Merge changes Ia2ab6b67,I85a9ef21

* changes:
  Update ConnectedDeviceGroupController
  Add infrastructure for connected device group.
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 43827e3..793498e 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -394,6 +394,11 @@
     <!-- Title for pairing bluetooth device page [CHAR LIMIT=none] -->
     <string name="bluetooth_pairing_page_title">Pair new device</string>
 
+    <!-- Title for connected device group [CHAR LIMIT=none]-->
+    <string name="connected_device_connected_title">Currently connected</string>
+    <!-- Title for connected device group [CHAR LIMIT=none]-->
+    <string name="connected_device_saved_title">Saved devices</string>
+
     <!-- Date & time settings screen title -->
     <string name="date_and_time">Date &amp; time</string>
     <!-- The title of the activity to pick a time zone. -->
diff --git a/res/xml/connected_devices.xml b/res/xml/connected_devices.xml
index c7f7f48..d24dd51 100644
--- a/res/xml/connected_devices.xml
+++ b/res/xml/connected_devices.xml
@@ -19,4 +19,7 @@
     android:key="connected_devices_screen"
     android:title="@string/connected_devices_dashboard_title">
 
+    <PreferenceCategory
+        android:key="connected_device_list"
+        android:title="@string/connected_device_connected_title"/>
 </PreferenceScreen>
diff --git a/src/com/android/settings/bluetooth/BluetoothDeviceUpdater.java b/src/com/android/settings/bluetooth/BluetoothDeviceUpdater.java
new file mode 100644
index 0000000..e053bc9
--- /dev/null
+++ b/src/com/android/settings/bluetooth/BluetoothDeviceUpdater.java
@@ -0,0 +1,181 @@
+/*
+ * 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.BluetoothDevice;
+import android.content.Context;
+import android.os.Bundle;
+import android.os.SystemProperties;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+
+import com.android.settings.R;
+import com.android.settings.SettingsActivity;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.connecteddevice.DevicePreferenceCallback;
+import com.android.settings.widget.GearPreference;
+import com.android.settingslib.bluetooth.BluetoothCallback;
+import com.android.settingslib.bluetooth.BluetoothDeviceFilter;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Update the bluetooth devices. It gets bluetooth event from {@link LocalBluetoothManager} using
+ * {@link BluetoothCallback}. It notifies the upper level whether to add/remove the preference
+ * through {@link DevicePreferenceCallback}
+ *
+ * In {@link BluetoothDeviceUpdater}, it uses {@link BluetoothDeviceFilter.Filter} to detect
+ * whether the {@link CachedBluetoothDevice} is relevant.
+ */
+public abstract class BluetoothDeviceUpdater implements BluetoothCallback {
+    private static final String BLUETOOTH_SHOW_DEVICES_WITHOUT_NAMES_PROPERTY =
+            "persist.bluetooth.showdeviceswithoutnames";
+
+    protected final LocalBluetoothManager mLocalManager;
+    protected final DevicePreferenceCallback mDevicePreferenceCallback;
+    protected final Map<BluetoothDevice, Preference> mPreferenceMap;
+    protected Context mPrefContext;
+
+    private final boolean mShowDeviceWithoutNames;
+    private DashboardFragment mFragment;
+
+    @VisibleForTesting
+    final GearPreference.OnGearClickListener mDeviceProfilesListener = pref -> {
+        final CachedBluetoothDevice device =
+                ((BluetoothDevicePreference) pref).getBluetoothDevice();
+        if (device == null) {
+            return;
+        }
+        final Bundle args = new Bundle();
+        args.putString(BluetoothDeviceDetailsFragment.KEY_DEVICE_ADDRESS,
+                device.getDevice().getAddress());
+        final SettingsActivity activity = (SettingsActivity) mFragment.getActivity();
+        activity.startPreferencePanel(mFragment,
+                BluetoothDeviceDetailsFragment.class.getName(), args,
+                R.string.device_details_title, null, null, 0);
