Merge changes I1efabf11,Ib4121d37,Ifbe498ba into tm-qpr-dev

* changes:
  UserProcessCondition Introduction.
  ConditionalCoreStartable Introduction.
  Add Preconditions and Nested Subscriptions.

packages/SystemUI/shared/src/com/android/systemui/shared/condition/Monitor.java

@@ -38,13 +38,19 @@ import javax.inject.Inject;
 public class Monitor {
     private final String mTag = getClass().getSimpleName();
     private final Executor mExecutor;
+    private final Set<Condition> mPreconditions;
 
     private final HashMap<Condition, ArraySet<Subscription.Token>> mConditions = new HashMap<>();
     private final HashMap<Subscription.Token, SubscriptionState> mSubscriptions = new HashMap<>();
 
     private static class SubscriptionState {
         private final Subscription mSubscription;
+
+        // A subscription must maintain a reference to any active nested subscription so that it may
+        // be later removed when the current subscription becomes invalid.
+        private Subscription.Token mNestedSubscriptionToken;
         private Boolean mAllConditionsMet;
+        private boolean mActive;
 
         SubscriptionState(Subscription subscription) {
             mSubscription = subscription;
@@ -54,7 +60,27 @@ public class Monitor {
             return mSubscription.mConditions;
         }
 
-        public void update() {
+        /**
+         * Signals that the {@link Subscription} is now being monitored and will receive updates
+         * based on its conditions.
+         */
+        private void setActive(boolean active) {
+            if (mActive == active) {
+                return;
+            }
+
+            mActive = active;
+
+            final Callback callback = mSubscription.getCallback();
+
+            if (callback == null) {
+                return;
+            }
+
+            callback.onActiveChanged(active);
+        }
+
+        public void update(Monitor monitor) {
             final Boolean result = Evaluator.INSTANCE.evaluate(mSubscription.mConditions,
                     Evaluator.OP_AND);
             // Consider unknown (null) as true
@@ -65,7 +91,50 @@ public class Monitor {
             }
 
             mAllConditionsMet = newAllConditionsMet;
-            mSubscription.mCallback.onConditionsChanged(mAllConditionsMet);
+
+            final Subscription nestedSubscription = mSubscription.getNestedSubscription();
+
+            if (nestedSubscription != null) {
+                if (mAllConditionsMet && mNestedSubscriptionToken == null) {
+                    // When all conditions are met for a subscription with a nested subscription
+                    // that is not currently being monitored, add the nested subscription for
+                    // monitor.
+                    mNestedSubscriptionToken =
+                            monitor.addSubscription(nestedSubscription, null);
+                } else if (!mAllConditionsMet && mNestedSubscriptionToken != null) {
+                    // When conditions are not met and there is an active nested condition, remove
+                    // the nested condition from monitoring.
+                    removeNestedSubscription(monitor);
+                }
+                return;
+            }
+
+            mSubscription.getCallback().onConditionsChanged(mAllConditionsMet);
+        }
+
+        /**
+         * Invoked when the {@link Subscription} has been added to the {@link Monitor}.
+         */
+        public void onAdded() {
+            setActive(true);
+        }
+
+        /**
+         * Invoked when the {@link Subscription} has been removed from the {@link Monitor},
+         * allowing cleanup code to run.
+         */
+        public void onRemoved(Monitor monitor) {
+            setActive(false);
+            removeNestedSubscription(monitor);
+        }
+
+        private void removeNestedSubscription(Monitor monitor) {
+            if (mNestedSubscriptionToken == null) {
+                return;
+            }
+
+            monitor.removeSubscription(mNestedSubscriptionToken);
+            mNestedSubscriptionToken = null;
         }
     }
 
@@ -77,9 +146,20 @@ public class Monitor {
         }
     };
 
