1 /* 2 * Copyright (C) 2018 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.support.v7.preference.Preference; 25 26 /** 27 * BaseNfcEnabler is a abstract helper to manage the Nfc state for Nfc and Android Beam 28 * preference. It will receive intent and update state to ensure preference show correct state. 29 */ 30 public abstract class BaseNfcEnabler { 31 private final Context mContext; 32 protected final NfcAdapter mNfcAdapter; 33 private final IntentFilter mIntentFilter; 34 35 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 36 @Override 37 public void onReceive(Context context, Intent intent) { 38 String action = intent.getAction(); 39 if (NfcAdapter.ACTION_ADAPTER_STATE_CHANGED.equals(action)) { 40 handleNfcStateChanged(intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE, 41 NfcAdapter.STATE_OFF)); 42 } 43 } 44 }; 45 BaseNfcEnabler(Context context)46 public BaseNfcEnabler(Context context) { 47 mContext = context; 48 mNfcAdapter = NfcAdapter.getDefaultAdapter(context); 49 50 if (!isNfcAvailable()) { 51 // NFC is not supported 52 mIntentFilter = null; 53 return; 54 } 55 mIntentFilter = new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED); 56 } 57 resume()58 public void resume() { 59 if (!isNfcAvailable()) { 60 return; 61 } 62 handleNfcStateChanged(mNfcAdapter.getAdapterState()); 63 mContext.registerReceiver(mReceiver, mIntentFilter); 64 } 65 pause()66 public void pause() { 67 if (!isNfcAvailable()) { 68 return; 69 } 70 mContext.unregisterReceiver(mReceiver); 71 } 72 isNfcAvailable()73 public boolean isNfcAvailable() { 74 return mNfcAdapter != null; 75 } 76 handleNfcStateChanged(int newState)77 protected abstract void handleNfcStateChanged(int newState); 78 } 79