Add ConnectedUsbDeviceUpdater

The usb updater listens to usb update and notify
ConnectedDeviceGroupController to add/remove
preference.

This cl:
1. Add ConntectedusbDeviceUpdater
2. Extract the UsbConnectionBroadcastReceiver since it would be
used both in controller and updater.
3. Add tests

Bug: 69333961
Test: RunSettingsRoboTests

Change-Id: Ic3b045a6faa4eba57d9b0c089ea1656141cc0220

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

@@ -19,6 +19,7 @@ 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;
@@ -42,26 +43,31 @@ public class ConnectedDeviceGroupController extends AbstractPreferenceController
     @VisibleForTesting
     PreferenceGroup mPreferenceGroup;
     private BluetoothDeviceUpdater mBluetoothDeviceUpdater;
+    private ConnectedUsbDeviceUpdater mConnectedUsbDeviceUpdater;
 
     public ConnectedDeviceGroupController(DashboardFragment fragment, Lifecycle lifecycle) {
         super(fragment.getContext());
-        init(lifecycle, new ConnectedBluetoothDeviceUpdater(fragment, this));
+        init(lifecycle, new ConnectedBluetoothDeviceUpdater(fragment, this),
+                new ConnectedUsbDeviceUpdater(fragment.getContext(), this));
     }
 
     @VisibleForTesting
     ConnectedDeviceGroupController(DashboardFragment fragment, Lifecycle lifecycle,
-            BluetoothDeviceUpdater bluetoothDeviceUpdater) {
+            BluetoothDeviceUpdater bluetoothDeviceUpdater,
+            ConnectedUsbDeviceUpdater connectedUsbDeviceUpdater) {
         super(fragment.getContext());
-        init(lifecycle, bluetoothDeviceUpdater);
+        init(lifecycle, bluetoothDeviceUpdater, connectedUsbDeviceUpdater);
     }
 
     @Override
     public void onStart() {
         mBluetoothDeviceUpdater.registerCallback();
+        mConnectedUsbDeviceUpdater.registerCallback();
     }
 
     @Override
     public void onStop() {
+        mConnectedUsbDeviceUpdater.unregisterCallback();
         mBluetoothDeviceUpdater.unregisterCallback();
     }
 
@@ -70,8 +76,10 @@ public class ConnectedDeviceGroupController extends AbstractPreferenceController
         super.displayPreference(screen);
         mPreferenceGroup = (PreferenceGroup) screen.findPreference(KEY);
         mPreferenceGroup.setVisible(false);
+
         mBluetoothDeviceUpdater.setPrefContext(screen.getContext());
         mBluetoothDeviceUpdater.forceUpdate();
+        mConnectedUsbDeviceUpdater.initUsbPreference(screen.getContext());
     }
 
     @Override
@@ -100,10 +108,12 @@ public class ConnectedDeviceGroupController extends AbstractPreferenceController
         }
     }
 
-    private void init(Lifecycle lifecycle, BluetoothDeviceUpdater bluetoothDeviceUpdater) {
+    private void init(Lifecycle lifecycle, BluetoothDeviceUpdater bluetoothDeviceUpdater,
+            ConnectedUsbDeviceUpdater connectedUsbDeviceUpdater) {
         if (lifecycle != null) {
             lifecycle.addObserver(this);
         }
         mBluetoothDeviceUpdater = bluetoothDeviceUpdater;
+        mConnectedUsbDeviceUpdater = connectedUsbDeviceUpdater;
     }
 }

