Merge "Scroll Capture Framework" into rvc-dev
diff --git a/core/java/android/view/IScrollCaptureClient.aidl b/core/java/android/view/IScrollCaptureClient.aidl
new file mode 100644
index 0000000..5f135a37
--- /dev/null
+++ b/core/java/android/view/IScrollCaptureClient.aidl
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.graphics.Rect;
+import android.view.Surface;
+
+
+ /**
+   * Interface implemented by a client of the Scroll Capture framework to receive requests
+   * to start, capture images and end the session.
+   *
+   * {@hide}
+   */
+interface IScrollCaptureClient {
+
+    /**
+     * Informs the client that it has been selected for scroll capture and should prepare to
+     * to begin handling capture requests.
+     */
+    oneway void startCapture(in Surface surface);
+
+    /**
+     * Request the client capture an image within the provided rectangle.
+     *
+     * @see android.view.ScrollCaptureCallback#onScrollCaptureRequest
+     */
+    oneway void requestImage(in Rect captureArea);
+
+    /**
+     * Inform the client that capture has ended. The client should shut down and release all
+     * local resources in use and prepare for return to normal interactive usage.
+     */
+    oneway void endCapture();
+}
diff --git a/core/java/android/view/IScrollCaptureController.aidl b/core/java/android/view/IScrollCaptureController.aidl
new file mode 100644
index 0000000..8474a00
--- /dev/null
+++ b/core/java/android/view/IScrollCaptureController.aidl
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.view.Surface;
+
+import android.view.IScrollCaptureClient;
+
+/**
+ * Interface to a controller passed to the {@link IScrollCaptureClient} which provides the client an
+ * asynchronous callback channel for responses.
+ *
+ * {@hide}
+ */
+interface IScrollCaptureController {
+    /**
+     * Scroll capture is available, and a client connect has been returned.
+     *
+     * @param client interface to a ScrollCaptureCallback in the window process
+     * @param scrollAreaInWindow the location of scrolling in global (window) coordinate space
+     */
+    oneway void onClientConnected(in IScrollCaptureClient client, in Rect scrollBounds,
+            in Point positionInWindow);
+
+    /**
+     * Nothing in the window can be scrolled, scroll capture not offered.
+     */
+    oneway void onClientUnavailable();
+
+    /**
+     * Notifies the system that the client has confirmed the request and is ready to begin providing
+     * image requests.
+     */
+    oneway void onCaptureStarted();
+
+    /**
+     * Received a response from a capture request.
+     */
+    oneway void onCaptureBufferSent(long frameNumber, in Rect capturedArea);
+
+    /**
+     * Signals that the capture session has completed and the target window may be returned to
+     * normal interactive use. This may be due to normal shutdown, or after a timeout or other
+     * unrecoverable state change such as activity lifecycle, window visibility or focus.
+     */
+    oneway void onConnectionClosed();
+}
diff --git a/core/java/android/view/IWindow.aidl b/core/java/android/view/IWindow.aidl
index 9f2d36d..e09bf9d 100644
--- a/core/java/android/view/IWindow.aidl
+++ b/core/java/android/view/IWindow.aidl
@@ -21,15 +21,16 @@
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
+import android.util.MergedConfiguration;
+import android.view.DisplayCutout;
 import android.view.DragEvent;
+import android.view.InsetsSourceControl;
+import android.view.InsetsState;
+import android.view.IScrollCaptureController;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
-import android.view.DisplayCutout;
-import android.view.InsetsState;
-import android.view.InsetsSourceControl;
 
 import com.android.internal.os.IResultReceiver;
-import android.util.MergedConfiguration;
 
