Add new preference class MasterSwitchPreference.

- Add a new preference type that has Title and optional summary on the
  left, and a toggle switch on the right. Clicking the left part of the
  preference will open a settings screen.
- Update Connected devices->Bluetooth to use this new preference.
- Refactor BluetoothSettings and BluetoothEnabler to share code between
  the new bluetooth preference controller and the bluetooth setting.

Bug: 34280769
Test: make RunSettingsRoboTests
Change-Id: I109ecdba640ecdd4748a6e5b2b4f4c47cbf653fd

AndroidManifest.xml

@@ -3312,17 +3312,6 @@
                        android:value="com.android.settings.applications.ProcessStatsSummary" />
         </activity-alias>
 
-        <activity-alias android:name="BluetoothDashboardAlias"
-                        android:targetActivity="Settings$BluetoothSettingsActivity">
-            <intent-filter android:priority="7">
-                <action android:name="com.android.settings.action.SETTINGS"/>
-            </intent-filter>
-            <meta-data android:name="com.android.settings.FRAGMENT_CLASS"
-                       android:value="com.android.settings.bluetooth.BluetoothSettings" />
-            <meta-data android:name="com.android.settings.category"
-                       android:value="com.android.settings.category.ia.device" />
-        </activity-alias>
-
         <activity-alias android:name="CastDashboardAlias"
                         android:targetActivity="Settings$WifiDisplaySettingsActivity">
             <intent-filter android:priority="6">

res/layout/preference_widget_master_switch.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  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.
+  -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+  android:layout_width="wrap_content"
+  android:layout_height="match_parent">
+
+    <LinearLayout
+      android:layout_width="wrap_content"
+      android:layout_height="match_parent"
+      android:gravity="start|center_vertical"
+      android:orientation="horizontal"
+      android:paddingStart="20dp"
+      android:paddingEnd="20dp"
+      android:paddingTop="16dp"
+      android:paddingBottom="16dp">
+        <View
+          android:layout_width="1dip"
+          android:layout_height="match_parent"
+          android:background="?android:attr/colorSecondary"/>
+    </LinearLayout>
+
+    <Switch android:id="@+id/switchWidget"
+      android:layout_width="wrap_content"
+      android:layout_height="match_parent"
+      android:gravity="center_vertical" />
+
+</LinearLayout>

res/xml/connected_devices.xml

@@ -18,6 +18,13 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:title="@string/connected_devices_dashboard_title">
 
+    <com.android.settings.widget.MasterSwitchPreference
+      android:fragment="com.android.settings.bluetooth.BluetoothSettings"
+      android:key="toggle_bluetooth"
+      android:title="@string/bluetooth_settings_title"
+      android:icon="@drawable/ic_settings_bluetooth"
+      android:order="-7"/>
+
     <SwitchPreference
         android:key="toggle_nfc"
         android:title="@string/nfc_quick_toggle_title"

src/com/android/settings/bluetooth/BluetoothEnabler.java

@@ -24,14 +24,13 @@ import android.content.IntentFilter;
 import android.os.Handler;
 import android.os.Message;
 import android.provider.Settings;
-import android.widget.Switch;
 import android.widget.Toast;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.settings.R;
 import com.android.settings.core.instrumentation.MetricsFeatureProvider;
 import com.android.settings.search.Index;
-import com.android.settings.widget.SwitchBar;
+import com.android.settings.widget.SwitchWidgetController;
 import com.android.settingslib.WirelessUtils;
 import com.android.settingslib.bluetooth.LocalBluetoothAdapter;
 import com.android.settingslib.bluetooth.LocalBluetoothManager;
@@ -41,9 +40,8 @@ import com.android.settingslib.bluetooth.LocalBluetoothManager;
  * preference. It turns on/off Bluetooth and ensures the summary of the
  * preference reflects the current state.
  */
-public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener {
-    private final Switch mSwitch;
-    private final SwitchBar mSwitchBar;
+public final class BluetoothEnabler implements SwitchWidgetController.OnSwitchChangeListener {
+    private final SwitchWidgetController mSwitchWidget;
     private final MetricsFeatureProvider mMetricsFeatureProvider;
     private Context mContext;
     private boolean mValidListener;
@@ -76,19 +74,18 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
         }
     };
 
-    public BluetoothEnabler(Context context, SwitchBar switchBar,
-            MetricsFeatureProvider metricsFeatureProvider) {
+    public BluetoothEnabler(Context context, SwitchWidgetController switchWidget,
+            MetricsFeatureProvider metricsFeatureProvider, LocalBluetoothManager manager) {
         mContext = context;
         mMetricsFeatureProvider = metricsFeatureProvider;
-        mSwitchBar = switchBar;
-        mSwitch = switchBar.getSwitch();
+        mSwitchWidget = switchWidget;
+        mSwitchWidget.setListener(this);
         mValidListener = false;
 
-        LocalBluetoothManager manager = Utils.getLocalBtManager(context);
         if (manager == null) {
             // Bluetooth is not supported
             mLocalAdapter = null;
-            mSwitch.setEnabled(false);
+            mSwitchWidget.setEnabled(false);
         } else {
             mLocalAdapter = manager.getBluetoothAdapter();
         }
@@ -96,16 +93,16 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
     }
 
     public void setupSwitchBar() {
-        mSwitchBar.show();
+        mSwitchWidget.setupView();
     }
 
     public void teardownSwitchBar() {
-        mSwitchBar.hide();
+        mSwitchWidget.teardownView();
     }
 
     public void resume(Context context) {
         if (mLocalAdapter == null) {
-            mSwitch.setEnabled(false);
+            mSwitchWidget.setEnabled(false);
             return;
         }
 
