[2/3] Create a new motion testing toolkit based on AnimatorTestRule.

This toolkit will allow us to test all Animator and Spring-based motion
using AnimatorTestRule.

Bug: 323863002
Flag: EXEMPT test only
Test: atest AnimatorTestRuleToolkitTest
Change-Id: Id5eb04abe896d6d58920ff3eaf1867e401f2b5ee
diff --git a/tests/testables/Android.bp b/tests/testables/Android.bp
index f211185..17cc0b2 100644
--- a/tests/testables/Android.bp
+++ b/tests/testables/Android.bp
@@ -35,4 +35,8 @@
         "androidx.test.rules",
         "mockito-target-inline-minus-junit4",
     ],
+    static_libs: [
+        "PlatformMotionTesting",
+        "kotlinx_coroutines_test",
+    ],
 }
diff --git a/tests/testables/src/android/animation/AnimatorTestRuleToolkit.kt b/tests/testables/src/android/animation/AnimatorTestRuleToolkit.kt
new file mode 100644
index 0000000..b27b826
--- /dev/null
+++ b/tests/testables/src/android/animation/AnimatorTestRuleToolkit.kt
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2024 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.AnimatorTestRuleToolkit.Companion.TAG
+import android.util.Log
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.take
+import kotlinx.coroutines.flow.takeWhile
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.runCurrent
+import platform.test.motion.MotionTestRule
+import platform.test.motion.RecordedMotion
+import platform.test.motion.RecordedMotion.Companion.create
+import platform.test.motion.golden.DataPoint
+import platform.test.motion.golden.Feature
+import platform.test.motion.golden.FrameId
+import platform.test.motion.golden.TimeSeries
+import platform.test.motion.golden.TimeSeriesCaptureScope
+import platform.test.motion.golden.TimestampFrameId
+
+class AnimatorTestRuleToolkit(val animatorTestRule: AnimatorTestRule, val testScope: TestScope) {
+    internal companion object {
+        const val TAG = "AnimatorRuleToolkit"
+    }
+}
+
+/**
+ * Controls the timing of the motion recording.
+ *
+ * The time series is recorded while the [recording] function is running.
+ */
+class MotionControl(val recording: MotionControlFn)
+
+typealias MotionControlFn = suspend MotionControlScope.() -> Unit
+
+interface MotionControlScope {
+    /** Waits until [check] returns true. Invoked on each frame. */
+    suspend fun awaitCondition(check: () -> Boolean)
+
+    /** Waits for [count] frames to be processed. */
+    suspend fun awaitFrames(count: Int = 1)
+}
+
+/** Defines the sampling of features during a test run. */
+data class AnimatorRuleRecordingSpec<T>(
+    /** The root `observing` object, available in [timeSeriesCapture]'s [TimeSeriesCaptureScope]. */
+    val captureRoot: T,
+
+    /** The timing for the recording. */
+    val motionControl: MotionControl,
+
+    /** Time interval between frame captures, in milliseconds. */
+    val frameDurationMs: Long = 16L,
+
+    /**  Produces the time-series, invoked on each animation frame. */
+    val timeSeriesCapture: TimeSeriesCaptureScope<T>.() -> Unit,
+)
+
+/** Records the time-series of the features specified in [recordingSpec]. */
+fun <T> MotionTestRule<AnimatorTestRuleToolkit>.recordMotion(
+    recordingSpec: AnimatorRuleRecordingSpec<T>,
+): RecordedMotion {
+    with(toolkit.animatorTestRule) {
+        val frameIdCollector = mutableListOf<FrameId>()
+        val propertyCollector = mutableMapOf<String, MutableList<DataPoint<*>>>()
+
+        fun recordFrame(frameId: FrameId) {
+            Log.i(TAG, "recordFrame($frameId)")
+            frameIdCollector.add(frameId)
+            recordingSpec.timeSeriesCapture.invoke(
+                TimeSeriesCaptureScope(recordingSpec.captureRoot, propertyCollector)
+            )
+        }
+
+        val motionControl =
+            MotionControlImpl(
+                toolkit.animatorTestRule,
+                toolkit.testScope,
+                recordingSpec.frameDurationMs,
+                recordingSpec.motionControl,
+            )
+
+        Log.i(TAG, "recordMotion() begin recording")
+
+        val startFrameTime = currentTime
+        while (!motionControl.recordingEnded) {
+            recordFrame(TimestampFrameId(currentTime - startFrameTime))
+            motionControl.nextFrame()
+        }
+
