     }
98 
99     @Override
isSliceable()100     public boolean isSliceable() {
101         return true;
102     }
103 
104     @Override
getBackgroundWorkerClass()105     public Class<? extends SliceBackgroundWorker> getBackgroundWorkerClass() {
106         return NfcSliceWorker.class;
107     }
108 
109     @Override
onResume()110     public void onResume() {
111         if (mAirplaneModeObserver != null) {
112             mAirplaneModeObserver.register();
113         }
114         if (mNfcEnabler != null) {
115             mNfcEnabler.resume();
116         }
117     }
118 
119     @Override
onPause()120     public void onPause() {
121         if (mAirplaneModeObserver != null) {
122             mAirplaneModeObserver.unregister();
123         }
124         if (mNfcEnabler != null) {
125             mNfcEnabler.pause();
126         }
127     }
128 
shouldTurnOffNFCInAirplaneMode(Context context)129     public static boolean shouldTurnOffNFCInAirplaneMode(Context context) {
130         final String airplaneModeRadios = Settings.Global.getString(context.getContentResolver(),
131                 Settings.Global.AIRPLANE_MODE_RADIOS);
132         return airplaneModeRadios != null && airplaneModeRadios.contains(Settings.Global.RADIO_NFC);
133     }
134 
isToggleableInAirplaneMode(Context context)135     public static boolean isToggleableInAirplaneMode(Context context) {
136         final String toggleable = Settings.Global.getString(context.getContentResolver(),
137                 Settings.Global.AIRPLANE_MODE_TOGGLEABLE_RADIOS);
138         return toggleable != null && toggleable.contains(Settings.Global.RADIO_NFC);
139     }
140 
141     /**
142      * Listener for background changes to NFC.
143      *
144      * <p>
145      *     Listen to broadcasts from {@link NfcAdapter}. The worker will call notify changed on the
146      *     NFC Slice only when the following extras are present in the broadcast:
147      *     <ul>
148      *      <li>{@link NfcAdapter#STATE_ON}</li>
149      *      <li>{@link NfcAdapter#STATE_OFF}</li>
150      *     </ul>
151      */
152     public static class NfcSliceWorker extends SliceBackgroundWorker<Void> {
153 
154         private static final String TAG = "NfcSliceWorker";
155 
156         private static final IntentFilter NFC_FILTER =
157                 new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED);
158 
159         private NfcUpdateReceiver mUpdateObserver;
160 
NfcSliceWorker(Context context, Uri uri)161         public NfcSliceWorker(Context context, Uri uri) {
162             super(context, uri);
163             mUpdateObserver = new NfcUpdateReceiver(this);
164         }
165 
166         @Override
onSlicePinned()167         protected void onSlicePinned() {
168             getContext().registerReceiver(mUpdateObserver, NFC_FILTER);
169         }
170 
171         @Override
onSliceUnpinned()172         protected void onSliceUnpinned() {
173             getContext().unregisterReceiver(mUpdateObserver);
174         }
175 
176         @Override
close()177         public void close() throws IOException {
178             mUpdateObserver = null;
179         }
180 
updateSlice()181         public void updateSlice() {
182             notifySliceChange();
183         }
184 
185         public class NfcUpdateReceiver extends BroadcastReceiver {
186 
187             private final int NO_EXTRA = -1;
188 
189             private final NfcSliceWorker mSliceBackgroundWorker;
190 
NfcUpdateReceiver(NfcSliceWorker sliceWorker)191             public NfcUpdateReceiver(NfcSliceWorker sliceWorker) {
192                 mSliceBackgroundWorker = sliceWorker;
193             }
194 
195             @Override
onReceive(Context context, Intent intent)196             public void onReceive(Context context, Intent intent) {
197                 final int nfcStateExtra = intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE,
198                         NO_EXTRA);
199 
200                 // Do nothing if state change is empty, or an intermediate step.
201                 if ( (nfcStateExtra == NO_EXTRA)
202                         || (nfcStateExtra == NfcAdapter.STATE_TURNING_ON)
203                         || (nfcStateExtra == NfcAdapter.STATE_TURNING_OFF)) {
204                     Log.d(TAG, "Transitional update, dropping broadcast");
205                     return;
206                 }
207 
208                 Log.d(TAG, "Nfc broadcast received, updating Slice.");
209                 mSliceBackgroundWorker.updateSlice();
210             }
211         }
212     }
213 }
214