+    /**
+     * Constructor for injected use-cases. By default, no preconditions are present.
+     */
     @Inject
     public Monitor(@Main Executor executor) {
+        this(executor, Collections.emptySet());
+    }
+
+    /**
+     * Main constructor, allowing specifying preconditions.
+     */
+    public Monitor(Executor executor, Set<Condition> preconditions) {
         mExecutor = executor;
+        mPreconditions = preconditions;
     }
 
     private void updateConditionMetState(Condition condition) {
@@ -91,7 +171,7 @@ public class Monitor {
             return;
         }
 
-        subscriptions.stream().forEach(token -> mSubscriptions.get(token).update());
+        subscriptions.stream().forEach(token -> mSubscriptions.get(token).update(this));
     }
 
     /**
@@ -101,15 +181,25 @@ public class Monitor {
      * @return A {@link Subscription.Token} that can be used to remove the subscription.
      */
     public Subscription.Token addSubscription(@NonNull Subscription subscription) {
+        return addSubscription(subscription, mPreconditions);
+    }
+
+    private Subscription.Token addSubscription(@NonNull Subscription subscription,
+            Set<Condition> preconditions) {
+        // If preconditions are set on the monitor, set up as a nested condition.
+        final Subscription normalizedCondition = preconditions != null
+                ? new Subscription.Builder(subscription).addConditions(preconditions).build()
+                : subscription;
+
         final Subscription.Token token = new Subscription.Token();
-        final SubscriptionState state = new SubscriptionState(subscription);
+        final SubscriptionState state = new SubscriptionState(normalizedCondition);
 
         mExecutor.execute(() -> {
             if (shouldLog()) Log.d(mTag, "adding subscription");
             mSubscriptions.put(token, state);
 
             // Add and associate conditions.
-            subscription.getConditions().stream().forEach(condition -> {
+            normalizedCondition.getConditions().stream().forEach(condition -> {
                 if (!mConditions.containsKey(condition)) {
                     mConditions.put(condition, new ArraySet<>());
                     condition.addCallback(mConditionCallback);
@@ -118,8 +208,10 @@ public class Monitor {
                 mConditions.get(condition).add(token);
             });
 
+            state.onAdded();
+
             // Update subscription state.
-            state.update();
+            state.update(this);
 
         });
         return token;
@@ -139,7 +231,9 @@ public class Monitor {
                 return;
             }
 
-            mSubscriptions.remove(token).getConditions().forEach(condition -> {
+            final SubscriptionState removedSubscription = mSubscriptions.remove(token);
+
+            removedSubscription.getConditions().forEach(condition -> {
                 if (!mConditions.containsKey(condition)) {
                     Log.e(mTag, "condition not present:" + condition);
                     return;
@@ -153,6 +247,8 @@ public class Monitor {
                     mConditions.remove(condition);
                 }
             });
+
+            removedSubscription.onRemoved(this);
         });
     }
 
@@ -168,12 +264,19 @@ public class Monitor {
         private final Set<Condition> mConditions;
         private final Callback mCallback;
 
-        /**
-         *
-         */
-        public Subscription(Set<Condition> conditions, Callback callback) {
+        // A nested {@link Subscription} is a special callback where the specified condition's
+        // active state is dependent on the conditions of the parent {@link Subscription} being met.
+        // Once active, the nested subscription's conditions are registered as normal with the
+        // monitor and its callback (which could also be a nested condition) is triggered based on
+        // those conditions. The nested condition will be removed from monitor if the outer
+        // subscription's conditions ever become invalid.
+        private final Subscription mNestedSubscription;
+
+        private Subscription(Set<Condition> conditions, Callback callback,
+                Subscription nestedSubscription) {
             this.mConditions = Collections.unmodifiableSet(conditions);
             this.mCallback = callback;
+            this.mNestedSubscription = nestedSubscription;
         }
 
         public Set<Condition> getConditions() {
@@ -184,6 +287,10 @@ public class Monitor {
             return mCallback;
         }
 