+
+    };
+
+    public BluetoothDeviceUpdater(DashboardFragment fragment,
+            DevicePreferenceCallback devicePreferenceCallback) {
+        this(fragment, devicePreferenceCallback, Utils.getLocalBtManager(fragment.getContext()));
+    }
+
+    @VisibleForTesting
+    BluetoothDeviceUpdater(DashboardFragment fragment,
+            DevicePreferenceCallback devicePreferenceCallback, LocalBluetoothManager localManager) {
+        mFragment = fragment;
+        mDevicePreferenceCallback = devicePreferenceCallback;
+        mShowDeviceWithoutNames = SystemProperties.getBoolean(
+                BLUETOOTH_SHOW_DEVICES_WITHOUT_NAMES_PROPERTY, false);
+        mPreferenceMap = new HashMap<>();
+        mLocalManager = localManager;
+    }
+
+    /**
+     * Register the bluetooth event callback and update the list
+     */
+    public void registerCallback() {
+        mLocalManager.setForegroundActivity(mFragment.getContext());
+        mLocalManager.getEventManager().registerCallback(this);
+        forceUpdate();
+    }
+
+    /**
+     * Unregister the bluetooth event callback
+     */
+    public void unregisterCallback() {
+        mLocalManager.setForegroundActivity(null);
+        mLocalManager.getEventManager().unregisterCallback(this);
+    }
+
+    /**
+     * Force to update the list of bluetooth devices
+     */
+    public void forceUpdate() {
+        Collection<CachedBluetoothDevice> cachedDevices =
+                mLocalManager.getCachedDeviceManager().getCachedDevicesCopy();
+        for (CachedBluetoothDevice cachedBluetoothDevice : cachedDevices) {
+            update(cachedBluetoothDevice);
+        }
+    }
+
+    @Override
+    public void onBluetoothStateChanged(int bluetoothState) {
+        forceUpdate();
+    }
+
+    @Override
+    public void onScanningStateChanged(boolean started) {}
+
+    @Override
+    public void onDeviceAdded(CachedBluetoothDevice cachedDevice) {
+        update(cachedDevice);
+    }
+
+    @Override
+    public void onDeviceDeleted(CachedBluetoothDevice cachedDevice) {}
+
+    @Override
+    public void onDeviceBondStateChanged(CachedBluetoothDevice cachedDevice, int bondState) {
+        update(cachedDevice);
+    }
+
+    @Override
+    public void onConnectionStateChanged(CachedBluetoothDevice cachedDevice, int state) {}
+
+    /**
+     * Set the context to generate the {@link Preference}, so it could get the correct theme.
+     */
+    public void setPrefContext(Context context) {
+        mPrefContext = context;
+    }
+
+    /**
+     * Update whether to show {@cde cachedBluetoothDevice} in the list.
+     */
+    abstract public void update(CachedBluetoothDevice cachedBluetoothDevice);
+
+    /**
+     * Add the {@link Preference} that represents the {@code cachedDevice}
+     */
+    protected void addPreference(CachedBluetoothDevice cachedDevice) {
+        final BluetoothDevice device = cachedDevice.getDevice();
+        if (!mPreferenceMap.containsKey(device)) {
+            BluetoothDevicePreference btPreference =
+                    new BluetoothDevicePreference(mPrefContext, cachedDevice,
+                            mShowDeviceWithoutNames);
+            btPreference.setOnGearClickListener(mDeviceProfilesListener);
+            mPreferenceMap.put(device, btPreference);
+            mDevicePreferenceCallback.onDeviceAdded(btPreference);
+        }
+    }
+
+    /**
+     * Remove the {@link Preference} that represents the {@code cachedDevice}
+     */
+    protected void removePreference(CachedBluetoothDevice cachedDevice) {
+        final BluetoothDevice device = cachedDevice.getDevice();
+        if (mPreferenceMap.containsKey(device)) {
+            mDevicePreferenceCallback.onDeviceRemoved(mPreferenceMap.get(device));
+            mPreferenceMap.remove(device);
+        }
+    }
+}
diff --git a/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdater.java b/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdater.java