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

@@ -0,0 +1,92 @@
+/*
+ * 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.content.Context;
+import android.content.Intent;
+import android.support.annotation.VisibleForTesting;
+
+import com.android.settings.R;
+import com.android.settings.deviceinfo.UsbBackend;
+import com.android.settings.deviceinfo.UsbModeChooserActivity;
+import com.android.settings.widget.GearPreference;
+
+/**
+ * Controller to maintain connected usb device
+ */
+public class ConnectedUsbDeviceUpdater {
+    private Context mContext;
+    private UsbBackend mUsbBackend;
+    private DevicePreferenceCallback mDevicePreferenceCallback;
+    @VisibleForTesting
+    GearPreference mUsbPreference;
+    @VisibleForTesting
+    UsbConnectionBroadcastReceiver mUsbReceiver;
+
+    private UsbConnectionBroadcastReceiver.UsbConnectionListener mUsbConnectionListener =
+            (connected) -> {
+                if (connected) {
+                    mUsbPreference.setSummary(
+                            UsbModePreferenceController.getSummary(mUsbBackend.getCurrentMode()));
+                    mDevicePreferenceCallback.onDeviceAdded(mUsbPreference);
+                } else {
+                    mDevicePreferenceCallback.onDeviceRemoved(mUsbPreference);
+                }
+            };
+
+    public ConnectedUsbDeviceUpdater(Context context,
+            DevicePreferenceCallback devicePreferenceCallback) {
+        this(context, devicePreferenceCallback, new UsbBackend(context));
+    }
+
+    @VisibleForTesting
+    ConnectedUsbDeviceUpdater(Context context, DevicePreferenceCallback devicePreferenceCallback,
+            UsbBackend usbBackend) {
+        mContext = context;
+        mDevicePreferenceCallback = devicePreferenceCallback;
+        mUsbBackend = usbBackend;
+        mUsbReceiver = new UsbConnectionBroadcastReceiver(context, mUsbConnectionListener);
+    }
+
+    public void registerCallback() {
+        // This method could handle multiple register
+        mUsbReceiver.register();
+    }
+
+    public void unregisterCallback() {
+        mUsbReceiver.unregister();
+    }
+
+    public void initUsbPreference(Context context) {
+        mUsbPreference = new GearPreference(context, null /* AttributeSet */);
+        mUsbPreference.setTitle(R.string.usb_pref);
+        mUsbPreference.setIcon(R.drawable.ic_usb);
+        mUsbPreference.setSelectable(false);
+        mUsbPreference.setOnGearClickListener((GearPreference p) -> {
+            final Intent intent = new Intent(mContext, UsbModeChooserActivity.class);
+            mContext.startActivity(intent);
+        });
+
+        forceUpdate();
+    }
+
+    private void forceUpdate() {
+        // Register so we can get the connection state from sticky intent.
+        //TODO(b/70336520): Use an API to get data instead of sticky intent
+        mUsbReceiver.register();
+        mUsbConnectionListener.onUsbConnectionChanged(mUsbReceiver.isConnected());
+    }
+}

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

@@ -0,0 +1,76 @@
+/*
+ * 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.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.hardware.usb.UsbManager;
+
+/**
+ * Receiver to receive usb update and use {@link UsbConnectionListener} to invoke callback
+ */
+public class UsbConnectionBroadcastReceiver extends BroadcastReceiver {
+    private Context mContext;
+    private UsbConnectionListener mUsbConnectionListener;
+    private boolean mListeningToUsbEvents;
+    private boolean mConnected;
+
+    public UsbConnectionBroadcastReceiver(Context context,
+            UsbConnectionListener usbConnectionListener) {
+        mContext = context;
+        mUsbConnectionListener = usbConnectionListener;
+    }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        mConnected = intent != null
+                && intent.getExtras().getBoolean(UsbManager.USB_CONNECTED);
+        if (mUsbConnectionListener != null) {
+            mUsbConnectionListener.onUsbConnectionChanged(mConnected);
+        }
+    }
+
+    public void register() {
+        if (!mListeningToUsbEvents) {
+            final IntentFilter intentFilter = new IntentFilter(UsbManager.ACTION_USB_STATE);
+            final Intent intent = mContext.registerReceiver(this, intentFilter);
+            mConnected = intent != null
+                    && intent.getExtras().getBoolean(UsbManager.USB_CONNECTED);
+            mListeningToUsbEvents = true;
+        }
+    }
+
+    public void unregister() {
+        if (mListeningToUsbEvents) {
+            mContext.unregisterReceiver(this);
+            mListeningToUsbEvents = false;
+        }
+    }
+
+    public boolean isConnected() {
+        return mConnected;
+    }
+
+    /**
+     * Interface definition for a callback to be invoked when usb connection is changed.
+     */
+    interface UsbConnectionListener {
+        void onUsbConnectionChanged(boolean connected);
+    }
+}