@@ -116,7 +113,7 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
         // Bluetooth state is not sticky, so set it manually
         handleStateChanged(mLocalAdapter.getBluetoothState());
 
-        mSwitchBar.addOnSwitchChangeListener(this);
+        mSwitchWidget.startListening();
         mContext.registerReceiver(mReceiver, mIntentFilter);
         mValidListener = true;
     }
@@ -125,47 +122,48 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
         if (mLocalAdapter == null) {
             return;
         }
-
-        mSwitchBar.removeOnSwitchChangeListener(this);
+        if (mValidListener) {
+            mSwitchWidget.stopListening();
             mContext.unregisterReceiver(mReceiver);
             mValidListener = false;
         }
+    }
 
     void handleStateChanged(int state) {
         switch (state) {
             case BluetoothAdapter.STATE_TURNING_ON:
-                mSwitch.setEnabled(false);
+                mSwitchWidget.setEnabled(false);
                 break;
             case BluetoothAdapter.STATE_ON:
                 setChecked(true);
-                mSwitch.setEnabled(true);
+                mSwitchWidget.setEnabled(true);
                 updateSearchIndex(true);
                 break;
             case BluetoothAdapter.STATE_TURNING_OFF:
-                mSwitch.setEnabled(false);
+                mSwitchWidget.setEnabled(false);
                 break;
             case BluetoothAdapter.STATE_OFF:
                 setChecked(false);
-                mSwitch.setEnabled(true);
+                mSwitchWidget.setEnabled(true);
                 updateSearchIndex(false);
                 break;
             default:
                 setChecked(false);
-                mSwitch.setEnabled(true);
+                mSwitchWidget.setEnabled(true);
                 updateSearchIndex(false);
         }
     }
 
     private void setChecked(boolean isChecked) {
-        if (isChecked != mSwitch.isChecked()) {
+        if (isChecked != mSwitchWidget.isChecked()) {
             // set listener to null, so onCheckedChanged won't be called
             // if the checked status on Switch isn't changed by user click
             if (mValidListener) {
-                mSwitchBar.removeOnSwitchChangeListener(this);
+                mSwitchWidget.stopListening();
             }
-            mSwitch.setChecked(isChecked);
+            mSwitchWidget.setChecked(isChecked);
             if (mValidListener) {
-                mSwitchBar.addOnSwitchChangeListener(this);
+                mSwitchWidget.startListening();
             }
         }
     }
@@ -180,13 +178,14 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
     }
 
     @Override
-    public void onSwitchChanged(Switch switchView, boolean isChecked) {
+    public boolean onSwitchToggled(boolean isChecked) {
         // Show toast message if Bluetooth is not allowed in airplane mode
         if (isChecked &&
                 !WirelessUtils.isRadioAllowed(mContext, Settings.Global.RADIO_BLUETOOTH)) {
             Toast.makeText(mContext, R.string.wifi_in_airplane_mode, Toast.LENGTH_SHORT).show();
             // Reset switch to off
-            switchView.setChecked(false);
+            mSwitchWidget.setChecked(false);
+            return false;
         }
 
         mMetricsFeatureProvider.action(mContext, MetricsEvent.ACTION_BLUETOOTH_TOGGLE, isChecked);
@@ -197,12 +196,13 @@ public final class BluetoothEnabler implements SwitchBar.OnSwitchChangeListener
             // a) The switch should be OFF but it should still be togglable (enabled = True)
             // b) The switch bar should have OFF text.
             if (isChecked && !status) {
-                switchView.setChecked(false);
-                mSwitch.setEnabled(true);
-                mSwitchBar.setTextViewLabel(false);
-                return;
+                mSwitchWidget.setChecked(false);
+                mSwitchWidget.setEnabled(true);
+                mSwitchWidget.updateTitle(false);
+                return false;
             }
         }
-        mSwitch.setEnabled(false);
+        mSwitchWidget.setEnabled(false);
+        return true;
     }
 }

src/com/android/settings/bluetooth/BluetoothMasterSwitchPreferenceController.java

@@ -0,0 +1,100 @@
+/*
+ * 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.bluetooth;
+
+import android.content.Context;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.core.PreferenceController;
+import com.android.settings.core.lifecycle.LifecycleObserver;
+import com.android.settings.core.lifecycle.events.OnPause;
+import com.android.settings.core.lifecycle.events.OnResume;
+import com.android.settings.core.lifecycle.events.OnStart;
+import com.android.settings.core.lifecycle.events.OnStop;
+import com.android.settings.overlay.FeatureFactory;
+import com.android.settings.widget.MasterSwitchPreference;
+import com.android.settings.widget.MasterSwitchController;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+
+public class BluetoothMasterSwitchPreferenceController extends PreferenceController
+        implements BluetoothSummaryHelper.OnSummaryChangeListener,
+        LifecycleObserver, OnResume, OnPause, OnStart, OnStop {
+
+    private static final String KEY_TOGGLE_BLUETOOTH = "toggle_bluetooth";
+
+    private LocalBluetoothManager mBluetoothManager;
+    private MasterSwitchPreference mBtPreference;
+    private BluetoothEnabler mBluetoothEnabler;
+    private BluetoothSummaryHelper mSummaryHelper;
+
+    public BluetoothMasterSwitchPreferenceController(Context context,
+            LocalBluetoothManager bluetoothManager) {
+        super(context);
+        mBluetoothManager = bluetoothManager;
+        mSummaryHelper = new BluetoothSummaryHelper(mContext, mBluetoothManager);
+        mSummaryHelper.setOnSummaryChangeListener(this);
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mBtPreference = (MasterSwitchPreference) screen.findPreference(KEY_TOGGLE_BLUETOOTH);
+        mBluetoothEnabler = new BluetoothEnabler(mContext,
+            new MasterSwitchController(mBtPreference),
+            FeatureFactory.getFactory(mContext).getMetricsFeatureProvider(), mBluetoothManager);
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_TOGGLE_BLUETOOTH;
+    }
+
+    public void onResume() {
+        mSummaryHelper.setListening(true);
+    }
+
+    @Override
+    public void onPause() {
+        mSummaryHelper.setListening(false);
+    }
+
+    @Override
+    public void onStart() {
+        if (mBluetoothEnabler != null) {
+            mBluetoothEnabler.resume(mContext);
+        }
+    }
+
+    @Override
+    public void onStop() {
+        if (mBluetoothEnabler != null) {
+            mBluetoothEnabler.pause();
+        }
+    }
+
+    @Override
+    public void onSummaryChanged(String summary) {
+        if (mBtPreference != null) {
+            mBtPreference.setSummary(summary);
+        }
+    }
+
+}