new file mode 100644
index 0000000..239e405
--- /dev/null
+++ b/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdater.java
@@ -0,0 +1,66 @@
+/*
+ * 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.bluetooth.BluetoothDevice;
+import android.support.annotation.VisibleForTesting;
+
+import com.android.settings.connecteddevice.DevicePreferenceCallback;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+import com.android.settingslib.bluetooth.LocalBluetoothManager;
+
+/**
+ * Controller to maintain connected bluetooth devices
+ */
+public class ConnectedBluetoothDeviceUpdater extends BluetoothDeviceUpdater {
+
+    public ConnectedBluetoothDeviceUpdater(DashboardFragment fragment,
+            DevicePreferenceCallback devicePreferenceCallback) {
+        super(fragment, devicePreferenceCallback);
+    }
+
+    @VisibleForTesting
+    ConnectedBluetoothDeviceUpdater(DashboardFragment fragment,
+            DevicePreferenceCallback devicePreferenceCallback,
+            LocalBluetoothManager localBluetoothManager) {
+        super(fragment, devicePreferenceCallback, localBluetoothManager);
+    }
+
+    @Override
+    public void onConnectionStateChanged(CachedBluetoothDevice cachedDevice, int state) {
+        if (state == BluetoothAdapter.STATE_CONNECTED) {
+            addPreference(cachedDevice);
+        } else if (state == BluetoothAdapter.STATE_DISCONNECTED) {
+            removePreference(cachedDevice);
+        }
+    }
+
+    @Override
+    public void update(CachedBluetoothDevice cachedDevice) {
+        final BluetoothDevice device = cachedDevice.getDevice();
+        final boolean filterMatch =
+                device.getBondState() == BluetoothDevice.BOND_BONDED && device.isConnected();
+
+        if (filterMatch) {
+            // Add the preference if it is new one
+            addPreference(cachedDevice);
+        } else {
+            removePreference(cachedDevice);
+        }
+    }
+}
diff --git a/src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java b/src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java
index 74f6ea2..14acd89 100644
--- a/src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java
+++ b/src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java
@@ -17,27 +17,20 @@
 
 import android.app.Activity;
 import android.content.Context;
-import android.content.pm.PackageManager;
 import android.provider.SearchIndexableResource;
 import android.support.annotation.VisibleForTesting;
 
 import com.android.internal.logging.nano.MetricsProto;
 import com.android.settings.R;
-import com.android.settings.SettingsActivity;
-import com.android.settings.bluetooth.BluetoothMasterSwitchPreferenceController;
-import com.android.settings.bluetooth.Utils;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.dashboard.SummaryLoader;
-import com.android.settings.deviceinfo.UsbBackend;
 import com.android.settings.nfc.NfcPreferenceController;
-import com.android.settings.overlay.FeatureFactory;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settings.search.Indexable;
 import com.android.settingslib.core.AbstractPreferenceController;
 import com.android.settingslib.core.lifecycle.Lifecycle;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 public class ConnectedDeviceDashboardFragment extends DashboardFragment {
@@ -66,7 +59,14 @@
 
     @Override
     protected List<AbstractPreferenceController> getPreferenceControllers(Context context) {
-        return null;
+        final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        final Lifecycle lifecycle = getLifecycle();
+
+        final ConnectedDeviceGroupController connectedDeviceGroupController =
+                new ConnectedDeviceGroupController(this, lifecycle);
+        controllers.add(connectedDeviceGroupController);
+        return controllers;
+
     }
 
     @VisibleForTesting
@@ -109,19 +109,26 @@
     /**
      * For Search.