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

@@ -15,17 +15,12 @@
  */
 package com.android.settings.connecteddevice;
 
-import android.content.BroadcastReceiver;
 import android.content.Context;
-import android.content.Intent;
-import android.content.IntentFilter;
-import android.hardware.usb.UsbManager;
-import android.support.annotation.VisibleForTesting;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceScreen;
 
-import com.android.settings.core.PreferenceControllerMixin;
 import com.android.settings.R;
+import com.android.settings.core.PreferenceControllerMixin;
 import com.android.settings.deviceinfo.UsbBackend;
 import com.android.settingslib.core.AbstractPreferenceController;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
@@ -44,19 +39,21 @@ public class UsbModePreferenceController extends AbstractPreferenceController
     public UsbModePreferenceController(Context context, UsbBackend usbBackend) {
         super(context);
         mUsbBackend = usbBackend;
-        mUsbReceiver = new UsbConnectionBroadcastReceiver();
+        mUsbReceiver = new UsbConnectionBroadcastReceiver(mContext, (connected) -> {
+            updateSummary(mUsbPreference);
+        });
     }
 
     @Override
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
         mUsbPreference = screen.findPreference(KEY_USB_MODE);
-        updataSummary(mUsbPreference);
+        updateSummary(mUsbPreference);
     }
 
     @Override
     public void updateState(Preference preference) {
-        updataSummary(preference);
+        updateSummary(preference);
     }
 
     @Override
@@ -79,8 +76,7 @@ public class UsbModePreferenceController extends AbstractPreferenceController
         mUsbReceiver.register();
     }
 
-    @VisibleForTesting
+    public static int getSummary(int mode) {
-    int getSummary(int mode) {
         switch (mode) {
             case UsbBackend.MODE_POWER_SINK | UsbBackend.MODE_DATA_NONE:
                 return R.string.usb_summary_charging_only;
@@ -96,11 +92,11 @@ public class UsbModePreferenceController extends AbstractPreferenceController
         return 0;
     }
 
-    private void updataSummary(Preference preference) {
+    private void updateSummary(Preference preference) {
-        updataSummary(preference, mUsbBackend.getCurrentMode());
+        updateSummary(preference, mUsbBackend.getCurrentMode());
     }
 
-    private void updataSummary(Preference preference, int mode) {
+    private void updateSummary(Preference preference, int mode) {
         if (preference != null) {
             if (mUsbReceiver.isConnected()) {
                 preference.setEnabled(true);
@@ -112,40 +108,4 @@ public class UsbModePreferenceController extends AbstractPreferenceController
         }
     }
 
-    private class UsbConnectionBroadcastReceiver extends BroadcastReceiver {
-        private boolean mListeningToUsbEvents;
-        private boolean mConnected;
-
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            boolean connected = intent != null
-                    && intent.getExtras().getBoolean(UsbManager.USB_CONNECTED);
-            if (connected != mConnected) {
-                mConnected = connected;
-                updataSummary(mUsbPreference);
-            }
-        }
-
-        public void register() {
-            if (!mListeningToUsbEvents) {
-                IntentFilter intentFilter = new IntentFilter(UsbManager.ACTION_USB_STATE);
-                Intent intent = mContext.registerReceiver(this, intentFilter);
-                mConnected = intent != null
-                        && intent.getExtras().getBoolean(UsbManager.USB_CONNECTED);
-                mListeningToUsbEvents = true;
-            }
-        }
-
-        public void unregister() {
-            if (mListeningToUsbEvents) {
-                mContext.unregisterReceiver(this);
-                mListeningToUsbEvents = false;
-            }
-        }
-
-        public boolean isConnected() {
-            return mConnected;
-        }
-    }
-
 }

tests/robotests/src/com/android/settings/connecteddevice/ConnectedDeviceGroupControllerTest.java