src/com/android/settings/bluetooth/BluetoothSettings.java

@@ -45,6 +45,7 @@ import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.settings.LinkifyUtils;
 import com.android.settings.R;
 import com.android.settings.SettingsActivity;
+import com.android.settings.bluetooth.BluetoothSummaryHelper.OnSummaryChangeListener;
 import com.android.settings.dashboard.SummaryLoader;
 import com.android.settings.location.ScanningSettings;
 import com.android.settings.search.BaseSearchIndexProvider;
@@ -52,13 +53,12 @@ import com.android.settings.search.Indexable;
 import com.android.settings.search.SearchIndexableRaw;
 import com.android.settings.widget.FooterPreference;
 import com.android.settings.widget.SwitchBar;
-import com.android.settingslib.bluetooth.BluetoothCallback;
+import com.android.settings.widget.SwitchBarController;
 import com.android.settingslib.bluetooth.BluetoothDeviceFilter;
 import com.android.settingslib.bluetooth.CachedBluetoothDevice;
 import com.android.settingslib.bluetooth.LocalBluetoothManager;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
@@ -148,7 +148,8 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
         final SettingsActivity activity = (SettingsActivity) getActivity();
         mSwitchBar = activity.getSwitchBar();
 
-        mBluetoothEnabler = new BluetoothEnabler(activity, mSwitchBar, mMetricsFeatureProvider);
+        mBluetoothEnabler = new BluetoothEnabler(activity, new SwitchBarController(mSwitchBar),
+            mMetricsFeatureProvider, Utils.getLocalBtManager(activity));
         mBluetoothEnabler.setupSwitchBar();
     }
 
@@ -508,112 +509,34 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment implem
     }
 
     @VisibleForTesting
-    static class SummaryProvider
-            implements SummaryLoader.SummaryProvider, BluetoothCallback {
+    static class SummaryProvider implements SummaryLoader.SummaryProvider, OnSummaryChangeListener {
 
         private final LocalBluetoothManager mBluetoothManager;
         private final Context mContext;
         private final SummaryLoader mSummaryLoader;
 
-        private boolean mEnabled;
-        private int mConnectionState;
+        @VisibleForTesting
+        BluetoothSummaryHelper mSummaryHelper;
 
         public SummaryProvider(Context context, SummaryLoader summaryLoader,
                 LocalBluetoothManager bluetoothManager) {
             mBluetoothManager = bluetoothManager;
             mContext = context;
             mSummaryLoader = summaryLoader;
+            mSummaryHelper = new BluetoothSummaryHelper(mContext, mBluetoothManager);
+            mSummaryHelper.setOnSummaryChangeListener(this);
         }
 
         @Override
         public void setListening(boolean listening) {
-            BluetoothAdapter defaultAdapter = BluetoothAdapter.getDefaultAdapter();
-            if (defaultAdapter == null) return;
-            if (listening) {
-                mEnabled = defaultAdapter.isEnabled();
-                mConnectionState = defaultAdapter.getConnectionState();
-                mSummaryLoader.setSummary(this, getSummary());
-                mBluetoothManager.getEventManager().registerCallback(this);
-            } else {
-                mBluetoothManager.getEventManager().unregisterCallback(this);
-            }
-        }
-
-        private CharSequence getSummary() {
-            if (!mEnabled) {
-                return mContext.getString(R.string.bluetooth_disabled);
-            } else if (mConnectionState == BluetoothAdapter.STATE_CONNECTED) {
-                return mContext.getString(R.string.bluetooth_connected);
-            } else {
-                return mContext.getString(R.string.bluetooth_disconnected);
-            }
+            mSummaryHelper.setListening(listening);
         }
 
         @Override
-        public void onBluetoothStateChanged(int bluetoothState) {
-            mEnabled = bluetoothState == BluetoothAdapter.STATE_ON
-                    || bluetoothState == BluetoothAdapter.STATE_TURNING_ON;
-            mSummaryLoader.setSummary(this, getSummary());
+        public void onSummaryChanged(String summary) {
+            if (mSummaryLoader != null) {
+                mSummaryLoader.setSummary(this, summary);
             }
-
-        @Override
-        public void onConnectionStateChanged(CachedBluetoothDevice cachedDevice, int state) {
-            mConnectionState = state;
-            updateConnected();
-            mSummaryLoader.setSummary(this, getSummary());
-        }
-
-        @Override
-        public void onScanningStateChanged(boolean started) {
-
-        }
-
-        @Override
-        public void onDeviceAdded(CachedBluetoothDevice cachedDevice) {
-
-        }
-
-        @Override
-        public void onDeviceDeleted(CachedBluetoothDevice cachedDevice) {
-
-        }
-
-        @Override
-        public void onDeviceBondStateChanged(CachedBluetoothDevice cachedDevice, int bondState) {
-
-        }
-
-        private void updateConnected() {
-            // Make sure our connection state is up to date.
-            int state = mBluetoothManager.getBluetoothAdapter().getConnectionState();
-            if (state != mConnectionState) {
-                mConnectionState = state;
-                return;
-            }
-            final Collection<CachedBluetoothDevice> devices = getDevices();
-            if (devices == null) {
-                mConnectionState = BluetoothAdapter.STATE_DISCONNECTED;
-                return;
-            }
-            if (mConnectionState == BluetoothAdapter.STATE_CONNECTED) {
-                CachedBluetoothDevice connectedDevice = null;
-                for (CachedBluetoothDevice device : devices) {
-                    if (device.isConnected()) {
-                        connectedDevice = device;
-                    }
-                }
-                if (connectedDevice == null) {
-                    // If somehow we think we are connected, but have no connected devices, we
-                    // aren't connected.
-                    mConnectionState = BluetoothAdapter.STATE_DISCONNECTED;
-                }
-            }
-        }
-
-        private Collection<CachedBluetoothDevice> getDevices() {
-            return mBluetoothManager != null
-                    ? mBluetoothManager.getCachedDeviceManager().getCachedDevicesCopy()
-                    : null;
         }
     }
 