 /**
  * API back to a client window that the Window Manager uses to inform it of
@@ -139,4 +140,11 @@
      * Tell the window that it is either gaining or losing pointer capture.
      */
     void dispatchPointerCaptureChanged(boolean hasCapture);
+
+    /**
+     * Called when Scroll Capture support is requested for a window.
+     *
+     * @param controller the controller to receive responses
+     */
+    void requestScrollCapture(in IScrollCaptureController controller);
 }
diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index b0bacb9..b3b53f0 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -42,6 +42,7 @@
 import android.view.IDisplayWindowRotationController;
 import android.view.IOnKeyguardExitResult;
 import android.view.IPinnedStackListener;
+import android.view.IScrollCaptureController;
 import android.view.RemoteAnimationAdapter;
 import android.view.IRotationWatcher;
 import android.view.ISystemGestureExclusionListener;
@@ -749,4 +750,18 @@
      * @param flags see definition in SurfaceTracing.cpp
      */
     void setLayerTracingFlags(int flags);
+
+    /**
+     * Forwards a scroll capture request to the appropriate window, if available.
+     *
+     * @param displayId the id of the display to target
+     * @param behindClient token for a window, used to filter the search to windows behind it, or
+     *                     {@code null} to accept a window at any zOrder
+     * @param taskId specifies the id of a task the result must belong to, or -1 to ignore task ids
+     * @param controller the controller to receive results, a call to either
+     *      {@link IScrollCaptureController#onClientConnected} or
+     *      {@link IScrollCaptureController#onClientUnavailable}.
+     */
+    void requestScrollCapture(int displayId, IBinder behindClient, int taskId,
+            IScrollCaptureController controller);
 }
diff --git a/core/java/android/view/ScrollCaptureCallback.java b/core/java/android/view/ScrollCaptureCallback.java
new file mode 100644
index 0000000..e1a4e74
--- /dev/null
+++ b/core/java/android/view/ScrollCaptureCallback.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.annotation.NonNull;
+import android.annotation.UiThread;
+import android.graphics.Rect;
+
+import java.util.function.Consumer;
+
+/**
+ * A ScrollCaptureCallback is responsible for providing rendered snapshots of scrolling content for
+ * the scroll capture system. A single callback is responsible for providing support to a single
+ * scrolling UI element. At request time, the system will select the best candidate from among all
+ * callbacks registered within the window.
+ * <p>
+ * A callback is assigned to a View using {@link View#setScrollCaptureCallback}, or to the window as
+ * {@link Window#addScrollCaptureCallback}. The point where the callback is registered defines the
+ * frame of reference for the bounds measurements used.
+ * <p>
+ * <b>Terminology</b>
+ * <dl>
+ * <dt>Containing View</dt>
+ * <dd>The view on which this callback is attached, or the root view of the window if the callback
+ * is assigned  directly to a window.</dd>
+ *
+ * <dt>Scroll Bounds</dt>
+ * <dd>A rectangle which describes an area within the containing view where scrolling content may
+ * be positioned. This may be the Containing View bounds itself, or any rectangle within.
+ * Requested by {@link #onScrollCaptureSearch}.</dd>
+ *
+ * <dt>Scroll Delta</dt>
+ * <dd>The distance the scroll position has moved since capture started. Implementations are
+ * responsible for tracking changes in vertical scroll position during capture. This is required to
+ * map the capture area to the correct location, given the current scroll position.
+ *
+ * <dt>Capture Area</dt>
+ * <dd>A rectangle which describes the area to capture, relative to scroll bounds. The vertical
+ * position remains relative to the starting scroll position and any movement since ("Scroll Delta")
+ * should be subtracted to locate the correct local position, and scrolled into view as necessary.
+ * </dd>
+ * </dl>
+ *
+ * @see View#setScrollCaptureHint(int)
+ * @see View#setScrollCaptureCallback(ScrollCaptureCallback)
+ * @see Window#addScrollCaptureCallback(ScrollCaptureCallback)
+ *
+ * @hide
+ */
+@UiThread
+public interface ScrollCaptureCallback {
+
+    /**
+     * The system is searching for the appropriate scrolling container to capture and would like to
+     * know the size and position of scrolling content handled by this callback.
+     * <p>
+     * Implementations should inset {@code containingViewBounds} to cover only the area within the
+     * containing view where scrolling content may be positioned. This should cover only the content
+     * which tracks with scrolling movement.
+     * <p>
+     * Return the updated rectangle to {@code resultConsumer}. If for any reason the scrolling
+     * content is not available to capture, a {@code null} rectangle may be returned, and this view
+     * will be excluded as the target for this request.
+     * <p>
+     * Responses received after XXXms will be discarded.
+     * <p>
+     * TODO: finalize timeout
+     *
+     * @param onReady              consumer for the updated rectangle
+     */
+    void onScrollCaptureSearch(@NonNull Consumer<Rect> onReady);
+
+    /**
+     * Scroll Capture has selected this callback to provide the scrolling image content.
+     * <p>
+     * The onReady signal should be called when ready to begin handling image requests.
+     */
+    void onScrollCaptureStart(@NonNull ScrollCaptureSession session, @NonNull Runnable onReady);
+
+    /**
+     * An image capture has been requested from the scrolling content.
+     * <p>
+     * <code>captureArea</code> contains the bounds of the image requested, relative to the
+     * rectangle provided by {@link ScrollCaptureCallback#onScrollCaptureSearch}, referred to as
+     * {@code scrollBounds}.
+     * here.
+     * <p>
+     * A series of requests will step by a constant vertical amount relative to {@code
+     * scrollBounds}, moving through the scrolling range of content, above and below the current
+     * visible area. The rectangle's vertical position will not account for any scrolling movement
+     * since capture started. Implementations therefore must track any scroll position changes and
+     * subtract this distance from requests.
+     * <p>
+     * To handle a request, the content should be scrolled to maximize the visible area of the
+     * requested rectangle. Offset {@code captureArea} again to account for any further scrolling.
+     * <p>
+     * Finally, clip this rectangle against scrollBounds to determine what portion, if any is
+     * visible content to capture. If the rectangle is completely clipped, set it to {@link
+     * Rect#setEmpty() empty} and skip the next step.
+     * <p>
+     * Make a copy of {@code captureArea}, transform to window coordinates and draw the window,
+     * clipped to this rectangle, into the {@link ScrollCaptureSession#getSurface() surface} at
+     * offset (0,0).
+     * <p>
+     * Finally, return the resulting {@code captureArea} using
+     * {@link ScrollCaptureSession#notifyBufferSent}.
+     * <p>
+     * If the response is not supplied within XXXms, the session will end with a call to {@link
+     * #onScrollCaptureEnd}, after which {@code session} is invalid and should be discarded.
+     * <p>
+     * TODO: finalize timeout
+     * <p>
+     *
+     * @param captureArea the area to capture, a rectangle within {@code scrollBounds}
+     */
+    void onScrollCaptureImageRequest(
+            @NonNull ScrollCaptureSession session, @NonNull Rect captureArea);
+
+    /**
+     * Signals that capture has ended. Implementations should release any temporary resources or
+     * references to objects in use during the capture. Any resources obtained from the session are
+     * now invalid and attempts to use them after this point may throw an exception.
+     * <p>
+     * The window should be returned as much as possible to its original state when capture started.
+     * At a minimum, the content should be scrolled to its original position.
+     * <p>
+     * <code>onReady</code> should be called when the window should be made visible and
+     * interactive. The system will wait up to XXXms for this call before proceeding.
+     * <p>
+     * TODO: finalize timeout
+     *
+     * @param onReady a callback to inform the system that the application has completed any
+     *                cleanup and is ready to become visible
+     */
+    void onScrollCaptureEnd(@NonNull Runnable onReady);
+}
+
diff --git a/core/java/android/view/ScrollCaptureClient.java b/core/java/android/view/ScrollCaptureClient.java
new file mode 100644
index 0000000..f163124
--- /dev/null
+++ b/core/java/android/view/ScrollCaptureClient.java
@@ -0,0 +1,312 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import static java.util.Objects.requireNonNull;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UiThread;
+import android.annotation.WorkerThread;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.os.Handler;
+import android.os.RemoteException;
+import android.util.CloseGuard;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A client of the system providing Scroll Capture capability on behalf of a Window.
+ * <p>
+ * An instance is created to wrap the selected {@link ScrollCaptureCallback}.
+ *
+ * @hide
+ */
+public class ScrollCaptureClient extends IScrollCaptureClient.Stub {
+
+    private static final String TAG = "ScrollCaptureClient";
+    private static final int DEFAULT_TIMEOUT = 1000;
+
+    private final Handler mHandler;
+    private ScrollCaptureTarget mSelectedTarget;
+    private int mTimeoutMillis = DEFAULT_TIMEOUT;
+
+    protected Surface mSurface;
+    private IScrollCaptureController mController;
+
+    private final Rect mScrollBounds;
+    private final Point mPositionInWindow;
+    private final CloseGuard mCloseGuard;
+
+    // The current session instance in use by the callback.
+    private ScrollCaptureSession mSession;
+
+    // Helps manage timeout callbacks registered to handler and aids testing.
+    private DelayedAction mTimeoutAction;
+
+    /**
+     * Constructs a ScrollCaptureClient.
+     *
+     * @param selectedTarget  the target the client is controlling
+     * @param controller the callbacks to reply to system requests
+     *
+     * @hide
+     */
+    public ScrollCaptureClient(
+            @NonNull ScrollCaptureTarget selectedTarget,
+            @NonNull IScrollCaptureController controller) {
+        requireNonNull(selectedTarget, "<selectedTarget> must non-null");
+        requireNonNull(controller, "<controller> must non-null");
+        final Rect scrollBounds = requireNonNull(selectedTarget.getScrollBounds(),
+                "target.getScrollBounds() must be non-null to construct a client");
+
+        mSelectedTarget = selectedTarget;
+        mHandler = selectedTarget.getContainingView().getHandler();
+        mScrollBounds = new Rect(scrollBounds);
+        mPositionInWindow = new Point(selectedTarget.getPositionInWindow());
+
+        mController = controller;
+        mCloseGuard = new CloseGuard();
+        mCloseGuard.open("close");
+
+        selectedTarget.getContainingView().addOnAttachStateChangeListener(
+                new View.OnAttachStateChangeListener() {
+                    @Override
+                    public void onViewAttachedToWindow(View v) {
+
+                    }
+
+                    @Override
+                    public void onViewDetachedFromWindow(View v) {
+                        selectedTarget.getContainingView().removeOnAttachStateChangeListener(this);
+                        endCapture();
+                    }
+                });
+    }
+
+    @VisibleForTesting
+    public void setTimeoutMillis(int timeoutMillis) {
+        mTimeoutMillis = timeoutMillis;
+    }
+
+    @Nullable
+    @VisibleForTesting
+    public DelayedAction getTimeoutAction() {
+        return mTimeoutAction;
+    }
+
+    private void checkConnected() {
+        if (mSelectedTarget == null || mController == null) {
+            throw new IllegalStateException("This client has been disconnected.");
+        }
+    }
+
+    private void checkStarted() {
+        if (mSession == null) {
+            throw new IllegalStateException("Capture session has not been started!");
+        }
+    }
+
+    @WorkerThread // IScrollCaptureClient
+    @Override
+    public void startCapture(Surface surface) throws RemoteException {
+        checkConnected();
+        mSurface = surface;
+        scheduleTimeout(mTimeoutMillis, this::onStartCaptureTimeout);
+        mSession = new ScrollCaptureSession(mSurface, mScrollBounds, mPositionInWindow, this);
+        mHandler.post(() -> mSelectedTarget.getCallback().onScrollCaptureStart(mSession,
+                this::onStartCaptureCompleted));
+    }
+
+    @UiThread
+    private void onStartCaptureCompleted() {
+        if (cancelTimeout()) {
+            mHandler.post(() -> {
+                try {
+                    mController.onCaptureStarted();
+                } catch (RemoteException e) {
+                    doShutdown();
+                }
+            });
+        }
+    }
+
+    @UiThread
+    private void onStartCaptureTimeout() {
+        endCapture();
+    }
+
+    @WorkerThread // IScrollCaptureClient
+    @Override
+    public void requestImage(Rect requestRect) {
+        checkConnected();
+        checkStarted();
+        scheduleTimeout(mTimeoutMillis, this::onRequestImageTimeout);
+        // Response is dispatched via ScrollCaptureSession, to onRequestImageCompleted
+        mHandler.post(() -> mSelectedTarget.getCallback().onScrollCaptureImageRequest(
+                mSession, new Rect(requestRect)));
+    }
+
+    @UiThread
+    void onRequestImageCompleted(long frameNumber, Rect capturedArea) {
+        final Rect finalCapturedArea = new Rect(capturedArea);
+        if (cancelTimeout()) {
+            mHandler.post(() -> {
+                try {
+                    mController.onCaptureBufferSent(frameNumber, finalCapturedArea);
+                } catch (RemoteException e) {
+                    doShutdown();
+                }
+            });
+        }
+    }
+
+    @UiThread
+    private void onRequestImageTimeout() {
+        endCapture();
+    }
+
+    @WorkerThread // IScrollCaptureClient
+    @Override
+    public void endCapture() {
+        if (isStarted()) {
+            scheduleTimeout(mTimeoutMillis, this::onEndCaptureTimeout);
+            mHandler.post(() ->
+                    mSelectedTarget.getCallback().onScrollCaptureEnd(this::onEndCaptureCompleted));
+        } else {
+            disconnect();
+        }
+    }
+
+    private boolean isStarted() {
+        return mController != null && mSelectedTarget != null;
+    }
+
+    @UiThread
+    private void onEndCaptureCompleted() { // onEndCaptureCompleted
+        if (cancelTimeout()) {
+            doShutdown();
+        }
+    }
+
+    @UiThread
+    private void onEndCaptureTimeout() {
+        doShutdown();
+    }
+
+
+    private void doShutdown() {
+        try {
+            if (mController != null) {
+                mController.onConnectionClosed();
+            }
+        } catch (RemoteException e) {
+            // Ignore
+        } finally {
+            disconnect();
+        }
+    }
+
+    /**
+     * Shuts down this client and releases references to dependent objects. No attempt is made
+     * to notify the controller, use with caution!
+     */
+    public void disconnect() {
+        if (mSession != null) {
+            mSession.disconnect();
+            mSession = null;
+        }
+
+        mSelectedTarget = null;
+        mController = null;
+    }
+
+    /** @return a string representation of the state of this client */
+    public String toString() {
+        return "ScrollCaptureClient{"
+                + ", session=" + mSession
+                + ", selectedTarget=" + mSelectedTarget
+                + ", clientCallbacks=" + mController
+                + "}";
+    }
+
+    private boolean cancelTimeout() {
+        if (mTimeoutAction != null) {
+            return mTimeoutAction.cancel();
+        }
+        return false;
+    }
+
+    private void scheduleTimeout(long timeoutMillis, Runnable action) {
+        if (mTimeoutAction != null) {
+            mTimeoutAction.cancel();
+        }
+        mTimeoutAction = new DelayedAction(mHandler, timeoutMillis, action);
+    }
+
+    /** @hide */
+    @VisibleForTesting
+    public static class DelayedAction {
+        private final AtomicBoolean mCompleted = new AtomicBoolean();
+        private final Object mToken = new Object();
+        private final Handler mHandler;
+        private final Runnable mAction;
+
+        @VisibleForTesting
+        public DelayedAction(Handler handler, long timeoutMillis, Runnable action) {
+            mHandler = handler;
+            mAction = action;
+            mHandler.postDelayed(this::onTimeout, mToken, timeoutMillis);
+        }
+
+        private boolean onTimeout() {
+            if (mCompleted.compareAndSet(false, true)) {
+                mAction.run();
+                return true;
+            }
+            return false;
+        }
+
+        /**
+         * Cause the timeout action to run immediately and mark as timed out.
+         *
+         * @return true if the timeout was run, false if the timeout had already been canceled
+         */
+        @VisibleForTesting
+        public boolean timeoutNow() {
+            return onTimeout();
+        }
+
+        /**
+         * Attempt to cancel the timeout action (such as after a callback is made)
+         *
+         * @return true if the timeout was canceled and will not run, false if time has expired and
+         * the timeout action has or will run momentarily
+         */
+        public boolean cancel() {
+            if (!mCompleted.compareAndSet(false, true)) {
+                // Whoops, too late!
+                return false;
+            }
+            mHandler.removeCallbacksAndMessages(mToken);
+            return true;
+        }
+    }
+}
diff --git a/core/java/android/view/ScrollCaptureSession.java b/core/java/android/view/ScrollCaptureSession.java
new file mode 100644
index 0000000..628e23f
--- /dev/null
+++ b/core/java/android/view/ScrollCaptureSession.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.graphics.Point;
+import android.graphics.Rect;
+
+/**
+ * A session represents the scope of interaction between a {@link ScrollCaptureCallback} and the
+ * system during an active scroll capture operation. During the scope of a session, a callback
+ * will receive a series of requests for image data. Resources provided here are valid for use
+ * until {@link ScrollCaptureCallback#onScrollCaptureEnd(Runnable)}.
+ *
+ * @hide
+ */
+public class ScrollCaptureSession {
+
+    private final Surface mSurface;
+    private final Rect mScrollBounds;
+    private final Point mPositionInWindow;
+
+    @Nullable
+    private ScrollCaptureClient mClient;
+
+    /** @hide */
+    public ScrollCaptureSession(Surface surface, Rect scrollBounds, Point positionInWindow,
+            ScrollCaptureClient client) {
+        mSurface = surface;
+        mScrollBounds = scrollBounds;
+        mPositionInWindow = positionInWindow;
+        mClient = client;
+    }
+
+    /**
+     * Returns a
+     * <a href="https://source.android.com/devices/graphics/arch-bq-gralloc">BufferQueue</a> in the
+     * form of a {@link Surface} for transfer of image buffers.
+     *
+     * @return the surface for transferring image buffers
+     * @throws IllegalStateException if the session has been closed
+     */
+    @NonNull
+    public Surface getSurface() {
+        return mSurface;
+    }
+
+    /**
+     * Returns the {@code scroll bounds}, as provided by
+     * {@link ScrollCaptureCallback#onScrollCaptureSearch}.
+     *
+     * @return the area of scrolling content within the containing view
+     */
+    @NonNull
+    public Rect getScrollBounds() {
+        return mScrollBounds;
+    }
+
+    /**
+     * Returns the offset of {@code scroll bounds} within the window.
+     *
+     * @return the area of scrolling content within the containing view
+     */
+    @NonNull
+    public Point getPositionInWindow() {
+        return mPositionInWindow;
+    }
+
+    /**
+     * Notify the system that an a buffer has been posted via the getSurface() channel.
+     *
+     * @param frameNumber  the frame number of the queued buffer
+     * @param capturedArea the area captured, relative to scroll bounds
+     */
+    public void notifyBufferSent(long frameNumber, @NonNull Rect capturedArea) {
+        if (mClient != null) {
+            mClient.onRequestImageCompleted(frameNumber, capturedArea);
+        }
+    }
+
+    /**
+     * @hide
+     */
+    public void disconnect() {
+        mClient = null;
+        if (mSurface.isValid()) {
+            mSurface.release();
+        }
+    }
+}
diff --git a/core/java/android/view/ScrollCaptureTarget.java b/core/java/android/view/ScrollCaptureTarget.java
new file mode 100644
index 0000000..f3fcabb
--- /dev/null
+++ b/core/java/android/view/ScrollCaptureTarget.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UiThread;
+import android.graphics.Matrix;
+import android.graphics.Point;
+import android.graphics.Rect;
+
+import com.android.internal.util.FastMath;
+
+/**
+ * A target collects the set of contextual information for a ScrollCaptureHandler discovered during
+ * a {@link View#dispatchScrollCaptureSearch scroll capture search}.
+ *
+ * @hide
+ */
+public final class ScrollCaptureTarget {
+    private final View mContainingView;
+    private final ScrollCaptureCallback mCallback;
+    private final Rect mLocalVisibleRect;
+    private final Point mPositionInWindow;
+    private final int mHint;
+    private Rect mScrollBounds;
+
+    private final float[] mTmpFloatArr = new float[2];
+    private final Matrix mMatrixViewLocalToWindow = new Matrix();
+    private final Rect mTmpRect = new Rect();
+
+    public ScrollCaptureTarget(@NonNull View scrollTarget, @NonNull Rect localVisibleRect,
+            @NonNull Point positionInWindow, @NonNull ScrollCaptureCallback callback) {
+        mContainingView = scrollTarget;
+        mHint = mContainingView.getScrollCaptureHint();
+        mCallback = callback;
+        mLocalVisibleRect = localVisibleRect;
+        mPositionInWindow = positionInWindow;
+    }
+
+    /** @return the hint that the {@code containing view} had during the scroll capture search */
+    @View.ScrollCaptureHint
+    public int getHint() {
+        return mHint;
+    }
+
+    /** @return the {@link ScrollCaptureCallback} for this target */
+    @NonNull
+    public ScrollCaptureCallback getCallback() {
+        return mCallback;
+    }
+
+    /** @return the {@code containing view} for this {@link ScrollCaptureCallback callback} */
+    @NonNull
+    public View getContainingView() {
+        return mContainingView;
+    }
+
+    /**
+     * Returns the un-clipped, visible bounds of the containing view during the scroll capture
+     * search. This is used to determine on-screen area to assist in selecting the primary target.
+     *
+     * @return the visible bounds of the {@code containing view} in view-local coordinates
+     */
+    @NonNull
+    public Rect getLocalVisibleRect() {
+        return mLocalVisibleRect;
+    }
+
+    /** @return the position of the {@code containing view} within the window */
+    @NonNull
+    public Point getPositionInWindow() {
+        return mPositionInWindow;
+    }
+
+    /** @return the {@code scroll bounds} for this {@link ScrollCaptureCallback callback} */
+    @Nullable
+    public Rect getScrollBounds() {
+        return mScrollBounds;
+    }
+
+    /**
+     * Sets the scroll bounds rect to the intersection of provided rect and the current bounds of
+     * the {@code containing view}.
+     */
+    public void setScrollBounds(@Nullable Rect scrollBounds) {
+        mScrollBounds = Rect.copyOrNull(scrollBounds);
+        if (mScrollBounds == null) {
+            return;
+        }
+        if (!mScrollBounds.intersect(0, 0,
+                mContainingView.getWidth(), mContainingView.getHeight())) {
+            mScrollBounds.setEmpty();
+        }
+    }
+
+    private static void zero(float[] pointArray) {
+        pointArray[0] = 0;
+        pointArray[1] = 0;
+    }
+
+    private static void roundIntoPoint(Point pointObj, float[] pointArray) {
+        pointObj.x = FastMath.round(pointArray[0]);
+        pointObj.y = FastMath.round(pointArray[1]);
+    }
+
+    /**
+     * Refresh the value of {@link #mLocalVisibleRect} and {@link #mPositionInWindow} based on the
+     * current state of the {@code containing view}.
+     */
+    @UiThread
+    public void updatePositionInWindow() {
+        mMatrixViewLocalToWindow.reset();
+        mContainingView.transformMatrixToGlobal(mMatrixViewLocalToWindow);
+
+        zero(mTmpFloatArr);
+        mMatrixViewLocalToWindow.mapPoints(mTmpFloatArr);
+        roundIntoPoint(mPositionInWindow, mTmpFloatArr);
+    }
+
+}
diff --git a/core/java/android/view/ScrollCaptureTargetResolver.java b/core/java/android/view/ScrollCaptureTargetResolver.java
new file mode 100644
index 0000000..71e82c5
--- /dev/null
+++ b/core/java/android/view/ScrollCaptureTargetResolver.java
@@ -0,0 +1,387 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import android.annotation.AnyThread;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UiThread;
+import android.graphics.Rect;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.SystemClock;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+
+import java.util.Queue;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Consumer;
+
+/**
+ * Queries additional state from a list of {@link ScrollCaptureTarget targets} via asynchronous
+ * callbacks, then aggregates and reduces the target list to a single target, or null if no target
+ * is suitable.
+ * <p>
+ * The rules for selection are (in order):
+ * <ul>
+ * <li>prefer getScrollBounds(): non-empty
+ * <li>prefer View.getScrollCaptureHint == SCROLL_CAPTURE_HINT_INCLUDE
+ * <li>prefer descendants before parents
+ * <li>prefer larger area for getScrollBounds() (clipped to view bounds)
+ * </ul>
+ *
+ * <p>
+ * All calls to {@link ScrollCaptureCallback#onScrollCaptureSearch} are made on the main thread,
+ * with results are queued and consumed to the main thread as well.
+ *
+ * @see #start(Handler, long, Consumer)
+ *
+ * @hide
+ */
+@UiThread
+public class ScrollCaptureTargetResolver {
+    private static final String TAG = "ScrollCaptureTargetRes";
+    private static final boolean DEBUG = true;
+
+    private final Object mLock = new Object();
+
+    private final Queue<ScrollCaptureTarget> mTargets;
+    private Handler mHandler;
+    private long mTimeLimitMillis;
+
+    private Consumer<ScrollCaptureTarget> mWhenComplete;
+    private int mPendingBoundsRequests;
+    private long mDeadlineMillis;
+
+    private ScrollCaptureTarget mResult;
+    private boolean mFinished;
+
+    private boolean mStarted;
+
+    private static int area(Rect r) {
+        return r.width() * r.height();
+    }
+
+    private static boolean nullOrEmpty(Rect r) {
+        return r == null || r.isEmpty();
+    }
+
+    /**
+     * Binary operator which selects the best {@link ScrollCaptureTarget}.
+     */
+    private static ScrollCaptureTarget chooseTarget(ScrollCaptureTarget a, ScrollCaptureTarget b) {
+        Log.d(TAG, "chooseTarget: " + a + " or " + b);
+        // Nothing plus nothing is still nothing.
+        if (a == null && b == null) {
+            Log.d(TAG, "chooseTarget: (both null) return " + null);
+            return null;
+        }
+        // Prefer non-null.
+        if (a == null || b == null) {
+            ScrollCaptureTarget c = (a == null) ? b : a;
+            Log.d(TAG, "chooseTarget: (other is null) return " + c);
+            return c;
+
+        }
+
+        boolean emptyScrollBoundsA = nullOrEmpty(a.getScrollBounds());
+        boolean emptyScrollBoundsB = nullOrEmpty(b.getScrollBounds());
+        if (emptyScrollBoundsA || emptyScrollBoundsB) {
+            if (emptyScrollBoundsA && emptyScrollBoundsB) {
+                // Both have an empty or null scrollBounds
+                Log.d(TAG, "chooseTarget: (both have empty or null bounds) return " + null);
+                return null;
+            }
+            // Prefer the one with a non-empty scroll bounds
+            if (emptyScrollBoundsA) {
+                Log.d(TAG, "chooseTarget: (a has empty or null bounds) return " + b);
+                return b;
+            }
+            Log.d(TAG, "chooseTarget: (b has empty or null bounds) return " + a);
+            return a;
+        }
+
+        final View viewA = a.getContainingView();
+        final View viewB = b.getContainingView();
+
+        // Prefer any view with scrollCaptureHint="INCLUDE", over one without
+        // This is an escape hatch for the next rule (descendants first)
+        boolean hintIncludeA = hasIncludeHint(viewA);
+        boolean hintIncludeB = hasIncludeHint(viewB);
+        if (hintIncludeA != hintIncludeB) {
+            ScrollCaptureTarget c = (hintIncludeA) ? a : b;
+            Log.d(TAG, "chooseTarget: (has hint=INCLUDE) return " + c);
+            return c;
+        }
+
+        // If the views are relatives, prefer the descendant. This allows implementations to
+        // leverage nested scrolling APIs by interacting with the innermost scrollable view (as
+        // would happen with touch input).
+        if (isDescendant(viewA, viewB)) {
+            Log.d(TAG, "chooseTarget: (b is descendant of a) return " + b);
+            return b;
+        }
+        if (isDescendant(viewB, viewA)) {
+            Log.d(TAG, "chooseTarget: (a is descendant of b) return " + a);
+            return a;
+        }
+
+        // finally, prefer one with larger scroll bounds
+        int scrollAreaA = area(a.getScrollBounds());
+        int scrollAreaB = area(b.getScrollBounds());
+        ScrollCaptureTarget c = (scrollAreaA >= scrollAreaB) ? a : b;
+        Log.d(TAG, "chooseTarget: return " + c);
+        return c;
+    }
+
+    /**
+     * Creates an instance to query and filter {@code target}.
+     *
+     * @param targets   a list of {@link ScrollCaptureTarget} as collected by {@link
+     *                  View#dispatchScrollCaptureSearch}.
+     * @param uiHandler the UI thread handler for the view tree
+     * @see #start(long, Consumer)
+     */
+    public ScrollCaptureTargetResolver(Queue<ScrollCaptureTarget> targets) {
+        mTargets = targets;
+    }
+
+    void checkThread() {
+        if (mHandler.getLooper() != Looper.myLooper()) {
+            throw new IllegalStateException("Called from wrong thread! ("
+                    + Thread.currentThread().getName() + ")");
+        }
+    }
+
+    /**
+     * Blocks until a result is returned (after completion or timeout).
+     * <p>
+     * For testing only. Normal usage should receive a callback after calling {@link #start}.
+     */
+    @VisibleForTesting
+    public ScrollCaptureTarget waitForResult() throws InterruptedException {
+        synchronized (mLock) {
+            while (!mFinished) {
+                mLock.wait();
+            }
+        }
+        return mResult;
+    }
+
+
+    private void supplyResult(ScrollCaptureTarget target) {
+        checkThread();
+        if (mFinished) {
+            return;
+        }
+        mResult = chooseTarget(mResult, target);
+        boolean finish = mPendingBoundsRequests == 0
+                || SystemClock.elapsedRealtime() >= mDeadlineMillis;
+        if (finish) {
+            System.err.println("We think we're done, or timed out");
+            mPendingBoundsRequests = 0;
+            mWhenComplete.accept(mResult);
+            synchronized (mLock) {
+                mFinished = true;
+                mLock.notify();
+            }
+            mWhenComplete = null;
+        }
+    }
+
+    /**
+     * Asks all targets for {@link ScrollCaptureCallback#onScrollCaptureSearch(Consumer)
+     * scrollBounds}, and selects the primary target according to the {@link
+     * #chooseTarget} function.
+     *
+     * @param timeLimitMillis the amount of time to wait for all responses before delivering the top
+     *                        result
+     * @param resultConsumer  the consumer to receive the primary target
+     */
+    @AnyThread
+    public void start(Handler uiHandler, long timeLimitMillis,
+            Consumer<ScrollCaptureTarget> resultConsumer) {
+        synchronized (mLock) {
+            if (mStarted) {
+                throw new IllegalStateException("already started!");
+            }
+            if (timeLimitMillis < 0) {
+                throw new IllegalArgumentException("Time limit must be positive");
+            }
+            mHandler = uiHandler;
+            mTimeLimitMillis = timeLimitMillis;
+            mWhenComplete = resultConsumer;
+            if (mTargets.isEmpty()) {
+                mHandler.post(() -> supplyResult(null));
+                return;
+            }
+            mStarted = true;
+            uiHandler.post(() -> run(timeLimitMillis, resultConsumer));
+        }
+    }
+
+
+    private void run(long timeLimitMillis, Consumer<ScrollCaptureTarget> resultConsumer) {
+        checkThread();
+
+        mPendingBoundsRequests = mTargets.size();
+        for (ScrollCaptureTarget target : mTargets) {
+            queryTarget(target);
+        }
+        mDeadlineMillis = SystemClock.elapsedRealtime() + mTimeLimitMillis;
+        mHandler.postAtTime(mTimeoutRunnable, mDeadlineMillis);
+    }
+
+    private final Runnable mTimeoutRunnable = new Runnable() {
+        @Override
+        public void run() {
+            checkThread();
+            supplyResult(null);
+        }
+    };
+
+
+    /**
+     * Adds a target to the list and requests {@link ScrollCaptureCallback#onScrollCaptureSearch}
+     * scrollBounds} from it. Results are returned by a call to {@link #onScrollBoundsProvided}.
+     *
+     * @param target the target to add
+     */
+    @UiThread
+    private void queryTarget(@NonNull ScrollCaptureTarget target) {
+        checkThread();
+        final ScrollCaptureCallback callback = target.getCallback();
+        // from the UI thread, request scroll bounds
+        callback.onScrollCaptureSearch(
+                // allow only one callback to onReady.accept():
+                new SingletonConsumer<Rect>(
+                        // Queue and consume on the UI thread
+                        ((scrollBounds) -> mHandler.post(
+                                () -> onScrollBoundsProvided(target, scrollBounds)))));
+
+    }
+
+    @UiThread
+    private void onScrollBoundsProvided(ScrollCaptureTarget target, @Nullable Rect scrollBounds) {
+        checkThread();
+        if (mFinished) {
+            return;
+        }
+
+        // Record progress.
+        mPendingBoundsRequests--;
+
+        // Remove the timeout.
+        mHandler.removeCallbacks(mTimeoutRunnable);
+
+        boolean doneOrTimedOut = mPendingBoundsRequests == 0
+                || SystemClock.elapsedRealtime() >= mDeadlineMillis;
+
+        final View containingView = target.getContainingView();
+        if (!nullOrEmpty(scrollBounds) && containingView.isAggregatedVisible()) {
+            target.updatePositionInWindow();
+            target.setScrollBounds(scrollBounds);
+            supplyResult(target);
+        }
+
+        System.err.println("mPendingBoundsRequests: " + mPendingBoundsRequests);
+        System.err.println("mDeadlineMillis: " + mDeadlineMillis);
+        System.err.println("SystemClock.elapsedRealtime(): " + SystemClock.elapsedRealtime());
+
+        if (!mFinished) {
+            // Reschedule the timeout.
+            System.err.println(
+                    "We think we're NOT done yet and will check back at " + mDeadlineMillis);
+            mHandler.postAtTime(mTimeoutRunnable, mDeadlineMillis);
+        }
+    }
+
+    private static boolean hasIncludeHint(View view) {
+        return (view.getScrollCaptureHint() & View.SCROLL_CAPTURE_HINT_INCLUDE) != 0;
+    }
+
+    /**
+     * Determines if {@code otherView} is a descendant of {@code view}.
+     *
+     * @param view      a view
+     * @param otherView another view
+     * @return true if {@code view} is an ancestor of {@code otherView}
+     */
+    private static boolean isDescendant(@NonNull View view, @NonNull View otherView) {
+        if (view == otherView) {
+            return false;
+        }
+        ViewParent otherParent = otherView.getParent();
+        while (otherParent != view && otherParent != null) {
+            otherParent = otherParent.getParent();
+        }
+        return otherParent == view;
+    }
+
+    private static int findRelation(@NonNull View a, @NonNull View b) {
+        if (a == b) {
+            return 0;
+        }
+
+        ViewParent parentA = a.getParent();
+        ViewParent parentB = b.getParent();
+
+        while (parentA != null || parentB != null) {
+            if (parentA == parentB) {
+                return 0;
+            }
+            if (parentA == b) {
+                return 1; // A is descendant of B
+            }
+            if (parentB == a) {
+                return -1; // B is descendant of A
+            }
+            if (parentA != null) {
+                parentA = parentA.getParent();
+            }
+            if (parentB != null) {
+                parentB = parentB.getParent();
+            }
+        }
+        return 0;
+    }
+
+    /**
+     * A safe wrapper for a consumer callbacks intended to accept a single value. It ensures
+     * that the receiver of the consumer does not retain a reference to {@code target} after use nor
+     * cause race conditions by invoking {@link Consumer#accept accept} more than once.
+     *
+     * @param target the target consumer
+     */
+    static class SingletonConsumer<T> implements Consumer<T> {
+        final AtomicReference<Consumer<T>> mAtomicRef;
+
+        SingletonConsumer(Consumer<T> target) {
+            mAtomicRef = new AtomicReference<>(target);
+        }
+
+        @Override
+        public void accept(T t) {
+            final Consumer<T> consumer = mAtomicRef.getAndSet(null);
+            if (consumer != null) {
+                consumer.accept(t);
+            }
+        }
+    }
+}
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 8abe72f..f98c1f6 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -144,6 +144,7 @@
 
 import com.android.internal.R;
 import com.android.internal.util.FrameworkStatsLog;
+import com.android.internal.view.ScrollCaptureInternal;
 import com.android.internal.view.TooltipPopup;
 import com.android.internal.view.menu.MenuBuilder;
 import com.android.internal.widget.ScrollBarUtils;
@@ -167,6 +168,7 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Queue;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
@@ -1311,7 +1313,6 @@
      */
     public static final int AUTOFILL_TYPE_LIST = 3;
 