@@ -37,6 +37,7 @@ import com.android.settingslib.core.lifecycle.Lifecycle;
 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;
@@ -45,13 +46,17 @@ import org.robolectric.annotation.Config;
 @RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class ConnectedDeviceGroupControllerTest {
+    private static final String PREFERENCE_KEY_1 = "pref_key_1";
+
     @Mock
     private DashboardFragment mDashboardFragment;
     @Mock
     private ConnectedBluetoothDeviceUpdater mConnectedBluetoothDeviceUpdater;
     @Mock
-    private PreferenceScreen mPreferenceScreen;
+    private ConnectedUsbDeviceUpdater mConnectedUsbDeviceUpdater;
     @Mock
+    private PreferenceScreen mPreferenceScreen;
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
     private PreferenceManager mPreferenceManager;
 
     private PreferenceGroup mPreferenceGroup;
@@ -66,30 +71,33 @@ public class ConnectedDeviceGroupControllerTest {
 
         mContext = RuntimeEnvironment.application;
         mPreference = new Preference(mContext);
+        mPreference.setKey(PREFERENCE_KEY_1);
         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);
+                mLifecycle, mConnectedBluetoothDeviceUpdater, mConnectedUsbDeviceUpdater);
         mConnectedDeviceGroupController.mPreferenceGroup = mPreferenceGroup;
     }
 
     @Test
-    public void testOnDeviceAdded_firstAdd_becomeVisible() {
+    public void testOnDeviceAdded_firstAdd_becomeVisibleAndPreferenceAdded() {
         mConnectedDeviceGroupController.onDeviceAdded(mPreference);
 
         assertThat(mPreferenceGroup.isVisible()).isTrue();
+        assertThat(mPreferenceGroup.findPreference(PREFERENCE_KEY_1)).isEqualTo(mPreference);
     }
 
     @Test
-    public void testOnDeviceRemoved_lastRemove_becomeInvisible() {
+    public void testOnDeviceRemoved_lastRemove_becomeInvisibleAndPreferenceRemoved() {
         mPreferenceGroup.addPreference(mPreference);
 
         mConnectedDeviceGroupController.onDeviceRemoved(mPreference);
 
         assertThat(mPreferenceGroup.isVisible()).isFalse();
+        assertThat(mPreferenceGroup.getPreferenceCount()).isEqualTo(0);
     }
 
     @Test
@@ -117,9 +125,11 @@ public class ConnectedDeviceGroupControllerTest {
         // register the callback in onStart()
         mLifecycle.handleLifecycleEvent(android.arch.lifecycle.Lifecycle.Event.ON_START);
         verify(mConnectedBluetoothDeviceUpdater).registerCallback();
+        verify(mConnectedUsbDeviceUpdater).registerCallback();
 
         // unregister the callback in onStop()
         mLifecycle.handleLifecycleEvent(android.arch.lifecycle.Lifecycle.Event.ON_STOP);
         verify(mConnectedBluetoothDeviceUpdater).unregisterCallback();
+        verify(mConnectedUsbDeviceUpdater).unregisterCallback();
     }
 }

tests/robotests/src/com/android/settings/connecteddevice/ConnectedUsbDeviceUpdaterTest.java

@@ -0,0 +1,89 @@
+/*
+ * 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.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+
+import com.android.settings.R;
+import com.android.settings.TestConfig;
+import com.android.settings.deviceinfo.UsbBackend;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+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)
+public class ConnectedUsbDeviceUpdaterTest {
+    private Context mContext;
+    private ConnectedUsbDeviceUpdater mDeviceUpdater;
+
+    @Mock
+    private UsbConnectionBroadcastReceiver mUsbReceiver;
+    @Mock
+    private DevicePreferenceCallback mDevicePreferenceCallback;
+    @Mock
+    private UsbBackend mUsbBackend;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        mDeviceUpdater = new ConnectedUsbDeviceUpdater(mContext, mDevicePreferenceCallback,
+                mUsbBackend);
+        mDeviceUpdater.mUsbReceiver = mUsbReceiver;
+    }
+
+    @Test
+    public void testInitUsbPreference_preferenceInit() {
+        mDeviceUpdater.initUsbPreference(mContext);
+
+        assertThat(mDeviceUpdater.mUsbPreference.getTitle()).isEqualTo("USB");
+        assertThat(mDeviceUpdater.mUsbPreference.getIcon()).isEqualTo(mContext.getDrawable(
+                R.drawable.ic_usb));
+        assertThat(mDeviceUpdater.mUsbPreference.isSelectable()).isFalse();
+    }
+
+    @Test
+    public void testInitUsbPreference_usbConnected_preferenceAdded() {
+        doReturn(true).when(mUsbReceiver).isConnected();
+
+        mDeviceUpdater.initUsbPreference(mContext);
+
+        verify(mDevicePreferenceCallback).onDeviceAdded(mDeviceUpdater.mUsbPreference);
+    }
+
+    @Test
+    public void testInitUsbPreference_usbDisconnected_preferenceRemoved() {
+        doReturn(false).when(mUsbReceiver).isConnected();
+
+        mDeviceUpdater.initUsbPreference(mContext);
+
+        verify(mDevicePreferenceCallback).onDeviceRemoved(mDeviceUpdater.mUsbPreference);
+    }
+
+}