src/com/android/settings/bluetooth/BluetoothSummaryHelper.java

@@ -0,0 +1,172 @@
+/*
+ * 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.bluetooth;
+
+import android.bluetooth.BluetoothAdapter;
+import android.content.Context;
+import android.text.TextUtils;
+import com.android.settings.R;
+import com.android.settingslib.bluetooth.BluetoothCallback;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+import com.android.settingslib.bluetooth.LocalBluetoothAdapter;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+import java.util.Collection;
+
+/**
+ * Helper class that listeners to bluetooth callback and notify client when there is update in
+ * bluetooth summary info.
+ */
+public final class BluetoothSummaryHelper implements BluetoothCallback {
+
+    private OnSummaryChangeListener mListener;
+
+    private final LocalBluetoothManager mBluetoothManager;
+    private final LocalBluetoothAdapter mBluetoothAdapter;
+    private final Context mContext;
+
+    private boolean mEnabled;
+    private int mConnectionState;
+    private String mSummary;
+
+    public interface OnSummaryChangeListener {
+        /**
+         * Called when bluetooth summary has changed.
+         *
+         * @param summary The new bluetooth summary .
+         */
+        void onSummaryChanged(String summary);
+    }
+
+    public BluetoothSummaryHelper(Context context, LocalBluetoothManager bluetoothManager) {
+        mContext = context;
+        mBluetoothManager = bluetoothManager;
+        mBluetoothAdapter = mBluetoothManager != null
+            ? mBluetoothManager.getBluetoothAdapter() : null;
+    }
+
+    @Override
+    public void onBluetoothStateChanged(int bluetoothState) {
+        mEnabled = bluetoothState == BluetoothAdapter.STATE_ON
+            || bluetoothState == BluetoothAdapter.STATE_TURNING_ON;
+        notifyChangeIfNeeded();
+    }
+
+    @Override
+    public void onConnectionStateChanged(CachedBluetoothDevice cachedDevice, int state) {
+        mConnectionState = state;
+        updateConnected();
+        notifyChangeIfNeeded();
+    }
+
+    @Override
+    public void onScanningStateChanged(boolean started) {
+    }
+
+    @Override
+    public void onDeviceAdded(CachedBluetoothDevice cachedDevice) {
+    }
+
+    @Override
+    public void onDeviceDeleted(CachedBluetoothDevice cachedDevice) {
+    }
+
+    @Override
+    public void onDeviceBondStateChanged(CachedBluetoothDevice cachedDevice, int bondState) {
+    }
+
+    public void setOnSummaryChangeListener(OnSummaryChangeListener listener) {
+        mListener = listener;
+    }
+
+    public void setListening(boolean listening) {
+        if (mBluetoothAdapter == null) {
+            return;
+        }
+        if (listening) {
+            mEnabled = mBluetoothAdapter.isEnabled();
+            mConnectionState = mBluetoothAdapter.getConnectionState();
+            notifyChangeIfNeeded();
+            mBluetoothManager.getEventManager().registerCallback(this);
+        } else {
+            mBluetoothManager.getEventManager().unregisterCallback(this);
+        }
+    }
+
+    private void notifyChangeIfNeeded() {
+        String summary = getSummary();
+        if (!TextUtils.equals(mSummary, summary)) {
+            mSummary = summary;
+            if (mListener != null) {
+                mListener.onSummaryChanged(summary);
+            }
+        }
+    }
+
+    private String getSummary() {
+        if (!mEnabled) {
+            return mContext.getString(R.string.bluetooth_disabled);
+        }
+        switch (mConnectionState) {
+            case BluetoothAdapter.STATE_CONNECTED:
+                return mContext.getString(R.string.bluetooth_connected);
+            case BluetoothAdapter.STATE_CONNECTING:
+                return mContext.getString(R.string.bluetooth_connecting);
+            case BluetoothAdapter.STATE_DISCONNECTING:
+                return mContext.getString(R.string.bluetooth_disconnecting);
+            default:
+                return mContext.getString(R.string.bluetooth_disconnected);
+        }
+    }
+
+    private void updateConnected() {
+        if (mBluetoothAdapter == null) {
+            return;
+        }
+        // Make sure our connection state is up to date.
+        int state = mBluetoothAdapter.getConnectionState();
+        if (state != mConnectionState) {
+            mConnectionState = state;
+            return;
+        }
+        final Collection<CachedBluetoothDevice> devices = getDevices();
+        if (devices == null) {
+            mConnectionState = BluetoothAdapter.STATE_DISCONNECTED;
+            return;
+        }
+        if (mConnectionState == BluetoothAdapter.STATE_CONNECTED) {
+            CachedBluetoothDevice connectedDevice = null;
+            for (CachedBluetoothDevice device : devices) {
+                if (device.isConnected()) {
+                    connectedDevice = device;
+                    break;
+                }
+            }
+            if (connectedDevice == null) {
+                // If somehow we think we are connected, but have no connected devices, we
+                // aren't connected.
+                mConnectionState = BluetoothAdapter.STATE_DISCONNECTED;
+            }
+        }
+    }
+
+    private Collection<CachedBluetoothDevice> getDevices() {
+        return mBluetoothManager != null
+            ? mBluetoothManager.getCachedDeviceManager().getCachedDevicesCopy()
+            : null;
+    }
+
+}

