diff --git a/src/com/android/settings/network/helper/LifecycleCallbackAdapter.java b/src/com/android/settings/network/helper/LifecycleCallbackAdapter.java new file mode 100644 index 00000000000..548eae572f4 --- /dev/null +++ b/src/com/android/settings/network/helper/LifecycleCallbackAdapter.java @@ -0,0 +1,100 @@ +/* + * Copyright (C) 2022 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.network.helper; + +import androidx.annotation.MainThread; +import androidx.annotation.NonNull; +import androidx.annotation.VisibleForTesting; +import androidx.lifecycle.Lifecycle; +import androidx.lifecycle.LifecycleEventObserver; +import androidx.lifecycle.LifecycleOwner; + +import java.util.concurrent.atomic.AtomicReference; + +/** + * A {@link androidx.lifecycle.LifecycleObserver} implementation of adapter over callback. + * + * Which including: + * 1. Request to active callback when Lifecycle.State.STARTED + * 2. Request to inactive callback when Lifecycle.State.STOPPED + * 3. Close (no further resume) when Lifecycle.State.DESTROYED + */ +@VisibleForTesting +abstract class LifecycleCallbackAdapter implements LifecycleEventObserver, AutoCloseable { + private static final String TAG = "LifecycleCallbackAdapter"; + private AtomicReference mLifecycle = new AtomicReference(); + + /** + * Constructor + * @param lifecycle {@link Lifecycle} to monitor + */ + @VisibleForTesting + protected LifecycleCallbackAdapter(@NonNull Lifecycle lifecycle) { + mLifecycle.set(lifecycle); + lifecycle.addObserver(this); + } + + /** + * Get {@link Lifecycle} under monitor. + * @return {@link Lifecycle}. Return {@code null} when closed. + */ + @VisibleForTesting + public Lifecycle getLifecycle() { + return mLifecycle.get(); + } + + /** + * Check current callback status. + * @return true when callback is active. + */ + public abstract boolean isCallbackActive(); + + /** + * Change callback status. + * @param isActive true to active callback, otherwise inactive. + */ + public abstract void setCallbackActive(boolean isActive); + + /** + * Implementation of LifecycleEventObserver. + */ + public void onStateChanged(LifecycleOwner source, Lifecycle.Event event) { + if (mLifecycle.get() == null) { + return; + } + + Lifecycle.State state = event.getTargetState(); + boolean expectCallbackActive = state.isAtLeast(Lifecycle.State.STARTED); + if (expectCallbackActive != isCallbackActive()) { + setCallbackActive(expectCallbackActive); + } + if (state == Lifecycle.State.DESTROYED) { + close(); + } + } + + /** + * Implementation of AutoCloseable. + */ + @MainThread + public void close() { + Lifecycle lifecycle = mLifecycle.getAndSet(null); + if (lifecycle != null) { + lifecycle.removeObserver(this); + } + } +} diff --git a/tests/unit/src/com/android/settings/network/helper/LifecycleCallbackAdapterTest.java b/tests/unit/src/com/android/settings/network/helper/LifecycleCallbackAdapterTest.java new file mode 100644 index 00000000000..ddeb3f81bd9 --- /dev/null +++ b/tests/unit/src/com/android/settings/network/helper/LifecycleCallbackAdapterTest.java @@ -0,0 +1,111 @@ +/* + * Copyright (C) 2022 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.network.helper; + +import static com.google.common.truth.Truth.assertThat; + +import androidx.lifecycle.Lifecycle; +import androidx.lifecycle.LifecycleOwner; +import androidx.lifecycle.LifecycleRegistry; +import androidx.test.ext.junit.runners.AndroidJUnit4; + +import org.junit.Before; +import org.junit.Test; +import org.junit.runner.RunWith; + +@RunWith(AndroidJUnit4.class) +public class LifecycleCallbackAdapterTest implements LifecycleOwner { + + private final LifecycleRegistry mRegistry = LifecycleRegistry.createUnsafe(this); + + private TestObj mTarget; + + @Before + public void setUp() { + mTarget = new TestObj(getLifecycle()); + } + + public Lifecycle getLifecycle() { + return mRegistry; + } + + @Test + public void lifecycle_get_lifecycleToMonitor() { + assertThat(mTarget.getLifecycle()).isEqualTo(mRegistry); + } + + @Test + public void lifecycle_stateChangeToStart_callbackActive() { + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE); + + assertThat(mTarget.getCallbackCount()).isEqualTo(0); + assertThat(mTarget.isCallbackActive()).isEqualTo(Boolean.FALSE); + + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_START); + + assertThat(mTarget.getCallbackCount()).isEqualTo(1); + assertThat(mTarget.isCallbackActive()).isEqualTo(Boolean.TRUE); + } + + @Test + public void lifecycle_stateChangeToStop_callbackInActive() { + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_START); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP); + + assertThat(mTarget.getCallbackCount()).isEqualTo(2); + assertThat(mTarget.isCallbackActive()).isEqualTo(Boolean.FALSE); + } + + @Test + public void lifecycle_stateChangeToDestroy_noFurtherActive() { + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_START); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY); + + assertThat(mTarget.getCallbackCount()).isEqualTo(2); + assertThat(mTarget.isCallbackActive()).isEqualTo(Boolean.FALSE); + + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE); + mRegistry.handleLifecycleEvent(Lifecycle.Event.ON_START); + + assertThat(mTarget.getCallbackCount()).isEqualTo(2); + assertThat(mTarget.isCallbackActive()).isEqualTo(Boolean.FALSE); + } + + public static class TestObj extends LifecycleCallbackAdapter { + boolean mIsActive; + int mNumberOfCallback; + + public TestObj(Lifecycle lifecycle) { + super(lifecycle); + } + + public boolean isCallbackActive() { + return mIsActive; + } + + public void setCallbackActive(boolean isActive) { + mIsActive = isActive; + mNumberOfCallback ++; + } + + protected int getCallbackCount() { + return mNumberOfCallback; + } + } +}