Merge "MediaProjection captures DisplayArea" into sc-v2-dev

core/java/android/hardware/display/DisplayManagerInternal.java

@@ -21,6 +21,7 @@ import android.annotation.Nullable;
 import android.graphics.Point;
 import android.hardware.SensorManager;
 import android.os.Handler;
+import android.os.IBinder;
 import android.os.PowerManager;
 import android.util.IntArray;
 import android.util.Slog;
@@ -339,6 +340,28 @@ public abstract class DisplayManagerInternal {
      */
     public abstract List<RefreshRateLimitation> getRefreshRateLimitations(int displayId);
 
+    /**
+     * Returns the window token of the level of the WindowManager hierarchy to mirror. Returns null
+     * if layer mirroring by SurfaceFlinger should not be performed for the given displayId.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    public abstract IBinder getWindowTokenClientToMirror(int displayId);
+
+    /**
+     * For the given displayId, updates the window token of the level of the WindowManager hierarchy
+     * to mirror. If windowToken is null, then SurfaceFlinger performs no layer mirroring to the
+     * given display.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    public abstract void setWindowTokenClientToMirror(int displayId, IBinder windowToken);
+
+    /**
+     * Returns the default size of the surface associated with the display, or null if the surface
+     * is not provided for layer mirroring by SurfaceFlinger.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    public abstract Point getDisplaySurfaceDefaultSize(int displayId);
+
     /**
      * Describes the requested power state of the display.
      *

core/java/android/hardware/display/VirtualDisplayConfig.java

@@ -23,6 +23,7 @@ import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.media.projection.MediaProjection;
 import android.os.Handler;
+import android.os.IBinder;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.view.Surface;
@@ -91,9 +92,16 @@ public final class VirtualDisplayConfig implements Parcelable {
      */
     private int mDisplayIdToMirror = DEFAULT_DISPLAY;
 
+    /**
+     * The window token of the level of the WindowManager hierarchy to mirror, or null if mirroring
+     * should not be performed.
+     */
+    @Nullable
+    private IBinder mWindowTokenClientToMirror = null;
 
 
-    // Code below generated by codegen v1.0.20.
+
+    // Code below generated by codegen v1.0.23.
     //
     // DO NOT MODIFY!
     // CHECKSTYLE:OFF Generated code
@@ -115,7 +123,8 @@ public final class VirtualDisplayConfig implements Parcelable {
             int flags,
             @Nullable Surface surface,
             @Nullable String uniqueId,
-            int displayIdToMirror) {
+            int displayIdToMirror,
+            @Nullable IBinder windowTokenClientToMirror) {
         this.mName = name;
         com.android.internal.util.AnnotationValidations.validate(
                 NonNull.class, null, mName);
@@ -135,6 +144,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         this.mSurface = surface;
         this.mUniqueId = uniqueId;
         this.mDisplayIdToMirror = displayIdToMirror;
+        this.mWindowTokenClientToMirror = windowTokenClientToMirror;
 
         // onConstructed(); // You can define this method to get a callback
     }
@@ -212,6 +222,15 @@ public final class VirtualDisplayConfig implements Parcelable {
         return mDisplayIdToMirror;
     }
 
+    /**
+     * The window token of the level of the WindowManager hierarchy to mirror, or null if mirroring
+     * should not be performed.
+     */
+    @DataClass.Generated.Member
+    public @Nullable IBinder getWindowTokenClientToMirror() {
+        return mWindowTokenClientToMirror;
+    }
+
     @Override
     @DataClass.Generated.Member
     public void writeToParcel(@NonNull Parcel dest, int flags) {
@@ -221,6 +240,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         int flg = 0;
         if (mSurface != null) flg |= 0x20;
         if (mUniqueId != null) flg |= 0x40;
+        if (mWindowTokenClientToMirror != null) flg |= 0x100;
         dest.writeInt(flg);
         dest.writeString(mName);
         dest.writeInt(mWidth);
@@ -230,6 +250,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         if (mSurface != null) dest.writeTypedObject(mSurface, flags);
         if (mUniqueId != null) dest.writeString(mUniqueId);
         dest.writeInt(mDisplayIdToMirror);
+        if (mWindowTokenClientToMirror != null) dest.writeStrongBinder(mWindowTokenClientToMirror);
     }
 