src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java

@@ -20,7 +20,10 @@ import android.provider.SearchIndexableResource;
 
 import com.android.internal.logging.nano.MetricsProto;
 import com.android.settings.R;
+import com.android.settings.bluetooth.BluetoothMasterSwitchPreferenceController;
+import com.android.settings.bluetooth.Utils;
 import com.android.settings.core.PreferenceController;
+import com.android.settings.core.lifecycle.Lifecycle;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.deviceinfo.UsbBackend;
 import com.android.settings.nfc.NfcPreferenceController;
@@ -37,6 +40,7 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
 
     private static final String TAG = "ConnectedDeviceFrag";
     private UsbModePreferenceController mUsbPrefController;
+    private BluetoothMasterSwitchPreferenceController mBluetoothPreferenceController;
 
     @Override
     public int getMetricsCategory() {
@@ -61,13 +65,19 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
     @Override
     protected List<PreferenceController> getPreferenceControllers(Context context) {
         final List<PreferenceController> controllers = new ArrayList<>();
+        final Lifecycle lifecycle = getLifecycle();
         final NfcPreferenceController nfcPreferenceController =
                 new NfcPreferenceController(context);
-        getLifecycle().addObserver(nfcPreferenceController);
+        lifecycle.addObserver(nfcPreferenceController);
         controllers.add(nfcPreferenceController);
         mUsbPrefController = new UsbModePreferenceController(context, new UsbBackend(context));
-        getLifecycle().addObserver(mUsbPrefController);
+        lifecycle.addObserver(mUsbPrefController);
         controllers.add(mUsbPrefController);
+        mBluetoothPreferenceController =
+            new BluetoothMasterSwitchPreferenceController(
+                context, Utils.getLocalBtManager(context));
+        lifecycle.addObserver(mBluetoothPreferenceController);
+        controllers.add(mBluetoothPreferenceController);
         return controllers;
     }
 

src/com/android/settings/widget/MasterSwitchController.java

@@ -0,0 +1,70 @@
+/*
+ * 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.widget;
+
+import android.support.v7.preference.Preference;
+
+/*
+ * The switch controller that is used to update the switch widget in the MasterSwitchPreference
+ * layout.
+ */
+public class MasterSwitchController extends SwitchWidgetController implements
+    Preference.OnPreferenceChangeListener {
+
+    private final MasterSwitchPreference mPreference;
+
+    public MasterSwitchController(MasterSwitchPreference preference) {
+        mPreference = preference;
+    }
+
+    @Override
+    public void updateTitle(boolean isChecked) {
+    }
+
+    @Override
+    public void startListening() {
+        mPreference.setOnPreferenceChangeListener(this);
+    }
+
+    @Override
+    public void stopListening() {
+        mPreference.setOnPreferenceChangeListener(null);
+    }
+
+    @Override
+    public void setChecked(boolean checked) {
+        mPreference.setChecked(checked);
+    }
+
+    @Override
+    public boolean isChecked() {
+        return mPreference.isChecked();
+    }
+
+    @Override
+    public void setEnabled(boolean enabled) {
+        mPreference.setSwitchEnabled(enabled);
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        if (mListener != null) {
+            return mListener.onSwitchToggled((Boolean) newValue);
+        }
+        return false;
+    }
+}

src/com/android/settings/widget/MasterSwitchPreference.java

@@ -0,0 +1,102 @@
+/*
+ * 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.widget;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceViewHolder;
+import android.util.AttributeSet;
+import android.widget.CompoundButton;
+import android.widget.Switch;
+
+import com.android.settings.R;
+
+/**
+ * A custom preference that provides inline switch toggle. It has a mandatory field for title, and
+ * optional fields for icon and sub-text.
+ */
+public class MasterSwitchPreference extends Preference {
+
+    private Switch mSwitch;
+    private boolean mChecked;
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs,
+            int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init();
+    }
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init();
+    }
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init();
+    }
+
+    public MasterSwitchPreference(Context context) {
+        super(context);
+        init();
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+        mSwitch = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        if (mSwitch != null) {
+            mSwitch.setChecked(mChecked);
+            mSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+                @Override
+                public void onCheckedChanged(CompoundButton button, boolean isChecked) {
+                    if (!callChangeListener(isChecked)) {
+                        button.setChecked(!isChecked);
+                    } else {
+                        persistBoolean(isChecked);
+                        mChecked = isChecked;
+                    }
+                }
+            });
+        }
+    }
+
+    public boolean isChecked() {
+        return isEnabled() && mChecked;
+    }
+
+    public void setChecked(boolean checked) {
+        mChecked = checked;
+        if (mSwitch != null) {
+            mSwitch.setChecked(checked);
+        }
+    }
+
+    public boolean isSwitchEnabled() {
+        return isEnabled() && mSwitch != null && mSwitch.isEnabled();
+    }
+
+    public void setSwitchEnabled(boolean enabled) {
+        if (mSwitch != null) {
+            mSwitch.setEnabled(enabled);
+        }
+    }
+
+    private void init() {
+        setWidgetLayoutResource(R.layout.preference_widget_master_switch);
+    }
+}

