ConditionalCoreStartable Introduction.

This changelist introduces ConditionalCoreStartable, an abstract
implementation of CoreStartable that allows conditions to gate
actions from lifecycle events (start/boot completed).

Bug: 261420431
Test: atest ConditionalCoreStartableTest
Change-Id: Ib4121d375f509ec16e8d2e34cdbee4f92f2ed7d6

packages/SystemUI/src/com/android/systemui/util/condition/ConditionalCoreStartable.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2023 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.systemui.util.condition;
+
+import com.android.systemui.CoreStartable;
+import com.android.systemui.shared.condition.Condition;
+import com.android.systemui.shared.condition.Monitor;
+
+import java.util.Set;
+
+/**
+ * {@link ConditionalCoreStartable} is a {@link com.android.systemui.CoreStartable} abstract
+ * implementation where conditions must be met before routines are executed.
+ */
+public abstract class ConditionalCoreStartable implements CoreStartable {
+    private final Monitor mMonitor;
+    private final Set<Condition> mConditionSet;
+    private Monitor.Subscription.Token mStartToken;
+    private Monitor.Subscription.Token mBootCompletedToken;
+
+    public ConditionalCoreStartable(Monitor monitor) {
+        this(monitor, null);
+    }
+
+    public ConditionalCoreStartable(Monitor monitor, Set<Condition> conditionSet) {
+        mMonitor = monitor;
+        mConditionSet = conditionSet;
+    }
+
+    @Override
+    public final void start() {
+        if (mConditionSet == null || mConditionSet.isEmpty()) {
+            onStart();
+            return;
+        }
+
+        mStartToken = mMonitor.addSubscription(
+                new Monitor.Subscription.Builder(allConditionsMet -> {
+                    if (allConditionsMet) {
+                        mMonitor.removeSubscription(mStartToken);
+                        mStartToken = null;
+                        onStart();
+                    }
+                }).addConditions(mConditionSet)
+                        .build());
+    }
+
+    protected abstract void onStart();
+
+    @Override
+    public final void onBootCompleted() {
+        if (mConditionSet == null || mConditionSet.isEmpty()) {
+            bootCompleted();
+            return;
+        }
+
+        mBootCompletedToken = mMonitor.addSubscription(
+                new Monitor.Subscription.Builder(allConditionsMet -> {
+                    if (allConditionsMet) {
+                        mMonitor.removeSubscription(mBootCompletedToken);
+                        mBootCompletedToken = null;
+                        bootCompleted();
+                    }
+                }).addConditions(mConditionSet)
+                        .build());
+    }
+
+    protected void bootCompleted() {
+    }
+}

packages/SystemUI/tests/src/com/android/systemui/util/condition/ConditionalCoreStartableTest.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2023 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.systemui.util.condition;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.testing.AndroidTestingRunner;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.systemui.CoreStartable;
+import com.android.systemui.SysuiTestCase;
+import com.android.systemui.shared.condition.Condition;
+import com.android.systemui.shared.condition.Monitor;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+@SmallTest
+@RunWith(AndroidTestingRunner.class)
+public class ConditionalCoreStartableTest extends SysuiTestCase {
+    public static class FakeConditionalCoreStartable extends ConditionalCoreStartable {
+        interface Callback {
+            void onStart();
+            void bootCompleted();
+        }
+
+        private final Callback mCallback;
+
+        public FakeConditionalCoreStartable(Monitor monitor, Set<Condition> conditions,
+                Callback callback) {
+            super(monitor, conditions);
+            mCallback = callback;
+        }
+
+        @Override
+        protected void onStart() {
+            mCallback.onStart();
+        }
+
+        @Override
+        protected void bootCompleted() {
+            mCallback.bootCompleted();
+        }
+    }
+
+
+    final Set<Condition> mConditions = new HashSet<>();
+
+    @Mock
+    Condition mCondition;
+
+    @Mock
+    Monitor mMonitor;
+
+    @Mock
+    FakeConditionalCoreStartable.Callback mCallback;
+
+    @Mock
+    Monitor.Subscription.Token mSubscriptionToken;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        mConditions.clear();
+    }
+
+    /**
+     * Verifies that {@link ConditionalCoreStartable#onStart()} is predicated on conditions being
+     * met.
+     */
+    @Test
+    public void testOnStartCallback() {
+        final CoreStartable coreStartable =
+                new FakeConditionalCoreStartable(mMonitor,
+                        new HashSet<>(Arrays.asList(mCondition)),
+                        mCallback);
+
+        when(mMonitor.addSubscription(any())).thenReturn(mSubscriptionToken);
+        coreStartable.start();
+
+        final ArgumentCaptor<Monitor.Subscription> subscriptionCaptor = ArgumentCaptor.forClass(
+                Monitor.Subscription.class);
+        verify(mMonitor).addSubscription(subscriptionCaptor.capture());
+
+        final Monitor.Subscription subscription = subscriptionCaptor.getValue();
+
+        assertThat(subscription.getConditions()).containsExactly(mCondition);
+
+        verify(mCallback, never()).onStart();
+
+        subscription.getCallback().onConditionsChanged(true);
+
+        verify(mCallback).onStart();
+        verify(mMonitor).removeSubscription(mSubscriptionToken);
+    }
+
+
+    /**
+     * Verifies that {@link ConditionalCoreStartable#bootCompleted()} ()} is predicated on
+     * conditions being met.
+     */
+    @Test
+    public void testBootCompleted() {
+        final CoreStartable coreStartable =
+                new FakeConditionalCoreStartable(mMonitor,
+                        new HashSet<>(Arrays.asList(mCondition)),
+                        mCallback);
+
+        when(mMonitor.addSubscription(any())).thenReturn(mSubscriptionToken);
+        coreStartable.onBootCompleted();
+
+        final ArgumentCaptor<Monitor.Subscription> subscriptionCaptor = ArgumentCaptor.forClass(
+                Monitor.Subscription.class);
+        verify(mMonitor).addSubscription(subscriptionCaptor.capture());
+
+        final Monitor.Subscription subscription = subscriptionCaptor.getValue();
+
+        assertThat(subscription.getConditions()).containsExactly(mCondition);
+
+        verify(mCallback, never()).bootCompleted();
+
+        subscription.getCallback().onConditionsChanged(true);
+
+        verify(mCallback).bootCompleted();
+        verify(mMonitor).removeSubscription(mSubscriptionToken);
+    }
+}