+        public Subscription getNestedSubscription() {
+            return mNestedSubscription;
+        }
+
         /**
          * A {@link Token} is an identifier that is associated with a {@link Subscription} which is
          * registered with a {@link Monitor}.
@@ -196,14 +303,26 @@ public class Monitor {
          */
         public static class Builder {
             private final Callback mCallback;
+            private final Subscription mNestedSubscription;
             private final ArraySet<Condition> mConditions;
+            private final ArraySet<Condition> mPreconditions;
 
             /**
              * Default constructor specifying the {@link Callback} for the {@link Subscription}.
              */
             public Builder(Callback callback) {
+                this(null, callback);
+            }
+
+            public Builder(Subscription nestedSubscription) {
+                this(nestedSubscription, null);
+            }
+
+            private Builder(Subscription nestedSubscription, Callback callback) {
+                mNestedSubscription = nestedSubscription;
                 mCallback = callback;
-                mConditions = new ArraySet<>();
+                mConditions = new ArraySet();
+                mPreconditions = new ArraySet();
             }
 
             /**
@@ -216,12 +335,39 @@ public class Monitor {
                 return this;
             }
 
+            /**
+             * Adds a set of {@link Condition} to be a precondition for {@link Subscription}.
+             *
+             * @return The updated {@link Builder}.
+             */
+            public Builder addPreconditions(Set<Condition> condition) {
+                if (condition == null) {
+                    return this;
+                }
+                mPreconditions.addAll(condition);
+                return this;
+            }
+
+            /**
+             * Adds a {@link Condition} to be a precondition for {@link Subscription}.
+             *
+             * @return The updated {@link Builder}.
+             */
+            public Builder addPrecondition(Condition condition) {
+                mPreconditions.add(condition);
+                return this;
+            }
+
             /**
              * Adds a set of {@link Condition} to be associated with the {@link Subscription}.
              *
              * @return The updated {@link Builder}.
              */
             public Builder addConditions(Set<Condition> condition) {
+                if (condition == null) {
+                    return this;
+                }
+
                 mConditions.addAll(condition);
                 return this;
             }
@@ -232,7 +378,11 @@ public class Monitor {
              * @return The resulting {@link Subscription}.
              */
             public Subscription build() {
-                return new Subscription(mConditions, mCallback);
+                final Subscription subscription =
+                        new Subscription(mConditions, mCallback, mNestedSubscription);
+                return !mPreconditions.isEmpty()
+                        ? new Subscription(mPreconditions, null, subscription)
+                        : subscription;
             }
         }
     }
@@ -255,5 +405,13 @@ public class Monitor {
          *                         only partial conditions have been fulfilled.
          */
         void onConditionsChanged(boolean allConditionsMet);
+
+        /**
+         * Called when the active state of the {@link Subscription} changes.
+         * @param active {@code true} when changes to the conditions will affect the
+         *               {@link Subscription}, {@code false} otherwise.
+         */
+        default void onActiveChanged(boolean active) {
+        }
     }
 }

packages/SystemUI/src/com/android/systemui/process/ProcessWrapper.java

@@ -0,0 +1,27 @@
+/*
+ * 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.process;
+
+/**
+ * A simple wrapper that provides access to process-related details. This facilitates testing by
+ * providing a mockable target around these details.
+ */
+public class ProcessWrapper {
+    public int getUserHandleIdentifier() {
+        return android.os.Process.myUserHandle().getIdentifier();
+    }
+}

packages/SystemUI/src/com/android/systemui/process/condition/UserProcessCondition.java

@@ -0,0 +1,48 @@
+/*
+ * 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.process.condition;
+
+import com.android.systemui.process.ProcessWrapper;
+import com.android.systemui.settings.UserTracker;
+import com.android.systemui.shared.condition.Condition;
+
+import javax.inject.Inject;
+
+/**
+ * {@link UserProcessCondition} provides a signal when the process handle belongs to the current
+ * user.
+ */
+public class UserProcessCondition extends Condition {
+    private final ProcessWrapper mProcessWrapper;
+    private final UserTracker mUserTracker;
+
+    @Inject
+    public UserProcessCondition(ProcessWrapper processWrapper, UserTracker userTracker) {
+        mProcessWrapper = processWrapper;
+        mUserTracker = userTracker;
+    }
+
+    @Override
+    protected void start() {
+        updateCondition(mUserTracker.getUserId()
+                == mProcessWrapper.getUserHandleIdentifier());
+    }
+
+    @Override
+    protected void stop() {
+    }
+}

