Merge "Add AnimatorTestRule for use with platform animators" into udc-qpr-dev

9 files changed, 821 insertions, 16 deletions

diff --git a/core/java/android/animation/AnimationHandler.java b/core/java/android/animation/AnimationHandler.java
index df8a50a1fa5c..4fc90ae9d22c 100644
--- a/core/java/android/animation/AnimationHandler.java
+++ b/core/java/android/animation/AnimationHandler.java
@@ -16,6 +16,7 @@
 
 package android.animation;
 
+import android.annotation.Nullable;
 import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.util.ArrayMap;
@@ -91,9 +92,13 @@ public class AnimationHandler {
     };
 
     public final static ThreadLocal<AnimationHandler> sAnimatorHandler = new ThreadLocal<>();
+    private static AnimationHandler sTestHandler = null;
     private boolean mListDirty = false;
 
     public static AnimationHandler getInstance() {
+        if (sTestHandler != null) {
+            return sTestHandler;
+        }
         if (sAnimatorHandler.get() == null) {
             sAnimatorHandler.set(new AnimationHandler());
         }
@@ -101,6 +106,17 @@ public class AnimationHandler {
     }
 
     /**
+     * Sets an instance that will be returned by {@link #getInstance()} on every thread.
+     * @return  the previously active test handler, if any.
+     * @hide
+     */
+    public static @Nullable AnimationHandler setTestHandler(@Nullable AnimationHandler handler) {
+        AnimationHandler oldHandler = sTestHandler;
+        sTestHandler = handler;
+        return oldHandler;
+    }
+
+    /**
      * System property that controls the behavior of pausing infinite animators when an app
      * is moved to the background.
      *
@@ -369,7 +385,10 @@ public class AnimationHandler {
      * Return the number of callbacks that have registered for frame callbacks.
      */
     public static int getAnimationCount() {
-        AnimationHandler handler = sAnimatorHandler.get();
+        AnimationHandler handler = sTestHandler;
+        if (handler == null) {
+            handler = sAnimatorHandler.get();
+        }
         if (handler == null) {
             return 0;
         }
diff --git a/packages/SystemUI/tests/src/android/animation/AnimatorTestRuleIsolationTest.kt b/packages/SystemUI/tests/src/android/animation/AnimatorTestRuleIsolationTest.kt
new file mode 100644
index 000000000000..7e105cf19e2b
--- /dev/null
+++ b/packages/SystemUI/tests/src/android/animation/AnimatorTestRuleIsolationTest.kt
@@ -0,0 +1,90 @@
+/*
+ * 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 android.animation
+
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper.RunWithLooper
+import androidx.core.animation.doOnEnd
+import androidx.test.filters.SmallTest
+import com.android.systemui.SysuiTestCase
+import com.google.common.truth.Truth.assertThat
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * This test class validates that two tests' animators are isolated from each other when using the
+ * same animator test rule. This is a test to prevent future instances of b/275602127.
+ */
+@RunWith(AndroidTestingRunner::class)
+@SmallTest
+@RunWithLooper(setAsMainLooper = true)
+class AnimatorTestRuleIsolationTest : SysuiTestCase() {
+
+    @get:Rule val animatorTestRule = AnimatorTestRule()
+
+    @Test
+    fun testA() {
+        // GIVEN global state is reset at the start of the test
+        didTouchA = false
+        didTouchB = false
+        // WHEN starting 2 animations of different durations, and setting didTouchA at the end
+        ObjectAnimator.ofFloat(0f, 1f).apply {
+            duration = 100
+            doOnEnd { didTouchA = true }
+            start()
+        }
+        ObjectAnimator.ofFloat(0f, 1f).apply {
+            duration = 150
+            doOnEnd { didTouchA = true }
+            start()
+        }
+        // WHEN when you advance time so that only one of the animations has ended
+        animatorTestRule.advanceTimeBy(100)
+        // VERIFY we did indeed end the current animation
+        assertThat(didTouchA).isTrue()
+        // VERIFY advancing the animator did NOT cause testB's animator to end
+        assertThat(didTouchB).isFalse()
+    }
+
+    @Test
+    fun testB() {
+        // GIVEN global state is reset at the start of the test
+        didTouchA = false
+        didTouchB = false
+        // WHEN starting 2 animations of different durations, and setting didTouchB at the end
+        ObjectAnimator.ofFloat(0f, 1f).apply {
+            duration = 100
+            doOnEnd { didTouchB = true }
+            start()
+        }
+        ObjectAnimator.ofFloat(0f, 1f).apply {
+            duration = 150
+            doOnEnd { didTouchB = true }
+            start()
+        }
+        animatorTestRule.advanceTimeBy(100)
+        // VERIFY advancing the animator did NOT cause testA's animator to end
+        assertThat(didTouchA).isFalse()
+        // VERIFY we did indeed end the current animation
+        assertThat(didTouchB).isTrue()
+    }
+
+    companion object {
+        var didTouchA = false
+        var didTouchB = false
+    }
+}