+        Log.i(TAG, "recordMotion() end recording")
+
+        val timeSeries =
+            TimeSeries(
+                frameIdCollector.toList(),
+                propertyCollector.entries.map { entry -> Feature(entry.key, entry.value) },
+            )
+
+        return create(timeSeries, null)
+    }
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+private class MotionControlImpl(
+    val animatorTestRule: AnimatorTestRule,
+    val testScope: TestScope,
+    val frameMs: Long,
+    motionControl: MotionControl,
+) : MotionControlScope {
+    private val recordingJob = motionControl.recording.launch()
+
+    private val frameEmitter = MutableStateFlow<Long>(0)
+    private val onFrame = frameEmitter.asStateFlow()
+
+    var recordingEnded: Boolean = false
+
+    fun nextFrame() {
+        animatorTestRule.advanceTimeBy(frameMs)
+
+        frameEmitter.tryEmit(animatorTestRule.currentTime)
+        testScope.runCurrent()
+
+        if (recordingJob.isCompleted) {
+            recordingEnded = true
+        }
+    }
+
+    override suspend fun awaitCondition(check: () -> Boolean) {
+        onFrame.takeWhile { !check() }.collect {}
+    }
+
+    override suspend fun awaitFrames(count: Int) {
+        onFrame.take(count).collect {}
+    }
+
+    private fun MotionControlFn.launch(): Job {
+        val function = this
+        return testScope.launch { function() }
+    }
+}
diff --git a/tests/testables/tests/Android.bp b/tests/testables/tests/Android.bp
index c23f41a..7110564 100644
--- a/tests/testables/tests/Android.bp
+++ b/tests/testables/tests/Android.bp
@@ -29,13 +29,17 @@
         "src/**/*.kt",
         "src/**/I*.aidl",
     ],
+    asset_dirs: ["goldens"],
     resource_dirs: ["res"],
     static_libs: [
+        "PlatformMotionTesting",
         "androidx.core_core-animation",
         "androidx.core_core-ktx",
+        "androidx.test.ext.junit",
         "androidx.test.rules",
         "androidx.test.ext.junit",
         "hamcrest-library",
+        "kotlinx_coroutines_test",
         "mockito-target-inline-minus-junit4",
         "testables",
         "truth",
diff --git a/tests/testables/tests/goldens/recordMotion_withAnimator.json b/tests/testables/tests/goldens/recordMotion_withAnimator.json
new file mode 100644
index 0000000..87fece5
--- /dev/null
+++ b/tests/testables/tests/goldens/recordMotion_withAnimator.json
@@ -0,0 +1,64 @@
+{
+  "frame_ids": [
+    0,
+    20,
+    40,
+    60,
+    80,
+    100,
+    120,
+    140,
+    160,
+    180,
+    200,
+    220,
+    240,
+    260,
+    280,
+    300,
+    320,
+    340,
+    360,
+    380,
+    400,
+    420,
+    440,
+    460,
+    480,
+    500
+  ],
+  "features": [
+    {
+      "name": "value",
+      "type": "float",
+      "data_points": [
+        1,
+        0.9960574,
+        0.98429155,
+        0.9648882,
+        0.9381534,
+        0.9045085,
+        0.8644843,
+        0.818712,
+        0.76791346,
+        0.7128896,
+        0.65450853,
+        0.5936906,
+        0.5313952,
+        0.46860474,
+        0.40630943,
+        0.34549147,
+        0.2871104,
+        0.23208654,
+        0.181288,
+        0.13551569,
+        0.09549153,
+        0.061846733,
+        0.035111785,
+        0.015708387,
+        0.003942609,
+        0
+      ]
+    }
+  ]
+}
diff --git a/tests/testables/tests/goldens/recordMotion_withSpring.json b/tests/testables/tests/goldens/recordMotion_withSpring.json
new file mode 100644
index 0000000..e9fb5b4
--- /dev/null
+++ b/tests/testables/tests/goldens/recordMotion_withSpring.json
@@ -0,0 +1,48 @@
+{
+  "frame_ids": [
+    0,
+    16,
+    32,
+    48,
+    64,
+    80,
+    96,
+    112,
+    128,
+    144,
+    160,
+    176,
+    192,
+    208,
+    224,
+    240,
+    256,
+    272
+  ],
+  "features": [
+    {
+      "name": "value",
+      "type": "float",
+      "data_points": [
+        1,
+        0.9488604,
+        0.83574325,
+        0.7016156,
+        0.5691678,
+        0.4497436,
+        0.34789434,
+        0.26431116,
+        0.19766562,
+        0.14572789,
+        0.10601636,
+        0.076149896,
+        0.05401709,
+        0.037837274,
+        0.026161024,
+        0.017839976,
+        0.011983856,