-
     /**
      * Autofill type for a field that contains a date, which is represented by a long representing
      * the number of milliseconds since the standard base time known as "the epoch", namely
@@ -1441,6 +1442,58 @@
      */
     public static final int IMPORTANT_FOR_CONTENT_CAPTURE_NO_EXCLUDE_DESCENDANTS = 0x8;
 
+    /** {@hide} */
+    @IntDef(flag = true, prefix = {"SCROLL_CAPTURE_HINT_"},
+            value = {
+                    SCROLL_CAPTURE_HINT_AUTO,
+                    SCROLL_CAPTURE_HINT_EXCLUDE,
+                    SCROLL_CAPTURE_HINT_INCLUDE,
+                    SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface ScrollCaptureHint {}
+
+    /**
+     * The content of this view will be considered for scroll capture if scrolling is possible.
+     *
+     * @see #getScrollCaptureHint()
+     * @see #setScrollCaptureHint(int)
+     * @hide
+     */
+    public static final int SCROLL_CAPTURE_HINT_AUTO = 0;
+
+    /**
+     * Explicitly exclcude this view as a potential scroll capture target. The system will not
+     * consider it. Mutually exclusive with {@link #SCROLL_CAPTURE_HINT_INCLUDE}, which this flag
+     * takes precedence over.
+     *
+     * @see #getScrollCaptureHint()
+     * @see #setScrollCaptureHint(int)
+     * @hide
+     */
+    public static final int SCROLL_CAPTURE_HINT_EXCLUDE = 0x1;
+
+    /**
+     * Explicitly include this view as a potential scroll capture target. When locating a scroll
+     * capture target, this view will be prioritized before others without this flag. Mutually
+     * exclusive with {@link #SCROLL_CAPTURE_HINT_EXCLUDE}, which takes precedence.
+     *
+     * @see #getScrollCaptureHint()
+     * @see #setScrollCaptureHint(int)
+     * @hide
+     */
+    public static final int SCROLL_CAPTURE_HINT_INCLUDE = 0x2;
+
+    /**
+     * Explicitly exclude all children of this view as potential scroll capture targets. This view
+     * is unaffected. Note: Excluded children are not considered, regardless of {@link
+     * #SCROLL_CAPTURE_HINT_INCLUDE}.
+     *
+     * @see #getScrollCaptureHint()
+     * @see #setScrollCaptureHint(int)
+     * @hide
+     */
+    public static final int SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS = 0x4;
 
     /**
      * This view is enabled. Interpretation varies by subclass.
@@ -3430,6 +3483,7 @@
      *                         11       PFLAG4_CONTENT_CAPTURE_IMPORTANCE_MASK
      *                        1         PFLAG4_FRAMEWORK_OPTIONAL_FITS_SYSTEM_WINDOWS
      *                       1          PFLAG4_AUTOFILL_HIDE_HIGHLIGHT
+     *                     11           PFLAG4_SCROLL_CAPTURE_HINT_MASK
      * |-------|-------|-------|-------|
      */
 
@@ -3477,6 +3531,15 @@
      */
     private static final int PFLAG4_AUTOFILL_HIDE_HIGHLIGHT = 0x200;
 
+    /**
+     * Shift for the bits in {@link #mPrivateFlags4} related to scroll capture.
+     */
+    static final int PFLAG4_SCROLL_CAPTURE_HINT_SHIFT = 10;
+
+    static final int PFLAG4_SCROLL_CAPTURE_HINT_MASK = (SCROLL_CAPTURE_HINT_INCLUDE
+            | SCROLL_CAPTURE_HINT_EXCLUDE | SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS)
+            << PFLAG4_SCROLL_CAPTURE_HINT_SHIFT;
+
     /* End of masks for mPrivateFlags4 */
 
     /** @hide */
@@ -4690,6 +4753,11 @@
          * Used to track {@link #mSystemGestureExclusionRects}
          */
         public RenderNode.PositionUpdateListener mPositionUpdateListener;
+
+        /**
+         * Allows the application to implement custom scroll capture support.
+         */
+        ScrollCaptureCallback mScrollCaptureCallback;
     }
 
     @UnsupportedAppUsage
@@ -5941,6 +6009,9 @@
                 case R.styleable.View_forceDarkAllowed:
                     mRenderNode.setForceDarkAllowed(a.getBoolean(attr, true));
                     break;
+                case R.styleable.View_scrollCaptureHint:
+                    setScrollCaptureHint((a.getInt(attr, SCROLL_CAPTURE_HINT_AUTO)));
+                    break;
             }
         }
 
@@ -29091,6 +29162,11 @@
         int mLeashedParentAccessibilityViewId;
 
         /**
+         *
+         */
+        ScrollCaptureInternal mScrollCaptureInternal;
+
+        /**
          * Creates a new set of attachment information with the specified
          * events handler and thread.
          *
@@ -29150,6 +29226,14 @@
 
             return events;
         }
+
+        @Nullable
+        ScrollCaptureInternal getScrollCaptureInternal() {
+            if (mScrollCaptureInternal != null) {
+                mScrollCaptureInternal = new ScrollCaptureInternal();
+            }
+            return mScrollCaptureInternal;
+        }
     }
 
     /**
@@ -29683,6 +29767,104 @@
         }
     }
 
+
+    /**
+     * Returns the current scroll capture hint for this view.
+     *
+     * @return the current scroll capture hint
+     *
+     * @hide
+     */
+    @ScrollCaptureHint
+    public int getScrollCaptureHint() {
+        return (mPrivateFlags4 & PFLAG4_SCROLL_CAPTURE_HINT_MASK)
+                >> PFLAG4_SCROLL_CAPTURE_HINT_SHIFT;
+    }
+
+    /**
+     * Sets the scroll capture hint for this View. These flags affect the search for a potential
+     * scroll capture targets.
+     *
+     * @param hint the scrollCaptureHint flags value to set
+     *
+     * @hide
+     */
+    public void setScrollCaptureHint(@ScrollCaptureHint int hint) {
+        mPrivateFlags4 &= ~PFLAG4_SCROLL_CAPTURE_HINT_MASK;
+        mPrivateFlags4 |= ((hint << PFLAG4_SCROLL_CAPTURE_HINT_SHIFT)
+                & PFLAG4_SCROLL_CAPTURE_HINT_MASK);
+    }
+
+    /**
+     * Sets the callback to receive scroll capture requests. This component is the adapter between
+     * the scroll capture API and application UI code. If no callback is set, the system may provide
+     * an implementation. Any value provided here will take precedence over a system version.
+     * <p>
+     * This view will be ignored when {@link #SCROLL_CAPTURE_HINT_EXCLUDE} is set in its {@link
+     * #setScrollCaptureHint(int) scrollCaptureHint}, regardless whether a callback has been set.
+     * <p>
+     * It is recommended to set the scroll capture hint {@link #SCROLL_CAPTURE_HINT_INCLUDE} when
+     * setting a custom callback to help ensure it is selected as the target.
+     *
+     * @param callback the new callback to assign
+     *
+     * @hide
+     */
+    public void setScrollCaptureCallback(@Nullable ScrollCaptureCallback callback) {
+        getListenerInfo().mScrollCaptureCallback = callback;
+    }
+
+    /** {@hide} */
+    @Nullable
+    public ScrollCaptureCallback createScrollCaptureCallbackInternal(@NonNull Rect localVisibleRect,
+            @NonNull Point windowOffset) {
+        if (mAttachInfo == null) {
+            return null;
+        }
+        if (mAttachInfo.mScrollCaptureInternal == null) {
+            mAttachInfo.mScrollCaptureInternal = new ScrollCaptureInternal();
+        }
+        return mAttachInfo.mScrollCaptureInternal.requestCallback(this, localVisibleRect,
+                windowOffset);
+    }
+
+    /**
+     * Called when scroll capture is requested, to search for appropriate content to scroll. If
+     * applicable, this view adds itself to the provided list for consideration, subject to the
+     * flags set by {@link #setScrollCaptureHint}.
+     *
+     * @param localVisibleRect the local visible rect of this view
+     * @param windowOffset     the offset of localVisibleRect within the window
+     * @param targets          a queue which collects potential targets
+     *
+     * @throws IllegalStateException if this view is not attached to a window
+     * @hide
+     */
+    public void dispatchScrollCaptureSearch(@NonNull Rect localVisibleRect,
+            @NonNull Point windowOffset, @NonNull Queue<ScrollCaptureTarget> targets) {
+        int hint = getScrollCaptureHint();
+        if ((hint & SCROLL_CAPTURE_HINT_EXCLUDE) != 0) {
+            return;
+        }
+
+        // Get a callback provided by the framework, library or application.
+        ScrollCaptureCallback callback =
+                (mListenerInfo == null) ? null : mListenerInfo.mScrollCaptureCallback;
+
+        // Try internal support for standard scrolling containers.
+        if (callback == null) {
+            callback = createScrollCaptureCallbackInternal(localVisibleRect, windowOffset);
+        }
+
+        // If found, then add it to the list.
+        if (callback != null) {
+            // Add to the list for consideration
+            Point offset = new Point(windowOffset.x, windowOffset.y);
+            Rect rect = new Rect(localVisibleRect);
+            targets.add(new ScrollCaptureTarget(this, rect, offset, callback));
+        }
+    }
+
     /**
      * Dump all private flags in readable format, useful for documentation and
      * sanity checking.
diff --git a/core/java/android/view/ViewGroup.java b/core/java/android/view/ViewGroup.java
index e34e84c..7935eb1 100644
--- a/core/java/android/view/ViewGroup.java
+++ b/core/java/android/view/ViewGroup.java
@@ -40,6 +40,7 @@
 import android.graphics.Insets;
 import android.graphics.Matrix;
 import android.graphics.Paint;
+import android.graphics.Point;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.graphics.RectF;
@@ -75,6 +76,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Queue;
 import java.util.function.Predicate;
 
 /**
@@ -188,7 +190,16 @@
     private PointF mLocalPoint;
 
     // Lazily-created holder for point computations.
-    private float[] mTempPoint;
+    private float[] mTempPosition;
+
+    // Lazily-created holder for point computations.
+    private Point mTempPoint;
+
+    // Lazily created Rect for dispatch to children
+    private Rect mTempRect;
+
+    // Lazily created int[2] for dispatch to children
+    private int[] mTempLocation;
 
     // Layout animation
     private LayoutAnimationController mLayoutAnimationController;
@@ -1860,7 +1871,7 @@
         final float tx = mCurrentDragStartEvent.mX;
         final float ty = mCurrentDragStartEvent.mY;
 
-        final float[] point = getTempPoint();
+        final float[] point = getTempLocationF();
         point[0] = tx;
         point[1] = ty;
         transformPointToViewLocal(point, child);
@@ -2932,9 +2943,23 @@
         }
     }
 
-    private float[] getTempPoint() {
+    private Rect getTempRect() {
+        if (mTempRect == null) {
+            mTempRect = new Rect();
+        }
+        return mTempRect;
+    }
+
+    private float[] getTempLocationF() {
+        if (mTempPosition == null) {
+            mTempPosition = new float[2];
+        }
+        return mTempPosition;
+    }
+
+    private Point getTempPoint() {
         if (mTempPoint == null) {
-            mTempPoint = new float[2];
+            mTempPoint = new Point();
         }
         return mTempPoint;
     }
@@ -2948,7 +2973,7 @@
     @UnsupportedAppUsage
     protected boolean isTransformedTouchPointInView(float x, float y, View child,
             PointF outLocalPoint) {
-        final float[] point = getTempPoint();
+        final float[] point = getTempLocationF();
         point[0] = x;
         point[1] = y;
         transformPointToViewLocal(point, child);
@@ -4568,7 +4593,7 @@
             final boolean nonActionable = !child.isClickable() && !child.isLongClickable();
             final boolean duplicatesState = (child.mViewFlags & DUPLICATE_PARENT_STATE) != 0;
             if (nonActionable || duplicatesState) {
-                final float[] point = getTempPoint();
+                final float[] point = getTempLocationF();
                 point[0] = x;
                 point[1] = y;
                 transformPointToViewLocal(point, child);
@@ -7354,6 +7379,97 @@
     }
 
     /**
+     * Offsets the given rectangle in parent's local coordinates into child's coordinate space
+     * and clips the result to the child View's bounds, padding and clipRect if appropriate. If the
+     * resulting rectangle is not empty, the request is forwarded to the child.
+     * <p>
+     * Note: This method does not account for any static View transformations which may be
+     * applied to the child view.
+     *
+     * @param child            the child to dispatch to
+     * @param localVisibleRect the visible (clipped) area of this ViewGroup, in local coordinates
+     * @param windowOffset     the offset of localVisibleRect within the window
+     * @param targets          a queue to collect located targets
+     */
+    private void dispatchTransformedScrollCaptureSearch(View child, Rect localVisibleRect,
+            Point windowOffset, Queue<ScrollCaptureTarget> targets) {
+
+        // copy local visible rect for modification and dispatch
+        final Rect childVisibleRect = getTempRect();
+        childVisibleRect.set(localVisibleRect);
+
+        // transform to child coords
+        final Point childWindowOffset = getTempPoint();
+        childWindowOffset.set(windowOffset.x, windowOffset.y);
+
+        final int dx = child.mLeft - mScrollX;
+        final int dy = child.mTop - mScrollY;
+
+        childVisibleRect.offset(-dx, -dy);
+        childWindowOffset.offset(dx, dy);
+
+        boolean rectIsVisible = true;
+        final int width = mRight - mLeft;
+        final int height = mBottom - mTop;
+
+        // Clip to child bounds
+        if (getClipChildren()) {
+            rectIsVisible = childVisibleRect.intersect(0, 0, child.getWidth(), child.getHeight());
+        }
+
+        // Clip to child padding.
+        if (rectIsVisible && (child instanceof ViewGroup)
+                && ((ViewGroup) child).getClipToPadding()) {
+            rectIsVisible = childVisibleRect.intersect(
+                    child.mPaddingLeft, child.mPaddingTop,
+                    child.getWidth() - child.mPaddingRight,
+                    child.getHeight() - child.mPaddingBottom);
+        }
+        // Clip to child clipBounds.
+        if (rectIsVisible && child.mClipBounds != null) {
+            rectIsVisible = childVisibleRect.intersect(child.mClipBounds);
+        }
+        if (rectIsVisible) {
+            child.dispatchScrollCaptureSearch(childVisibleRect, childWindowOffset, targets);
+        }
+    }
+
+    /**
+     * Handle the scroll capture search request by checking this view if applicable, then to each
+     * child view.
+     *
+     * @param localVisibleRect the visible area of this ViewGroup in local coordinates, according to
+     *                         the parent
+     * @param windowOffset     the offset of this view within the window
+     * @param targets          the collected list of scroll capture targets
+     *
+     * @hide
+     */
+    @Override
+    public void dispatchScrollCaptureSearch(
+            @NonNull Rect localVisibleRect, @NonNull Point windowOffset,
+            @NonNull Queue<ScrollCaptureTarget> targets) {
+
+        // Dispatch to self first.
+        super.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targets);
+
+        // Then dispatch to children, if not excluding descendants.
+        if ((getScrollCaptureHint() & SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS) == 0) {
+            final int childCount = getChildCount();
+            for (int i = 0; i < childCount; i++) {
+                View child = getChildAt(i);
+                // Only visible views can be captured.
+                if (child.getVisibility() != View.VISIBLE) {
+                    continue;
+                }
+                // Transform to child coords and dispatch
+                dispatchTransformedScrollCaptureSearch(child, localVisibleRect, windowOffset,
+                        targets);
+            }
+        }
+    }
+
+    /**
      * Returns the animation listener to which layout animation events are
      * sent.
      *
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index ed1edc3..68a185d 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -206,6 +206,7 @@
     private static final boolean DEBUG_INPUT_STAGES = false || LOCAL_LOGV;
     private static final boolean DEBUG_KEEP_SCREEN_ON = false || LOCAL_LOGV;
     private static final boolean DEBUG_CONTENT_CAPTURE = false || LOCAL_LOGV;
+    private static final boolean DEBUG_SCROLL_CAPTURE = false || LOCAL_LOGV;
 
     /**
      * Set to false if we do not want to use the multi threaded renderer even though
@@ -653,6 +654,8 @@
     private final InsetsController mInsetsController;
     private final ImeFocusController mImeFocusController;
 
+    private ScrollCaptureClient mScrollCaptureClient;
+
     /**
      * @return {@link ImeFocusController} for this instance.
      */
@@ -661,6 +664,11 @@
         return mImeFocusController;
     }
 
+    /** @return The current {@link ScrollCaptureClient} for this instance, if any is active. */
+    @Nullable
+    public ScrollCaptureClient getScrollCaptureClient() {
+        return mScrollCaptureClient;
+    }
 
     private final GestureExclusionTracker mGestureExclusionTracker = new GestureExclusionTracker();
 
@@ -694,6 +702,8 @@
     // draw returns.
     private SurfaceControl.Transaction mRtBLASTSyncTransaction = new SurfaceControl.Transaction();
 
+    private HashSet<ScrollCaptureCallback> mRootScrollCaptureCallbacks;
+
     private String mTag = TAG;
 
     public ViewRootImpl(Context context, Display display) {
@@ -4778,6 +4788,7 @@
     private static final int MSG_LOCATION_IN_PARENT_DISPLAY_CHANGED = 33;
     private static final int MSG_SHOW_INSETS = 34;
     private static final int MSG_HIDE_INSETS = 35;
+    private static final int MSG_REQUEST_SCROLL_CAPTURE = 36;
 
 
     final class ViewRootHandler extends Handler {
@@ -5080,6 +5091,9 @@
                 case MSG_LOCATION_IN_PARENT_DISPLAY_CHANGED: {
                     updateLocationInParentDisplay(msg.arg1, msg.arg2);
                 } break;
+                case MSG_REQUEST_SCROLL_CAPTURE:
+                    handleScrollCaptureRequest((IScrollCaptureController) msg.obj);
+                    break;
             }
         }
     }
@@ -8789,6 +8803,131 @@
         return false;
     }
 
