Merge "[Motion] Split-shade expansion: implement over scroll effect [v1]" into tm-dev

2022-04-29 12:14:23 +00:00
parent ca88bd0806 352c4e44db
commit fa9d138be0
13 changed files with 503 additions and 10 deletions
--- a/packages/SystemUI/res/values/dimens.xml
+++ b/packages/SystemUI/res/values/dimens.xml
@@ -1179,6 +1179,10 @@
    <!-- Maximum over scroll amount for the shade when transition to the full shade. -->
    <dimen name="lockscreen_shade_max_over_scroll_amount">24dp</dimen>

+    <!-- Maximum over scroll amount for the shade when transition to the full shade.
+         Only used for split-shade. -->
+    <dimen name="shade_max_over_scroll_amount">@dimen/lockscreen_shade_max_over_scroll_amount</dimen>
+
    <!-- Maximum overshoot for the pulse expansion -->
    <dimen name="pulse_expansion_max_top_overshoot">32dp</dimen>

--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutController.java
@@ -117,6 +117,7 @@ import com.android.systemui.statusbar.phone.KeyguardBypassController;
 import com.android.systemui.statusbar.phone.ScrimController;
 import com.android.systemui.statusbar.phone.ShadeController;
 import com.android.systemui.statusbar.phone.dagger.CentralSurfacesComponent;
+import com.android.systemui.statusbar.phone.shade.transition.ShadeTransitionController;
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.ConfigurationController.ConfigurationListener;
 import com.android.systemui.statusbar.policy.DeviceProvisionedController;
@@ -178,6 +179,7 @@ public class NotificationStackScrollLayoutController {
    private final CentralSurfaces mCentralSurfaces;
    private final SectionHeaderController mSilentHeaderController;
    private final LockscreenShadeTransitionController mLockscreenShadeTransitionController;
+    private final ShadeTransitionController mShadeTransitionController;
    private final InteractionJankMonitor mJankMonitor;
    private final NotificationStackSizeCalculator mNotificationStackSizeCalculator;
    private final StackStateLogger mStackStateLogger;
@@ -647,6 +649,7 @@ public class NotificationStackScrollLayoutController {
            NotifCollection notifCollection,
            NotificationEntryManager notificationEntryManager,
            LockscreenShadeTransitionController lockscreenShadeTransitionController,
+            ShadeTransitionController shadeTransitionController,
            IStatusBarService iStatusBarService,
            UiEventLogger uiEventLogger,
            LayoutInflater layoutInflater,
@@ -675,6 +678,7 @@ public class NotificationStackScrollLayoutController {
        mLockscreenUserManager = lockscreenUserManager;
        mMetricsLogger = metricsLogger;
        mLockscreenShadeTransitionController = lockscreenShadeTransitionController;
+        mShadeTransitionController = shadeTransitionController;
        mFalsingCollector = falsingCollector;
        mFalsingManager = falsingManager;
        mResources = resources;
@@ -769,6 +773,7 @@ public class NotificationStackScrollLayoutController {
        mScrimController.setScrimBehindChangeRunnable(mView::updateBackgroundDimming);

        mLockscreenShadeTransitionController.setStackScroller(this);
+        mShadeTransitionController.setNotificationStackScrollLayoutController(this);

        mLockscreenUserManager.addUserChangedListener(mLockscreenUserChangeListener);

--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java
@@ -179,6 +179,7 @@ import com.android.systemui.statusbar.phone.dagger.CentralSurfacesComponent;
 import com.android.systemui.statusbar.phone.fragment.CollapsedStatusBarFragment;
 import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager;
 import com.android.systemui.statusbar.phone.panelstate.PanelState;
+import com.android.systemui.statusbar.phone.shade.transition.ShadeTransitionController;
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.KeyguardQsUserSwitchController;
 import com.android.systemui.statusbar.policy.KeyguardStateController;
@@ -310,6 +311,7 @@ public class NotificationPanelViewController extends PanelViewController {
    private final NotificationRemoteInputManager mRemoteInputManager;

    private final LockscreenShadeTransitionController mLockscreenShadeTransitionController;
+    private final ShadeTransitionController mShadeTransitionController;
    private final TapAgainViewController mTapAgainViewController;
    private final LargeScreenShadeHeaderController mLargeScreenShadeHeaderController;
    private final RecordingController mRecordingController;
@@ -745,7 +747,8 @@ public class NotificationPanelViewController extends PanelViewController {
            NotificationListContainer notificationListContainer,
            PanelEventsEmitter panelEventsEmitter,
            NotificationStackSizeCalculator notificationStackSizeCalculator,