diff --git a/packages/SystemUI/tests/src/android/animation/AnimatorTestRulePrecisionTest.kt b/packages/SystemUI/tests/src/android/animation/AnimatorTestRulePrecisionTest.kt
new file mode 100644
index 000000000000..6c4036852802
--- /dev/null
+++ b/packages/SystemUI/tests/src/android/animation/AnimatorTestRulePrecisionTest.kt
@@ -0,0 +1,193 @@
+/*
+ * 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 android.animation
+
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper.RunWithLooper
+import androidx.core.animation.doOnEnd
+import androidx.test.filters.SmallTest
+import com.android.app.animation.Interpolators
+import com.android.systemui.SysuiTestCase
+import com.google.common.truth.Truth.assertThat
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidTestingRunner::class)
+@SmallTest
+@RunWithLooper(setAsMainLooper = true)
+class AnimatorTestRulePrecisionTest : SysuiTestCase() {
+
+    @get:Rule val animatorTestRule = AnimatorTestRule()
+
+    var value1: Float = -1f
+    var value2: Float = -1f
+
+    private inline fun animateThis(
+        propertyName: String,
+        duration: Long,
+        startDelay: Long = 0,
+        crossinline onEndAction: (animator: Animator) -> Unit,
+    ) {
+        ObjectAnimator.ofFloat(this, propertyName, 0f, 1f).also {
+            it.interpolator = Interpolators.LINEAR
+            it.duration = duration
+            it.startDelay = startDelay
+            it.doOnEnd(onEndAction)
+            it.start()
+        }
+    }
+
+    @Test
+    fun testSingleAnimator() {
+        var ended = false
+        animateThis("value1", duration = 100) { ended = true }
+
+        assertThat(value1).isEqualTo(0f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(50)
+        assertThat(value1).isEqualTo(0.5f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(49)
+        assertThat(value1).isEqualTo(0.99f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(ended).isTrue()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(0)
+    }
+
+    @Test
+    fun testDelayedAnimator() {
+        var ended = false
+        animateThis("value1", duration = 100, startDelay = 50) { ended = true }
+
+        assertThat(value1).isEqualTo(-1f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(49)
+        assertThat(value1).isEqualTo(-1f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(0f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(99)
+        assertThat(value1).isEqualTo(0.99f)
+        assertThat(ended).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(ended).isTrue()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(0)
+    }
+
+    @Test
+    fun testTwoAnimators() {
+        var ended1 = false
+        var ended2 = false
+        animateThis("value1", duration = 100) { ended1 = true }
+        animateThis("value2", duration = 200) { ended2 = true }
+        assertThat(value1).isEqualTo(0f)
+        assertThat(value2).isEqualTo(0f)
+        assertThat(ended1).isFalse()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(2)
+
+        animatorTestRule.advanceTimeBy(99)
+        assertThat(value1).isEqualTo(0.99f)
+        assertThat(value2).isEqualTo(0.495f)
+        assertThat(ended1).isFalse()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(2)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(0.5f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(99)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(0.995f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(1f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isTrue()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(0)
+    }
+
+    @Test
+    fun testChainedAnimators() {
+        var ended1 = false
+        var ended2 = false
+        animateThis("value1", duration = 100) {
+            ended1 = true
+            animateThis("value2", duration = 100) { ended2 = true }
+        }
+
+        assertThat(value1).isEqualTo(0f)
+        assertThat(value2).isEqualTo(-1f)
+        assertThat(ended1).isFalse()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(99)
+        assertThat(value1).isEqualTo(0.99f)
+        assertThat(value2).isEqualTo(-1f)
+        assertThat(ended1).isFalse()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(0f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(99)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(0.99f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isFalse()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(1)
+
+        animatorTestRule.advanceTimeBy(1)
+        assertThat(value1).isEqualTo(1f)
+        assertThat(value2).isEqualTo(1f)
+        assertThat(ended1).isTrue()
+        assertThat(ended2).isTrue()
+        assertThat(AnimationHandler.getAnimationCount()).isEqualTo(0)
+    }
+}
diff --git a/packages/SystemUI/tests/src/androidx/core/animation/AnimatorTestRuleTest.kt b/packages/SystemUI/tests/src/androidx/core/animation/AnimatorTestRuleIsolationTest.kt
index e7738aff6278..d034093a71b3 100644
--- a/packages/SystemUI/tests/src/androidx/core/animation/AnimatorTestRuleTest.kt
+++ b/packages/SystemUI/tests/src/androidx/core/animation/AnimatorTestRuleIsolationTest.kt
@@ -25,17 +25,23 @@ import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
 