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/process/condition/UserProcessConditionTest.java

@@ -0,0 +1,105 @@
+/*
+ * 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.process.condition;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.testing.AndroidTestingRunner;
+import android.testing.TestableLooper;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.systemui.SysuiTestCase;
+import com.android.systemui.process.ProcessWrapper;
+import com.android.systemui.settings.UserTracker;
+import com.android.systemui.shared.condition.Condition;
+import com.android.systemui.shared.condition.Monitor;
+import com.android.systemui.util.concurrency.FakeExecutor;
+import com.android.systemui.util.time.FakeSystemClock;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(AndroidTestingRunner.class)
+@TestableLooper.RunWithLooper
+@SmallTest
+public class UserProcessConditionTest extends SysuiTestCase {
+    @Mock
+    UserTracker mUserTracker;
+
+    @Mock
+    ProcessWrapper mProcessWrapper;
+
+    @Mock
+    Monitor.Callback mCallback;
+
+    private final FakeExecutor mExecutor = new FakeExecutor(new FakeSystemClock());
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    /**
+     * Verifies condition reports false when tracker reports a different user id than the
+     * identifier from the process handle.
+     */
+    @Test
+    public void testConditionFailsWithDifferentIds() {
+
+        final Condition condition = new UserProcessCondition(mProcessWrapper, mUserTracker);
+        when(mProcessWrapper.getUserHandleIdentifier()).thenReturn(0);
+        when(mUserTracker.getUserId()).thenReturn(1);
+
+        final Monitor monitor = new Monitor(mExecutor);
+
+        monitor.addSubscription(new Monitor.Subscription.Builder(mCallback)
+                .addCondition(condition)
+                .build());
+
+        mExecutor.runAllReady();
+
+        verify(mCallback).onConditionsChanged(false);
+    }
+
+    /**
+     * Verifies condition reports false when tracker reports a different user id than the
+     * identifier from the process handle.
+     */
+    @Test
+    public void testConditionSucceedsWithSameIds() {
+
+        final Condition condition = new UserProcessCondition(mProcessWrapper, mUserTracker);
+        when(mProcessWrapper.getUserHandleIdentifier()).thenReturn(0);
+        when(mUserTracker.getUserId()).thenReturn(0);
+
+        final Monitor monitor = new Monitor(mExecutor);
+
+        monitor.addSubscription(new Monitor.Subscription.Builder(mCallback)
+                .addCondition(condition)
+                .build());
+
+        mExecutor.runAllReady();
+
+        verify(mCallback).onConditionsChanged(true);
+    }
+
+}

packages/SystemUI/tests/src/com/android/systemui/shared/condition/ConditionMonitorTest.java