-            UnlockedScreenOffAnimationController unlockedScreenOffAnimationController) {
+            UnlockedScreenOffAnimationController unlockedScreenOffAnimationController,
+            ShadeTransitionController shadeTransitionController) {
        super(view,
                falsingManager,
                dozeLog,
@@ -826,7 +829,9 @@ public class NotificationPanelViewController extends PanelViewController {
        mKeyguardBypassController = bypassController;
        mUpdateMonitor = keyguardUpdateMonitor;
        mLockscreenShadeTransitionController = lockscreenShadeTransitionController;
+        mShadeTransitionController = shadeTransitionController;
        lockscreenShadeTransitionController.setNotificationPanelController(this);
+        shadeTransitionController.setNotificationPanelViewController(this);
        DynamicPrivacyControlListener
                dynamicPrivacyControlListener =
                new DynamicPrivacyControlListener();
@@ -3625,6 +3630,7 @@ public class NotificationPanelViewController extends PanelViewController {
                }
            });
            mLockscreenShadeTransitionController.setQS(mQs);
+            mShadeTransitionController.setQs(mQs);
            mNotificationStackScrollLayoutController.setQsHeader((ViewGroup) mQs.getHeader());
            mQs.setScrollListener(mScrollListener);
            updateQsExpansion();
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/PanelViewController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/PanelViewController.java
@@ -108,6 +108,8 @@ public abstract class PanelViewController {
     */
    private boolean mIsSpringBackAnimation;

+    private boolean mInSplitShade;
+
    private void logf(String fmt, Object... args) {
        Log.v(TAG, (mViewName != null ? (mViewName + ": ") : "") + String.format(fmt, args));
    }
@@ -303,8 +305,9 @@ public abstract class PanelViewController {
        mSlopMultiplier = configuration.getScaledAmbiguousGestureMultiplier();
        mHintDistance = mResources.getDimension(R.dimen.hint_move_distance);
        mPanelFlingOvershootAmount = mResources.getDimension(R.dimen.panel_overshoot_amount);
-        mUnlockFalsingThreshold = mResources.getDimensionPixelSize(
-                R.dimen.unlock_falsing_threshold);
+        mUnlockFalsingThreshold =
+                mResources.getDimensionPixelSize(R.dimen.unlock_falsing_threshold);
+        mInSplitShade = mResources.getBoolean(R.bool.config_use_split_notification_shade);
    }

    protected float getTouchSlop(MotionEvent event) {
@@ -600,10 +603,12 @@ public abstract class PanelViewController {
        }
        mIsFlinging = true;
        // we want to perform an overshoot animation when flinging open
-        final boolean addOverscroll = expand
-                && mStatusBarStateController.getState() != StatusBarState.KEYGUARD
-                && mOverExpansion == 0.0f
-                && vel >= 0;
+        final boolean addOverscroll =
+                expand
+                        && !mInSplitShade // Split shade has its own overscroll logic
+                        && mStatusBarStateController.getState() != StatusBarState.KEYGUARD
+                        && mOverExpansion == 0.0f
+                        && vel >= 0;
        final boolean shouldSpringBack = addOverscroll || (mOverExpansion != 0.0f && expand);
        float overshootAmount = 0.0f;
        if (addOverscroll) {
@@ -777,7 +782,8 @@ public abstract class PanelViewController {
            }
            float maxPanelHeight = getMaxPanelHeight();
            if (mHeightAnimator == null) {
-                if (mTracking) {
+                // Split shade has its own overscroll logic
+                if (mTracking && !mInSplitShade) {
                    float overExpansionPixels = Math.max(0, h - maxPanelHeight);
                    setOverExpansionInternal(overExpansionPixels, true /* isFromGesture */);
                }
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/panelstate/PanelStateListener.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/panelstate/PanelStateListener.kt
@@ -17,7 +17,7 @@
 package com.android.systemui.statusbar.phone.panelstate

 /** A listener interface to be notified of state change events for the notification panel. */
-interface PanelStateListener {
+fun interface PanelStateListener {
    /** Called when the panel's expansion state has changed.   */
    fun onPanelStateChanged(@PanelState state: Int)
 }
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/NoOpOverScroller.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/NoOpOverScroller.kt
@@ -0,0 +1,14 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import javax.inject.Inject
+
+/**
+ * An implementation on [ShadeOverScroller] that does nothing.