+    /**
+     * Adds a scroll capture callback to this window.
+     *
+     * @param callback the callback to add
+     */
+    public void addScrollCaptureCallback(ScrollCaptureCallback callback) {
+        if (mRootScrollCaptureCallbacks == null) {
+            mRootScrollCaptureCallbacks = new HashSet<>();
+        }
+        mRootScrollCaptureCallbacks.add(callback);
+    }
+
+    /**
+     * Removes a scroll capture callback from this window.
+     *
+     * @param callback the callback to remove
+     */
+    public void removeScrollCaptureCallback(ScrollCaptureCallback callback) {
+        if (mRootScrollCaptureCallbacks != null) {
+            mRootScrollCaptureCallbacks.remove(callback);
+            if (mRootScrollCaptureCallbacks.isEmpty()) {
+                mRootScrollCaptureCallbacks = null;
+            }
+        }
+    }
+
+    /**
+     * Dispatches a scroll capture request to the view hierarchy on the ui thread.
+     *
+     * @param controller the controller to receive replies
+     */
+    public void dispatchScrollCaptureRequest(@NonNull IScrollCaptureController controller) {
+        mHandler.obtainMessage(MSG_REQUEST_SCROLL_CAPTURE, controller).sendToTarget();
+    }
+
+    /**
+     * Collect and include any ScrollCaptureCallback instances registered with the window.
+     *
+     * @see #addScrollCaptureCallback(ScrollCaptureCallback)
+     * @param targets the search queue for targets
+     */
+    private void collectRootScrollCaptureTargets(Queue<ScrollCaptureTarget> targets) {
+        for (ScrollCaptureCallback cb : mRootScrollCaptureCallbacks) {
+            // Add to the list for consideration
+            Point offset = new Point(mView.getLeft(), mView.getTop());
+            Rect rect = new Rect(0, 0, mView.getWidth(), mView.getHeight());
+            targets.add(new ScrollCaptureTarget(mView, rect, offset, cb));
+        }
+    }
+
+    /**
+     * Handles an inbound request for scroll capture from the system. If a client is not already
+     * active, a search will be dispatched through the view tree to locate scrolling content.
+     * <p>
+     * Either {@link IScrollCaptureController#onClientConnected(IScrollCaptureClient, Rect,
+     * Point)} or {@link IScrollCaptureController#onClientUnavailable()} will be returned
+     * depending on the results of the search.
+     *
+     * @param controller the interface to the system controller
+     * @see ScrollCaptureTargetResolver
+     */
+    private void handleScrollCaptureRequest(@NonNull IScrollCaptureController controller) {
+        LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Window (root) level callbacks
+        collectRootScrollCaptureTargets(targetList);
+
+        // Search through View-tree
+        View rootView = getView();
+        Point point = new Point();
+        Rect rect = new Rect(0, 0, rootView.getWidth(), rootView.getHeight());
+        getChildVisibleRect(rootView, rect, point);
+        rootView.dispatchScrollCaptureSearch(rect, point, targetList);
+
+        // No-op path. Scroll capture not offered for this window.
+        if (targetList.isEmpty()) {
+            dispatchScrollCaptureSearchResult(controller, null);
+            return;
+        }
+
+        // Request scrollBounds from each of the targets.
+        // Continues with the consumer once all responses are consumed, or the timeout expires.
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetList);
+        resolver.start(mHandler, 1000,
+                (selected) -> dispatchScrollCaptureSearchResult(controller, selected));
+    }
+
+    /** Called by {@link #handleScrollCaptureRequest} when a result is returned */
+    private void dispatchScrollCaptureSearchResult(
+            @NonNull IScrollCaptureController controller,
+            @Nullable ScrollCaptureTarget selectedTarget) {
+
+        // If timeout or no eligible targets found.
+        if (selectedTarget == null) {
+            try {
+                if (DEBUG_SCROLL_CAPTURE) {
+                    Log.d(TAG, "scrollCaptureSearch returned no targets available.");
+                }
+                controller.onClientUnavailable();
+            } catch (RemoteException e) {
+                if (DEBUG_SCROLL_CAPTURE) {
+                    Log.w(TAG, "Failed to notify controller of scroll capture search result.", e);
+                }
+            }
+            return;
+        }
+
+        // Create a client instance and return it to the caller
+        mScrollCaptureClient = new ScrollCaptureClient(selectedTarget, controller);
+        try {
+            if (DEBUG_SCROLL_CAPTURE) {
+                Log.d(TAG, "scrollCaptureSearch returning client: " + getScrollCaptureClient());
+            }
+            controller.onClientConnected(
+                    mScrollCaptureClient,
+                    selectedTarget.getScrollBounds(),
+                    selectedTarget.getPositionInWindow());
+        } catch (RemoteException e) {
+            if (DEBUG_SCROLL_CAPTURE) {
+                Log.w(TAG, "Failed to notify controller of scroll capture search result.", e);
+            }
+            mScrollCaptureClient.disconnect();
+            mScrollCaptureClient = null;
+        }
+    }
 
     private void reportNextDraw() {
         if (mReportNextDraw == false) {
@@ -9091,6 +9230,13 @@
             }
         }
 
+        @Override
+        public void requestScrollCapture(IScrollCaptureController controller) {
+            final ViewRootImpl viewAncestor = mViewAncestor.get();
+            if (viewAncestor != null) {
+                viewAncestor.dispatchScrollCaptureRequest(controller);
+            }
+        }
     }
 
     public static final class CalledFromWrongThreadException extends AndroidRuntimeException {
diff --git a/core/java/android/view/Window.java b/core/java/android/view/Window.java
index ae9afaba..b153648 100644
--- a/core/java/android/view/Window.java
+++ b/core/java/android/view/Window.java
@@ -2535,6 +2535,33 @@
         return Collections.emptyList();
     }
 
+    /**
+     * System request to begin scroll capture.
+     *
+     * @param controller the controller to receive responses
+     * @hide
+     */
+    public void requestScrollCapture(IScrollCaptureController controller) {
+    }
+
+    /**
+     * Registers a {@link ScrollCaptureCallback} with the root of this window.
+     *
+     * @param callback the callback to add
+     * @hide
+     */
+    public void addScrollCaptureCallback(@NonNull ScrollCaptureCallback callback) {
+    }
+
+    /**
+     * Unregisters a {@link ScrollCaptureCallback} previously registered with this window.
+     *
+     * @param callback the callback to remove
+     * @hide
+     */
+    public void removeScrollCaptureCallback(@NonNull ScrollCaptureCallback callback) {
+    }
+
     /** @hide */
     public void setTheme(int resId) {
     }
diff --git a/core/java/android/view/WindowlessWindowManager.java b/core/java/android/view/WindowlessWindowManager.java
index ec51301..397bce4 100644
--- a/core/java/android/view/WindowlessWindowManager.java
+++ b/core/java/android/view/WindowlessWindowManager.java
@@ -24,7 +24,6 @@
 import android.os.RemoteException;
 import android.util.Log;
 import android.util.MergedConfiguration;
-import android.view.IWindowSession;
 
 import java.util.HashMap;
 
diff --git a/core/java/com/android/internal/policy/PhoneWindow.java b/core/java/com/android/internal/policy/PhoneWindow.java
index 25c114f..23ba653 100644
--- a/core/java/com/android/internal/policy/PhoneWindow.java
+++ b/core/java/com/android/internal/policy/PhoneWindow.java
@@ -79,6 +79,7 @@
 import android.view.ContextThemeWrapper;
 import android.view.Gravity;
 import android.view.IRotationWatcher.Stub;
+import android.view.IScrollCaptureController;
 import android.view.IWindowManager;
 import android.view.InputDevice;
 import android.view.InputEvent;
@@ -89,6 +90,7 @@
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MotionEvent;
+import android.view.ScrollCaptureCallback;
 import android.view.SearchEvent;
 import android.view.SurfaceHolder.Callback2;
 import android.view.View;
@@ -3916,4 +3918,35 @@
                     : null);
         }
     }
+
+    /**
+     * System request to begin scroll capture.
+     *
+     * @param controller the controller to receive responses
+     * @hide
+     */
+    @Override
+    public void requestScrollCapture(IScrollCaptureController controller) {
+        getViewRootImpl().dispatchScrollCaptureRequest(controller);
+    }
+
+    /**
+     * Registers a handler providing scrolling capture support for window content.
+     *
+     * @param callback the callback to add
+     */
+    @Override
+    public void addScrollCaptureCallback(@NonNull ScrollCaptureCallback callback) {
+        getViewRootImpl().addScrollCaptureCallback(callback);
+    }
+
+    /**
+     * Unregisters the given {@link ScrollCaptureCallback}.
+     *
+     * @param callback the callback to remove
+     */
+    @Override
+    public void removeScrollCaptureCallback(@NonNull ScrollCaptureCallback callback) {
+        getViewRootImpl().removeScrollCaptureCallback(callback);
+    }
 }
diff --git a/core/java/com/android/internal/view/BaseIWindow.java b/core/java/com/android/internal/view/BaseIWindow.java
index 47f094f..7f3eb45 100644
--- a/core/java/com/android/internal/view/BaseIWindow.java
+++ b/core/java/com/android/internal/view/BaseIWindow.java
@@ -26,6 +26,7 @@
 import android.util.MergedConfiguration;
 import android.view.DisplayCutout;
 import android.view.DragEvent;
+import android.view.IScrollCaptureController;
 import android.view.IWindow;
 import android.view.IWindowSession;
 import android.view.InsetsSourceControl;
@@ -169,4 +170,13 @@
     @Override
     public void dispatchPointerCaptureChanged(boolean hasCapture) {
     }
+
+    @Override
+    public void requestScrollCapture(IScrollCaptureController controller) {
+        try {
+            controller.onClientUnavailable();
+        } catch (RemoteException ex) {
+            // ignore
+        }
+    }
 }
diff --git a/core/java/com/android/internal/view/ScrollCaptureInternal.java b/core/java/com/android/internal/view/ScrollCaptureInternal.java
new file mode 100644
index 0000000..c589afde
--- /dev/null
+++ b/core/java/com/android/internal/view/ScrollCaptureInternal.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2020 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.internal.view;
+
+import android.annotation.Nullable;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.view.ScrollCaptureCallback;
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * Provides built-in framework level Scroll Capture support for standard scrolling Views.
+ */
+public class ScrollCaptureInternal {
+    private static final String TAG = "ScrollCaptureInternal";
+
+    private static final int UP = -1;
+    private static final int DOWN = 1;
+
+    /**
+     * Not a ViewGroup, or cannot scroll according to View APIs.
+     */
+    public static final int TYPE_FIXED = 0;
+
+    /**
+     * Slides a single child view using mScrollX/mScrollY.
+     */
+    public static final int TYPE_SCROLLING = 1;
+
+    /**
+     * Slides child views through the viewport by translating their layout positions with {@link
+     * View#offsetTopAndBottom(int)}. Manages Child view lifecycle, creating as needed and
+     * binding views to data from an adapter. Views are reused whenever possible.
+     */
+    public static final int TYPE_RECYCLING = 2;
+
+    /**
+     * Performs tests on the given View and determines:
+     * 1. If scrolling is possible
+     * 2. What mechanisms are used for scrolling.
+     * <p>
+     * This needs to be fast and not alloc memory. It's called on everything in the tree not marked
+     * as excluded during scroll capture search.
+     */
+    public static int detectScrollingType(View view) {
+        // Must be a ViewGroup
+        if (!(view instanceof ViewGroup)) {
+            return TYPE_FIXED;
+        }
+        // Confirm that it can scroll.
+        if (!(view.canScrollVertically(DOWN) || view.canScrollVertically(UP))) {
+            // Nothing to scroll here, move along.
+            return TYPE_FIXED;
+        }
+        // ScrollViews accept only a single child.
+        if (((ViewGroup) view).getChildCount() > 1) {
+            return TYPE_RECYCLING;
+        }
+        //Because recycling containers don't use scrollY, a non-zero value means Scroll view.
+        if (view.getScrollY() != 0) {
+            return TYPE_SCROLLING;
+        }
+        // Since scrollY cannot be negative, this means a Recycling view.
+        if (view.canScrollVertically(UP)) {
+            return TYPE_RECYCLING;
+        }
+        // canScrollVertically(UP) == false, getScrollY() == 0, getChildCount() == 1.
+
+        // For Recycling containers, this should be a no-op (RecyclerView logs a warning)
+        view.scrollTo(view.getScrollX(), 1);
+
+        // A scrolling container would have moved by 1px.
+        if (view.getScrollY() == 1) {
+            view.scrollTo(view.getScrollX(), 0);
+            return TYPE_SCROLLING;
+        }
+        return TYPE_RECYCLING;
+    }
+
+    /**
+     * Creates a scroll capture callback for the given view if possible.
+     *
+     * @param view             the view to capture
+     * @param localVisibleRect the visible area of the given view in local coordinates, as supplied
+     *                         by the view parent
+     * @param positionInWindow the offset of localVisibleRect within the window
+     *
+     * @return a new callback or null if the View isn't supported
+     */
+    @Nullable
+    public ScrollCaptureCallback requestCallback(View view, Rect localVisibleRect,
+            Point positionInWindow) {
+        // Nothing to see here yet.
+        int i = detectScrollingType(view);
+        switch (i) {
+            case TYPE_SCROLLING:
+                return new ScrollCaptureViewSupport<>((ViewGroup) view,
+                        new ScrollViewCaptureHelper());
+        }
+        return null;
+    }
+}
diff --git a/core/java/com/android/internal/view/ScrollCaptureViewHelper.java b/core/java/com/android/internal/view/ScrollCaptureViewHelper.java
new file mode 100644
index 0000000..9f100bd
--- /dev/null
+++ b/core/java/com/android/internal/view/ScrollCaptureViewHelper.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2020 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.internal.view;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.graphics.Rect;
+import android.view.View;
+
+interface ScrollCaptureViewHelper<V extends View> {
+    int UP = -1;
+    int DOWN = 1;
+
+    /**
+     * Verifies that the view is still visible and scrollable. If true is returned here, expect a
+     * call to {@link #onComputeScrollBounds(View)} to follow.
+     *
+     * @param view the view being captured
+     * @return true if the callback should respond to a request with scroll bounds
+     */
+    default boolean onAcceptSession(@Nullable V view) {
+        return view != null && view.isVisibleToUser()
+                && (view.canScrollVertically(UP) || view.canScrollVertically(DOWN));
+    }
+
+    /**
+     * Given a scroll capture request for a view, adjust the provided rect to cover the scrollable
+     * content area. The default implementation returns the padded content area of {@code view}.
+     *
+     * @param view the view being captured
+     */
+    default Rect onComputeScrollBounds(@Nullable V view) {
+        return new Rect(view.getPaddingLeft(), view.getPaddingTop(),
+                view.getWidth() - view.getPaddingRight(),
+                view.getHeight() - view.getPaddingBottom());
+    }
+    /**
+     * Adjust the target for capture.
+     * <p>
+     * Do not touch anything that may change layout positions or sizes on screen. Anything else may
+     * be adjusted as long as it can be reversed in {@link #onPrepareForEnd(View)}.
+     *
+     * @param view         the view being captured
+     * @param scrollBounds the bounds within {@code view} where content scrolls
+     */
+    void onPrepareForStart(@NonNull V view, Rect scrollBounds);
+
+    /**
+     * Map the request onto the screen.
+     * <p>
+     * Given a  rect describing the area to capture, relative to scrollBounds, take actions
+     * necessary to bring the content within the rectangle into the visible area of the view if
+     * needed and return the resulting rectangle describing the position and bounds of the area
+     * which is visible.
+     *
+     * @param scrollBounds the area in which scrolling content moves, local to the {@code containing
+     *                     view}
+     * @param requestRect  the area relative to {@code scrollBounds} which describes the location of
+     *                     content to capture for the request
+     * @return the visible area within scrollBounds of the requested rectangle, return {@code null}
+     * in the case of an unrecoverable error condition, to abort the capture process
+     */
+    Rect onScrollRequested(@NonNull V view, Rect scrollBounds, Rect requestRect);
+
+    /**
+     * Restore the target after capture.
+     * <p>
+     * Put back anything that was changed in {@link #onPrepareForStart(View, Rect)}.
+     *
+     * @param view the view being captured
+     */
+    void onPrepareForEnd(@NonNull V view);
+}
diff --git a/core/java/com/android/internal/view/ScrollCaptureViewSupport.java b/core/java/com/android/internal/view/ScrollCaptureViewSupport.java
new file mode 100644
index 0000000..4087eda
--- /dev/null
+++ b/core/java/com/android/internal/view/ScrollCaptureViewSupport.java
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2020 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.internal.view;
+
+import android.graphics.HardwareRenderer;
+import android.graphics.Matrix;
+import android.graphics.RecordingCanvas;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.graphics.RenderNode;
+import android.os.Handler;
+import android.os.SystemClock;
+import android.util.DisplayMetrics;
+import android.view.ScrollCaptureCallback;
+import android.view.ScrollCaptureSession;
+import android.view.Surface;
+import android.view.View;
+
+import java.lang.ref.WeakReference;
+import java.util.function.Consumer;
+
+/**
+ * Provides a ScrollCaptureCallback implementation for to handle arbitrary View-based scrolling
+ * containers.
+ * <p>
+ * To use this class, supply the target view and an implementation of {@ScrollCaptureViewHelper}
+ * to the callback.
+ *
+ * @param <V> the specific View subclass handled
+ * @hide
+ */
+public class ScrollCaptureViewSupport<V extends View> implements ScrollCaptureCallback {
+
+    private final WeakReference<V> mWeakView;
+    private final ScrollCaptureViewHelper<V> mViewHelper;
+    private ViewRenderer mRenderer;
+    private Handler mUiHandler;
+    private boolean mStarted;
+    private boolean mEnded;
+
+    static <V extends View> ScrollCaptureCallback createCallback(V view,
+            ScrollCaptureViewHelper<V> impl) {
+        return new ScrollCaptureViewSupport<>(view, impl);
+    }
+
+    ScrollCaptureViewSupport(V containingView, ScrollCaptureViewHelper<V> viewHelper) {
+        mWeakView = new WeakReference<>(containingView);
+        mRenderer = new ViewRenderer();
+        mUiHandler = containingView.getHandler();
+        mViewHelper = viewHelper;
+    }
+
+    // Base implementation of ScrollCaptureCallback
+
+    @Override
+    public final void onScrollCaptureSearch(Consumer<Rect> onReady) {
+        V view = mWeakView.get();
+        mStarted = false;
+        mEnded = false;
+
+        if (view != null && view.isVisibleToUser() && mViewHelper.onAcceptSession(view)) {
+            onReady.accept(mViewHelper.onComputeScrollBounds(view));
+            return;
+        }
+        onReady.accept(null);
+    }
+
+    @Override
+    public final void onScrollCaptureStart(ScrollCaptureSession session, Runnable onReady) {
+        V view = mWeakView.get();
+        mEnded = false;
+        mStarted = true;
+
+        // Note: If somehow the view is already gone or detached, the first call to
+        // {@code onScrollCaptureImageRequest} will return an error and request the session to
+        // end.
+        if (view != null && view.isVisibleToUser()) {
+            mRenderer.setSurface(session.getSurface());
+            mViewHelper.onPrepareForStart(view, session.getScrollBounds());
+        }
+        onReady.run();
+    }
+
+    @Override
+    public final void onScrollCaptureImageRequest(ScrollCaptureSession session, Rect requestRect) {
+        V view = mWeakView.get();
+        if (view == null || !view.isVisibleToUser()) {
+            // Signal to the controller that we have a problem and can't continue.
+            session.notifyBufferSent(0, null);
+            return;
+        }
+        Rect captureArea = mViewHelper.onScrollRequested(view, session.getScrollBounds(),
+                requestRect);
+        mRenderer.renderFrame(view, captureArea, mUiHandler,
+                () -> session.notifyBufferSent(0, captureArea));
+    }
+
+    @Override
+    public final void onScrollCaptureEnd(Runnable onReady) {
+        V view = mWeakView.get();
+        if (mStarted && !mEnded) {
+            mViewHelper.onPrepareForEnd(view);
+            /* empty */
+            mEnded = true;
+            mRenderer.trimMemory();
+            mRenderer.setSurface(null);
+        }
+        onReady.run();
+    }
+
+    /**
+     * Internal helper class which assists in rendering sections of the view hierarchy relative to a
+     * given view. Used by framework implementations of ScrollCaptureHandler to render and dispatch
+     * image requests.
+     */
+    static final class ViewRenderer {
+        // alpha, "reasonable default" from Javadoc
+        private static final float AMBIENT_SHADOW_ALPHA = 0.039f;
+        private static final float SPOT_SHADOW_ALPHA = 0.039f;
+
+        // Default values:
+        //    lightX = (screen.width() / 2) - windowLeft
+        //    lightY = 0 - windowTop
+        //    lightZ = 600dp
+        //    lightRadius = 800dp
+        private static final float LIGHT_Z_DP = 400;
+        private static final float LIGHT_RADIUS_DP = 800;
+        private static final String TAG = "ViewRenderer";
+
+        private HardwareRenderer mRenderer;
+        private RenderNode mRootRenderNode;
+        private final RectF mTempRectF = new RectF();
+        private final Rect mSourceRect = new Rect();
+        private final Rect mTempRect = new Rect();
+        private final Matrix mTempMatrix = new Matrix();
+        private final int[] mTempLocation = new int[2];
+        private long mLastRenderedSourceDrawingId = -1;
+
+
+        ViewRenderer() {
+            mRenderer = new HardwareRenderer();
+            mRootRenderNode = new RenderNode("ScrollCaptureRoot");
+            mRenderer.setContentRoot(mRootRenderNode);
+
+            // TODO: Figure out a way to flip this on when we are sure the source window is opaque
+            mRenderer.setOpaque(false);
+        }
+
+        public void setSurface(Surface surface) {
+            mRenderer.setSurface(surface);
+        }
+
+        /**
+         * Cache invalidation check. If the source view is the same as the previous call (which is
+         * mostly always the case, then we can skip setting up lighting on each call (for now)
+         *
+         * @return true if the view changed, false if the view was previously rendered by this class
+         */
+        private boolean updateForView(View source) {
+            if (mLastRenderedSourceDrawingId == source.getUniqueDrawingId()) {
+                return false;
+            }
+            mLastRenderedSourceDrawingId = source.getUniqueDrawingId();
+            return true;
+        }
+
+        // TODO: may need to adjust lightY based on the virtual canvas position to get
+        //       consistent shadow positions across the whole capture. Or possibly just
+        //       pull lightZ way back to make shadows more uniform.
+        private void setupLighting(View mSource) {
+            mLastRenderedSourceDrawingId = mSource.getUniqueDrawingId();
+            DisplayMetrics metrics = mSource.getResources().getDisplayMetrics();
+            mSource.getLocationOnScreen(mTempLocation);
+            final float lightX = metrics.widthPixels / 2f - mTempLocation[0];
+            final float lightY = metrics.heightPixels - mTempLocation[1];
+            final int lightZ = (int) (LIGHT_Z_DP * metrics.density);
+            final int lightRadius = (int) (LIGHT_RADIUS_DP * metrics.density);
+
+            // Enable shadows for elevation/Z
+            mRenderer.setLightSourceGeometry(lightX, lightY, lightZ, lightRadius);
+            mRenderer.setLightSourceAlpha(AMBIENT_SHADOW_ALPHA, SPOT_SHADOW_ALPHA);
+
+        }
+
+        public void renderFrame(View localReference, Rect sourceRect, Handler handler,
+                Runnable onFrameCommitted) {
+            if (updateForView(localReference)) {
+                setupLighting(localReference);
+            }
+            buildRootDisplayList(localReference, sourceRect);
+            HardwareRenderer.FrameRenderRequest request = mRenderer.createRenderRequest();
+            request.setVsyncTime(SystemClock.elapsedRealtimeNanos());
+            request.setFrameCommitCallback(handler::post, onFrameCommitted);
+            request.setWaitForPresent(true);
+            request.syncAndDraw();
+        }
+
+        public void trimMemory() {
+            mRenderer.clearContent();
+        }
+
+        public void destroy() {
+            mRenderer.destroy();
+        }
+
+        private void transformToRoot(View local, Rect localRect, Rect outRect) {
+            mTempMatrix.reset();
+            local.transformMatrixToGlobal(mTempMatrix);
+            mTempRectF.set(localRect);
+            mTempMatrix.mapRect(mTempRectF);
+            mTempRectF.round(outRect);
+        }
+
+        private void buildRootDisplayList(View source, Rect localSourceRect) {
+            final View captureSource = source.getRootView();
+            transformToRoot(source, localSourceRect, mTempRect);
+            mRootRenderNode.setPosition(0, 0, mTempRect.width(), mTempRect.height());
+            RecordingCanvas canvas = mRootRenderNode.beginRecording(mTempRect.width(),
+                    mTempRect.height());
+            canvas.translate(-mTempRect.left, -mTempRect.top);
+            canvas.drawRenderNode(captureSource.updateDisplayListIfDirty());
+            mRootRenderNode.endRecording();
+        }
+    }
+}
diff --git a/core/java/com/android/internal/view/ScrollViewCaptureHelper.java b/core/java/com/android/internal/view/ScrollViewCaptureHelper.java
new file mode 100644
index 0000000..12bd461
--- /dev/null
+++ b/core/java/com/android/internal/view/ScrollViewCaptureHelper.java
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2020 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.internal.view;
+
+import android.annotation.NonNull;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+
+/**
+ * ScrollCapture for ScrollView and <i>ScrollView-like</i> ViewGroups.
+ * <p>
+ * Requirements for proper operation:
+ * <ul>
+ * <li>contains at most 1 child.
+ * <li>scrolls to absolute positions with {@link View#scrollTo(int, int)}.
+ * <li>has a finite, known content height and scrolling range
+ * <li>correctly implements {@link View#canScrollVertically(int)}
+ * <li>correctly implements {@link ViewParent#requestChildRectangleOnScreen(View,
+ * Rect, boolean)}
+ * </ul>
+ */
+public class ScrollViewCaptureHelper implements ScrollCaptureViewHelper<ViewGroup> {
+    private int mStartScrollY;
+    private boolean mScrollBarEnabled;
+    private int mOverScrollMode;
+
+    /** @see ScrollCaptureViewHelper#onPrepareForStart(View, Rect) */
+    public void onPrepareForStart(@NonNull ViewGroup view, Rect scrollBounds) {
+        mStartScrollY = view.getScrollY();
+        mOverScrollMode = view.getOverScrollMode();
+        if (mOverScrollMode != View.OVER_SCROLL_NEVER) {
+            view.setOverScrollMode(View.OVER_SCROLL_NEVER);
+        }
+        mScrollBarEnabled = view.isVerticalScrollBarEnabled();
+        if (mScrollBarEnabled) {
+            view.setVerticalScrollBarEnabled(false);
+        }
+    }
+
+    /** @see ScrollCaptureViewHelper#onScrollRequested(View, Rect, Rect) */
+    public Rect onScrollRequested(@NonNull ViewGroup view, Rect scrollBounds, Rect requestRect) {
+        final View contentView = view.getChildAt(0); // returns null, does not throw IOOBE
+        if (contentView == null) {
+            return null;
+        }
+        /*
+               +---------+ <----+ Content [25,25 - 275,1025] (w=250,h=1000)
+               |         |
+            ...|.........|...  startScrollY=100
+               |         |
+            +--+---------+---+ <--+ Container View [0,0 - 300,300] (scrollY=200)
+            |  .         .   |
+        --- |  . +-----+   <------+ Scroll Bounds [50,50 - 250,250] (200x200)
+         ^  |  . |     | .   |      (Local to Container View, fixed/un-scrolled)
+         |  |  . |     | .   |
+         |  |  . |     | .   |
+         |  |  . +-----+ .   |
+         |  |  .         .   |
+         |  +--+---------+---+
+         |     |         |
+        -+-    | +-----+ |
+               | |#####| |   <--+ Requested Bounds [0,300 - 200,400] (200x100)
+               | +-----+ |       (Local to Scroll Bounds, fixed/un-scrolled)
+               |         |
+               +---------+
+
+        Container View (ScrollView) [0,0 - 300,300] (scrollY = 200)
+        \__ Content [25,25 - 275,1025]  (250x1000) (contentView)
+        \__ Scroll Bounds[50,50 - 250,250]  (w=200,h=200)
+            \__ Requested Bounds[0,300 - 200,400] (200x100)
+       */
+
+        // 0) adjust the requestRect to account for scroll change since start
+        //
+        //  Scroll Bounds[50,50 - 250,250]  (w=200,h=200)
+        //  \__ Requested Bounds[0,200 - 200,300] (200x100)
+
+        // (y-100) (scrollY - mStartScrollY)
+        int scrollDelta = view.getScrollY() - mStartScrollY;
+
+        //  1) Translate request rect to make it relative to container view
+        //
+        //  Container View [0,0 - 300,300] (scrollY=200)
+        //  \__ Requested Bounds[50,250 - 250,350] (w=250, h=100)
+
+        // (x+50,y+50)
+        Rect requestedContainerBounds = new Rect(requestRect);
+        requestedContainerBounds.offset(0, -scrollDelta);
+        requestedContainerBounds.offset(scrollBounds.left, scrollBounds.top);
+
+        //  2) Translate from container to contentView relative (applying container scrollY)
+        //
+        //  Container View [0,0 - 300,300] (scrollY=200)
+        //  \__ Content [25,25 - 275,1025]  (250x1000) (contentView)
+        //      \__ Requested Bounds[25,425 - 200,525] (w=250, h=100)
+
+        // (x-25,y+175) (scrollY - content.top)
+        Rect requestedContentBounds = new Rect(requestedContainerBounds);
+        requestedContentBounds.offset(
+                view.getScrollX() - contentView.getLeft(),
+                view.getScrollY() - contentView.getTop());
+
+
+
+        // requestRect is now local to contentView as requestedContentBounds
+        // contentView (and each parent in turn if possible) will be scrolled
+        // (if necessary) to make all of requestedContent visible, (if possible!)
+        contentView.requestRectangleOnScreen(new Rect(requestedContentBounds), true);
+
+        // update new offset between starting and current scroll position
+        scrollDelta = view.getScrollY() - mStartScrollY;
+
+
+        // TODO: adjust to avoid occlusions/minimize scroll changes
+
+        Point offset = new Point();
+        final Rect capturedRect = new Rect(requestedContentBounds); // empty
+        if (!view.getChildVisibleRect(contentView, capturedRect, offset)) {
+            capturedRect.setEmpty();
+            return capturedRect;
+        }
+        // Transform back from global to content-view local
+        capturedRect.offset(-offset.x, -offset.y);
+
+        // Then back to container view
+        capturedRect.offset(
+                contentView.getLeft() - view.getScrollX(),
+                contentView.getTop() - view.getScrollY());
+
+
+        // And back to relative to scrollBounds
+        capturedRect.offset(-scrollBounds.left, -scrollBounds.top);
+
+        // Apply scrollDelta again to return to make capturedRect relative to scrollBounds at
+        // the scroll position at start of capture.
+        capturedRect.offset(0, scrollDelta);
+        return capturedRect;
+    }
+
+    /** @see ScrollCaptureViewHelper#onPrepareForEnd(View)  */
+    public void onPrepareForEnd(@NonNull ViewGroup view) {
+        view.scrollTo(0, mStartScrollY);
+        if (mOverScrollMode != View.OVER_SCROLL_NEVER) {
+            view.setOverScrollMode(mOverScrollMode);
+        }
+        if (mScrollBarEnabled) {
+            view.setVerticalScrollBarEnabled(true);
+        }
+    }
+}
diff --git a/core/res/res/values/attrs.xml b/core/res/res/values/attrs.xml
index 4065a6c..a8d1605 100644
--- a/core/res/res/values/attrs.xml
+++ b/core/res/res/values/attrs.xml
@@ -2527,6 +2527,21 @@
             <flag name="noExcludeDescendants" value="0x8" />
         </attr>
 
