Bluetooth: reset mConnectionState when adapter is OFF

* No device is connected when Bluetooth adapter is OFF
* BluetoothSummaryUpdater should reset its connection state tracker in
  order to display the correct summary message on ConnectedDevice
  preference
* Otherwise, "Connected to null" will be shown because no device is
  connected while BluetoothSummaryUpdater is still in CONNECTED state
* Removed unused imports from BluetoothSummaryUpdater
* Write additional unit test to verify the above behaviour
* Add additional logging when deviceName is null in CONNECTED state

Bug: 62492716
Test: Pair and connect to Bluetooth device, turning Bluetooth ON/OFF,
      unit tests
Change-Id: I30726636f5678d61d6052f5b8d211aa20f26f409

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

@@ -20,7 +20,7 @@ import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.content.Context;
 import android.support.annotation.VisibleForTesting;
-import android.text.TextUtils;
+import android.util.Log;
 
 import com.android.settings.R;
 import com.android.settings.widget.SummaryUpdater;
@@ -29,9 +29,7 @@ import com.android.settingslib.bluetooth.CachedBluetoothDevice;
 import com.android.settingslib.bluetooth.LocalBluetoothAdapter;
 import com.android.settingslib.bluetooth.LocalBluetoothManager;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 import java.util.Set;
 
 /**
@@ -39,6 +37,7 @@ import java.util.Set;
  * bluetooth summary info.
  */
 public final class BluetoothSummaryUpdater extends SummaryUpdater implements BluetoothCallback {
+    private static final String TAG = "BluetoothSummaryUpdater";
 
     private final LocalBluetoothManager mBluetoothManager;
     private final LocalBluetoothAdapter mBluetoothAdapter;
@@ -58,6 +57,9 @@ public final class BluetoothSummaryUpdater extends SummaryUpdater implements Blu
     public void onBluetoothStateChanged(int bluetoothState) {
         mEnabled = bluetoothState == BluetoothAdapter.STATE_ON
             || bluetoothState == BluetoothAdapter.STATE_TURNING_ON;
+        if (!mEnabled) {
+            mConnectionState = BluetoothAdapter.STATE_DISCONNECTED;
+        }
         notifyChangeIfNeeded();
     }
 
@@ -161,7 +163,6 @@ public final class BluetoothSummaryUpdater extends SummaryUpdater implements Blu
         if (devices == null || devices.isEmpty()) {
             return null;
         }
-
         for (BluetoothDevice device : devices) {
             if (device.isConnected()) {
                 deviceName = device.getName();
@@ -171,7 +172,14 @@ public final class BluetoothSummaryUpdater extends SummaryUpdater implements Blu
                 }
             }
         }
-
+        if (deviceName == null) {
+            Log.w(TAG, "getConnectedDeviceSummary, deviceName is null, numBondedDevices="
+                    + devices.size());
+            for (BluetoothDevice device : devices) {
+                Log.w(TAG, "getConnectedDeviceSummary, device=" + device.getName() + "["
+                        + device.getAddress() + "]" + ", isConnected=" + device.isConnected());
+            }
+        }
         return count > 1 ? mContext.getString(R.string.bluetooth_connected_multiple_devices_summary)
                 : mContext.getString(R.string.bluetooth_connected_summary, deviceName);
     }

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

@@ -44,8 +44,11 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -132,6 +135,36 @@ public class BluetoothSummaryUpdaterTest {
                 mContext.getString(R.string.disconnected));
     }
 
+    @Test
+    public void onBluetoothStateChanged_ConnectedDisabledEnabled_shouldSendDisconnectedSummary() {
+        final boolean[] connected = {false};
+        final List<CachedBluetoothDevice> devices = new ArrayList<>();
+        devices.add(mock(CachedBluetoothDevice.class));
+        doAnswer(invocation -> connected[0]).when(devices.get(0)).isConnected();
+        when(mBluetoothManager.getCachedDeviceManager().getCachedDevicesCopy())
+                .thenReturn(devices);
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_DISCONNECTED);
+        prepareConnectedDevice(false);
+
+        mSummaryUpdater.register(true);
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.disconnected));
+
+        connected[0] = true;
+        when(mBtAdapter.getConnectionState()).thenReturn(BluetoothAdapter.STATE_CONNECTED);
+        mSummaryUpdater.onConnectionStateChanged(null /* device */,
+                BluetoothAdapter.STATE_CONNECTED);
+        verify(mListener).onSummaryChanged(
+                mContext.getString(R.string.bluetooth_connected_summary, DEVICE_NAME));
+
+        mSummaryUpdater.onBluetoothStateChanged(BluetoothAdapter.STATE_OFF);
+        verify(mListener).onSummaryChanged(mContext.getString(R.string.bluetooth_disabled));
+
+        connected[0] = false;
+        mSummaryUpdater.onBluetoothStateChanged(BluetoothAdapter.STATE_TURNING_ON);
+        verify(mListener, times(2)).onSummaryChanged(mContext.getString(R.string.disconnected));
+        verify(mListener, times(4)).onSummaryChanged(anyString());
+    }
+
     @Test
     public void onConnectionStateChanged_connected_shouldSendConnectedMessage() {
         final List<CachedBluetoothDevice> devices = new ArrayList<>();