+ *
+ * At the moment there is only a concrete implementation [ShadeOverScroller] for split-shade, so
+ * this one is used when we are not in split-shade.
+ */
+class NoOpOverScroller @Inject constructor() : ShadeOverScroller {
+    override fun onPanelStateChanged(newPanelState: Int) {}
+    override fun onDragDownAmountChanged(newDragDownAmount: Float) {}
+}
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/ShadeOverScroller.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/ShadeOverScroller.kt
@@ -0,0 +1,11 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import com.android.systemui.statusbar.phone.panelstate.PanelState
+
+/** Represents an over scroller for the non-lockscreen shade. */
+interface ShadeOverScroller {
+
+    fun onPanelStateChanged(@PanelState newPanelState: Int)
+
+    fun onDragDownAmountChanged(newDragDownAmount: Float)
+}
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/ShadeTransitionController.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/ShadeTransitionController.kt
@@ -0,0 +1,73 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import android.content.Context
+import android.content.res.Configuration
+import com.android.systemui.R
+import com.android.systemui.dagger.SysUISingleton
+import com.android.systemui.plugins.qs.QS
+import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController
+import com.android.systemui.statusbar.phone.NotificationPanelViewController
+import com.android.systemui.statusbar.phone.panelstate.PanelExpansionChangeEvent
+import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager
+import com.android.systemui.statusbar.phone.panelstate.PanelState
+import com.android.systemui.statusbar.policy.ConfigurationController
+import javax.inject.Inject
+
+/** Controls the shade expansion transition on non-lockscreen. */
+@SysUISingleton
+class ShadeTransitionController
+@Inject
+constructor(
+    configurationController: ConfigurationController,
+    panelExpansionStateManager: PanelExpansionStateManager,
+    private val context: Context,
+    private val splitShadeOverScrollerFactory: SplitShadeOverScroller.Factory,
+    private val noOpOverScroller: NoOpOverScroller
+) {
+
+    lateinit var notificationPanelViewController: NotificationPanelViewController
+    lateinit var notificationStackScrollLayoutController: NotificationStackScrollLayoutController
+    lateinit var qs: QS
+
+    private var inSplitShade = false
+
+    private val splitShadeOverScroller by lazy {
+        splitShadeOverScrollerFactory.create(qs, notificationStackScrollLayoutController)
+    }
+    private val shadeOverScroller: ShadeOverScroller
+        get() =
+            if (inSplitShade && propertiesInitialized()) {
+                splitShadeOverScroller
+            } else {
+                noOpOverScroller
+            }
+
+    init {
+        updateResources()
+        configurationController.addCallback(
+            object : ConfigurationController.ConfigurationListener {
+                override fun onConfigChanged(newConfig: Configuration?) {
+                    updateResources()
+                }
+            })
+        panelExpansionStateManager.addExpansionListener(this::onPanelExpansionChanged)
+        panelExpansionStateManager.addStateListener(this::onPanelStateChanged)
+    }
+
+    private fun updateResources() {
+        inSplitShade = context.resources.getBoolean(R.bool.config_use_split_notification_shade)
+    }
+
+    private fun onPanelStateChanged(@PanelState state: Int) {
+        shadeOverScroller.onPanelStateChanged(state)
+    }
+
+    private fun onPanelExpansionChanged(event: PanelExpansionChangeEvent) {
+        shadeOverScroller.onDragDownAmountChanged(event.dragDownPxAmount)
+    }
+
+    private fun propertiesInitialized() =
+        this::qs.isInitialized &&
+            this::notificationPanelViewController.isInitialized &&
+            this::notificationStackScrollLayoutController.isInitialized
+}
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/SplitShadeOverScroller.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/shade/transition/SplitShadeOverScroller.kt
@@ -0,0 +1,142 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import android.animation.Animator
