1 /*
2  * Copyright (C) 2016 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.settings.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.util.Log;
25 import android.widget.CompoundButton;
26 import android.widget.CompoundButton.OnCheckedChangeListener;
27 
28 import androidx.preference.PreferenceScreen;
29 
30 import com.android.settings.R;
31 import com.android.settings.core.TogglePreferenceController;
32 import com.android.settings.slices.SliceBackgroundWorker;
33 import com.android.settingslib.core.lifecycle.LifecycleObserver;
34 import com.android.settingslib.core.lifecycle.events.OnPause;
35 import com.android.settingslib.core.lifecycle.events.OnResume;
36 import com.android.settingslib.widget.MainSwitchPreference;
37 
38 import java.io.IOException;
39 
40 public class NfcPreferenceController extends TogglePreferenceController
41         implements LifecycleObserver, OnResume, OnPause, OnCheckedChangeListener {
42 
43     public static final String KEY_TOGGLE_NFC = "toggle_nfc";
44     private final NfcAdapter mNfcAdapter;
45     private NfcEnabler mNfcEnabler;
46     private MainSwitchPreference mPreference;
47 
NfcPreferenceController(Context context, String key)48     public NfcPreferenceController(Context context, String key) {
49         super(context, key);
50         mNfcAdapter = NfcAdapter.getDefaultAdapter(context);
51     }
52 
53     @Override
displayPreference(PreferenceScreen screen)54     public void displayPreference(PreferenceScreen screen) {
55         super.displayPreference(screen);
56         if (!isAvailable()) {
57             mNfcEnabler = null;
58             return;
59         }
60 
61         mPreference = screen.findPreference(getPreferenceKey());
62         mPreference.addOnSwitchChangeListener(this);
63         mNfcEnabler = new NfcEnabler(mContext, mPreference);
64     }
65 
66     @Override
onCheckedChanged(CompoundButton buttonView, boolean isChecked)67     public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
68         if (isChecked != mNfcAdapter.isEnabled()) {
69             setChecked(isChecked);
70         }
71     }
72 
73     @Override
isChecked()74     public boolean isChecked() {
75         return mNfcAdapter.isEnabled();
76     }
77 
78     @Override
setChecked(boolean isChecked)79     public boolean setChecked(boolean isChecked) {
80         if (isChecked) {
81             mNfcAdapter.enable();
82         } else {
83             mNfcAdapter.disable();
84         }
85         return true;
86     }
87 
88     @Override
89     @AvailabilityStatus
getAvailabilityStatus()90     public int getAvailabilityStatus() {
91         return mNfcAdapter != null
92                 ? AVAILABLE
93                 : UNSUPPORTED_ON_DEVICE;
94     }
95 
96     @Override
hasAsyncUpdate()97     public boolean hasAsyncUpdate() {
98         return true;
99     }
100 
101     @Override
isPublicSlice()102     public boolean isPublicSlice() {
103         return true;
104     }
105 
106     @Override
getSliceHighlightMenuRes()107     public int getSliceHighlightMenuRes() {
108         return R.string.menu_key_connected_devices;
109     }
110 
111     @Override
getBackgroundWorkerClass()112     public Class<? extends SliceBackgroundWorker> getBackgroundWorkerClass() {
113         return NfcSliceWorker.class;
114     }
115 
116     @Override
onResume()117     public void onResume() {
118         if (mNfcEnabler != null) {
119             mNfcEnabler.resume();
120         }
121     }
122 
123     @Override
onPause()124     public void onPause() {
125         if (mNfcEnabler != null) {
126             mNfcEnabler.pause();
127         }
128     }
129 
130     /**
131      * Listener for background changes to NFC.
132      *
133      * <p>
134      * Listen to broadcasts from {@link NfcAdapter}. The worker will call notify changed on the
135      * NFC Slice only when the following extras are present in the broadcast:
136      * <ul>
137      * <li>{@link NfcAdapter#STATE_ON}</li>
138      * <li>{@link NfcAdapter#STATE_OFF}</li>
139      * </ul>
140      */
141     public static class NfcSliceWorker extends SliceBackgroundWorker<Void> {
142 
143         private static final String TAG = "NfcSliceWorker";
144 
145         private static final IntentFilter NFC_FILTER =
146                 new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED);
147 
148         private NfcUpdateReceiver mUpdateObserver;
149 
NfcSliceWorker(Context context, Uri uri)150         public NfcSliceWorker(Context context, Uri uri) {
151             super(context, uri);
152             mUpdateObserver = new NfcUpdateReceiver(this);
153         }
154 
155         @Override
onSlicePinned()156         protected void onSlicePinned() {
157             getContext().registerReceiver(mUpdateObserver, NFC_FILTER);
158         }
159 
160         @Override
onSliceUnpinned()161         protected void onSliceUnpinned() {
162             getContext().unregisterReceiver(mUpdateObserver);
163         }
164 
165         @Override
close()166         public void close() throws IOException {
167             mUpdateObserver = null;
168         }
169 
updateSlice()170         public void updateSlice() {
171             notifySliceChange();
172         }
173 
174         public class NfcUpdateReceiver extends BroadcastReceiver {
175 
176             private final int NO_EXTRA = -1;
177 
178             private final NfcSliceWorker mSliceBackgroundWorker;
179 
NfcUpdateReceiver(NfcSliceWorker sliceWorker)180             public NfcUpdateReceiver(NfcSliceWorker sliceWorker) {
181                 mSliceBackgroundWorker = sliceWorker;
182             }
183 
184             @Override
onReceive(Context context, Intent intent)185             public void onReceive(Context context, Intent intent) {
186                 final int nfcStateExtra = intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE,
187                         NO_EXTRA);
188 
189                 // Do nothing if state change is empty, or an intermediate step.
190                 if ((nfcStateExtra == NO_EXTRA)
191                         || (nfcStateExtra == NfcAdapter.STATE_TURNING_ON)
192                         || (nfcStateExtra == NfcAdapter.STATE_TURNING_OFF)) {
193                     Log.d(TAG, "Transitional update, dropping broadcast");
194                     return;
195                 }
196 
197                 Log.d(TAG, "Nfc broadcast received, updating Slice.");
198                 mSliceBackgroundWorker.updateSlice();
199             }
200         }
201     }
202 }
203