src/com/android/settings/widget/SwitchBarController.java

@@ -0,0 +1,81 @@
+/*
+ * 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.widget;
+
+import android.widget.Switch;
+
+/*
+ * The switch controller that is used to update the switch widget in the SwitchBar layout.
+ */
+public class SwitchBarController extends SwitchWidgetController implements
+    SwitchBar.OnSwitchChangeListener {
+
+    private final SwitchBar mSwitchBar;
+    private final Switch mSwitch;
+
+    public SwitchBarController(SwitchBar switchBar) {
+        mSwitchBar = switchBar;
+        mSwitch = switchBar.getSwitch();
+    }
+
+    @Override
+    public void setupView() {
+        mSwitchBar.show();
+    }
+
+    @Override
+    public void teardownView() {
+        mSwitchBar.hide();
+    }
+
+    @Override
+    public void updateTitle(boolean isChecked) {
+        mSwitchBar.setTextViewLabel(isChecked);
+    }
+
+    @Override
+    public void startListening() {
+        mSwitchBar.addOnSwitchChangeListener(this);
+    }
+
+    @Override
+    public void stopListening() {
+        mSwitchBar.removeOnSwitchChangeListener(this);
+    }
+
+    @Override
+    public void setChecked(boolean checked) {
+        mSwitch.setChecked(checked);
+    }
+
+    @Override
+    public boolean isChecked() {
+        return mSwitch.isChecked();
+    }
+
+    @Override
+    public void setEnabled(boolean enabled) {
+        mSwitch.setEnabled(enabled);
+    }
+
+    @Override
+    public void onSwitchChanged(Switch switchView, boolean isChecked) {
+        if (mListener != null) {
+            mListener.onSwitchToggled(isChecked);
+        }
+    }
+}

src/com/android/settings/widget/SwitchWidgetController.java

@@ -0,0 +1,58 @@
+/*
+ * 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.widget;
+
+/*
+ * A controller class for general switch widget handling. We have different containers that provide
+ * different forms of switch layout. Provide a centralized control for updating the switch widget.
+ */
+public abstract class SwitchWidgetController {
+
+    protected OnSwitchChangeListener mListener;
+
+    public interface OnSwitchChangeListener {
+        /**
+         * Called when the checked state of the Switch has changed.
+         *
+         * @param isChecked  The new checked state of switchView.
+         */
+        boolean onSwitchToggled(boolean isChecked);
+    }
+
+    public void setupView() {
+    }
+
+    public void teardownView() {
+    }
+
+    public void setListener(OnSwitchChangeListener listener) {
+        mListener = listener;
+    }
+
+    public abstract void updateTitle(boolean isChecked);
+
+    public abstract void startListening();
+
+    public abstract void stopListening();
+
+    public abstract void setChecked(boolean checked);
+
+    public abstract boolean isChecked();
+
+    public abstract void setEnabled(boolean enabled);
+
+}

tests/robotests/src/com/android/settings/bluetooth/BluetoothMasterSwitchPreferenceControllerTest.java

@@ -0,0 +1,114 @@
+/*
+ * 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.bluetooth;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.Preference.OnPreferenceChangeListener;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settings.widget.MasterSwitchPreference;
+import com.android.settingslib.bluetooth.BluetoothCallback;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Answers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class BluetoothMasterSwitchPreferenceControllerTest {
+
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private LocalBluetoothManager mBluetoothManager;
+    @Mock
+    private PreferenceScreen mScreen;
+    @Mock
+    private MasterSwitchPreference mPreference;
+
+    private Context mContext;
+    private BluetoothMasterSwitchPreferenceController mController;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application.getApplicationContext();
+        mController = new BluetoothMasterSwitchPreferenceController(mContext, mBluetoothManager);
+        when(mScreen.findPreference(mController.getPreferenceKey())).thenReturn(mPreference);
+    }
+
+    @Test
+    public void isAvailable_shouldAlwaysReturnTrue() {
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void onResume_shouldRegisterCallback() {
+        mController.onResume();
+
+        verify(mBluetoothManager.getEventManager()).registerCallback(any(BluetoothCallback.class));
+    }
+
+    @Test
+    public void onPause_shouldUnregisterCallback() {
+        mController.onPause();
+
+        verify(mBluetoothManager.getEventManager()).unregisterCallback(
+            any(BluetoothCallback.class));
+    }
+
+    @Test
+    public void onStart_shouldRegisterPreferenceChangeListener() {
+        mController.displayPreference(mScreen);
+        mController.onStart();
+
+        verify(mPreference).setOnPreferenceChangeListener(any(OnPreferenceChangeListener.class));
+    }
+
+    @Test
+    public void onStop_shouldRegisterPreferenceChangeListener() {
+        mController.displayPreference(mScreen);
+        mController.onStart();
+
+        mController.onStop();
+
+        verify(mPreference).setOnPreferenceChangeListener(null);
+    }
+
+    @Test
+    public void onSummaryUpdated_shouldUpdatePreferenceSummary() {
+        mController.displayPreference(mScreen);
+
+        mController.onSummaryChanged("test summary");
+
+        verify(mPreference).setSummary("test summary");
+    }
+
+}

tests/robotests/src/com/android/settings/bluetooth/BluetoothSettingsSummaryProviderTest.java

@@ -16,14 +16,11 @@
 
 package com.android.settings.bluetooth;
 
