Update Network & internet->Wi-Fi to use MasterSwitchPreference.

- Add a preference controller for Network & internet->Wi-Fi to control
  the preference toggling and summary update.
- Refactor WifiSettings and WifiEnabler to share code between the new
  wifi preference controller and the wifi setting.
- Refactor BluetoothSummaryHelper to have a common base class with the
  WifiSummaryHelper.
- Rename the summary helper to summary updater.

Bug: 34280769
Test: make RunSettingsRoboTests
Change-Id: I00ebfc161bcef89331bb41ba405ed8cb8232d248

src/com/android/settings/wifi/WifiSummaryUpdater.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2017 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.wifi;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.wifi.WifiManager;
+import android.support.annotation.VisibleForTesting;
+import com.android.settings.R;
+import com.android.settings.widget.SummaryUpdater;
+import com.android.settingslib.wifi.WifiStatusTracker;
+
+/**
+ * Helper class that listeners to wifi callback and notify client when there is update in
+ * wifi summary info.
+ */
+public final class WifiSummaryUpdater extends SummaryUpdater {
+
+    private final WifiStatusTracker mWifiTracker;
+    private final BroadcastReceiver mReceiver;
+
+    private static final IntentFilter INTENT_FILTER;
+    static {
+        INTENT_FILTER = new IntentFilter();
+        INTENT_FILTER.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
+        INTENT_FILTER.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
+        INTENT_FILTER.addAction(WifiManager.RSSI_CHANGED_ACTION);
+    }
+
+    public WifiSummaryUpdater(Context context, OnSummaryChangeListener listener) {
+        this(context, listener, new WifiStatusTracker(context.getSystemService(WifiManager.class)));
+    }
+
+    @VisibleForTesting
+    public WifiSummaryUpdater(Context context, OnSummaryChangeListener listener,
+        WifiStatusTracker wifiTracker) {
+        super(context, listener);
+        mWifiTracker = wifiTracker;
+        mReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                mWifiTracker.handleBroadcast(intent);
+                notifyChangeIfNeeded();
+            }
+        };
+    }
+
+    @Override
+    public void register(boolean register) {
+        if (register) {
+            mContext.registerReceiver(mReceiver, INTENT_FILTER);
+        } else {
+            mContext.unregisterReceiver(mReceiver);
+        }
+    }
+
+    @Override
+    public String getSummary() {
+        if (!mWifiTracker.enabled) {
+            return mContext.getString(R.string.wifi_disabled_generic);
+        }
+        if (!mWifiTracker.connected) {
+            return mContext.getString(R.string.disconnected);
+        }
+        return mWifiTracker.ssid;
+    }
+
+}