+        <!-- Hints the Android System whether the this View should be considered a scroll capture target. -->
+        <attr name="scrollCaptureHint">
+            <!-- Let the Android System  determine if the view can be a scroll capture target. -->
+            <flag name="auto" value="0" />
+            <!-- Hint the Android System that this view is a likely target. If capable, it will
+                 be ranked above other views without this flag. -->
+            <flag name="include" value="0x1" />
+            <!-- Hint the Android System that this view should never be considered a scroll capture
+                 target. -->
+            <flag name="exclude" value="0x2" />
+            <!-- Hint the Android System that this view's children should not be examined and should
+                 be excluded as a scroll capture target. -->
+            <flag name="excludeDescendants" value="0x4" />
+        </attr>
+
         <!-- Boolean that controls whether a view can take focus while in touch mode.
              If this is true for a view, that view can gain focus when clicked on, and can keep
              focus if another view is clicked on that doesn't have this attribute set to true. -->
diff --git a/core/res/res/values/public.xml b/core/res/res/values/public.xml
index 67d20da..fb887c3 100644
--- a/core/res/res/values/public.xml
+++ b/core/res/res/values/public.xml
@@ -3020,6 +3020,8 @@
       <public name="preserveLegacyExternalStorage" />
       <public name="mimeGroup" />
       <public name="gwpAsanMode" />
+      <!-- @hide -->
+      <public name="scrollCaptureHint" />
     </public-group>
 