     @Override
@@ -252,6 +273,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         Surface surface = (flg & 0x20) == 0 ? null : (Surface) in.readTypedObject(Surface.CREATOR);
         String uniqueId = (flg & 0x40) == 0 ? null : in.readString();
         int displayIdToMirror = in.readInt();
+        IBinder windowTokenClientToMirror = (flg & 0x100) == 0 ? null : (IBinder) in.readStrongBinder();
 
         this.mName = name;
         com.android.internal.util.AnnotationValidations.validate(
@@ -272,6 +294,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         this.mSurface = surface;
         this.mUniqueId = uniqueId;
         this.mDisplayIdToMirror = displayIdToMirror;
+        this.mWindowTokenClientToMirror = windowTokenClientToMirror;
 
         // onConstructed(); // You can define this method to get a callback
     }
@@ -305,6 +328,7 @@ public final class VirtualDisplayConfig implements Parcelable {
         private @Nullable Surface mSurface;
         private @Nullable String mUniqueId;
         private int mDisplayIdToMirror;
+        private @Nullable IBinder mWindowTokenClientToMirror;
 
         private long mBuilderFieldsSet = 0L;
 
@@ -439,10 +463,22 @@ public final class VirtualDisplayConfig implements Parcelable {
             return this;
         }
 
+        /**
+         * The window token of the level of the WindowManager hierarchy to mirror, or null if mirroring
+         * should not be performed.
+         */
+        @DataClass.Generated.Member
+        public @NonNull Builder setWindowTokenClientToMirror(@NonNull IBinder value) {
+            checkNotUsed();
+            mBuilderFieldsSet |= 0x100;
+            mWindowTokenClientToMirror = value;
+            return this;
+        }
+
         /** Builds the instance. This builder should not be touched after calling this! */
         public @NonNull VirtualDisplayConfig build() {
             checkNotUsed();
-            mBuilderFieldsSet |= 0x100; // Mark builder used
+            mBuilderFieldsSet |= 0x200; // Mark builder used
 
             if ((mBuilderFieldsSet & 0x10) == 0) {
                 mFlags = 0;
@@ -456,6 +492,9 @@ public final class VirtualDisplayConfig implements Parcelable {
             if ((mBuilderFieldsSet & 0x80) == 0) {
                 mDisplayIdToMirror = DEFAULT_DISPLAY;
             }
+            if ((mBuilderFieldsSet & 0x100) == 0) {
+                mWindowTokenClientToMirror = null;
+            }
             VirtualDisplayConfig o = new VirtualDisplayConfig(
                     mName,
                     mWidth,
@@ -464,12 +503,13 @@ public final class VirtualDisplayConfig implements Parcelable {
                     mFlags,
                     mSurface,
                     mUniqueId,
-                    mDisplayIdToMirror);
+                    mDisplayIdToMirror,
+                    mWindowTokenClientToMirror);
             return o;
         }
 
         private void checkNotUsed() {
-            if ((mBuilderFieldsSet & 0x100) != 0) {
+            if ((mBuilderFieldsSet & 0x200) != 0) {
                 throw new IllegalStateException(
                         "This Builder should not be reused. Use a new Builder instance instead");
             }
@@ -477,10 +517,10 @@ public final class VirtualDisplayConfig implements Parcelable {
     }
 
     @DataClass.Generated(
-            time = 1604456298440L,
+            time = 1620657851981L,
-            codegenVersion = "1.0.20",
+            codegenVersion = "1.0.23",
             sourceFile = "frameworks/base/core/java/android/hardware/display/VirtualDisplayConfig.java",
-            inputSignatures = "private @android.annotation.NonNull java.lang.String mName\nprivate @android.annotation.IntRange int mWidth\nprivate @android.annotation.IntRange int mHeight\nprivate @android.annotation.IntRange int mDensityDpi\nprivate  int mFlags\nprivate @android.annotation.Nullable android.view.Surface mSurface\nprivate @android.annotation.Nullable java.lang.String mUniqueId\nprivate  int mDisplayIdToMirror\nclass VirtualDisplayConfig extends java.lang.Object implements [android.os.Parcelable]\n@com.android.internal.util.DataClass(genParcelable=true, genAidl=true, genBuilder=true)")
+            inputSignatures = "private @android.annotation.NonNull java.lang.String mName\nprivate @android.annotation.IntRange int mWidth\nprivate @android.annotation.IntRange int mHeight\nprivate @android.annotation.IntRange int mDensityDpi\nprivate  int mFlags\nprivate @android.annotation.Nullable android.view.Surface mSurface\nprivate @android.annotation.Nullable java.lang.String mUniqueId\nprivate  int mDisplayIdToMirror\nprivate @android.annotation.Nullable android.os.IBinder mWindowTokenClientToMirror\nclass VirtualDisplayConfig extends java.lang.Object implements [android.os.Parcelable]\n@com.android.internal.util.DataClass(genParcelable=true, genAidl=true, genBuilder=true)")
     @Deprecated
     private void __metadata() {}
 