+/**
+ * This test class validates that two tests' animators are isolated from each other when using the
+ * same animator test rule. This is a test to prevent future instances of b/275602127.
+ */
 @RunWith(AndroidTestingRunner::class)
 @SmallTest
 @RunWithLooper(setAsMainLooper = true)
-class AnimatorTestRuleTest : SysuiTestCase() {
+class AnimatorTestRuleIsolationTest : SysuiTestCase() {
 
     @get:Rule val animatorTestRule = AnimatorTestRule()
 
     @Test
     fun testA() {
+        // GIVEN global state is reset at the start of the test
         didTouchA = false
         didTouchB = false
+        // WHEN starting 2 animations of different durations, and setting didTouchA at the end
         ObjectAnimator.ofFloat(0f, 1f).apply {
             duration = 100
             doOnEnd { didTouchA = true }
@@ -46,15 +52,20 @@ class AnimatorTestRuleTest : SysuiTestCase() {
             doOnEnd { didTouchA = true }
             start()
         }
+        // WHEN when you advance time so that only one of the animations has ended
         animatorTestRule.advanceTimeBy(100)
+        // VERIFY we did indeed end the current animation
         assertThat(didTouchA).isTrue()
+        // VERIFY advancing the animator did NOT cause testB's animator to end
         assertThat(didTouchB).isFalse()
     }
 
     @Test
     fun testB() {
+        // GIVEN global state is reset at the start of the test
         didTouchA = false
         didTouchB = false
+        // WHEN starting 2 animations of different durations, and setting didTouchB at the end
         ObjectAnimator.ofFloat(0f, 1f).apply {
             duration = 100
             doOnEnd { didTouchB = true }
@@ -66,7 +77,9 @@ class AnimatorTestRuleTest : SysuiTestCase() {
             start()
         }
         animatorTestRule.advanceTimeBy(100)
+        // VERIFY advancing the animator did NOT cause testA's animator to end
         assertThat(didTouchA).isFalse()
+        // VERIFY we did indeed end the current animation
         assertThat(didTouchB).isTrue()
     }
 