     <public-group type="drawable" first-id="0x010800b5">
diff --git a/core/tests/coretests/src/android/view/ScrollCaptureClientTest.java b/core/tests/coretests/src/android/view/ScrollCaptureClientTest.java
new file mode 100644
index 0000000..e6ac2d6
--- /dev/null
+++ b/core/tests/coretests/src/android/view/ScrollCaptureClientTest.java
@@ -0,0 +1,309 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import static androidx.test.InstrumentationRegistry.getInstrumentation;
+import static androidx.test.InstrumentationRegistry.getTargetContext;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
+
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.os.Handler;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.mockito.stubbing.Answer;
+
+/**
+ * Tests of {@link ScrollCaptureClient}.
+ */
+@SuppressWarnings("UnnecessaryLocalVariable")
+@RunWith(AndroidJUnit4.class)
+public class ScrollCaptureClientTest {
+
+    private final Point mPositionInWindow = new Point(1, 2);
+    private final Rect mLocalVisibleRect = new Rect(2, 3, 4, 5);
+    private final Rect mScrollBounds = new Rect(3, 4, 5, 6);
+
+    private Handler mHandler;
+    private ScrollCaptureTarget mTarget1;
+
+    @Mock
+    private Surface mSurface;
+    @Mock
+    private IScrollCaptureController mClientCallbacks;
+    @Mock
+    private View mMockView1;
+    @Mock
+    private ScrollCaptureCallback mCallback1;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mHandler = new Handler(getTargetContext().getMainLooper());
+
+        when(mMockView1.getHandler()).thenReturn(mHandler);
+        when(mMockView1.getScrollCaptureHint()).thenReturn(View.SCROLL_CAPTURE_HINT_INCLUDE);
+
+        mTarget1 = new ScrollCaptureTarget(
+                mMockView1, mLocalVisibleRect, mPositionInWindow, mCallback1);
+        mTarget1.setScrollBounds(mScrollBounds);
+    }
+
+    /** Test the DelayedAction timeout helper class works as expected. */
+    @Test
+    public void testDelayedAction() {
+        Runnable action = Mockito.mock(Runnable.class);
+        ScrollCaptureClient.DelayedAction delayed =
+                new ScrollCaptureClient.DelayedAction(mHandler, 100, action);
+        try {
+            Thread.sleep(200);
+        } catch (InterruptedException ex) {
+            /* ignore */
+        }
+        getInstrumentation().waitForIdleSync();
+        assertFalse(delayed.cancel());
+        assertFalse(delayed.timeoutNow());
+        verify(action, times(1)).run();
+    }
+
+    /** Test the DelayedAction cancel() */
+    @Test
+    public void testDelayedAction_cancel() {
+        Runnable action = Mockito.mock(Runnable.class);
+        ScrollCaptureClient.DelayedAction delayed =
+                new ScrollCaptureClient.DelayedAction(mHandler, 100, action);
+        try {
+            Thread.sleep(50);
+        } catch (InterruptedException ex) {
+            /* ignore */
+        }
+        assertTrue(delayed.cancel());
+        assertFalse(delayed.timeoutNow());
+        try {
+            Thread.sleep(200);
+        } catch (InterruptedException ex) {
+            /* ignore */
+        }
+        getInstrumentation().waitForIdleSync();
+        verify(action, never()).run();
+    }
+
+    /** Test the DelayedAction timeoutNow() - for testing only */
+    @Test
+    public void testDelayedAction_timeoutNow() {
+        Runnable action = Mockito.mock(Runnable.class);
+        ScrollCaptureClient.DelayedAction delayed =
+                new ScrollCaptureClient.DelayedAction(mHandler, 100, action);
+        try {
+            Thread.sleep(50);
+        } catch (InterruptedException ex) {
+            /* ignore */
+        }
+        assertTrue(delayed.timeoutNow());
+        assertFalse(delayed.cancel());
+        getInstrumentation().waitForIdleSync();
+        verify(action, times(1)).run();
+    }
+
+    /** Test creating a client with valid info */
+    @Test
+    public void testConstruction() {
+        new ScrollCaptureClient(mTarget1, mClientCallbacks);
+    }
+
+    /** Test creating a client fails if arguments are not valid. */
+    @Test
+    public void testConstruction_requiresScrollBounds() {
+        try {
+            mTarget1.setScrollBounds(null);
+            new ScrollCaptureClient(mTarget1, mClientCallbacks);
+            fail("An exception was expected.");
+        } catch (RuntimeException ex) {
+            // Ignore, expected.
+        }
+    }
+
+    @SuppressWarnings("SameParameterValue")
+    private static Answer<Void> runRunnable(int arg) {
+        return invocation -> {
+            Runnable r = invocation.getArgument(arg);
+            r.run();
+            return null;
+        };
+    }
+
+    @SuppressWarnings("SameParameterValue")
+    private static Answer<Void> reportBufferSent(int sessionArg, long frameNum, Rect capturedArea) {
+        return invocation -> {
+            ScrollCaptureSession session = invocation.getArgument(sessionArg);
+            session.notifyBufferSent(frameNum, capturedArea);
+            return null;
+        };
+    }
+
+    /** @see ScrollCaptureClient#startCapture(Surface) */
+    @Test
+    public void testStartCapture() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+
+        // Have the session start accepted immediately
+        doAnswer(runRunnable(1)).when(mCallback1)
+                .onScrollCaptureStart(any(ScrollCaptureSession.class), any(Runnable.class));
+        client.startCapture(mSurface);
+        getInstrumentation().waitForIdleSync();
+
+        verify(mCallback1, times(1))
+                .onScrollCaptureStart(any(ScrollCaptureSession.class), any(Runnable.class));
+        verify(mClientCallbacks, times(1)).onCaptureStarted();
+        verifyNoMoreInteractions(mClientCallbacks);
+    }
+
+    @Test
+    public void testStartCaptureTimeout() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+        client.startCapture(mSurface);
+
+        // Force timeout to fire
+        client.getTimeoutAction().timeoutNow();
+
+        getInstrumentation().waitForIdleSync();
+        verify(mCallback1, times(1)).onScrollCaptureEnd(any(Runnable.class));
+    }
+
+    private void startClient(ScrollCaptureClient client) throws Exception {
+        doAnswer(runRunnable(1)).when(mCallback1)
+                .onScrollCaptureStart(any(ScrollCaptureSession.class), any(Runnable.class));
+        client.startCapture(mSurface);
+        getInstrumentation().waitForIdleSync();
+        reset(mCallback1, mClientCallbacks);
+    }
+
+    /** @see ScrollCaptureClient#requestImage(Rect) */
+    @Test
+    public void testRequestImage() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+        startClient(client);
+
+        // Stub the callback to complete the request immediately
+        doAnswer(reportBufferSent(/* sessionArg */ 0, /* frameNum */ 1L, new Rect(1, 2, 3, 4)))
+                .when(mCallback1)
+                .onScrollCaptureImageRequest(any(ScrollCaptureSession.class), any(Rect.class));
+
+        // Make the inbound binder call
+        client.requestImage(new Rect(1, 2, 3, 4));
+
+        // Wait for handler thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mCallback1, times(1)).onScrollCaptureImageRequest(
+                any(ScrollCaptureSession.class), eq(new Rect(1, 2, 3, 4)));
+
+        // Wait for binder thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mClientCallbacks, times(1)).onCaptureBufferSent(eq(1L), eq(new Rect(1, 2, 3, 4)));
+
+        verifyNoMoreInteractions(mCallback1, mClientCallbacks);
+    }
+
+    @Test
+    public void testRequestImageTimeout() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+        startClient(client);
+
+        // Make the inbound binder call
+        client.requestImage(new Rect(1, 2, 3, 4));
+
+        // Wait for handler thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mCallback1, times(1)).onScrollCaptureImageRequest(
+                any(ScrollCaptureSession.class), eq(new Rect(1, 2, 3, 4)));
+
+        // Force timeout to fire
+        client.getTimeoutAction().timeoutNow();
+        getInstrumentation().waitForIdleSync();
+
+        // (callback not stubbed, does nothing)
+        // Timeout triggers request to end capture
+        verify(mCallback1, times(1)).onScrollCaptureEnd(any(Runnable.class));
+        verifyNoMoreInteractions(mCallback1, mClientCallbacks);
+    }
+
+    /** @see ScrollCaptureClient#endCapture() */
+    @Test
+    public void testEndCapture() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+        startClient(client);
+
+        // Stub the callback to complete the request immediately
+        doAnswer(runRunnable(0))
+                .when(mCallback1)
+                .onScrollCaptureEnd(any(Runnable.class));
+
+        // Make the inbound binder call
+        client.endCapture();
+
+        // Wait for handler thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mCallback1, times(1)).onScrollCaptureEnd(any(Runnable.class));
+
+        // Wait for binder thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mClientCallbacks, times(1)).onConnectionClosed();
+
+        verifyNoMoreInteractions(mCallback1, mClientCallbacks);
+    }
+
+    @Test
+    public void testEndCaptureTimeout() throws Exception {
+        final ScrollCaptureClient client = new ScrollCaptureClient(mTarget1, mClientCallbacks);
+        startClient(client);
+
+        // Make the inbound binder call
+        client.endCapture();
+
+        // Wait for handler thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mCallback1, times(1)).onScrollCaptureEnd(any(Runnable.class));
+
+        // Force timeout to fire
+        client.getTimeoutAction().timeoutNow();
+
+        // Wait for binder thread dispatch
+        getInstrumentation().waitForIdleSync();
+        verify(mClientCallbacks, times(1)).onConnectionClosed();
+
+        verifyNoMoreInteractions(mCallback1, mClientCallbacks);
+    }
+}
diff --git a/core/tests/coretests/src/android/view/ScrollCaptureTargetResolverTest.java b/core/tests/coretests/src/android/view/ScrollCaptureTargetResolverTest.java
new file mode 100644
index 0000000..8b21b8e
--- /dev/null
+++ b/core/tests/coretests/src/android/view/ScrollCaptureTargetResolverTest.java
@@ -0,0 +1,498 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import static androidx.test.InstrumentationRegistry.getTargetContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.os.Handler;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.LinkedList;
+import java.util.function.Consumer;
+
+/**
+ * Tests of {@link ScrollCaptureTargetResolver}.
+ */
+@RunWith(AndroidJUnit4.class)
+public class ScrollCaptureTargetResolverTest {
+
+    private static final long TEST_TIMEOUT_MS = 2000;
+    private static final long RESOLVER_TIMEOUT_MS = 1000;
+
+    private Handler mHandler;
+    private TargetConsumer mTargetConsumer;
+
+    @Before
+    public void setUp() {
+        mTargetConsumer = new TargetConsumer();
+        mHandler = new Handler(getTargetContext().getMainLooper());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testEmptyQueue() throws InterruptedException {
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(new LinkedList<>());
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        // Test only
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertNull("Expected null due to empty queue", result);
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testNoValidTargets() throws InterruptedException {
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+
+        // Supplies scrollBounds = null
+        FakeScrollCaptureCallback callback1 = new FakeScrollCaptureCallback();
+        callback1.setScrollBounds(null);
+        ScrollCaptureTarget target1 = createTarget(callback1, new Rect(20, 30, 40, 50),
+                new Point(0, 0), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        // Supplies scrollBounds = empty rect
+        FakeScrollCaptureCallback callback2 = new FakeScrollCaptureCallback();
+        callback2.setScrollBounds(new Rect());
+        ScrollCaptureTarget target2 = createTarget(callback2, new Rect(20, 30, 40, 50),
+                new Point(0, 20), View.SCROLL_CAPTURE_HINT_INCLUDE);
+
+        targetQueue.add(target1);
+        targetQueue.add(target2);
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        // Test only
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertNull("Expected null due to no valid targets", result);
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testSingleTarget() throws InterruptedException {
+        FakeScrollCaptureCallback callback = new FakeScrollCaptureCallback();
+        ScrollCaptureTarget target = createTarget(callback,
+                new Rect(20, 30, 40, 50), new Point(10, 10),
+                View.SCROLL_CAPTURE_HINT_AUTO);
+        callback.setScrollBounds(new Rect(2, 2, 18, 18));
+
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+        targetQueue.add(target);
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        // Test only
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertSame("Excepted the same target as a result", target, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(2, 2, 18, 18), result.getScrollBounds());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testSingleTarget_backgroundThread() throws InterruptedException {
+        BackgroundTestCallback callback1 = new BackgroundTestCallback();
+        ScrollCaptureTarget target1 = createTarget(callback1,
+                new Rect(20, 30, 40, 50), new Point(10, 10),
+                View.SCROLL_CAPTURE_HINT_AUTO);
+        callback1.setDelay(100);
+        callback1.setScrollBounds(new Rect(2, 2, 18, 18));
+
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+        targetQueue.add(target1);
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        // Test only
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertSame("Excepted the single target1 as a result", target1, result);
+        assertEquals("Result has wrong scroll bounds",
+                new Rect(2, 2, 18, 18), result.getScrollBounds());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testPreferNonEmptyBounds() throws InterruptedException {
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+
+        FakeScrollCaptureCallback callback1 = new FakeScrollCaptureCallback();
+        callback1.setScrollBounds(new Rect());
+        ScrollCaptureTarget target1 = createTarget(callback1, new Rect(20, 30, 40, 50),
+                new Point(0, 0), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        FakeScrollCaptureCallback callback2 = new FakeScrollCaptureCallback();
+        callback2.setScrollBounds(new Rect(0, 0, 20, 20));
+        ScrollCaptureTarget target2 = createTarget(callback2, new Rect(20, 30, 40, 50),
+                new Point(0, 20), View.SCROLL_CAPTURE_HINT_INCLUDE);
+
+        FakeScrollCaptureCallback callback3 = new FakeScrollCaptureCallback();
+        callback3.setScrollBounds(null);
+        ScrollCaptureTarget target3 = createTarget(callback3, new Rect(20, 30, 40, 50),
+                new Point(0, 40), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        targetQueue.add(target1);
+        targetQueue.add(target2); // scrollBounds not null or empty()
+        targetQueue.add(target3);
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertEquals("Expected " + target2 + " as a result", target2, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(0, 0, 20, 20), result.getScrollBounds());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testPreferHintInclude() throws InterruptedException {
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+
+        FakeScrollCaptureCallback callback1 = new FakeScrollCaptureCallback();
+        callback1.setScrollBounds(new Rect(0, 0, 20, 20));
+        ScrollCaptureTarget target1 = createTarget(callback1, new Rect(20, 30, 40, 50),
+                new Point(0, 0), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        FakeScrollCaptureCallback callback2 = new FakeScrollCaptureCallback();
+        callback2.setScrollBounds(new Rect(1, 1, 19, 19));
+        ScrollCaptureTarget target2 = createTarget(callback2, new Rect(20, 30, 40, 50),
+                new Point(0, 20), View.SCROLL_CAPTURE_HINT_INCLUDE);
+
+        FakeScrollCaptureCallback callback3 = new FakeScrollCaptureCallback();
+        callback3.setScrollBounds(new Rect(2, 2, 18, 18));
+        ScrollCaptureTarget target3 = createTarget(callback3, new Rect(20, 30, 40, 50),
+                new Point(0, 40), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        targetQueue.add(target1);
+        targetQueue.add(target2); // * INCLUDE > AUTO
+        targetQueue.add(target3);
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertEquals("input = " + targetQueue + " Expected " + target2
+                + " as the result, due to hint=INCLUDE", target2, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(1, 1, 19, 19), result.getScrollBounds());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testDescendantPreferred() throws InterruptedException {
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+
+        ViewGroup targetView1 = new FakeRootView(getTargetContext(), 0, 0, 60, 60); // 60x60
+        ViewGroup targetView2 = new FakeRootView(getTargetContext(), 20, 30, 40, 50); // 20x20
+        ViewGroup targetView3 = new FakeRootView(getTargetContext(), 5, 5, 15, 15); // 10x10
+
+        targetView1.addView(targetView2);
+        targetView2.addView(targetView3);
+
+        // Create first target with an unrelated parent
+        FakeScrollCaptureCallback callback1 = new FakeScrollCaptureCallback();
+        callback1.setScrollBounds(new Rect(0, 0, 60, 60));
+        ScrollCaptureTarget target1 = createTargetWithView(targetView1, callback1,
+                new Rect(0, 0, 60, 60),
+                new Point(0, 0), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        // Create second target associated with a view within parent2
+        FakeScrollCaptureCallback callback2 = new FakeScrollCaptureCallback();
+        callback2.setScrollBounds(new Rect(0, 0, 20, 20));
+        ScrollCaptureTarget target2 = createTargetWithView(targetView2, callback2,
+                new Rect(0, 0, 20, 20),
+                new Point(20, 30), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        // Create third target associated with a view within parent3
+        FakeScrollCaptureCallback callback3 = new FakeScrollCaptureCallback();
+        callback3.setScrollBounds(new Rect(0, 0, 15, 15));
+        ScrollCaptureTarget target3 = createTargetWithView(targetView3, callback3,
+                new Rect(0, 0, 15, 15),
+                new Point(25, 35), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        targetQueue.add(target1); // auto, 60x60
+        targetQueue.add(target2); // auto, 20x20
+        targetQueue.add(target3); // auto, 15x15 <- innermost scrollable
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        // Test only
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertSame("Expected target3 as the result, due to relation", target3, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(0, 0, 15, 15), result.getScrollBounds());
+    }
+
+    /**
+     * If a timeout expires, late results are ignored.
+     */
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testTimeout() throws InterruptedException {
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+
+        // callback 1, 10x10, hint=AUTO, responds immediately from bg thread
+        BackgroundTestCallback callback1 = new BackgroundTestCallback();
+        callback1.setScrollBounds(new Rect(5, 5, 15, 15));
+        ScrollCaptureTarget target1 = createTarget(
+                callback1, new Rect(20, 30, 40, 50), new Point(10, 10),
+                View.SCROLL_CAPTURE_HINT_AUTO);
+        targetQueue.add(target1);
+
+        // callback 2, 20x20, hint=AUTO, responds after 5s from bg thread
+        BackgroundTestCallback callback2 = new BackgroundTestCallback();
+        callback2.setScrollBounds(new Rect(0, 0, 20, 20));
+        callback2.setDelay(5000);
+        ScrollCaptureTarget target2 = createTarget(
+                callback2, new Rect(20, 30, 40, 50), new Point(10, 10),
+                View.SCROLL_CAPTURE_HINT_AUTO);
+        targetQueue.add(target2);
+
+        // callback 3, 20x20, hint=INCLUDE, responds after 10s from bg thread
+        BackgroundTestCallback callback3 = new BackgroundTestCallback();
+        callback3.setScrollBounds(new Rect(0, 0, 20, 20));
+        callback3.setDelay(10000);
+        ScrollCaptureTarget target3 = createTarget(
+                callback3, new Rect(20, 30, 40, 50), new Point(10, 10),
+                View.SCROLL_CAPTURE_HINT_INCLUDE);
+        targetQueue.add(target3);
+
+        // callback 1 will be received
+        // callback 2 & 3 will be ignored due to timeout
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertSame("Expected target1 as the result, due to timeouts of others", target1, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(5, 5, 15, 15), result.getScrollBounds());
+        assertEquals("callback1 should have been called",
+                1, callback1.getOnScrollCaptureSearchCount());
+        assertEquals("callback2 should have been called",
+                1, callback2.getOnScrollCaptureSearchCount());
+        assertEquals("callback3 should have been called",
+                1, callback3.getOnScrollCaptureSearchCount());
+    }
+
+    @Test(timeout = TEST_TIMEOUT_MS)
+    public void testWithCallbackMultipleReplies() throws InterruptedException {
+        // Calls response methods 3 times each
+        RepeatingCaptureCallback callback1 = new RepeatingCaptureCallback(3);
+        callback1.setScrollBounds(new Rect(2, 2, 18, 18));
+        ScrollCaptureTarget target1 = createTarget(callback1, new Rect(20, 30, 40, 50),
+                new Point(10, 10), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        FakeScrollCaptureCallback callback2 = new FakeScrollCaptureCallback();
+        callback2.setScrollBounds(new Rect(0, 0, 20, 20));
+        ScrollCaptureTarget target2 = createTarget(callback2, new Rect(20, 30, 40, 50),
+                new Point(10, 10), View.SCROLL_CAPTURE_HINT_AUTO);
+
+        LinkedList<ScrollCaptureTarget> targetQueue = new LinkedList<>();
+        targetQueue.add(target1);
+        targetQueue.add(target2);
+
+        ScrollCaptureTargetResolver resolver = new ScrollCaptureTargetResolver(targetQueue);
+        resolver.start(mHandler, RESOLVER_TIMEOUT_MS, mTargetConsumer);
+
+        resolver.waitForResult();
+
+        ScrollCaptureTarget result = mTargetConsumer.getLastValue();
+        assertSame("Expected target2 as the result, due to hint=INCLUDE", target2, result);
+        assertEquals("result has wrong scroll bounds",
+                new Rect(0, 0, 20, 20), result.getScrollBounds());
+        assertEquals("callback1 should have been called once",
+                1, callback1.getOnScrollCaptureSearchCount());
+        assertEquals("callback2 should have been called once",
+                1, callback2.getOnScrollCaptureSearchCount());
+    }
+
+    private static class TargetConsumer implements Consumer<ScrollCaptureTarget> {
+        volatile ScrollCaptureTarget mResult;
+        int mAcceptCount;
+
+        ScrollCaptureTarget getLastValue() {
+            return mResult;
+        }
+
+        int acceptCount() {
+            return mAcceptCount;
+        }
+
+        @Override
+        public void accept(@Nullable ScrollCaptureTarget t) {
+            mAcceptCount++;
+            mResult = t;
+        }
+    }
+
+    private void setupTargetView(View view, Rect localVisibleRect, int scrollCaptureHint) {
+        view.setScrollCaptureHint(scrollCaptureHint);
+        view.onVisibilityAggregated(true);
+        // Treat any offset as padding, outset localVisibleRect on all sides and use this as
+        // child bounds
+        Rect bounds = new Rect(localVisibleRect);
+        bounds.inset(-bounds.left, -bounds.top, bounds.left, bounds.top);
+        view.layout(bounds.left, bounds.top, bounds.right, bounds.bottom);
+        view.onVisibilityAggregated(true);
+    }
+
+    private ScrollCaptureTarget createTarget(ScrollCaptureCallback callback, Rect localVisibleRect,
+            Point positionInWindow, int scrollCaptureHint) {
+        View mockView = new View(getTargetContext());
+        return createTargetWithView(mockView, callback, localVisibleRect, positionInWindow,
+                scrollCaptureHint);
+    }
+
+    private ScrollCaptureTarget createTargetWithView(View view, ScrollCaptureCallback callback,
+            Rect localVisibleRect, Point positionInWindow, int scrollCaptureHint) {
+        setupTargetView(view, localVisibleRect, scrollCaptureHint);
+        return new ScrollCaptureTarget(view, localVisibleRect, positionInWindow, callback);
+    }
+
+
+    static class FakeRootView extends ViewGroup implements ViewParent {
+        FakeRootView(Context context, int l, int t, int r, int b) {
+            super(context);
+            layout(l, t, r, b);
+        }
+
+        @Override
+        protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        }
+    }
+
+    static class FakeScrollCaptureCallback implements ScrollCaptureCallback {
+        private Rect mScrollBounds;
+        private long mDelayMillis;
+        private int mOnScrollCaptureSearchCount;
+
+        public int getOnScrollCaptureSearchCount() {
+            return mOnScrollCaptureSearchCount;
+        }
+
+        @Override
+        public void onScrollCaptureSearch(Consumer<Rect> onReady) {
+            mOnScrollCaptureSearchCount++;
+            run(() -> {
+                Rect b = getScrollBounds();
+                onReady.accept(b);
+            });
+        }
+
+        @Override
+        public void onScrollCaptureStart(ScrollCaptureSession session, Runnable onReady) {
+            run(onReady);
+        }
+
+        @Override
+        public void onScrollCaptureImageRequest(ScrollCaptureSession session, Rect captureArea) {
+            run(() -> session.notifyBufferSent(0, captureArea));
+        }
+
+        @Override
+        public void onScrollCaptureEnd(Runnable onReady) {
+            run(onReady);
+        }
+
+        public void setScrollBounds(@Nullable Rect scrollBounds) {
+            mScrollBounds = scrollBounds;
+        }
+
+        public void setDelay(long delayMillis) {
+            mDelayMillis = delayMillis;
+        }
+
+        protected Rect getScrollBounds() {
+            return mScrollBounds;
+        }
+
+        protected void run(Runnable r) {
+            delay();
+            r.run();
+        }
+
+        protected void delay() {
+            if (mDelayMillis > 0) {
+                try {
+                    Thread.sleep(mDelayMillis);
+                } catch (InterruptedException e) {
+                    // Ignore
+                }
+            }
+        }
+    }
+
+    static class RepeatingCaptureCallback extends FakeScrollCaptureCallback {
+        private int mRepeatCount;
+
+        RepeatingCaptureCallback(int repeatCount) {
+            mRepeatCount = repeatCount;
+        }
+
+        protected void run(Runnable r) {
+            delay();
+            for (int i = 0; i < mRepeatCount; i++) {
+                r.run();
+            }
+        }
+    }
+
+    /** Response to async calls on an arbitrary background thread */
+    static class BackgroundTestCallback extends FakeScrollCaptureCallback {
+        static int sCount = 0;
+        private void runOnBackgroundThread(Runnable r) {
+            final Runnable target = () -> {
+                delay();
+                r.run();
+            };
+            Thread t = new Thread(target);
+            synchronized (BackgroundTestCallback.this) {
+                sCount++;
+            }
+            t.setName("Background-Thread-" + sCount);
+            t.start();
+        }
+
+        @Override
+        protected void run(Runnable r) {
+            runOnBackgroundThread(r);
+        }
+    }
+}
diff --git a/core/tests/coretests/src/android/view/ViewGroupScrollCaptureTest.java b/core/tests/coretests/src/android/view/ViewGroupScrollCaptureTest.java
new file mode 100644
index 0000000..3af0533
--- /dev/null
+++ b/core/tests/coretests/src/android/view/ViewGroupScrollCaptureTest.java
@@ -0,0 +1,480 @@
+/*
+ * Copyright (C) 2020 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.view;
+
+import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.testng.AssertJUnit.assertSame;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.platform.test.annotations.Presubmit;
+
+import androidx.test.filters.FlakyTest;
+import androidx.test.filters.MediumTest;
+import androidx.test.filters.SmallTest;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+/**
+ * Exercises Scroll Capture search in {@link ViewGroup}.
+ */
+@Presubmit
+@SmallTest
+@FlakyTest(detail = "promote once confirmed flake-free")
+@RunWith(MockitoJUnitRunner.class)
+public class ViewGroupScrollCaptureTest {
+
+    @Mock
+    ScrollCaptureCallback mMockCallback;
+    @Mock
+    ScrollCaptureCallback mMockCallback2;
+
+    /** Make sure the hint flags are saved and loaded correctly. */
+    @Test
+    public void testSetScrollCaptureHint() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        final MockViewGroup viewGroup = new MockViewGroup(context);
+
+        assertNotNull(viewGroup);
+        assertEquals("Default scroll capture hint flags should be [SCROLL_CAPTURE_HINT_AUTO]",
+                ViewGroup.SCROLL_CAPTURE_HINT_AUTO, viewGroup.getScrollCaptureHint());
+
+        viewGroup.setScrollCaptureHint(View.SCROLL_CAPTURE_HINT_INCLUDE);
+        assertEquals("The scroll capture hint was not stored correctly.",
+                ViewGroup.SCROLL_CAPTURE_HINT_INCLUDE, viewGroup.getScrollCaptureHint());
+
+        viewGroup.setScrollCaptureHint(ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE);
+        assertEquals("The scroll capture hint was not stored correctly.",
+                ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE, viewGroup.getScrollCaptureHint());
+
+        viewGroup.setScrollCaptureHint(ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS);
+        assertEquals("The scroll capture hint was not stored correctly.",
+                ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS,
+                viewGroup.getScrollCaptureHint());
+
+        viewGroup.setScrollCaptureHint(ViewGroup.SCROLL_CAPTURE_HINT_INCLUDE
+                | ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS);
+        assertEquals("The scroll capture hint was not stored correctly.",
+                ViewGroup.SCROLL_CAPTURE_HINT_INCLUDE
+                        | ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS,
+                viewGroup.getScrollCaptureHint());
+
+        viewGroup.setScrollCaptureHint(ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE
+                | ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS);
+        assertEquals("The scroll capture hint was not stored correctly.",
+                ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE
+                        | ViewGroup.SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS,
+                viewGroup.getScrollCaptureHint());
+    }
+
+    /**
+     * Ensure a ViewGroup with 'scrollCaptureHint=auto', but no ScrollCaptureCallback set dispatches
+     * correctly. Verifies that the framework helper is called. Verifies a that non-null callback
+     * return results in an expected target in the results.
+     */
+    @MediumTest
+    @Test
+    public void testDispatchScrollCaptureSearch_noCallback_hintAuto() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        final MockViewGroup viewGroup = new MockViewGroup(context, 0, 0, 200, 200);