+import android.animation.ValueAnimator
+import android.content.Context
+import android.content.res.Configuration
+import android.util.MathUtils
+import com.android.internal.annotations.VisibleForTesting
+import com.android.systemui.R
+import com.android.systemui.animation.Interpolators
+import com.android.systemui.dump.DumpManager
+import com.android.systemui.plugins.qs.QS
+import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController
+import com.android.systemui.statusbar.phone.ScrimController
+import com.android.systemui.statusbar.phone.panelstate.PanelState
+import com.android.systemui.statusbar.phone.panelstate.STATE_CLOSED
+import com.android.systemui.statusbar.phone.panelstate.STATE_OPENING
+import com.android.systemui.statusbar.policy.ConfigurationController
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
+import java.io.PrintWriter
+
+class SplitShadeOverScroller
+@AssistedInject
+constructor(
+    configurationController: ConfigurationController,
+    dumpManager: DumpManager,
+    private val context: Context,
+    private val scrimController: ScrimController,
+    @Assisted private val qS: QS,
+    @Assisted private val nsslController: NotificationStackScrollLayoutController
+) : ShadeOverScroller {
+
+    private var releaseOverScrollDuration = 0L
+    private var maxOverScrollAmount = 0
+    private var previousOverscrollAmount = 0
+    private var dragDownAmount: Float = 0f
+    @PanelState private var panelState: Int = STATE_CLOSED
+    private var releaseOverScrollAnimator: Animator? = null
+
+    init {
+        updateResources()
+        configurationController.addCallback(
+            object : ConfigurationController.ConfigurationListener {
+                override fun onConfigChanged(newConfig: Configuration?) {
+                    updateResources()
+                }
+            })
+        dumpManager.registerDumpable(this::dump)
+    }
+
+    private fun updateResources() {
+        val resources = context.resources
+        maxOverScrollAmount = resources.getDimensionPixelSize(R.dimen.shade_max_over_scroll_amount)
+        releaseOverScrollDuration =
+            resources.getInteger(R.integer.lockscreen_shade_over_scroll_release_duration).toLong()
+    }
+
+    override fun onPanelStateChanged(@PanelState newPanelState: Int) {
+        if (shouldReleaseOverscroll(previousState = panelState, newState = newPanelState)) {
+            releaseOverScroll()
+        }
+        panelState = newPanelState
+    }
+
+    override fun onDragDownAmountChanged(newDragDownAmount: Float) {
+        if (dragDownAmount == newDragDownAmount) {
+            return
+        }
+        dragDownAmount = newDragDownAmount
+        if (shouldOverscroll()) {
+            overScroll(newDragDownAmount)
+        }
+    }
+
+    private fun shouldOverscroll() = panelState == STATE_OPENING
+
+    private fun shouldReleaseOverscroll(@PanelState previousState: Int, @PanelState newState: Int) =
+        previousState == STATE_OPENING && newState != STATE_OPENING
+
+    private fun overScroll(dragDownAmount: Float) {
+        val overscrollAmount: Int = calculateOverscrollAmount(dragDownAmount)
+        applyOverscroll(overscrollAmount)
+        previousOverscrollAmount = overscrollAmount
+    }
+
+    private fun calculateOverscrollAmount(dragDownAmount: Float): Int {
+        val fullHeight: Int = nsslController.height
+        val fullHeightProgress: Float = MathUtils.saturate(dragDownAmount / fullHeight)
+        return (fullHeightProgress * maxOverScrollAmount).toInt()
+    }
+
+    private fun applyOverscroll(overscrollAmount: Int) {
+        qS.setOverScrollAmount(overscrollAmount)
+        scrimController.setNotificationsOverScrollAmount(overscrollAmount)
+        nsslController.setOverScrollAmount(overscrollAmount)
+    }
+
+    private fun releaseOverScroll() {
+        val animator = ValueAnimator.ofInt(previousOverscrollAmount, 0)
+        animator.addUpdateListener {
+            val overScrollAmount = it.animatedValue as Int
+            qS.setOverScrollAmount(overScrollAmount)
+            scrimController.setNotificationsOverScrollAmount(overScrollAmount)
+            nsslController.setOverScrollAmount(overScrollAmount)
+        }