diff --git a/packages/SystemUI/tests/utils/src/android/animation/AnimatorIsolationWorkaroundRule.kt b/packages/SystemUI/tests/utils/src/android/animation/AnimatorIsolationWorkaroundRule.kt
new file mode 100644
index 000000000000..b74ddae77e62
--- /dev/null
+++ b/packages/SystemUI/tests/utils/src/android/animation/AnimatorIsolationWorkaroundRule.kt
@@ -0,0 +1,111 @@
+/*
+ * 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 android.animation
+
+import android.os.Looper
+import android.util.Log
+import com.android.systemui.util.test.TestExceptionDeferrer
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+
+/**
+ * This rule is intended to be used by System UI tests that are otherwise blocked from using
+ * animators because of [PlatformAnimatorIsolationRule]. It is preferred that test authors use
+ * [AnimatorTestRule], as that rule allows test authors to step through animations and removes the
+ * need for tests to handle multiple threads. However, many System UI tests were written before this
+ * was conceivable, so this rule is intended to support those legacy tests.
+ */
+class AnimatorIsolationWorkaroundRule(
+    private val requiredLooper: Looper? = Looper.getMainLooper(),
+) : TestRule {
+    private inner class IsolationWorkaroundHandler(ruleThread: Thread) : AnimationHandler() {
+        private val exceptionDeferrer = TestExceptionDeferrer(TAG, ruleThread)
+        private val addedCallbacks = mutableSetOf<AnimationFrameCallback>()
+
+        fun tearDownAndThrowDeferred() {
+            addedCallbacks.forEach { super.removeCallback(it) }
+            exceptionDeferrer.throwDeferred()
+        }
+
+        override fun addAnimationFrameCallback(callback: AnimationFrameCallback?, delay: Long) {
+            checkLooper()
+            if (callback != null) {
+                addedCallbacks.add(callback)
+            }
+            super.addAnimationFrameCallback(callback, delay)
+        }
+
+        override fun addOneShotCommitCallback(callback: AnimationFrameCallback?) {
+            checkLooper()
+            super.addOneShotCommitCallback(callback)
+        }
+
+        override fun removeCallback(callback: AnimationFrameCallback?) {
+            super.removeCallback(callback)
+        }
+
+        override fun setProvider(provider: AnimationFrameCallbackProvider?) {
+            checkLooper()
+            super.setProvider(provider)
+        }
+
+        override fun autoCancelBasedOn(objectAnimator: ObjectAnimator?) {
+            checkLooper()
+            super.autoCancelBasedOn(objectAnimator)
+        }
+
+        private fun checkLooper() {
+            exceptionDeferrer.check(requiredLooper == null || Looper.myLooper() == requiredLooper) {
+                "Animations are being registered on a different looper than the expected one!" +
+                    " expected=$requiredLooper actual=${Looper.myLooper()}"
+            }
+        }
+    }
+
+    override fun apply(base: Statement, description: Description): Statement {
+        return object : Statement() {
+            @Throws(Throwable::class)
+            override fun evaluate() {
+                val workaroundHandler = IsolationWorkaroundHandler(Thread.currentThread())
+                val prevInstance = AnimationHandler.setTestHandler(workaroundHandler)
+                check(PlatformAnimatorIsolationRule.isIsolatingHandler(prevInstance)) {
+                    "AnimatorIsolationWorkaroundRule must be used within " +
+                        "PlatformAnimatorIsolationRule, but test handler was $prevInstance"
+                }
+                try {
+                    base.evaluate()
+                    val count = AnimationHandler.getAnimationCount()
+                    if (count > 0) {
+                        Log.w(TAG, "Animations still running: $count")
+                    }
+                } finally {
+                    val handlerAtEnd = AnimationHandler.setTestHandler(prevInstance)
+                    check(workaroundHandler == handlerAtEnd) {
+                        "Test handler was altered: expected=$workaroundHandler actual=$handlerAtEnd"
+                    }