      */
+    //TODO(b/69333961): update the index for this new fragment
     public static final Indexable.SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider() {
                 @Override
                 public List<SearchIndexableResource> getXmlResourcesToIndex(
                         Context context, boolean enabled) {
-                   return new ArrayList<>();
+                    return new ArrayList<>();
                 }
 
                 @Override
                 public List<String> getNonIndexableKeys(Context context) {
 
-
                     return new ArrayList<>();
                 }
+
+                @Override
+                public List<AbstractPreferenceController> getPreferenceControllers(
+                        Context context) {
+                    //TODO(b/69333961): update the index for controllers
+                    return super.getPreferenceControllers(context);
+                }
             };
 }
diff --git a/src/com/android/settings/connecteddevice/ConnectedDeviceGroupController.java b/src/com/android/settings/connecteddevice/ConnectedDeviceGroupController.java
new file mode 100644
index 0000000..a0b5cb8
--- /dev/null
+++ b/src/com/android/settings/connecteddevice/ConnectedDeviceGroupController.java
@@ -0,0 +1,109 @@
+/*
+ * 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.connecteddevice;
+
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceGroup;
+import android.support.v7.preference.PreferenceScreen;
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settings.bluetooth.BluetoothDeviceUpdater;
+import com.android.settings.bluetooth.ConnectedBluetoothDeviceUpdater;
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+
+/**
+ * Controller to maintain the {@link android.support.v7.preference.PreferenceGroup} for all
+ * connected devices. It uses {@link DevicePreferenceCallback} to add/remove {@link Preference}
+ */
+public class ConnectedDeviceGroupController extends AbstractPreferenceController
+        implements PreferenceControllerMixin, LifecycleObserver, OnStart, OnStop,
+        DevicePreferenceCallback {
+
+    private static final String KEY = "connected_device_list";
+
+    @VisibleForTesting
+    PreferenceGroup mPreferenceGroup;
+    private BluetoothDeviceUpdater mBluetoothDeviceUpdater;
+
+    public ConnectedDeviceGroupController(DashboardFragment fragment, Lifecycle lifecycle) {
+        super(fragment.getContext());
+        init(lifecycle, new ConnectedBluetoothDeviceUpdater(fragment, this));
+    }
+
+    @VisibleForTesting
+    ConnectedDeviceGroupController(DashboardFragment fragment, Lifecycle lifecycle,
+            BluetoothDeviceUpdater bluetoothDeviceUpdater) {
+        super(fragment.getContext());
+        init(lifecycle, bluetoothDeviceUpdater);
+    }
+
+    @Override
+    public void onStart() {
+        mBluetoothDeviceUpdater.registerCallback();
+    }
+
+    @Override
+    public void onStop() {
+        mBluetoothDeviceUpdater.unregisterCallback();
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreferenceGroup = (PreferenceGroup) screen.findPreference(KEY);
+        mPreferenceGroup.setVisible(false);
+        mBluetoothDeviceUpdater.setPrefContext(screen.getContext());
+        mBluetoothDeviceUpdater.forceUpdate();
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY;
+    }
+
+    @Override
+    public void onDeviceAdded(Preference preference) {
+        if (mPreferenceGroup.getPreferenceCount() == 0) {
+            mPreferenceGroup.setVisible(true);
+        }
+        mPreferenceGroup.addPreference(preference);
+    }
+
+    @Override
+    public void onDeviceRemoved(Preference preference) {
+        mPreferenceGroup.removePreference(preference);
+        if (mPreferenceGroup.getPreferenceCount() == 0) {
+            mPreferenceGroup.setVisible(false);
+        }
+    }
+
+    private void init(Lifecycle lifecycle, BluetoothDeviceUpdater bluetoothDeviceUpdater) {
+        if (lifecycle != null) {
+            lifecycle.addObserver(this);
+        }
+        mBluetoothDeviceUpdater = bluetoothDeviceUpdater;
+    }
+}
diff --git a/src/com/android/settings/connecteddevice/DevicePreferenceCallback.java b/src/com/android/settings/connecteddevice/DevicePreferenceCallback.java
new file mode 100644
index 0000000..5f04700
--- /dev/null
+++ b/src/com/android/settings/connecteddevice/DevicePreferenceCallback.java
@@ -0,0 +1,36 @@
+/*
+ * 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.connecteddevice;
+
+import android.support.v7.preference.Preference;
+
+/**
+ * Callback to add or remove {@link Preference} in device group.