+        animator.interpolator = Interpolators.STANDARD
+        animator.duration = releaseOverScrollDuration
+        animator.start()
+        releaseOverScrollAnimator = animator
+        previousOverscrollAmount = 0
+    }
+
+    @VisibleForTesting
+    internal fun finishAnimations() {
+        releaseOverScrollAnimator?.end()
+        releaseOverScrollAnimator = null
+    }
+
+    private fun dump(pw: PrintWriter, strings: Array<String>) {
+        pw.println(
+            """
+            SplitShadeOverScroller:
+                Resources:
+                    releaseOverScrollDuration: $releaseOverScrollDuration
+                    maxOverScrollAmount: $maxOverScrollAmount
+                State:
+                    previousOverscrollAmount: $previousOverscrollAmount
+                    dragDownAmount: $dragDownAmount
+                    panelState: $panelState
+            """.trimIndent())
+    }
+
+    @AssistedFactory
+    fun interface Factory {
+        fun create(
+            qS: QS,
+            nsslController: NotificationStackScrollLayoutController
+        ): SplitShadeOverScroller
+    }
+}
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutControllerTest.java
@@ -74,6 +74,7 @@ import com.android.systemui.statusbar.phone.HeadsUpManagerPhone;
 import com.android.systemui.statusbar.phone.KeyguardBypassController;
 import com.android.systemui.statusbar.phone.ScrimController;
 import com.android.systemui.statusbar.phone.ShadeController;
+import com.android.systemui.statusbar.phone.shade.transition.ShadeTransitionController;
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.DeviceProvisionedController;
 import com.android.systemui.statusbar.policy.ZenModeController;
@@ -135,6 +136,7 @@ public class NotificationStackScrollLayoutControllerTest extends SysuiTestCase {
    @Mock private StackStateLogger mStackLogger;
    @Mock private NotificationStackScrollLogger mLogger;
    @Mock private NotificationStackSizeCalculator mNotificationStackSizeCalculator;
+    @Mock private ShadeTransitionController mShadeTransitionController;

    @Captor
    private ArgumentCaptor<StatusBarStateController.StateListener> mStateListenerArgumentCaptor;
@@ -179,6 +181,7 @@ public class NotificationStackScrollLayoutControllerTest extends SysuiTestCase {
                mNotifCollection,
                mEntryManager,
                mLockscreenShadeTransitionController,
+                mShadeTransitionController,
                mIStatusBarService,
                mUiEventLogger,
                mLayoutInflater,
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java
@@ -128,6 +128,7 @@ import com.android.systemui.statusbar.notification.stack.NotificationStackScroll
 import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController;
 import com.android.systemui.statusbar.notification.stack.NotificationStackSizeCalculator;
 import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager;
+import com.android.systemui.statusbar.phone.shade.transition.ShadeTransitionController;
 import com.android.systemui.statusbar.policy.ConfigurationController;
 import com.android.systemui.statusbar.policy.KeyguardQsUserSwitchController;
 import com.android.systemui.statusbar.policy.KeyguardStateController;
@@ -337,6 +338,8 @@ public class NotificationPanelViewControllerTest extends SysuiTestCase {
    @Mock
    private UnlockedScreenOffAnimationController mUnlockedScreenOffAnimationController;
    @Mock
+    private ShadeTransitionController mShadeTransitionController;
+    @Mock
    private QS mQs;
    @Mock
    private View mQsHeader;
@@ -529,7 +532,8 @@ public class NotificationPanelViewControllerTest extends SysuiTestCase {
                mNotificationListContainer,
                mPanelEventsEmitter,
                mNotificationStackSizeCalculator,
-                mUnlockedScreenOffAnimationController);
+                mUnlockedScreenOffAnimationController,
+                mShadeTransitionController);
        mNotificationPanelViewController.initDependencies(
                mCentralSurfaces,
                () -> {},
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/shade/transition/ShadeTransitionControllerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/shade/transition/ShadeTransitionControllerTest.kt