-import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 
-import com.android.settings.R;
 import com.android.settings.SettingsRobolectricTestRunner;
 import com.android.settings.TestConfig;
 import com.android.settings.dashboard.SummaryLoader;
-import com.android.settingslib.bluetooth.CachedBluetoothDevice;
 import com.android.settingslib.bluetooth.LocalBluetoothManager;
 
 import org.junit.Before;
@@ -34,15 +31,10 @@ import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
-import org.robolectric.shadows.ShadowBluetoothAdapter;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.mockito.Matchers.anyString;
-import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -67,102 +59,27 @@ public class BluetoothSettingsSummaryProviderTest {
     }
 
     @Test
-    public void setListening_shouldUpdateSummary() {
+    public void setListening_shouldRegister() {
         mSummaryProvider.setListening(true);
 
-        verify(mBluetoothManager.getEventManager()).registerCallback(mSummaryProvider);
-        verify(mSummaryLoader).setSummary(eq(mSummaryProvider), anyString());
+        verify(mBluetoothManager.getEventManager()).registerCallback(
+            mSummaryProvider.mSummaryHelper);
     }
 
     @Test
     public void setNotListening_shouldUnregister() {
         mSummaryProvider.setListening(false);
 
-        verify(mBluetoothManager.getEventManager()).unregisterCallback(mSummaryProvider);
+        verify(mBluetoothManager.getEventManager()).unregisterCallback(
+            mSummaryProvider.mSummaryHelper);
     }
 
     @Test
-    public void updateSummary_btDisabled_shouldShowDisabledMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().disable();
-        mSummaryProvider.setListening(true);
+    public void onSummaryChanged_shouldSetSummary() {
+        final String summary = "Bluetooth summary";
+        mSummaryProvider.onSummaryChanged(summary);
 
-        verify(mSummaryLoader).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disabled));
-    }
-
-    @Test
-    public void updateSummary_btEnabled_noDevice_shouldShowDisconnectedMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        mSummaryProvider.setListening(true);
-
-        verify(mSummaryLoader).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disconnected));
-    }
-
-    @Test
-    public void updateState_btEnabled_noDevice_shouldShowDisconnectedMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        mSummaryProvider.onBluetoothStateChanged(BluetoothAdapter.STATE_TURNING_ON);
-
-        verify(mSummaryLoader).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disconnected));
-    }
-
-    @Test
-    public void updateState_btDisabled_shouldShowDisabledMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        mSummaryProvider.onBluetoothStateChanged(BluetoothAdapter.STATE_TURNING_OFF);
-
-        verify(mSummaryLoader).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disabled));
-    }
-
-    @Test
-    public void updateConnectionState_disconnected_shouldShowDisconnectedMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        when(mBluetoothManager.getBluetoothAdapter().getConnectionState())
-                .thenReturn(BluetoothAdapter.STATE_DISCONNECTED);
-
-        mSummaryProvider.setListening(true);
-        mSummaryProvider.onConnectionStateChanged(null /* device */,
-                BluetoothAdapter.STATE_DISCONNECTED);
-
-        verify(mSummaryLoader, times(2)).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disconnected));
-    }
-
-
-    @Test
-    public void updateConnectionState_connected_shouldShowConnectedMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        when(mBluetoothManager.getBluetoothAdapter().getConnectionState())
-                .thenReturn(BluetoothAdapter.STATE_CONNECTED);
-        final List<CachedBluetoothDevice> devices = new ArrayList<>();
-        devices.add(mock(CachedBluetoothDevice.class));
-        when(devices.get(0).isConnected()).thenReturn(true);
-        when(mBluetoothManager.getCachedDeviceManager().getCachedDevicesCopy())
-                .thenReturn(devices);
-
-        mSummaryProvider.setListening(true);
-        mSummaryProvider.onConnectionStateChanged(null /* device */,
-                BluetoothAdapter.STATE_CONNECTED);
-
-        verify(mSummaryLoader).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_connected));
-    }
-
-    @Test
-    public void updateConnectionState_inconsistentState_shouldShowDisconnectedMessage() {
-        ShadowBluetoothAdapter.getDefaultAdapter().enable();
-        when(mBluetoothManager.getBluetoothAdapter().getConnectionState())
-                .thenReturn(BluetoothAdapter.STATE_CONNECTED);
-
-        mSummaryProvider.setListening(true);
-        mSummaryProvider.onConnectionStateChanged(null /* device */,
-                BluetoothAdapter.STATE_CONNECTED);
-
-        verify(mSummaryLoader, times(2)).setSummary(mSummaryProvider,
-                mContext.getString(R.string.bluetooth_disconnected));
+        verify(mSummaryLoader).setSummary(mSummaryProvider, summary);
     }
 
 }

tests/robotests/src/com/android/settings/bluetooth/BluetoothSummaryHelperTest.java