+ */
+public interface DevicePreferenceCallback {
+    /**
+     * Called when a device(i.e. bluetooth, usb) is added
+     * @param preference present the device
+     */
+    void onDeviceAdded(Preference preference);
+
+    /**
+     * Called when a device(i.e. bluetooth, usb) is removed
+     * @param preference present the device
+     */
+    void onDeviceRemoved(Preference preference);
+}
diff --git a/tests/robotests/src/com/android/settings/bluetooth/BluetoothDeviceUpdaterTest.java b/tests/robotests/src/com/android/settings/bluetooth/BluetoothDeviceUpdaterTest.java
new file mode 100644
index 0000000..525f70e
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/bluetooth/BluetoothDeviceUpdaterTest.java
@@ -0,0 +1,127 @@
+/*
+ * 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 static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import android.bluetooth.BluetoothDevice;
+import android.content.Context;
+import android.support.v7.preference.Preference;
+
+import com.android.settings.R;
+import com.android.settings.SettingsActivity;
+import com.android.settings.TestConfig;
+import com.android.settings.connecteddevice.DevicePreferenceCallback;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION_O)
+public class BluetoothDeviceUpdaterTest {
+    @Mock
+    private DashboardFragment mDashboardFragment;
+    @Mock
+    private DevicePreferenceCallback mDevicePreferenceCallback;
+    @Mock
+    private CachedBluetoothDevice mCachedBluetoothDevice;
+    @Mock
+    private BluetoothDevice mBluetoothDevice;
+    @Mock
+    private SettingsActivity mSettingsActivity;
+
+    private Context mContext;
+    private BluetoothDeviceUpdater mBluetoothDeviceUpdater;
+    private BluetoothDevicePreference mPreference;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        doReturn(mContext).when(mDashboardFragment).getContext();
+        doReturn(mBluetoothDevice).when(mCachedBluetoothDevice).getDevice();
+
+        mPreference = new BluetoothDevicePreference(mContext, mCachedBluetoothDevice, false);
+        mBluetoothDeviceUpdater = new BluetoothDeviceUpdater(mDashboardFragment,
+                mDevicePreferenceCallback, null) {
+            @Override
+            public void update(CachedBluetoothDevice cachedBluetoothDevice) {
+                // do nothing
+            }
+        };
+        mBluetoothDeviceUpdater.setPrefContext(mContext);
+    }
+
+    @Test
+    public void testAddPreference_deviceExist_doNothing() {
+        mBluetoothDeviceUpdater.mPreferenceMap.put(mBluetoothDevice, mPreference);
+
+        mBluetoothDeviceUpdater.addPreference(mCachedBluetoothDevice);
+
+        verify(mDevicePreferenceCallback, never()).onDeviceAdded(any(Preference.class));
+    }
+
+    @Test
+    public void testAddPreference_deviceNotExist_addPreference() {
+        mBluetoothDeviceUpdater.addPreference(mCachedBluetoothDevice);
+
+        verify(mDevicePreferenceCallback).onDeviceAdded(any(Preference.class));
+        assertThat(mBluetoothDeviceUpdater.mPreferenceMap.containsKey(mBluetoothDevice)).isTrue();
+    }
+
+    @Test
+    public void testRemovePreference_deviceExist_removePreference() {
+        mBluetoothDeviceUpdater.mPreferenceMap.put(mBluetoothDevice, mPreference);
+
+        mBluetoothDeviceUpdater.removePreference(mCachedBluetoothDevice);
+
+        verify(mDevicePreferenceCallback).onDeviceRemoved(mPreference);
+        assertThat(mBluetoothDeviceUpdater.mPreferenceMap.containsKey(mBluetoothDevice)).isFalse();
+    }
+
+    @Test
+    public void testRemovePreference_deviceNotExist_doNothing() {
+        mBluetoothDeviceUpdater.removePreference(mCachedBluetoothDevice);
+