@@ -471,4 +471,142 @@ public class ConditionMonitorTest extends SysuiTestCase {
         mExecutor.runAllReady();
         verify(callback).onConditionsChanged(true);
     }
+
+    /**
+     * Ensures that the result of a condition being true leads to its nested condition being
+     * activated.
+     */
+    @Test
+    public void testNestedCondition() {
+        mCondition1.fakeUpdateCondition(false);
+        final Monitor.Callback callback =
+                mock(Monitor.Callback.class);
+
+        mCondition2.fakeUpdateCondition(false);
+
+        // Create a nested condition
+        mConditionMonitor.addSubscription(new Monitor.Subscription.Builder(
+                new Monitor.Subscription.Builder(callback)
+                        .addCondition(mCondition2)
+                        .build())
+                .addCondition(mCondition1)
+                .build());
+
+        mExecutor.runAllReady();
+
+        // Ensure the nested condition callback is not called at all.
+        verify(callback, never()).onActiveChanged(anyBoolean());
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+
+        // Update the inner condition to true and ensure that the nested condition is not triggered.
+        mCondition2.fakeUpdateCondition(true);
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+        mCondition2.fakeUpdateCondition(false);
+
+        // Set outer condition and make sure the inner condition becomes active and reports that
+        // conditions aren't met
+        mCondition1.fakeUpdateCondition(true);
+        mExecutor.runAllReady();
+
+        verify(callback).onActiveChanged(eq(true));
+        verify(callback).onConditionsChanged(eq(false));
+
+        Mockito.clearInvocations(callback);
+
+        // Update the inner condition and make sure the callback is updated.
+        mCondition2.fakeUpdateCondition(true);
+        mExecutor.runAllReady();
+
+        verify(callback).onConditionsChanged(true);
+
+        Mockito.clearInvocations(callback);
+        // Invalidate outer condition and make sure callback is informed, but the last state is
+        // not affected.
+        mCondition1.fakeUpdateCondition(false);
+        mExecutor.runAllReady();
+
+        verify(callback).onActiveChanged(eq(false));
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+    }
+
+    /**
+     * Ensures a subscription is predicated on its precondition.
+     */
+    @Test
+    public void testPrecondition() {
+        mCondition1.fakeUpdateCondition(false);
+        final Monitor.Callback callback =
+                mock(Monitor.Callback.class);
+
+        mCondition2.fakeUpdateCondition(false);
+
+        // Create a nested condition
+        mConditionMonitor.addSubscription(new Monitor.Subscription.Builder(callback)
+                .addPrecondition(mCondition1)
+                .addCondition(mCondition2)
+                .build());
+
+        mExecutor.runAllReady();
+
+        // Ensure the nested condition callback is not called at all.
+        verify(callback, never()).onActiveChanged(anyBoolean());
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+
+        // Update the condition to true and ensure that the nested condition is not triggered.
+        mCondition2.fakeUpdateCondition(true);
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+        mCondition2.fakeUpdateCondition(false);
+
+        // Set precondition and make sure the inner condition becomes active and reports that
+        // conditions aren't met
+        mCondition1.fakeUpdateCondition(true);
+        mExecutor.runAllReady();
+
+        verify(callback).onActiveChanged(eq(true));
+        verify(callback).onConditionsChanged(eq(false));
+
+        Mockito.clearInvocations(callback);
+
+        // Update the condition and make sure the callback is updated.
+        mCondition2.fakeUpdateCondition(true);
+        mExecutor.runAllReady();
+
+        verify(callback).onConditionsChanged(true);
+
+        Mockito.clearInvocations(callback);
+        // Invalidate precondition and make sure callback is informed, but the last state is
+        // not affected.
+        mCondition1.fakeUpdateCondition(false);
+        mExecutor.runAllReady();
+
+        verify(callback).onActiveChanged(eq(false));
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+    }
+
+    /**
+     * Ensure preconditions are applied to every subscription added to a monitor.
+     */
+    @Test
+    public void testPreconditionMonitor() {
+        final Monitor.Callback callback =
+                mock(Monitor.Callback.class);
+
+        mCondition2.fakeUpdateCondition(true);
+        final Monitor monitor = new Monitor(mExecutor, new HashSet<>(Arrays.asList(mCondition1)));
+
+        monitor.addSubscription(new Monitor.Subscription.Builder(callback)
+                .addCondition(mCondition2)
+                .build());
+
+        mExecutor.runAllReady();
+
+        verify(callback, never()).onActiveChanged(anyBoolean());
+        verify(callback, never()).onConditionsChanged(anyBoolean());
+
+        mCondition1.fakeUpdateCondition(true);
+        mExecutor.runAllReady();
+
+        verify(callback).onActiveChanged(eq(true));
+        verify(callback).onConditionsChanged(eq(true));
+    }
 }

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);
+    }
+}