@@ -0,0 +1,118 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import android.testing.AndroidTestingRunner
+import androidx.test.filters.SmallTest
+import com.android.systemui.R
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.plugins.qs.QS
+import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController
+import com.android.systemui.statusbar.phone.NotificationPanelViewController
+import com.android.systemui.statusbar.phone.panelstate.PanelExpansionStateManager
+import com.android.systemui.statusbar.phone.panelstate.STATE_OPENING
+import com.android.systemui.statusbar.policy.FakeConfigurationController
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.reset
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.verifyZeroInteractions
+import org.mockito.MockitoAnnotations
+
+@RunWith(AndroidTestingRunner::class)
+@SmallTest
+class ShadeTransitionControllerTest : SysuiTestCase() {
+
+    @Mock private lateinit var npvc: NotificationPanelViewController
+    @Mock private lateinit var nsslController: NotificationStackScrollLayoutController
+    @Mock private lateinit var qs: QS
+    @Mock private lateinit var noOpOverScroller: NoOpOverScroller
+    @Mock private lateinit var splitShadeOverScroller: SplitShadeOverScroller
+
+    private lateinit var controller: ShadeTransitionController
+
+    private val configurationController = FakeConfigurationController()
+    private val panelExpansionStateManager = PanelExpansionStateManager()
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+
+        controller =
+            ShadeTransitionController(
+                configurationController,
+                panelExpansionStateManager,
+                context,
+                splitShadeOverScrollerFactory = { _, _ -> splitShadeOverScroller },
+                noOpOverScroller)
+
+        // Resetting as they are notified upon initialization.
+        reset(noOpOverScroller, splitShadeOverScroller)
+    }
+
+    @Test
+    fun onPanelExpansionChanged_inSplitShade_forwardsToSplitShadeOverScroller() {
+        initLateProperties()
+        enableSplitShade()
+
+        startPanelExpansion()
+
+        verify(splitShadeOverScroller).onPanelStateChanged(STATE_OPENING)
+        verify(splitShadeOverScroller).onDragDownAmountChanged(DEFAULT_DRAG_DOWN_AMOUNT)
+        verifyZeroInteractions(noOpOverScroller)
+    }
+
+    @Test
+    fun onPanelStateChanged_inSplitShade_propertiesNotInitialized_forwardsToNoOpOverScroller() {
+        enableSplitShade()
+
+        startPanelExpansion()
+
+        verify(noOpOverScroller).onPanelStateChanged(STATE_OPENING)
+        verify(noOpOverScroller).onDragDownAmountChanged(DEFAULT_DRAG_DOWN_AMOUNT)
+        verifyZeroInteractions(splitShadeOverScroller)
+    }
+
+    @Test
+    fun onPanelStateChanged_notInSplitShade_forwardsToNoOpOverScroller() {
+        initLateProperties()
+        disableSplitShade()
+
+        startPanelExpansion()
+
+        verify(noOpOverScroller).onPanelStateChanged(STATE_OPENING)
+        verify(noOpOverScroller).onDragDownAmountChanged(DEFAULT_DRAG_DOWN_AMOUNT)
+        verifyZeroInteractions(splitShadeOverScroller)
+    }
+
+    private fun initLateProperties() {
+        controller.qs = qs
+        controller.notificationStackScrollLayoutController = nsslController
+        controller.notificationPanelViewController = npvc
+    }
+
+    private fun disableSplitShade() {
+        setSplitShadeEnabled(false)
+    }
+
+    private fun enableSplitShade() {
+        setSplitShadeEnabled(true)
+    }
+
+    private fun setSplitShadeEnabled(enabled: Boolean) {
+        overrideResource(R.bool.config_use_split_notification_shade, enabled)
+        configurationController.notifyConfigurationChanged()
+    }
+
+    private fun startPanelExpansion() {
+        panelExpansionStateManager.onPanelExpansionChanged(
+            fraction = 0.5f,
+            expanded = true,
+            tracking = true,
+            dragDownPxAmount = DEFAULT_DRAG_DOWN_AMOUNT)
+    }
+
+    companion object {
+        private const val DEFAULT_DRAG_DOWN_AMOUNT = 123f
+    }
+}
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/shade/transition/SplitShadeOverScrollerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/shade/transition/SplitShadeOverScrollerTest.kt