+        verify(mDevicePreferenceCallback, never()).onDeviceRemoved(any(Preference.class));
+    }
+
+    @Test
+    public void testDeviceProfilesListener_click_startBluetoothDeviceDetailPage() {
+        doReturn(mSettingsActivity).when(mDashboardFragment).getActivity();
+
+        mBluetoothDeviceUpdater.mDeviceProfilesListener.onGearClick(mPreference);
+
+        verify(mSettingsActivity).startPreferencePanel(eq(mDashboardFragment),
+                eq(BluetoothDeviceDetailsFragment.class.getName()), any(),
+                eq(R.string.device_details_title), eq(null), eq(null), eq(0));
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdaterTest.java b/tests/robotests/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdaterTest.java
new file mode 100644
index 0000000..c86664c
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/bluetooth/ConnectedBluetoothDeviceUpdaterTest.java
@@ -0,0 +1,108 @@
+/*
+ * 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 static org.mockito.Matchers.any;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.content.Context;
+
+import com.android.settings.TestConfig;
+import com.android.settings.connecteddevice.DevicePreferenceCallback;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settingslib.bluetooth.CachedBluetoothDevice;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION_O)
+public class ConnectedBluetoothDeviceUpdaterTest {
+    @Mock
+    private DashboardFragment mDashboardFragment;
+    @Mock
+    private DevicePreferenceCallback mDevicePreferenceCallback;
+    @Mock
+    private CachedBluetoothDevice mCachedBluetoothDevice;
+    @Mock
+    private BluetoothDevice mBluetoothDevice;
+
+    private Context mContext;
+    private ConnectedBluetoothDeviceUpdater mBluetoothDeviceUpdater;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        doReturn(mContext).when(mDashboardFragment).getContext();
+        doReturn(mBluetoothDevice).when(mCachedBluetoothDevice).getDevice();
+
+        mBluetoothDeviceUpdater = spy(new ConnectedBluetoothDeviceUpdater(mDashboardFragment,
+                mDevicePreferenceCallback, null));
+        mBluetoothDeviceUpdater.setPrefContext(mContext);
+        doNothing().when(mBluetoothDeviceUpdater).addPreference(any());
+        doNothing().when(mBluetoothDeviceUpdater).removePreference(any());
+    }
+
+    @Test
+    public void testUpdate_filterMatch_addPreference() {
+        doReturn(BluetoothDevice.BOND_BONDED).when(mBluetoothDevice).getBondState();
+        doReturn(true).when(mBluetoothDevice).isConnected();
+
+        mBluetoothDeviceUpdater.update(mCachedBluetoothDevice);
+
+        verify(mBluetoothDeviceUpdater).addPreference(mCachedBluetoothDevice);
+    }
+
+    @Test
+    public void testUpdate_filterNotMatch_removePreference() {
+        doReturn(BluetoothDevice.BOND_NONE).when(mBluetoothDevice).getBondState();
+        doReturn(false).when(mBluetoothDevice).isConnected();
+
+        mBluetoothDeviceUpdater.update(mCachedBluetoothDevice);
+
+        verify(mBluetoothDeviceUpdater).removePreference(mCachedBluetoothDevice);
+    }
+
+    @Test
+    public void testOnConnectionStateChanged_deviceConnected_addPreference() {
+        mBluetoothDeviceUpdater.onConnectionStateChanged(mCachedBluetoothDevice,
+                BluetoothAdapter.STATE_CONNECTED);
+
+        verify(mBluetoothDeviceUpdater).addPreference(mCachedBluetoothDevice);
+    }
+
+    @Test
+    public void testOnConnectionStateChanged_deviceDisconnected_removePreference() {
+        mBluetoothDeviceUpdater.onConnectionStateChanged(mCachedBluetoothDevice,
+                BluetoothAdapter.STATE_DISCONNECTED);
+
+        verify(mBluetoothDeviceUpdater).removePreference(mCachedBluetoothDevice);