core/java/android/view/Surface.java

@@ -29,6 +29,7 @@ import android.graphics.Canvas;
 import android.graphics.ColorSpace;
 import android.graphics.HardwareRenderer;
 import android.graphics.Matrix;
+import android.graphics.Point;
 import android.graphics.RecordingCanvas;
 import android.graphics.Rect;
 import android.graphics.RenderNode;
@@ -407,6 +408,20 @@ public class Surface implements Parcelable {
         }
     }
 
+    /**
+     * Returns the default size of this Surface provided by the consumer of the surface.
+     * Should only be used by the producer of the surface.
+     *
+     * @hide
+     */
+    @NonNull
+    public Point getDefaultSize() {
+        synchronized (mLock) {
+            checkNotReleasedLocked();
+            return new Point(nativeGetWidth(mNativeObject), nativeGetHeight(mNativeObject));
+        }
+    }
+
     /**
      * Gets a {@link Canvas} for drawing into this surface.
      *

media/java/android/media/projection/MediaProjection.java

@@ -16,14 +16,14 @@
 
 package android.media.projection;
 
+import static android.view.WindowManager.LayoutParams.TYPE_APPLICATION;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.VirtualDisplay;
 import android.hardware.display.VirtualDisplayConfig;
-import android.media.projection.IMediaProjection;
-import android.media.projection.IMediaProjectionCallback;
 import android.os.Handler;
 import android.os.RemoteException;
 import android.util.ArrayMap;
@@ -106,7 +106,7 @@ public final class MediaProjection {
         if (isSecure) {
             flags |= DisplayManager.VIRTUAL_DISPLAY_FLAG_SECURE;
         }
-        final VirtualDisplayConfig.Builder builder = new VirtualDisplayConfig.Builder(name, width,
+        final VirtualDisplayConfig.Builder builder = buildMirroredVirtualDisplay(name, width,
                 height, dpi);
         builder.setFlags(flags);
         if (surface != null) {
@@ -141,7 +141,7 @@ public final class MediaProjection {
     public VirtualDisplay createVirtualDisplay(@NonNull String name,
             int width, int height, int dpi, int flags, @Nullable Surface surface,
             @Nullable VirtualDisplay.Callback callback, @Nullable Handler handler) {
-        final VirtualDisplayConfig.Builder builder = new VirtualDisplayConfig.Builder(name, width,
+        final VirtualDisplayConfig.Builder builder = buildMirroredVirtualDisplay(name, width,
                 height, dpi);
         builder.setFlags(flags);
         if (surface != null) {
@@ -150,6 +150,26 @@ public final class MediaProjection {
         return createVirtualDisplay(builder.build(), callback, handler);
     }
 
+    /**
+     * Constructs a {@link VirtualDisplayConfig.Builder}, which will mirror the contents of a
+     * DisplayArea. The DisplayArea to mirror is from the DisplayArea the caller is launched on.
+     *
+     * @param name   The name of the virtual display, must be non-empty.
+     * @param width  The width of the virtual display in pixels. Must be greater than 0.
+     * @param height The height of the virtual display in pixels. Must be greater than 0.
+     * @param dpi    The density of the virtual display in dpi. Must be greater than 0.
+     * @return a config representing a VirtualDisplay
+     */
+    private VirtualDisplayConfig.Builder buildMirroredVirtualDisplay(@NonNull String name,
+            int width, int height, int dpi) {
+        Context windowContext = mContext.createWindowContext(mContext.getDisplayNoVerify(),
+                TYPE_APPLICATION, null /* options */);
+        final VirtualDisplayConfig.Builder builder = new VirtualDisplayConfig.Builder(name, width,
+                height, dpi);
+        builder.setWindowTokenClientToMirror(windowContext.getWindowContextToken());
+        return builder;
+    }
+
     /**
      * Creates a {@link android.hardware.display.VirtualDisplay} to capture the
      * contents of the screen.

