Move BT, NFC out of Conntection pref

Move BT, NFC preference out of Connection Preference,
To Connected devices page.
Because NFC and Android Beam are controlled by the same controller,
Create each controller for those preference and leave the sharing part.

Change-Id: I8bc303a5f487de9c667487119b49e1e4130aa80c
Fixes: 72458929
Test: manually test, make RunSettingsRoboTests

src/com/android/settings/nfc/BaseNfcEnabler.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.nfc;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.nfc.NfcAdapter;
+import android.support.v7.preference.Preference;
+
+/**
+ * BaseNfcEnabler is a abstract helper to manage the Nfc state for Nfc and Android Beam
+ * preference. It will receive intent and update state to ensure preference show correct state.
+ */
+public abstract class BaseNfcEnabler {
+    private final Context mContext;
+    protected final NfcAdapter mNfcAdapter;
+    private final IntentFilter mIntentFilter;
+
+    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            String action = intent.getAction();
+            if (NfcAdapter.ACTION_ADAPTER_STATE_CHANGED.equals(action)) {
+                handleNfcStateChanged(intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE,
+                        NfcAdapter.STATE_OFF));
+            }
+        }
+    };
+
+    public BaseNfcEnabler(Context context) {
+        mContext = context;
+        mNfcAdapter = NfcAdapter.getDefaultAdapter(context);
+
+        if (!isNfcAvailable()) {
+            // NFC is not supported
+            mIntentFilter = null;
+            return;
+        }
+        mIntentFilter = new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED);
+    }
+
+    public void resume() {
+        if (!isNfcAvailable()) {
+            return;
+        }
+        handleNfcStateChanged(mNfcAdapter.getAdapterState());
+        mContext.registerReceiver(mReceiver, mIntentFilter);
+    }
+
+    public void pause() {
+        if (!isNfcAvailable()) {
+            return;
+        }
+        mContext.unregisterReceiver(mReceiver);
+    }
+
+    public boolean isNfcAvailable() {
+        return mNfcAdapter != null;
+    }
+
+    protected abstract void handleNfcStateChanged(int newState);
+}