+    }
+
+}
diff --git a/tests/robotests/src/com/android/settings/connecteddevice/ConnectedDeviceGroupControllerTest.java b/tests/robotests/src/com/android/settings/connecteddevice/ConnectedDeviceGroupControllerTest.java
new file mode 100644
index 0000000..e18115a
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/connecteddevice/ConnectedDeviceGroupControllerTest.java
@@ -0,0 +1,126 @@
+/*
+ * 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.connecteddevice;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceGroup;
+import android.support.v7.preference.PreferenceManager;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.TestConfig;
+import com.android.settings.bluetooth.ConnectedBluetoothDeviceUpdater;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION_O)
+public class ConnectedDeviceGroupControllerTest {
+    @Mock
+    private DashboardFragment mDashboardFragment;
+    @Mock
+    private ConnectedBluetoothDeviceUpdater mConnectedBluetoothDeviceUpdater;
+    @Mock
+    private PreferenceScreen mPreferenceScreen;
+    @Mock
+    private PreferenceManager mPreferenceManager;
+
+    private PreferenceGroup mPreferenceGroup;
+    private Context mContext;
+    private Preference mPreference;
+    private ConnectedDeviceGroupController mConnectedDeviceGroupController;
+    private Lifecycle mLifecycle;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        mPreference = new Preference(mContext);
+        mLifecycle = new Lifecycle(() -> mLifecycle);
+        mPreferenceGroup = spy(new PreferenceScreen(mContext, null));
+        doReturn(mPreferenceManager).when(mPreferenceGroup).getPreferenceManager();
+        doReturn(mContext).when(mDashboardFragment).getContext();
+
+        mConnectedDeviceGroupController = new ConnectedDeviceGroupController(mDashboardFragment,
+                mLifecycle, mConnectedBluetoothDeviceUpdater);
+        mConnectedDeviceGroupController.mPreferenceGroup = mPreferenceGroup;
+    }
+
+    @Test
+    public void testOnDeviceAdded_firstAdd_becomeVisible() {
+        mConnectedDeviceGroupController.onDeviceAdded(mPreference);
+
+        assertThat(mPreferenceGroup.isVisible()).isTrue();
+    }
+
+    @Test
+    public void testOnDeviceRemoved_lastRemove_becomeInvisible() {
+        mPreferenceGroup.addPreference(mPreference);
+
+        mConnectedDeviceGroupController.onDeviceRemoved(mPreference);
+
+        assertThat(mPreferenceGroup.isVisible()).isFalse();
+    }
+
+    @Test
+    public void testOnDeviceRemoved_notLastRemove_stillVisible() {
+        mPreferenceGroup.setVisible(true);
+        mPreferenceGroup.addPreference(mPreference);
+        mPreferenceGroup.addPreference(new Preference(mContext));
+
+        mConnectedDeviceGroupController.onDeviceRemoved(mPreference);
+
+        assertThat(mPreferenceGroup.isVisible()).isTrue();
+    }
+
+    @Test
+    public void testDisplayPreference_becomeInvisible() {
+        doReturn(mPreferenceGroup).when(mPreferenceScreen).findPreference(anyString());
+
+        mConnectedDeviceGroupController.displayPreference(mPreferenceScreen);
+
+        assertThat(mPreferenceGroup.isVisible()).isFalse();
+    }
+
+    @Test
+    public void testLifecycle() {
+        // register the callback in onStart()
+        mLifecycle.handleLifecycleEvent(android.arch.lifecycle.Lifecycle.Event.ON_START);
+        verify(mConnectedBluetoothDeviceUpdater).registerCallback();
+
+        // unregister the callback in onStop()
+        mLifecycle.handleLifecycleEvent(android.arch.lifecycle.Lifecycle.Event.ON_STOP);
+        verify(mConnectedBluetoothDeviceUpdater).unregisterCallback();
+    }
+}