+                    // Pass or fail, errors caught here should be the reason the test fails
+                    workaroundHandler.tearDownAndThrowDeferred()
+                }
+            }
+        }
+    }
+
+    private companion object {
+        private const val TAG = "AnimatorIsolationWorkaroundRule"
+    }
+}
diff --git a/packages/SystemUI/tests/utils/src/android/animation/AnimatorTestRule.java b/packages/SystemUI/tests/utils/src/android/animation/AnimatorTestRule.java
new file mode 100644
index 000000000000..6535f333f428
--- /dev/null
+++ b/packages/SystemUI/tests/utils/src/android/animation/AnimatorTestRule.java
@@ -0,0 +1,236 @@
+/*
+ * 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 android.animation;
+
+import android.animation.AnimationHandler.AnimationFrameCallback;
+import android.annotation.NonNull;
+import android.os.Looper;
+import android.os.SystemClock;
+import android.util.AndroidRuntimeException;
+import android.view.Choreographer;
+
+import com.android.internal.util.Preconditions;
+
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * JUnit {@link TestRule} that can be used to run {@link Animator}s without actually waiting for the
+ * duration of the animation. This also helps the test to be written in a deterministic manner.
+ *
+ * Create an instance of {@code AnimatorTestRule} and specify it as a {@link org.junit.Rule}
+ * of the test class. Use {@link #advanceTimeBy(long)} to advance animators that have been started.
+ * Note that {@link #advanceTimeBy(long)} should be called from the same thread you have used to
+ * start the animator.
+ *
+ * <pre>
+ * {@literal @}SmallTest
+ * {@literal @}RunWith(AndroidJUnit4.class)
+ * public class SampleAnimatorTest {
+ *
+ *     {@literal @}Rule
+ *     public AnimatorTestRule sAnimatorTestRule = new AnimatorTestRule();
+ *
+ *     {@literal @}UiThreadTest
+ *     {@literal @}Test
+ *     public void sample() {
+ *         final ValueAnimator animator = ValueAnimator.ofInt(0, 1000);
+ *         animator.setDuration(1000L);
+ *         assertThat(animator.getAnimatedValue(), is(0));
+ *         animator.start();
+ *         sAnimatorTestRule.advanceTimeBy(500L);
+ *         assertThat(animator.getAnimatedValue(), is(500));
+ *     }
+ * }
+ * </pre>
+ */
+public final class AnimatorTestRule implements TestRule {
+
+    private final Object mLock = new Object();
+    private final TestHandler mTestHandler = new TestHandler();
+    /**
+     * initializing the start time with {@link SystemClock#uptimeMillis()} reduces the discrepancies
+     * with various internals of classes like ValueAnimator which can sometimes read that clock via
+     * {@link android.view.animation.AnimationUtils#currentAnimationTimeMillis()}.
+     */
+    private final long mStartTime = SystemClock.uptimeMillis();
+    private long mTotalTimeDelta = 0;
+
+    @NonNull
+    @Override
+    public Statement apply(@NonNull final Statement base, @NonNull Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                AnimationHandler objAtStart = AnimationHandler.setTestHandler(mTestHandler);
+                try {
+                    base.evaluate();
+                } finally {
+                    AnimationHandler objAtEnd = AnimationHandler.setTestHandler(objAtStart);
+                    if (mTestHandler != objAtEnd) {
+                        // pass or fail, inner logic not restoring the handler needs to be reported.
+                        // noinspection ThrowFromFinallyBlock
+                        throw new IllegalStateException("Test handler was altered: expected="
+                                + mTestHandler + " actual=" + objAtEnd);
+                    }
+                }
+            }
+        };
+    }
+
+    /**
+     * If any new {@link Animator}s have been registered since the last time the frame time was
+     * advanced, initialize them with the current frame time.  Failing to do this will result in the
+     * animations beginning on the *next* advancement instead, so this is done automatically for
+     * test authors inside of {@link #advanceTimeBy}.  However this is exposed in case authors want
+     * to validate operations performed by onStart listeners.