+        0.007914998
+      ]
+    }
+  ]
+}
diff --git a/tests/testables/tests/src/android/animation/AnimatorTestRuleToolkitTest.kt b/tests/testables/tests/src/android/animation/AnimatorTestRuleToolkitTest.kt
new file mode 100644
index 0000000..fbef489
--- /dev/null
+++ b/tests/testables/tests/src/android/animation/AnimatorTestRuleToolkitTest.kt
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2024 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.util.FloatProperty
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import com.android.internal.dynamicanimation.animation.SpringAnimation
+import com.android.internal.dynamicanimation.animation.SpringForce
+import kotlinx.coroutines.test.TestScope
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import platform.test.motion.MotionTestRule
+import platform.test.motion.RecordedMotion
+import platform.test.motion.golden.FeatureCapture
+import platform.test.motion.golden.asDataPoint
+import platform.test.motion.testing.createGoldenPathManager
+
+@SmallTest
+@RunWith(AndroidJUnit4::class)
+class AnimatorTestRuleToolkitTest {
+    companion object {
+        private val GOLDEN_PATH_MANAGER =
+            createGoldenPathManager("frameworks/base/tests/testables/tests/goldens")
+
+        private val TEST_PROPERTY =
+            object : FloatProperty<TestState>("value") {
+                override fun get(state: TestState): Float {
+                    return state.animatedValue
+                }
+
+                override fun setValue(state: TestState, value: Float) {
+                    state.animatedValue = value
+                }
+            }
+    }
+
+    @get:Rule(order = 0) val animatorTestRule = AnimatorTestRule(this)
+    @get:Rule(order = 1)
+    val motionRule =
+        MotionTestRule(AnimatorTestRuleToolkit(animatorTestRule, TestScope()), GOLDEN_PATH_MANAGER)
+
+    @Test
+    fun recordMotion_withAnimator() {
+        val state = TestState()
+        AnimatorSet().apply {
+            duration = 500
+            play(
+                ValueAnimator.ofFloat(state.animatedValue, 0f).apply {
+                    addUpdateListener { state.animatedValue = it.animatedValue as Float }
+                }
+            )
+            getInstrumentation().runOnMainSync { start() }
+        }
+
+        val recordedMotion =
+            record(state, MotionControl { awaitFrames(count = 26) }, sampleIntervalMs = 20L)
+
+        motionRule.assertThat(recordedMotion).timeSeriesMatchesGolden("recordMotion_withAnimator")
+    }
+
+    @Test
+    fun recordMotion_withSpring() {
+        val state = TestState()
+        var isDone = false
+        SpringAnimation(state, TEST_PROPERTY).apply {
+            spring =
+                SpringForce(0f).apply {
+                    stiffness = 500f
+                    dampingRatio = 0.95f
+                }
+
+            setStartValue(1f)
+            setMinValue(0f)
+            setMaxValue(1f)
+            minimumVisibleChange = 0.01f
+
+            addEndListener { _, _, _, _ -> isDone = true }
+            getInstrumentation().runOnMainSync { start() }
+        }
+
+        val recordedMotion =
+            record(state, MotionControl { awaitCondition { isDone } }, sampleIntervalMs = 16L)
+
+        motionRule.assertThat(recordedMotion).timeSeriesMatchesGolden("recordMotion_withSpring")
+    }
+
+    private fun record(
+        state: TestState,
+        motionControl: MotionControl,
+        sampleIntervalMs: Long,
+    ): RecordedMotion {
+        var recordedMotion: RecordedMotion? = null
+        getInstrumentation().runOnMainSync {
+            recordedMotion =
+                motionRule.recordMotion(
+                    AnimatorRuleRecordingSpec(
+                        state,
+                        motionControl,
+                        sampleIntervalMs,
+                    ) {
+                        feature(
+                            FeatureCapture("value") { state -> state.animatedValue.asDataPoint() },
+                            "value",
+                        )
+                    }
+                )
+        }
+        return recordedMotion!!
+    }
+
+    data class TestState(var animatedValue: Float = 1f)
+}