+
+        // When system internal scroll capture is requested, this callback is returned.
+        viewGroup.setScrollCaptureCallbackInternalForTest(mMockCallback);
+
+        Rect localVisibleRect = new Rect(0, 0, 200, 200);
+        Point windowOffset = new Point();
+        LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Dispatch
+        viewGroup.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targetList);
+
+        // Verify the system checked for fallback support
+        viewGroup.assertDispatchScrollCaptureCount(1);
+        viewGroup.assertLastDispatchScrollCaptureArgs(localVisibleRect, windowOffset);
+
+        // Verify the target is as expected.
+        assertEquals(1, targetList.size());
+        ScrollCaptureTarget target = targetList.get(0);
+        assertSame("Target has the wrong callback", mMockCallback, target.getCallback());
+        assertSame("Target has the wrong View", viewGroup, target.getContainingView());
+        assertEquals("Target hint is incorrect", View.SCROLL_CAPTURE_HINT_AUTO,
+                target.getContainingView().getScrollCaptureHint());
+    }
+
+    /**
+     * Ensure a ViewGroup with 'scrollCaptureHint=exclude' is ignored. The Framework helper is
+     * stubbed to return a callback. Verifies that the framework helper is not called (because of
+     * exclude), and no scroll capture target is added to the results.
+     */
+    @MediumTest
+    @Test
+    public void testDispatchScrollCaptureSearch_noCallback_hintExclude() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        final MockViewGroup viewGroup =
+                new MockViewGroup(context, 0, 0, 200, 200, View.SCROLL_CAPTURE_HINT_EXCLUDE);
+
+        // When system internal scroll capture is requested, this callback is returned.
+        viewGroup.setScrollCaptureCallbackInternalForTest(mMockCallback);
+
+        Rect localVisibleRect = new Rect(0, 0, 200, 200);
+        Point windowOffset = new Point();
+        LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Dispatch
+        viewGroup.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targetList);
+
+        // Verify the results.
+        assertEquals("Target list size should be zero.", 0, targetList.size());
+    }
+
+    /**
+     * Ensure that a ViewGroup with 'scrollCaptureHint=auto', and a scroll capture callback set
+     * dispatches as expected. Also verifies that the system fallback support is not called, and the
+     * the returned target is constructed correctly.
+     */
+    @MediumTest
+    @Test
+    public void testDispatchScrollCaptureSearch_withCallback_hintAuto() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        MockViewGroup viewGroup = new MockViewGroup(context, 0, 0, 200, 200);
+
+        // With an already provided scroll capture callback
+        viewGroup.setScrollCaptureCallback(mMockCallback);
+
+        // When system internal scroll capture is requested, this callback is returned.
+        viewGroup.setScrollCaptureCallbackInternalForTest(mMockCallback);
+
+        Rect localVisibleRect = new Rect(0, 0, 200, 200);
+        Point windowOffset = new Point();
+        LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Dispatch to the ViewGroup
+        viewGroup.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targetList);
+
+        // Confirm that framework support was not requested,
+        // because this view already had a callback set.
+        viewGroup.assertCreateScrollCaptureCallbackInternalCount(0);
+
+        // Verify the target is as expected.
+        assertEquals(1, targetList.size());
+        ScrollCaptureTarget target = targetList.get(0);
+        assertSame("Target has the wrong callback", mMockCallback, target.getCallback());
+        assertSame("Target has the wrong View", viewGroup, target.getContainingView());
+        assertEquals("Target hint is incorrect", View.SCROLL_CAPTURE_HINT_AUTO,
+                target.getContainingView().getScrollCaptureHint());
+    }
+
+    /**
+     * Ensure a ViewGroup with a callback set, but 'scrollCaptureHint=exclude' is ignored. The
+     * exclude flag takes precedence.  Verifies that the framework helper is not called (because of
+     * exclude, and a callback being set), and no scroll capture target is added to the results.
+     */
+    @MediumTest
+    @Test
+    public void testDispatchScrollCaptureSearch_withCallback_hintExclude() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        MockViewGroup viewGroup =
+                new MockViewGroup(context, 0, 0, 200, 200, View.SCROLL_CAPTURE_HINT_EXCLUDE);
+        // With an already provided scroll capture callback
+        viewGroup.setScrollCaptureCallback(mMockCallback);
+
+        Rect localVisibleRect = new Rect(0, 0, 200, 200);
+        Point windowOffset = new Point();
+        LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Dispatch to the ViewGroup itself
+        viewGroup.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targetList);
+
+        // Confirm that framework support was not requested, because this view is excluded.
+        // (And because this view has a callback set.)
+        viewGroup.assertCreateScrollCaptureCallbackInternalCount(0);
+
+        // Has callback, but hint=excluded, so excluded.
+        assertTrue(targetList.isEmpty());
+    }
+
+    /**
+     * Test scroll capture search dispatch to child views.
+     * <p>
+     * Verifies computation of child visible bounds.
+     * TODO: with scrollX / scrollY, split up into discrete tests
+     */
+    @MediumTest
+    @Test
+    public void testDispatchScrollCaptureSearch_toChildren() throws Exception {
+        final Context context = getInstrumentation().getContext();
+        final MockViewGroup viewGroup = new MockViewGroup(context, 0, 0, 200, 200);
+
+        Rect localVisibleRect = new Rect(25, 50, 175, 150);
+        Point windowOffset = new Point(0, 0);
+
+        //        visible area
+        //       |<- l=25,    |
+        //       |    r=175 ->|
+        // +--------------------------+
+        // | view1 (0, 0, 200, 25)    |
+        // +---------------+----------+
+        // |               |          |
+        // | view2         | view4    | --+
+        // | (0, 25,       |    (inv) |   | visible area
+        // |      150, 100)|          |   |
+        // +---------------+----------+   | t=50, b=150
+        // | view3         | view5    |   |
+        // | (0, 100       |(150, 100 | --+
+        // |     200, 200) | 200, 200)|
+        // |               |          |
+        // |               |          |
+        // +---------------+----------+ (200,200)
+
+        // View 1 is clipped and not visible.
+        final MockView view1 = new MockView(context, 0, 0, 200, 25);
+        viewGroup.addView(view1);
+
+        // View 2 is partially visible.
+        final MockView view2 = new MockView(context, 0, 25, 150, 100);
+        viewGroup.addView(view2);
+
+        // View 3 is partially visible.
+        // Pretend View3 can scroll by having framework provide fallback support
+        final MockView view3 = new MockView(context, 0, 100, 200, 200);
+        // When system internal scroll capture is requested for this view, return this callback.
+        view3.setScrollCaptureCallbackInternalForTest(mMockCallback);
+        viewGroup.addView(view3);
+
+        // View 4 is invisible and should be ignored.
+        final MockView view4 = new MockView(context, 150, 25, 200, 100, View.INVISIBLE);
+        viewGroup.addView(view4);
+
+        // View 4 is invisible and should be ignored.
+        final MockView view5 = new MockView(context, 150, 100, 200, 200);
+        // When system internal scroll capture is requested for this view, return this callback.
+        view5.setScrollCaptureCallback(mMockCallback2);
+        view5.setScrollCaptureHint(View.SCROLL_CAPTURE_HINT_INCLUDE);
+        viewGroup.addView(view5);
+
+        // Where targets are added
+        final LinkedList<ScrollCaptureTarget> targetList = new LinkedList<>();
+
+        // Dispatch to the ViewGroup
+        viewGroup.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targetList);
+
+        // View 1 is entirely clipped by the parent and not visible, dispatch
+        // skips this view entirely.
+        view1.assertDispatchScrollCaptureSearchCount(0);
+        view1.assertCreateScrollCaptureCallbackInternalCount(0);
+
+        // View 2, verify the computed localVisibleRect and windowOffset are correctly transformed
+        // to the child coordinate space
+        view2.assertDispatchScrollCaptureSearchCount(1);
+        view2.assertDispatchScrollCaptureSearchLastArgs(
+                new Rect(25, 25, 150, 75), new Point(0, 25));
+        // No callback set, so the framework is asked for support
+        view2.assertCreateScrollCaptureCallbackInternalCount(1);
+
+        // View 3, verify the computed localVisibleRect and windowOffset are correctly transformed
+        // to the child coordinate space
+        view3.assertDispatchScrollCaptureSearchCount(1);
+        view3.assertDispatchScrollCaptureSearchLastArgs(
+                new Rect(25, 0, 175, 50), new Point(0, 100));
+        // No callback set, so the framework is asked for support
+        view3.assertCreateScrollCaptureCallbackInternalCount(1);
+
+        // view4 is invisible, so it should be skipped entirely.
+        view4.assertDispatchScrollCaptureSearchCount(0);
+        view4.assertCreateScrollCaptureCallbackInternalCount(0);
+
+        // view5 is partially visible
+        view5.assertDispatchScrollCaptureSearchCount(1);
+        view5.assertDispatchScrollCaptureSearchLastArgs(
+                new Rect(0, 0, 25, 50), new Point(150, 100));
+        // view5 has a callback set on it, so internal framework support should not be consulted.
+        view5.assertCreateScrollCaptureCallbackInternalCount(0);
+
+        // 2 views should have been returned, view3 & view5
+        assertEquals(2, targetList.size());
+
+        ScrollCaptureTarget target = targetList.get(0);
+        assertSame("First target has the wrong View", view3, target.getContainingView());
+        assertSame("First target has the wrong callback", mMockCallback, target.getCallback());
+        assertEquals("First target hint is incorrect", View.SCROLL_CAPTURE_HINT_AUTO,
+                target.getContainingView().getScrollCaptureHint());
+
+        target = targetList.get(1);
+        assertSame("Second target has the wrong View", view5, target.getContainingView());
+        assertSame("Second target has the wrong callback", mMockCallback2, target.getCallback());
+        assertEquals("Second target hint is incorrect", View.SCROLL_CAPTURE_HINT_INCLUDE,
+                target.getContainingView().getScrollCaptureHint());
+    }
+
+    public static final class MockView extends View {
+        private ScrollCaptureCallback mInternalCallback;
+
+        private int mDispatchScrollCaptureSearchNumCalls;
+        private Rect mDispatchScrollCaptureSearchLastLocalVisibleRect;
+        private Point mDispatchScrollCaptureSearchLastWindowOffset;
+        private int mCreateScrollCaptureCallbackInternalCount;
+
+        MockView(Context context) {
+            this(context, /* left */ 0, /* top */0, /* right */ 0, /* bottom */0);
+        }
+
+        MockView(Context context, int left, int top, int right, int bottom) {
+            this(context, left, top, right, bottom, View.VISIBLE);
+        }
+
+        MockView(Context context, int left, int top, int right, int bottom, int visibility) {
+            super(context);
+            setVisibility(visibility);
+            setFrame(left, top, right, bottom);
+        }
+
+        public void setScrollCaptureCallbackInternalForTest(ScrollCaptureCallback internal) {
+            mInternalCallback = internal;
+        }
+
+        void assertDispatchScrollCaptureSearchCount(int count) {
+            assertEquals("Unexpected number of calls to dispatchScrollCaptureSearch",
+                    count, mDispatchScrollCaptureSearchNumCalls);
+        }
+
+        void assertDispatchScrollCaptureSearchLastArgs(Rect localVisibleRect, Point windowOffset) {
+            assertEquals("arg localVisibleRect was incorrect.",
+                    localVisibleRect, mDispatchScrollCaptureSearchLastLocalVisibleRect);
+            assertEquals("arg windowOffset was incorrect.",
+                    windowOffset, mDispatchScrollCaptureSearchLastWindowOffset);
+        }
+
+        void assertCreateScrollCaptureCallbackInternalCount(int count) {
+            assertEquals("Unexpected number of calls to createScrollCaptureCallackInternal",
+                    count, mCreateScrollCaptureCallbackInternalCount);
+        }
+
+        void reset() {
+            mDispatchScrollCaptureSearchNumCalls = 0;
+            mDispatchScrollCaptureSearchLastWindowOffset = null;
+            mDispatchScrollCaptureSearchLastLocalVisibleRect = null;
+            mCreateScrollCaptureCallbackInternalCount = 0;
+
+        }
+
+        @Override
+        public void dispatchScrollCaptureSearch(Rect localVisibleRect, Point windowOffset,
+                Queue<ScrollCaptureTarget> targets) {
+            mDispatchScrollCaptureSearchNumCalls++;
+            mDispatchScrollCaptureSearchLastLocalVisibleRect = new Rect(localVisibleRect);
+            mDispatchScrollCaptureSearchLastWindowOffset = new Point(windowOffset);
+            super.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targets);
+        }
+
+        @Override
+        @Nullable
+        public ScrollCaptureCallback createScrollCaptureCallbackInternal(Rect localVisibleRect,
+                Point offsetInWindow) {
+            mCreateScrollCaptureCallbackInternalCount++;
+            return mInternalCallback;
+        }
+    }
+
+    public static final class MockViewGroup extends ViewGroup {
+        private ScrollCaptureCallback mInternalCallback;
+        private int mDispatchScrollCaptureSearchNumCalls;
+        private Rect mDispatchScrollCaptureSearchLastLocalVisibleRect;
+        private Point mDispatchScrollCaptureSearchLastWindowOffset;
+        private int mCreateScrollCaptureCallbackInternalCount;
+
+
+        MockViewGroup(Context context) {
+            this(context, /* left */ 0, /* top */0, /* right */ 0, /* bottom */0);
+        }
+
+        MockViewGroup(Context context, int left, int top, int right, int bottom) {
+            this(context, left, top, right, bottom, View.SCROLL_CAPTURE_HINT_AUTO);
+        }
+
+        MockViewGroup(Context context, int left, int top, int right, int bottom,
+                int scrollCaptureHint) {
+            super(context);
+            setScrollCaptureHint(scrollCaptureHint);
+            setFrame(left, top, right, bottom);
+        }
+
+        public void setScrollCaptureCallbackInternalForTest(ScrollCaptureCallback internal) {
+            mInternalCallback = internal;
+        }
+
+        void assertDispatchScrollCaptureSearchCount(int count) {
+            assertEquals("Unexpected number of calls to dispatchScrollCaptureSearch",
+                    count, mDispatchScrollCaptureSearchNumCalls);
+        }
+
+        @Override
+        @Nullable
+        public ScrollCaptureCallback createScrollCaptureCallbackInternal(Rect localVisibleRect,
+                Point offsetInWindow) {
+            mCreateScrollCaptureCallbackInternalCount++;
+            return mInternalCallback;
+        }
+
+        @Override
+        protected void onLayout(boolean changed, int l, int t, int r, int b) {
+            // We don't layout this view.
+        }
+
+        void assertDispatchScrollCaptureCount(int count) {
+            assertEquals(count, mDispatchScrollCaptureSearchNumCalls);
+        }
+
+        void assertLastDispatchScrollCaptureArgs(Rect localVisibleRect, Point windowOffset) {
+            assertEquals("arg localVisibleRect to dispatchScrollCaptureCallback was incorrect.",
+                    localVisibleRect, mDispatchScrollCaptureSearchLastLocalVisibleRect);
+            assertEquals("arg windowOffset to dispatchScrollCaptureCallback was incorrect.",
+                    windowOffset, mDispatchScrollCaptureSearchLastWindowOffset);
+        }
+        void assertCreateScrollCaptureCallbackInternalCount(int count) {
+            assertEquals("Unexpected number of calls to createScrollCaptureCallackInternal",
+                    count, mCreateScrollCaptureCallbackInternalCount);
+        }
+
+        void reset() {
+            mDispatchScrollCaptureSearchNumCalls = 0;
+            mDispatchScrollCaptureSearchLastWindowOffset = null;
+            mDispatchScrollCaptureSearchLastLocalVisibleRect = null;
+            mCreateScrollCaptureCallbackInternalCount = 0;
+        }
+
+        @Override
+        public void dispatchScrollCaptureSearch(Rect localVisibleRect, Point windowOffset,
+                Queue<ScrollCaptureTarget> targets) {
+            mDispatchScrollCaptureSearchNumCalls++;
+            mDispatchScrollCaptureSearchLastLocalVisibleRect = new Rect(localVisibleRect);
+            mDispatchScrollCaptureSearchLastWindowOffset = new Point(windowOffset);
+            super.dispatchScrollCaptureSearch(localVisibleRect, windowOffset, targets);
+        }
+    }
+}
diff --git a/core/tests/coretests/src/com/android/internal/view/ScrollViewCaptureHelperTest.java b/core/tests/coretests/src/com/android/internal/view/ScrollViewCaptureHelperTest.java
new file mode 100644
index 0000000..63a68e9
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/view/ScrollViewCaptureHelperTest.java
@@ -0,0 +1,352 @@
+/*
+ * Copyright (C) 2020 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.internal.view;
+
+import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
+import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
+import static android.view.WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
+import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
+
+import static androidx.test.InstrumentationRegistry.getContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import android.graphics.Color;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.WindowManager;
+import android.widget.FrameLayout;
+import android.widget.LinearLayout;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+import androidx.test.annotation.UiThreadTest;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.Random;
+
+public class ScrollViewCaptureHelperTest {
+
+    private FrameLayout mParent;
+    private ScrollView mTarget;
+    private LinearLayout mContent;
+    private WindowManager mWm;
+
+    private WindowManager.LayoutParams mWindowLayoutParams;
+
+    private static final int CHILD_VIEWS = 12;
+    public static final int CHILD_VIEW_HEIGHT = 300;
+
+    private static final int WINDOW_WIDTH = 800;
+    private static final int WINDOW_HEIGHT = 1200;
+
+    private static final int CAPTURE_HEIGHT = 600;
+
+    private Random mRandom;
+
+    private static float sDensity;
+
+    @BeforeClass
+    public static void setUpClass() {
+        sDensity = getContext().getResources().getDisplayMetrics().density;
+    }
+
+    @Before
+    @UiThreadTest
+    public void setUp() {
+        mRandom = new Random();
+        mParent = new FrameLayout(getContext());
+
+        mTarget = new ScrollView(getContext());
+        mParent.addView(mTarget, new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
+
+        mContent = new LinearLayout(getContext());
+        mContent.setOrientation(LinearLayout.VERTICAL);
+        mTarget.addView(mContent, new ViewGroup.LayoutParams(MATCH_PARENT, WRAP_CONTENT));
+
+        for (int i = 0; i < CHILD_VIEWS; i++) {
+            TextView view = new TextView(getContext());
+            view.setText("Child #" + i);
+            view.setTextColor(Color.WHITE);
+            view.setTextSize(30f);
+            view.setBackgroundColor(Color.rgb(mRandom.nextFloat(), mRandom.nextFloat(),
+                    mRandom.nextFloat()));
+            mContent.addView(view, new ViewGroup.LayoutParams(MATCH_PARENT, CHILD_VIEW_HEIGHT));
+        }
+
+        // Window -> Parent -> Target -> Content
+
+        mWm = getContext().getSystemService(WindowManager.class);
+
+        // Setup the window that we are going to use
+        mWindowLayoutParams = new WindowManager.LayoutParams(WINDOW_WIDTH, WINDOW_HEIGHT,
+                TYPE_APPLICATION_OVERLAY, FLAG_NOT_TOUCHABLE, PixelFormat.OPAQUE);
+        mWindowLayoutParams.setTitle("ScrollViewCaptureHelper");
+        mWindowLayoutParams.gravity = Gravity.CENTER;
+        mWm.addView(mParent, mWindowLayoutParams);
+    }
+
+    @After
+    @UiThreadTest
+    public void tearDown() {
+        mWm.removeViewImmediate(mParent);
+    }
+
+    @Test
+    @UiThreadTest
+    public void onPrepareForStart() {
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+    }
+
+    static void assertEmpty(Rect r) {
+        if (r != null && !r.isEmpty()) {
+            fail("Not true that " + r + " is empty");
+        }
+    }
+
+    static void assertContains(Rect parent, Rect child) {
+        if (!parent.contains(child)) {
+            fail("Not true that " + parent + " contains " + child);
+        }
+    }
+
+    static void assertRectEquals(Rect parent, Rect child) {
+        if (!parent.equals(child)) {
+            fail("Not true that " + parent + " is equal to " + child);
+        }
+    }
+
+    static Rect getVisibleRect(View v) {
+        Rect r = new Rect(0, 0, v.getWidth(), v.getHeight());
+        v.getLocalVisibleRect(r);
+        return r;
+    }
+
+
+    static int assertScrollToY(View v, int scrollY) {
+        v.scrollTo(0, scrollY);
+        int dest = v.getScrollY();
+        assertEquals(scrollY, dest);
+        return scrollY;
+    }
+
+
+    static void assertCapturedAreaCompletelyVisible(int startScrollY, Rect requestRect,
+            Rect localVisibleNow) {
+        Rect captured = new Rect(localVisibleNow);
+        captured.offset(0, -startScrollY); // make relative
+
+        if (!captured.contains(requestRect)) {
+            fail("Not true that all of " + requestRect + " is contained by " + captured);
+        }
+    }
+    static void assertCapturedAreaPartiallyVisible(int startScrollY, Rect requestRect,
+            Rect localVisibleNow) {
+        Rect captured = new Rect(localVisibleNow);
+        captured.offset(0, -startScrollY); // make relative
+
+        if (!Rect.intersects(captured, requestRect)) {
+            fail("Not true that any of " + requestRect + " intersects " + captured);
+        }
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_up_fromTop() {
+        final int startScrollY = assertScrollToY(mTarget, 0);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        assertTrue(scrollBounds.height() > CAPTURE_HEIGHT);
+
+        Rect request = new Rect(0, -CAPTURE_HEIGHT, scrollBounds.width(), 0);
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+
+        // The result is an empty rectangle and no scrolling, since it
+        // is not possible to physically scroll further up to make the
+        // requested area visible at all (it doesn't exist).
+        assertEmpty(result);
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_down_fromTop() {
+        final int startScrollY = assertScrollToY(mTarget, 0);
+
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        assertTrue(scrollBounds.height() > CAPTURE_HEIGHT);
+
+        // Capture between y = +1200 to +1500 pixels BELOW current top
+        Rect request = new Rect(0, WINDOW_HEIGHT, scrollBounds.width(),
+                WINDOW_HEIGHT + CAPTURE_HEIGHT);
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+        assertRectEquals(request, result);
+
+        assertCapturedAreaCompletelyVisible(startScrollY, request, getVisibleRect(mContent));
+    }
+
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_up_fromMiddle() {
+        final int startScrollY = assertScrollToY(mTarget, WINDOW_HEIGHT);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        Rect request = new Rect(0, -CAPTURE_HEIGHT, scrollBounds.width(), 0);
+
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+
+        assertRectEquals(request, result);
+
+        assertCapturedAreaCompletelyVisible(startScrollY, request, getVisibleRect(mContent));
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_down_fromMiddle() {
+        final int startScrollY = assertScrollToY(mTarget, WINDOW_HEIGHT);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        Rect request = new Rect(0, WINDOW_HEIGHT, scrollBounds.width(),
+                WINDOW_HEIGHT + CAPTURE_HEIGHT);
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+        assertRectEquals(request, result);
+
+        assertCapturedAreaCompletelyVisible(startScrollY, request, getVisibleRect(mContent));
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_up_fromBottom() {
+        final int startScrollY = assertScrollToY(mTarget, WINDOW_HEIGHT * 2);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        Rect request = new Rect(0, -CAPTURE_HEIGHT, scrollBounds.width(), 0);
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+        assertRectEquals(request, result);
+
+        assertCapturedAreaCompletelyVisible(startScrollY, request, getVisibleRect(mContent));
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_down_fromBottom() {
+        final int startScrollY = assertScrollToY(mTarget, WINDOW_HEIGHT * 2);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        Rect request = new Rect(0, WINDOW_HEIGHT, scrollBounds.width(),
+                WINDOW_HEIGHT + CAPTURE_HEIGHT);
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+
+        // The result is an empty rectangle and no scrolling, since it
+        // is not possible to physically scroll further down to make the
+        // requested area visible at all (it doesn't exist).
+        assertEmpty(result);
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_offTopEdge() {
+        final int startScrollY = assertScrollToY(mTarget, 0);
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        // Create a request which lands halfway off the top of the content
+        //from -1500 to -900, (starting at 1200 = -300 to +300 within the content)
+        int top = 0;
+        Rect request = new Rect(
+                0, top - (CAPTURE_HEIGHT / 2),
+                scrollBounds.width(), top + (CAPTURE_HEIGHT / 2));
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+        // The result is a partial result
+        Rect expectedResult = new Rect(request);
+        expectedResult.top += 300; // top half clipped
+        assertRectEquals(expectedResult, result);
+        assertCapturedAreaPartiallyVisible(startScrollY, request, getVisibleRect(mContent));
+    }
+
+    @Test
+    @UiThreadTest
+    public void onScrollRequested_offBottomEdge() {
+        final int startScrollY = assertScrollToY(mTarget, WINDOW_HEIGHT * 2); // 2400
+
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        Rect scrollBounds = svc.onComputeScrollBounds(mTarget);
+        svc.onPrepareForStart(mTarget, scrollBounds);
+
+        // Create a request which lands halfway off the bottom of the content
+        //from 600 to to 1200, (starting at 2400 = 3000 to  3600 within the content)
+
+        int bottom = WINDOW_HEIGHT;
+        Rect request = new Rect(
+                0, bottom - (CAPTURE_HEIGHT / 2),
+                scrollBounds.width(), bottom + (CAPTURE_HEIGHT / 2));
+
+        Rect result = svc.onScrollRequested(mTarget, scrollBounds, request);
+
+        Rect expectedResult = new Rect(request);
+        expectedResult.bottom -= 300; // bottom half clipped
+        assertRectEquals(expectedResult, result);
+        assertCapturedAreaPartiallyVisible(startScrollY, request, getVisibleRect(mContent));
+
+    }
+
+    @Test
+    @UiThreadTest
+    public void onPrepareForEnd() {
+        ScrollViewCaptureHelper svc = new ScrollViewCaptureHelper();
+        svc.onPrepareForEnd(mTarget);
+    }
+}
diff --git a/data/etc/services.core.protolog.json b/data/etc/services.core.protolog.json
index 18086ec..c5ac451 100644
--- a/data/etc/services.core.protolog.json
+++ b/data/etc/services.core.protolog.json
@@ -283,6 +283,12 @@
       "group": "WM_DEBUG_APP_TRANSITIONS",
       "at": "com\/android\/server\/wm\/ActivityRecord.java"
     },
+    "-1517908912": {
+      "message": "requestScrollCapture: caught exception dispatching to window.token=%s",
+      "level": "WARN",
+      "group": "WM_ERROR",
+      "at": "com\/android\/server\/wm\/WindowManagerService.java"
+    },
     "-1515151503": {
       "message": ">>> OPEN TRANSACTION removeReplacedWindows",
       "level": "INFO",
@@ -1441,6 +1447,12 @@
       "group": "WM_DEBUG_RECENTS_ANIMATIONS",
       "at": "com\/android\/server\/wm\/RecentsAnimation.java"
     },
+    "646981048": {
+      "message": "Invalid displayId for requestScrollCapture: %d",
+      "level": "ERROR",
+      "group": "WM_ERROR",
+      "at": "com\/android\/server\/wm\/WindowManagerService.java"
+    },
     "662572728": {
       "message": "Attempted to add a toast window with bad token %s.  Aborting.",
       "level": "WARN",
@@ -1597,6 +1609,12 @@
       "group": "WM_ERROR",
       "at": "com\/android\/server\/wm\/WindowManagerService.java"
     },
+    "1046922686": {
+      "message": "requestScrollCapture: caught exception dispatching callback: %s",
+      "level": "WARN",
+      "group": "WM_ERROR",
+      "at": "com\/android\/server\/wm\/WindowManagerService.java"
+    },
     "1051545910": {
       "message": "Exit animation finished in %s: remove=%b",
       "level": "VERBOSE",
diff --git a/packages/SystemUI/src/com/android/systemui/screenshot/ScrollCaptureController.java b/packages/SystemUI/src/com/android/systemui/screenshot/ScrollCaptureController.java
new file mode 100644
index 0000000..5ced40c
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/screenshot/ScrollCaptureController.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2020 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.screenshot;
+
+import android.os.IBinder;
+import android.view.IWindowManager;
+
+import javax.inject.Inject;
+
+/**
+ * Stub
+ */
+public class ScrollCaptureController {
+
+    public static final int STATUS_A = 0;
+    public static final int STATUS_B = 1;
+
+    private final IWindowManager mWindowManagerService;
+    private StatusListener mListener;
+
+    /**
+     *
+     * @param windowManagerService
+     */
+    @Inject
+    public ScrollCaptureController(IWindowManager windowManagerService) {
+        mWindowManagerService = windowManagerService;
+    }
+
+    interface StatusListener {
+        void onScrollCaptureStatus(boolean available);
+    }
+
+    /**
+     *
+     * @param window
+     * @param listener
+     */
+    public void getStatus(IBinder window, StatusListener listener) {
+        mListener = listener;
+//        try {
+//           mWindowManagerService.requestScrollCapture(window, new ClientCallbacks());
+//        } catch (RemoteException e) {
+//        }
+    }
+
+}
diff --git a/packages/SystemUI/src/com/android/systemui/wm/SystemWindows.java b/packages/SystemUI/src/com/android/systemui/wm/SystemWindows.java
index e5da603..899aabb 100644
--- a/packages/SystemUI/src/com/android/systemui/wm/SystemWindows.java
+++ b/packages/SystemUI/src/com/android/systemui/wm/SystemWindows.java
@@ -32,6 +32,7 @@
 import android.view.Display;
 import android.view.DisplayCutout;
 import android.view.DragEvent;
+import android.view.IScrollCaptureController;
 import android.view.IWindow;
 import android.view.IWindowManager;
 import android.view.IWindowSession;
@@ -352,5 +353,14 @@
 