+     * <p>
+     * NOTE: This is only required of the platform ValueAnimator because its start() method calls
+     * {@link AnimationHandler#addAnimationFrameCallback} BEFORE it calls startAnimation(), so this
+     * rule can't synchronously trigger the callback at that time.
+     */
+    public void initNewAnimators() {
+        requireLooper("AnimationTestRule#initNewAnimators()");
+        long currentTime = getCurrentTime();
+        List<AnimationFrameCallback> newCallbacks = new ArrayList<>(mTestHandler.mNewCallbacks);
+        mTestHandler.mNewCallbacks.clear();
+        for (AnimationFrameCallback newCallback : newCallbacks) {
+            newCallback.doAnimationFrame(currentTime);
+        }
+    }
+
+    /**
+     * Advances the animation clock by the given amount of delta in milliseconds. This call will
+     * produce an animation frame to all the ongoing animations. This method needs to be
+     * called on the same thread as {@link Animator#start()}.
+     *
+     * @param timeDelta the amount of milliseconds to advance
+     */
+    public void advanceTimeBy(long timeDelta) {
+        Preconditions.checkArgumentNonnegative(timeDelta, "timeDelta must not be negative");
+        requireLooper("AnimationTestRule#advanceTimeBy(long)");
+        // before advancing time, start new animators with the current time
+        initNewAnimators();
+        synchronized (mLock) {
+            // advance time
+            mTotalTimeDelta += timeDelta;
+        }
+        // produce a frame
+        mTestHandler.doFrame();
+    }
+
+    /**
+     * Returns the current time in milliseconds tracked by AnimationHandler. Note that this is a
+     * different time than the time tracked by {@link SystemClock} This method needs to be called on
+     * the same thread as {@link Animator#start()}.
+     */
+    public long getCurrentTime() {
+        requireLooper("AnimationTestRule#getCurrentTime()");
+        synchronized (mLock) {
+            return mStartTime + mTotalTimeDelta;
+        }
+    }
+
+    private static void requireLooper(String method) {
+        if (Looper.myLooper() == null) {
+            throw new AndroidRuntimeException(method + " may only be called on Looper threads");
+        }
+    }
+
+    private class TestHandler extends AnimationHandler {
+        public final TestProvider mTestProvider = new TestProvider();
+        private final List<AnimationFrameCallback> mNewCallbacks = new ArrayList<>();
+
+        TestHandler() {
+            setProvider(mTestProvider);
+        }
+
+        public void doFrame() {
+            mTestProvider.animateFrame();
+            mTestProvider.commitFrame();
+        }
+
+        @Override
+        public void addAnimationFrameCallback(AnimationFrameCallback callback, long delay) {
+            // NOTE: using the delay is infeasible because the AnimationHandler uses
+            //  SystemClock.uptimeMillis(); -- If we fix this to use an overridable method, then we
+            //  could fix this for tests.
+            super.addAnimationFrameCallback(callback, 0);
+            if (delay <= 0) {
+                mNewCallbacks.add(callback);
+            }
+        }
+
+        @Override
+        public void removeCallback(AnimationFrameCallback callback) {
+            super.removeCallback(callback);
+            mNewCallbacks.remove(callback);
+        }
+    }
+
+    private class TestProvider implements AnimationHandler.AnimationFrameCallbackProvider {
+        private long mFrameDelay = 10;
+        private Choreographer.FrameCallback mFrameCallback = null;
+        private final List<Runnable> mCommitCallbacks = new ArrayList<>();
+
+        public void animateFrame() {
+            Choreographer.FrameCallback frameCallback = mFrameCallback;
+            mFrameCallback = null;
+            if (frameCallback != null) {
+                frameCallback.doFrame(getFrameTime());
+            }
+        }
+
+        public void commitFrame() {
+            List<Runnable> commitCallbacks = new ArrayList<>(mCommitCallbacks);
+            mCommitCallbacks.clear();
+            for (Runnable commitCallback : commitCallbacks) {