@@ -0,0 +1,107 @@
+package com.android.systemui.statusbar.phone.shade.transition
+
+import org.mockito.Mockito.`when` as whenever
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import androidx.test.filters.SmallTest
+import com.android.systemui.R
+import com.android.systemui.SysuiTestCase
+import com.android.systemui.dump.DumpManager
+import com.android.systemui.plugins.qs.QS
+import com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayoutController
+import com.android.systemui.statusbar.phone.ScrimController
+import com.android.systemui.statusbar.phone.panelstate.STATE_CLOSED
+import com.android.systemui.statusbar.phone.panelstate.STATE_OPEN
+import com.android.systemui.statusbar.phone.panelstate.STATE_OPENING
+import com.android.systemui.statusbar.policy.FakeConfigurationController
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.atLeastOnce
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.verifyZeroInteractions
+import org.mockito.MockitoAnnotations
+
+@RunWith(AndroidTestingRunner::class)
+@TestableLooper.RunWithLooper(setAsMainLooper = true)
+@SmallTest
+class SplitShadeOverScrollerTest : SysuiTestCase() {
+
+    @Mock private lateinit var dumpManager: DumpManager
+    @Mock private lateinit var scrimController: ScrimController
+    @Mock private lateinit var qs: QS
+    @Mock private lateinit var nsslController: NotificationStackScrollLayoutController
+
+    private val configurationController = FakeConfigurationController()
+    private lateinit var overScroller: SplitShadeOverScroller
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+
+        whenever(nsslController.height).thenReturn(1000)
+        overScroller =
+            SplitShadeOverScroller(
+                configurationController, dumpManager, context, scrimController, qs, nsslController)
+    }
+
+    @Test
+    fun onDragDownAmountChanged_panelOpening_overScrolls_basedOnHeightAndMaxAmount() {
+        val maxOverScrollAmount = 50
+        val dragDownAmount = 100f
+        overrideResource(R.dimen.shade_max_over_scroll_amount, maxOverScrollAmount)
+        configurationController.notifyConfigurationChanged()
+
+        overScroller.onPanelStateChanged(STATE_OPENING)
+        overScroller.onDragDownAmountChanged(dragDownAmount)
+
+        val expectedOverScrollAmount =
+            (dragDownAmount / nsslController.height * maxOverScrollAmount).toInt()
+        verify(qs).setOverScrollAmount(expectedOverScrollAmount)
+        verify(nsslController).setOverScrollAmount(expectedOverScrollAmount)
+        verify(scrimController).setNotificationsOverScrollAmount(expectedOverScrollAmount)
+    }
+
+    @Test
+    fun onDragDownAmountChanged_panelClosed_doesNotOverScroll() {
+        overScroller.onPanelStateChanged(STATE_CLOSED)
+        overScroller.onDragDownAmountChanged(100f)
+
+        verifyZeroInteractions(qs, scrimController, nsslController)
+    }
+
+    @Test
+    fun onDragDownAmountChanged_panelOpen_doesNotOverScroll() {
+        overScroller.onPanelStateChanged(STATE_OPEN)
+        overScroller.onDragDownAmountChanged(100f)
+
+        verifyZeroInteractions(qs, scrimController, nsslController)
+    }
+
+    @Test
+    fun onPanelStateChanged_opening_thenOpen_releasesOverScroll() {
+        overScroller.onPanelStateChanged(STATE_OPENING)
+        overScroller.onDragDownAmountChanged(100f)
+
+        overScroller.onPanelStateChanged(STATE_OPEN)
+        overScroller.finishAnimations()
+
+        verify(qs, atLeastOnce()).setOverScrollAmount(0)
+        verify(scrimController, atLeastOnce()).setNotificationsOverScrollAmount(0)
+        verify(nsslController, atLeastOnce()).setOverScrollAmount(0)
+    }
+
+    @Test
+    fun onPanelStateChanged_opening_thenClosed_releasesOverScroll() {
+        overScroller.onPanelStateChanged(STATE_OPENING)
+        overScroller.onDragDownAmountChanged(100f)
+
+        overScroller.onPanelStateChanged(STATE_CLOSED)
+        overScroller.finishAnimations()
+
+        verify(qs, atLeastOnce()).setOverScrollAmount(0)
+        verify(scrimController, atLeastOnce()).setNotificationsOverScrollAmount(0)
+        verify(nsslController, atLeastOnce()).setOverScrollAmount(0)
+    }
+}