tests/robotests/src/com/android/settings/connecteddevice/UsbConnectionBroadcastReceiverTest.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 com.google.common.truth.Truth.assertWithMessage;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.hardware.usb.UsbManager;
+
+import com.android.settings.TestConfig;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+
+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;
+import org.robolectric.shadows.ShadowApplication;
+
+import java.util.List;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class UsbConnectionBroadcastReceiverTest {
+    private Context mContext;
+    private UsbConnectionBroadcastReceiver mReceiver;
+    private ShadowApplication mShadowApplication;
+
+    @Mock
+    private UsbConnectionBroadcastReceiver.UsbConnectionListener mListener;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mShadowApplication = ShadowApplication.getInstance();
+        mContext = RuntimeEnvironment.application;
+        mReceiver = new UsbConnectionBroadcastReceiver(mContext, mListener);
+    }
+
+    @Test
+    public void testOnReceive_usbConnected_invokeCallback() {
+        final Intent intent = new Intent();
+        intent.putExtra(UsbManager.USB_CONNECTED, true);
+
+        mReceiver.onReceive(mContext, intent);
+
+        verify(mListener).onUsbConnectionChanged(true);
+    }
+
+    @Test
+    public void testOnReceive_usbDisconnected_invokeCallback() {
+        final Intent intent = new Intent();
+        intent.putExtra(UsbManager.USB_CONNECTED, false);
+
+        mReceiver.onReceive(mContext, intent);
+
+        verify(mListener).onUsbConnectionChanged(false);
+    }
+
+    @Test
+    public void testRegister_invokeMethodTwice_registerOnce() {
+        mReceiver.register();
+        mReceiver.register();
+
+        final List<BroadcastReceiver> receivers = mShadowApplication.getReceiversForIntent(
+                new Intent(UsbManager.ACTION_USB_STATE));
+        assertHasOneUsbConnectionBroadcastReceiver(receivers);
+    }
+
+    @Test
+    public void testUnregister_invokeMethodTwice_unregisterOnce() {
+        mReceiver.register();
+        mReceiver.unregister();
+        mReceiver.unregister();
+
+        final List<BroadcastReceiver> receivers = mShadowApplication.getReceiversForIntent(
+                new Intent(UsbManager.ACTION_USB_STATE));
+        assertHasNoUsbConnectionBroadcastReceiver(receivers);
+    }
+
+    private void assertHasOneUsbConnectionBroadcastReceiver(List<BroadcastReceiver> receivers) {
+        boolean hasReceiver = false;
+        for (final BroadcastReceiver receiver : receivers) {
+            if (receiver instanceof UsbConnectionBroadcastReceiver) {
+                // If hasReceiver is true, then we're at the second copy of it so fail.
+                assertWithMessage(
+                        "Only one instance of UsbConnectionBroadcastReceiver should be "
+                                + "registered").that(
+                        hasReceiver).isFalse();
+                hasReceiver = true;
+            }
+        }
+        assertThat(hasReceiver).isTrue();
+    }
+
+    private void assertHasNoUsbConnectionBroadcastReceiver(List<BroadcastReceiver> receivers) {
+        for (final BroadcastReceiver receiver : receivers) {
+            assertThat(receiver instanceof UsbConnectionBroadcastReceiver).isFalse();
+        }
+    }
+}