+                commitCallback.run();
+            }
+        }
+
+        @Override
+        public void postFrameCallback(Choreographer.FrameCallback callback) {
+            assert mFrameCallback == null;
+            mFrameCallback = callback;
+        }
+
+        @Override
+        public void postCommitCallback(Runnable runnable) {
+            mCommitCallbacks.add(runnable);
+        }
+
+        @Override
+        public void setFrameDelay(long delay) {
+            mFrameDelay = delay;
+        }
+
+        @Override
+        public long getFrameDelay() {
+            return mFrameDelay;
+        }
+
+        @Override
+        public long getFrameTime() {
+            return getCurrentTime();
+        }
+    }
+}
diff --git a/packages/SystemUI/tests/utils/src/android/animation/PlatformAnimatorIsolationRule.kt b/packages/SystemUI/tests/utils/src/android/animation/PlatformAnimatorIsolationRule.kt
new file mode 100644
index 000000000000..43a26f34ef2e
--- /dev/null
+++ b/packages/SystemUI/tests/utils/src/android/animation/PlatformAnimatorIsolationRule.kt
@@ -0,0 +1,76 @@
+/*
+ * 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 android.animation
+
+import com.android.systemui.util.test.TestExceptionDeferrer
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+
+/**
+ * This rule is used by [com.android.systemui.SysuiTestCase] to fail any test which attempts to
+ * start a Platform [Animator] without using [android.animation.AnimatorTestRule].
+ *
+ * TODO(b/291645410): enable this; currently this causes hundreds of test failures.
+ */
+class PlatformAnimatorIsolationRule : TestRule {
+
+    private class IsolatingAnimationHandler(ruleThread: Thread) : AnimationHandler() {
+        private val exceptionDeferrer = TestExceptionDeferrer(TAG, ruleThread)
+        override fun addOneShotCommitCallback(callback: AnimationFrameCallback?) = onError()
+        override fun removeCallback(callback: AnimationFrameCallback?) = onError()
+        override fun setProvider(provider: AnimationFrameCallbackProvider?) = onError()
+        override fun autoCancelBasedOn(objectAnimator: ObjectAnimator?) = onError()
+        override fun addAnimationFrameCallback(callback: AnimationFrameCallback?, delay: Long) =
+            onError()
+
+        private fun onError() =
+            exceptionDeferrer.fail(
+                "Test's animations are not isolated! " +
+                    "Did you forget to add an AnimatorTestRule to your test class?"
+            )
+
+        fun throwDeferred() = exceptionDeferrer.throwDeferred()
+    }
+
+    override fun apply(base: Statement, description: Description): Statement {
+        return object : Statement() {
+            @Throws(Throwable::class)
+            override fun evaluate() {
+                val isolationHandler = IsolatingAnimationHandler(Thread.currentThread())
+                val originalHandler = AnimationHandler.setTestHandler(isolationHandler)
+                try {
+                    base.evaluate()
+                } finally {
+                    val handlerAtEnd = AnimationHandler.setTestHandler(originalHandler)
+                    check(isolationHandler == handlerAtEnd) {
+                        "Test handler was altered: expected=$isolationHandler actual=$handlerAtEnd"
+                    }
+                    // Pass or fail, a deferred exception should be the failure reason
+                    isolationHandler.throwDeferred()
+                }
+            }
+        }
+    }
+
+    companion object {
+        private const val TAG = "PlatformAnimatorIsolationRule"
+
+        fun isIsolatingHandler(handler: AnimationHandler?): Boolean =
+            handler is IsolatingAnimationHandler
+    }
+}
diff --git a/packages/SystemUI/tests/utils/src/androidx/core/animation/AndroidXAnimatorIsolationRule.kt b/packages/SystemUI/tests/utils/src/androidx/core/animation/AndroidXAnimatorIsolationRule.kt
index 026372f64e2c..7a97029ca6b0 100644
--- a/packages/SystemUI/tests/utils/src/androidx/core/animation/AndroidXAnimatorIsolationRule.kt
+++ b/packages/SystemUI/tests/utils/src/androidx/core/animation/AndroidXAnimatorIsolationRule.kt
@@ -16,40 +16,51 @@
 