         @Override
         public void dispatchPointerCaptureChanged(boolean hasCapture) {}
+
+        @Override
+        public void requestScrollCapture(IScrollCaptureController controller) {
+            try {
+                controller.onClientUnavailable();
+            } catch (RemoteException ex) {
+                // ignore
+            }
+        }
     }
 }
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index a47cdc6..b01acca 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -5450,6 +5450,46 @@
         return mWmService.mDisplayManagerInternal.getDisplayPosition(getDisplayId());
     }
 
+    /**
+     * Locates the appropriate target window for scroll capture. The search progresses top to
+     * bottom.
+     * If {@code searchBehind} is non-null, the search will only consider windows behind this one.
+     * If a valid taskId is specified, the target window must belong to the given task.
+     *
+     * @param searchBehind a window used to filter the search to windows behind it, or null to begin
+     *                     the search at the top window of the display
+     * @param taskId       specifies the id of a task the result must belong to or
+     *                     {@link android.app.ActivityTaskManager#INVALID_TASK_ID INVALID_TASK_ID}
+     *                     to match any window
+     * @return the located window or null if none could be found matching criteria
+     */
+    @Nullable
+    WindowState findScrollCaptureTargetWindow(@Nullable WindowState searchBehind, int taskId) {
+        return getWindow(new Predicate<WindowState>() {
+            boolean behindTopWindow = (searchBehind == null); // optional filter
+            @Override
+            public boolean test(WindowState nextWindow) {
+                // Skip through all windows until we pass topWindow (if specified)
+                if (!behindTopWindow) {
+                    if (nextWindow == searchBehind) {
+                        behindTopWindow = true;
+                    }
+                    return false; /* continue */
+                }
+                if (taskId != INVALID_TASK_ID) {
+                    Task task = nextWindow.getTask();
+                    if (task == null || !task.isTaskId(taskId)) {
+                        return false; /* continue */
+                    }
+                }
+                if (!nextWindow.canReceiveKeys()) {
+                    return false; /* continue */
+                }
+                return true; /* stop */
+            }
+        });
+    }
+
     class RemoteInsetsControlTarget implements InsetsControlTarget {
         private final IDisplayWindowInsetsController mRemoteInsetsController;
 
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index f55a1b3..a501414 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -219,6 +219,7 @@
 import android.view.IPinnedStackListener;
 import android.view.IRecentsAnimationRunner;
 import android.view.IRotationWatcher;
+import android.view.IScrollCaptureController;
 import android.view.ISystemGestureExclusionListener;
 import android.view.IWallpaperVisibilityListener;
 import android.view.IWindow;
@@ -6837,6 +6838,58 @@
         }
     }
 
+    /**
+     * Forwards a scroll capture request to the appropriate window, if available.
+     *
+     * @param displayId the display for the request
+     * @param behindClient token for a window, used to filter the search to windows behind it
+     * @param taskId specifies the id of a task the result must belong to or -1 to ignore task ids
+     * @param controller the controller to receive results; a call to either
+     *      {@link IScrollCaptureController#onClientConnected} or
+     *      {@link IScrollCaptureController#onClientUnavailable}.
+     */
+    public void requestScrollCapture(int displayId, @Nullable IBinder behindClient, int taskId,
+            IScrollCaptureController controller) {
+        if (!checkCallingPermission(READ_FRAME_BUFFER, "requestScrollCapture()")) {
+            throw new SecurityException("Requires READ_FRAME_BUFFER permission");
+        }
+        final long token = Binder.clearCallingIdentity();
+        try {
+            synchronized (mGlobalLock) {
+                DisplayContent dc = mRoot.getDisplayContent(displayId);
+                if (dc == null) {
+                    ProtoLog.e(WM_ERROR,
+                            "Invalid displayId for requestScrollCapture: %d", displayId);
+                    controller.onClientUnavailable();
+                    return;
+                }
+                WindowState topWindow = null;
+                if (behindClient != null) {
+                    topWindow = windowForClientLocked(null, behindClient, /* throwOnError*/ true);
+                }
+                WindowState targetWindow = dc.findScrollCaptureTargetWindow(topWindow, taskId);
+                if (targetWindow == null) {
+                    controller.onClientUnavailable();
+                    return;
+                }
+                // Forward to the window for handling.
+                try {
+                    targetWindow.mClient.requestScrollCapture(controller);
+                } catch (RemoteException e) {
+                    ProtoLog.w(WM_ERROR,
+                            "requestScrollCapture: caught exception dispatching to window."
+                                    + "token=%s", targetWindow.mClient.asBinder());
+                    controller.onClientUnavailable();
+                }
+            }
+        } catch (RemoteException e) {
+            ProtoLog.w(WM_ERROR,
+                    "requestScrollCapture: caught exception dispatching callback: %s", e);
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
     @Override
     public void dontOverrideDisplayInfo(int displayId) {
         final long token = Binder.clearCallingIdentity();
diff --git a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
index daff149..80fcf2e 100644
--- a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
@@ -41,6 +41,7 @@
 import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
 import static android.view.WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
 import static android.view.WindowManager.LayoutParams.TYPE_NOTIFICATION_SHADE;
+import static android.view.WindowManager.LayoutParams.TYPE_SCREENSHOT;
 import static android.view.WindowManager.LayoutParams.TYPE_STATUS_BAR;
 import static android.view.WindowManager.LayoutParams.TYPE_VOICE_INTERACTION;
 import static android.view.WindowManager.LayoutParams.TYPE_WALLPAPER;
@@ -74,6 +75,7 @@
 import static org.mockito.ArgumentMatchers.eq;
 
 import android.annotation.SuppressLint;
+import android.app.ActivityTaskManager;
 import android.app.WindowConfiguration;
 import android.content.res.Configuration;
 import android.graphics.Rect;
@@ -1207,6 +1209,31 @@
         assertNull(taskDisplayArea.getOrCreateRootHomeTask());
     }
 
+    @Test
+    public void testFindScrollCaptureTargetWindow_behindWindow() {
+        DisplayContent display = createNewDisplay();
+        ActivityStack stack = createTaskStackOnDisplay(display);
+        Task task = createTaskInStack(stack, 0 /* userId */);
+        WindowState activityWindow = createAppWindow(task, TYPE_APPLICATION, "App Window");
+        WindowState behindWindow = createWindow(null, TYPE_SCREENSHOT, display, "Screenshot");
+
+        WindowState result = display.findScrollCaptureTargetWindow(behindWindow,
+                ActivityTaskManager.INVALID_TASK_ID);
+        assertEquals(activityWindow, result);
+    }
+
+    @Test
+    public void testFindScrollCaptureTargetWindow_taskId() {
+        DisplayContent display = createNewDisplay();
+        ActivityStack stack = createTaskStackOnDisplay(display);
+        Task task = createTaskInStack(stack, 0 /* userId */);
+        WindowState window = createAppWindow(task, TYPE_APPLICATION, "App Window");
+        WindowState behindWindow = createWindow(null, TYPE_SCREENSHOT, display, "Screenshot");
+
+        WindowState result = display.findScrollCaptureTargetWindow(null, task.mTaskId);
+        assertEquals(window, result);
+    }
+
     private boolean isOptionsPanelAtRight(int displayId) {
         return (mWm.getPreferredOptionsPanelGravity(displayId) & Gravity.RIGHT) == Gravity.RIGHT;
     }
diff --git a/services/tests/wmtests/src/com/android/server/wm/TestIWindow.java b/services/tests/wmtests/src/com/android/server/wm/TestIWindow.java
index 91c3c27..e39b4bc 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TestIWindow.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TestIWindow.java
@@ -24,6 +24,7 @@
 import android.util.MergedConfiguration;
 import android.view.DisplayCutout;
 import android.view.DragEvent;
+import android.view.IScrollCaptureController;
 import android.view.IWindow;
 import android.view.InsetsSourceControl;
 import android.view.InsetsState;
@@ -113,6 +114,10 @@
     }
 
     @Override
+    public void requestScrollCapture(IScrollCaptureController controller) throws RemoteException {
+    }
+
+    @Override
     public void showInsets(int types, boolean fromIme) throws RemoteException {
     }
 
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
index e561c13..6a64d1c 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
@@ -247,7 +247,7 @@
     WindowState createAppWindow(Task task, int type, String name) {
         synchronized (mWm.mGlobalLock) {
             final ActivityRecord activity =
-                    WindowTestUtils.createTestActivityRecord(mDisplayContent);
+                    WindowTestUtils.createTestActivityRecord(task.getDisplayContent());
             task.addChild(activity, 0);
             return createWindow(null, type, activity, name);
         }