1 /*
2  * Copyright (C) 2010 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.nfc;
18 
19 import android.content.BroadcastReceiver;
20 import android.content.Context;
21 import android.content.Intent;
22 import android.content.IntentFilter;
23 import android.nfc.NfcAdapter;
24 import android.os.UserHandle;
25 import android.os.UserManager;
26 import android.support.v14.preference.SwitchPreference;
27 import android.support.v7.preference.Preference;
28 import android.support.v7.preference.PreferenceScreen;
29 
30 import com.android.settings.R;
31 import com.android.settingslib.RestrictedLockUtils;
32 import com.android.settingslib.RestrictedPreference;
33 
34 /**
35  * NfcEnabler is a helper to manage the Nfc on/off checkbox preference. It is
36  * turns on/off Nfc and ensures the summary of the preference reflects the
37  * current state.
38  */
39 public class NfcEnabler implements Preference.OnPreferenceChangeListener {
40     private final Context mContext;
41     private final SwitchPreference mSwitch;
42     private final RestrictedPreference mAndroidBeam;
43     private final NfcAdapter mNfcAdapter;
44     private final IntentFilter mIntentFilter;
45     private boolean mBeamDisallowedBySystem;
46 
47     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
48         @Override
49         public void onReceive(Context context, Intent intent) {
50             String action = intent.getAction();
51             if (NfcAdapter.ACTION_ADAPTER_STATE_CHANGED.equals(action)) {
52                 handleNfcStateChanged(intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE,
53                         NfcAdapter.STATE_OFF));
54             }
55         }
56     };
57 
NfcEnabler(Context context, SwitchPreference switchPreference, RestrictedPreference androidBeam)58     public NfcEnabler(Context context, SwitchPreference switchPreference,
59             RestrictedPreference androidBeam) {
60         mContext = context;
61         mSwitch = switchPreference;
62         mAndroidBeam = androidBeam;
63         mNfcAdapter = NfcAdapter.getDefaultAdapter(context);
64         mBeamDisallowedBySystem = RestrictedLockUtils.hasBaseUserRestriction(context,
65                 UserManager.DISALLOW_OUTGOING_BEAM, UserHandle.myUserId());
66 
67         if (mNfcAdapter == null) {
68             // NFC is not supported
69             mSwitch.setEnabled(false);
70             mAndroidBeam.setEnabled(false);
71             mIntentFilter = null;
72             return;
73         }
74         if (mBeamDisallowedBySystem) {
75             mAndroidBeam.setEnabled(false);
76         }
77         mIntentFilter = new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED);
78     }
79 
resume()80     public void resume() {
81         if (mNfcAdapter == null) {
82             return;
83         }
84         handleNfcStateChanged(mNfcAdapter.getAdapterState());
85         mContext.registerReceiver(mReceiver, mIntentFilter);
86         mSwitch.setOnPreferenceChangeListener(this);
87     }
88 
pause()89     public void pause() {
90         if (mNfcAdapter == null) {
91             return;
92         }
93         mContext.unregisterReceiver(mReceiver);
94         mSwitch.setOnPreferenceChangeListener(null);
95     }
96 
onPreferenceChange(Preference preference, Object value)97     public boolean onPreferenceChange(Preference preference, Object value) {
98         // Turn NFC on/off
99 
100         final boolean desiredState = (Boolean) value;
101         mSwitch.setEnabled(false);
102 
103         if (desiredState) {
104             mNfcAdapter.enable();
105         } else {
106             mNfcAdapter.disable();
107         }
108 
109         return false;
110     }
111 
handleNfcStateChanged(int newState)112     private void handleNfcStateChanged(int newState) {
113         switch (newState) {
114         case NfcAdapter.STATE_OFF:
115             mSwitch.setChecked(false);
116             mSwitch.setEnabled(true);
117             mAndroidBeam.setEnabled(false);
118             mAndroidBeam.setSummary(R.string.android_beam_disabled_summary);
119             break;
120         case NfcAdapter.STATE_ON:
121             mSwitch.setChecked(true);
122             mSwitch.setEnabled(true);
123             if (mBeamDisallowedBySystem) {
124                 mAndroidBeam.setDisabledByAdmin(null);
125                 mAndroidBeam.setEnabled(false);
126             } else {
127                 mAndroidBeam.checkRestrictionAndSetDisabled(UserManager.DISALLOW_OUTGOING_BEAM);
128             }
129             if (mNfcAdapter.isNdefPushEnabled() && mAndroidBeam.isEnabled()) {
130                 mAndroidBeam.setSummary(R.string.android_beam_on_summary);
131             } else {
132                 mAndroidBeam.setSummary(R.string.android_beam_off_summary);
133             }
134             break;
135         case NfcAdapter.STATE_TURNING_ON:
136             mSwitch.setChecked(true);
137             mSwitch.setEnabled(false);
138             mAndroidBeam.setEnabled(false);
139             break;
140         case NfcAdapter.STATE_TURNING_OFF:
141             mSwitch.setChecked(false);
142             mSwitch.setEnabled(false);
143             mAndroidBeam.setEnabled(false);
144             break;
145         }
146     }
147 }
148