 package androidx.core.animation
 
+import com.android.systemui.util.test.TestExceptionDeferrer
 import org.junit.rules.TestRule
 import org.junit.runner.Description
 import org.junit.runners.model.Statement
 
+/**
+ * This rule is used by [com.android.systemui.SysuiTestCase] to fail any test which attempts to
+ * start an AndroidX [Animator] without using [androidx.core.animation.AnimatorTestRule].
+ */
 class AndroidXAnimatorIsolationRule : TestRule {
 
-    private class TestAnimationHandler : AnimationHandler(null) {
-        override fun addAnimationFrameCallback(callback: AnimationFrameCallback?) = doFail()
-        override fun removeCallback(callback: AnimationFrameCallback?) = doFail()
-        override fun onAnimationFrame(frameTime: Long) = doFail()
-        override fun setFrameDelay(frameDelay: Long) = doFail()
-        override fun getFrameDelay(): Long = doFail()
+    private class IsolatingAnimationHandler(ruleThread: Thread) : AnimationHandler(null) {
+        private val exceptionDeferrer = TestExceptionDeferrer(TAG, ruleThread)
+        override fun addAnimationFrameCallback(callback: AnimationFrameCallback?) = onError()
+        override fun removeCallback(callback: AnimationFrameCallback?) = onError()
+        override fun onAnimationFrame(frameTime: Long) = onError()
+        override fun setFrameDelay(frameDelay: Long) = onError()
+
+        private fun onError() =
+            exceptionDeferrer.fail(
+                "Test's animations are not isolated! " +
+                    "Did you forget to add an AnimatorTestRule to your test class?"
+            )
+
+        fun throwDeferred() = exceptionDeferrer.throwDeferred()
     }
 
     override fun apply(base: Statement, description: Description): Statement {
         return object : Statement() {
             @Throws(Throwable::class)
             override fun evaluate() {
-                AnimationHandler.setTestHandler(testHandler)
+                val isolationHandler = IsolatingAnimationHandler(Thread.currentThread())
+                AnimationHandler.setTestHandler(isolationHandler)
                 try {
                     base.evaluate()
                 } finally {
                     AnimationHandler.setTestHandler(null)
+                    // Pass or fail, a deferred exception should be the failure reason
+                    isolationHandler.throwDeferred()
                 }
             }
         }
     }
 
-    companion object {
-        private val testHandler = TestAnimationHandler()
-        private fun doFail(): Nothing =
-            error(
-                "Test's animations are not isolated! " +
-                    "Did you forget to add an AnimatorTestRule to your test class?"
-            )
+    private companion object {
+        private const val TAG = "AndroidXAnimatorIsolationRule"
     }
 }
diff --git a/packages/SystemUI/tests/utils/src/com/android/systemui/util/test/TestExceptionDeferrer.kt b/packages/SystemUI/tests/utils/src/com/android/systemui/util/test/TestExceptionDeferrer.kt
new file mode 100644
index 000000000000..90281ca7c2e7
--- /dev/null
+++ b/packages/SystemUI/tests/utils/src/com/android/systemui/util/test/TestExceptionDeferrer.kt
@@ -0,0 +1,56 @@
+/*
+ * 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.test
+
+import android.util.Log
+
+/**
+ * Helper class that intercepts test errors which may be occurring on the wrong thread, and saves
+ * them so that they can be rethrown back on the correct thread.
+ */
+class TestExceptionDeferrer(private val tag: String, private val testThread: Thread) {
+    private val deferredErrors = mutableListOf<IllegalStateException>()
+
+    /** Ensure the [value] is `true`; otherwise [fail] with the produced [message] */
+    fun check(value: Boolean, message: () -> Any?) {
+        if (value) return
+        fail(message().toString())
+    }
+
+    /**
+     * If the [Thread.currentThread] is the [testThread], then [error], otherwise [Log] and defer
+     * the error until [throwDeferred] is called.
+     */
+    fun fail(message: String) {
+        if (testThread == Thread.currentThread()) {
+            error(message)
+        } else {
+            val exception = IllegalStateException(message)
+            Log.e(tag, "Deferring error: ", exception)
+            deferredErrors.add(exception)
+        }
+    }
+
+    /** If any [fail] or failed [check] has happened, throw the first one. */
+    fun throwDeferred() {
+        deferredErrors.firstOrNull()?.let { firstError ->
+            Log.e(tag, "Deferred errors: ${deferredErrors.size}")
+            deferredErrors.clear()
+            throw firstError
+        }
+    }
+}