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