@@ -0,0 +1,168 @@
+/*
+ * 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.bluetooth;
+
+import android.bluetooth.BluetoothAdapter;
+import android.content.Context;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+import com.android.settingslib.bluetooth.LocalBluetoothAdapter;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Answers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowBluetoothAdapter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class BluetoothSummaryHelperTest {
+
+    private Context mContext;
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private LocalBluetoothManager mBluetoothManager;
+    @Mock
+    private LocalBluetoothAdapter mBtAdapter;
+
+    private BluetoothSummaryHelper mHelper;
+    @Mock
+    private SummaryListener mListener;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        when(mBluetoothManager.getBluetoothAdapter()).thenReturn(mBtAdapter);
+        when(mBtAdapter.isEnabled()).thenReturn(true);
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_CONNECTED);
+        mContext = RuntimeEnvironment.application.getApplicationContext();
+        mHelper = new BluetoothSummaryHelper(mContext, mBluetoothManager);
+        mHelper.setOnSummaryChangeListener(mListener);
+    }
+
+    @Test
+    public void setListening_shouldRegisterListener() {
+        mHelper.setListening(true);
+
+        verify(mBluetoothManager.getEventManager()).registerCallback(mHelper);
+    }
+
+    @Test
+    public void setNotListening_shouldUnregisterListener() {
+        mHelper.setListening(false);
+
+        verify(mBluetoothManager.getEventManager()).unregisterCallback(mHelper);
+    }
+
+    @Test
+    public void setListening_shouldSendSummaryChange() {
+        mHelper.setListening(true);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_connected));
+    }
+
+    @Test
+    public void onBluetoothStateChanged_btDisabled_shouldSendDisabledSummary() {
+        mHelper.setListening(true);
+        mHelper.onBluetoothStateChanged(BluetoothAdapter.STATE_OFF);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_disabled));
+    }
+
+    @Test
+    public void onBluetoothStateChanged_btEnabled_connected_shouldSendConnectedSummary() {
+        mHelper.setListening(true);
+        mHelper.onBluetoothStateChanged(BluetoothAdapter.STATE_ON);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_connected));
+    }
+
+    @Test
+    public void onBluetoothStateChanged_btEnabled_notConnected_shouldSendDisconnectedMessage() {
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_DISCONNECTED);
+        mHelper.setListening(true);
+        mHelper.onBluetoothStateChanged(BluetoothAdapter.STATE_TURNING_ON);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_disconnected));
+    }
+
+    @Test
+    public void onConnectionStateChanged_connected_shouldSendConnectedMessage() {
+        final List<CachedBluetoothDevice> devices = new ArrayList<>();
+        devices.add(mock(CachedBluetoothDevice.class));
+        when(devices.get(0).isConnected()).thenReturn(true);
+        when(mBluetoothManager.getCachedDeviceManager().getCachedDevicesCopy())
+            .thenReturn(devices);
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_DISCONNECTED);
+        mHelper.setListening(true);
+
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_CONNECTED);
+        mHelper.onConnectionStateChanged(null /* device */, BluetoothAdapter.STATE_CONNECTED);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_connected));
+    }
+
+    @Test
+    public void onConnectionStateChanged_inconsistentState_shouldSendDisconnectedMessage() {
+        mHelper.setListening(true);
+        mHelper.onConnectionStateChanged(null /* device */, BluetoothAdapter.STATE_CONNECTED);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_disconnected));
+    }
+
+    @Test
+    public void onConnectionStateChanged_connecting_shouldSendConnectingMessage() {
+        mHelper.setListening(true);
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_CONNECTING);
+        mHelper.onConnectionStateChanged(null /* device */, BluetoothAdapter.STATE_CONNECTING);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_connecting));
+    }
+
+    @Test
+    public void onConnectionStateChanged_disconnecting_shouldSendDisconnectingMessage() {
+        mHelper.setListening(true);
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_DISCONNECTING);
+        mHelper.onConnectionStateChanged(null /* device */, BluetoothAdapter.STATE_DISCONNECTING);
+
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_disconnecting));
+    }
+
+    private class SummaryListener implements BluetoothSummaryHelper.OnSummaryChangeListener {
+        String summary;
+
+        @Override
+        public void onSummaryChanged(String summary) {
+            this.summary = summary;
+        }
+    }
+
+}

tests/robotests/src/com/android/settings/widget/MasterSwitchPreferenceTest.java

@@ -0,0 +1,121 @@
+/*
+ * 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.widget;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceViewHolder;
+import android.support.v7.preference.Preference.OnPreferenceChangeListener;
+import android.view.LayoutInflater;
+import android.widget.CompoundButton.OnCheckedChangeListener;
+import android.widget.Switch;
+
+import com.android.settings.R;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class MasterSwitchPreferenceTest {
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = ShadowApplication.getInstance().getApplicationContext();
+    }
+
+    @Test
+    public void createNewPreference_shouldSetLayout() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+
+        assertThat(preference.getWidgetLayoutResource()).isEqualTo(
+            R.layout.preference_widget_master_switch);
+    }
+
+    @Test
+    public void setChecked_shouldUpdateButtonCheckedState() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(LayoutInflater.from(mContext)
+            .inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        preference.onBindViewHolder(holder);
+
+        preference.setChecked(true);
+        assertThat(toggle.isChecked()).isTrue();
+
+        preference.setChecked(false);
+        assertThat(toggle.isChecked()).isFalse();
+    }
+
+    @Test
+    public void setSwitchEnabled_shouldUpdateButtonEnabledState() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        preference.onBindViewHolder(holder);
+
+        preference.setSwitchEnabled(true);
+        assertThat(toggle.isEnabled()).isTrue();
+
+        preference.setSwitchEnabled(false);
+        assertThat(toggle.isEnabled()).isFalse();
+    }
+
+    @Test
+    public void toggleButtonOn_shouldNotifyChecked() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        final OnPreferenceChangeListener listener = mock(OnPreferenceChangeListener.class);
+        preference.setOnPreferenceChangeListener(listener);
+        preference.onBindViewHolder(holder);
+
+        toggle.setChecked(true);
+        verify(listener).onPreferenceChange(preference, true);
+    }
+
+    @Test
+    public void toggleButtonOff_shouldNotifyUnchecked() {
+        final MasterSwitchPreference preference = new MasterSwitchPreference(mContext);
+        final PreferenceViewHolder holder = new PreferenceViewHolder(
+            LayoutInflater.from(mContext).inflate(R.layout.preference_widget_master_switch, null));
+        final Switch toggle = (Switch) holder.itemView.findViewById(R.id.switchWidget);
+        final OnPreferenceChangeListener listener = mock(OnPreferenceChangeListener.class);
+        preference.setChecked(true);
+        preference.setOnPreferenceChangeListener(listener);
+        preference.onBindViewHolder(holder);
+
+        toggle.setChecked(false);
+        verify(listener).onPreferenceChange(preference, false);
+    }
+}