services/core/java/com/android/server/display/DisplayDevice.java

@@ -16,7 +16,9 @@
 
 package com.android.server.display;
 
+import android.annotation.Nullable;
 import android.content.Context;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.hardware.display.DisplayViewport;
 import android.os.IBinder;
@@ -104,6 +106,34 @@ abstract class DisplayDevice {
         return Display.DEFAULT_DISPLAY;
     }
 
+    /**
+     * Returns the window token of the level of the WindowManager hierarchy to mirror, or null
+     * if layer mirroring by SurfaceFlinger should not be performed.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    @Nullable
+    public IBinder getWindowTokenClientToMirrorLocked() {
+        return null;
+    }
+
+    /**
+     * Updates the window token of the level of the level of the WindowManager hierarchy to mirror.
+     * If windowToken is null, then no layer mirroring by SurfaceFlinger to should be performed.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    public void setWindowTokenClientToMirrorLocked(IBinder windowToken) {
+    }
+
+    /**
+     * Returns the default size of the surface associated with the display, or null if the surface
+     * is not provided for layer mirroring by SurfaceFlinger.
+     * For now, only used for mirroring started from MediaProjection.
+     */
+    @Nullable
+    public Point getDisplaySurfaceDefaultSize() {
+        return null;
+    }
+
     /**
      * Gets the name of the display device.
      *

services/core/java/com/android/server/display/DisplayManagerService.java

@@ -1765,10 +1765,13 @@ public final class DisplayManagerService extends SystemService {
         final DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked();
         final boolean ownContent = (info.flags & DisplayDeviceInfo.FLAG_OWN_CONTENT_ONLY) != 0;
 
+        // Mirror the part of WM hierarchy that corresponds to the provided window token.
+        IBinder windowTokenClientToMirror = device.getWindowTokenClientToMirrorLocked();
+
         // Find the logical display that the display device is showing.
         // Certain displays only ever show their own content.
         LogicalDisplay display = mLogicalDisplayMapper.getDisplayLocked(device);
-        if (!ownContent) {
+        if (!ownContent && windowTokenClientToMirror == null) {
             if (display != null && !display.hasContentLocked()) {
                 // If the display does not have any content of its own, then
                 // automatically mirror the requested logical display contents if possible.
@@ -3330,6 +3333,40 @@ public final class DisplayManagerService extends SystemService {
             }
             return config.getRefreshRateLimitations();
         }
+
+        @Override
+        public IBinder getWindowTokenClientToMirror(int displayId) {
+            final DisplayDevice device;
+            synchronized (mSyncRoot) {
+                device = getDeviceForDisplayLocked(displayId);
+                if (device == null) {
+                    return null;
+                }
+            }
+            return device.getWindowTokenClientToMirrorLocked();
+        }
+
+        @Override
+        public void setWindowTokenClientToMirror(int displayId, IBinder windowToken) {
+            synchronized (mSyncRoot) {
+                final DisplayDevice device = getDeviceForDisplayLocked(displayId);
+                if (device != null) {
+                    device.setWindowTokenClientToMirrorLocked(windowToken);
+                }
+            }
+        }
+
+        @Override
+        public Point getDisplaySurfaceDefaultSize(int displayId) {
+            final DisplayDevice device;
+            synchronized (mSyncRoot) {
+                device = getDeviceForDisplayLocked(displayId);
+                if (device == null) {
+                    return null;
+                }
+            }
+            return device.getDisplaySurfaceDefaultSize();
+        }
     }
 
     class DesiredDisplayModeSpecsObserver

services/core/java/com/android/server/display/VirtualDisplayAdapter.java

@@ -31,7 +31,9 @@ import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_TRUST
 import static com.android.server.display.DisplayDeviceInfo.FLAG_OWN_DISPLAY_GROUP;
 import static com.android.server.display.DisplayDeviceInfo.FLAG_TRUSTED;
 
+import android.annotation.Nullable;
 import android.content.Context;
+import android.graphics.Point;
 import android.hardware.display.IVirtualDisplayCallback;
 import android.hardware.display.VirtualDisplayConfig;
 import android.media.projection.IMediaProjection;
@@ -231,6 +233,7 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
         private Display.Mode mMode;
         private boolean mIsDisplayOn;
         private int mDisplayIdToMirror;
+        private IBinder mWindowTokenClientToMirror;
 
         public VirtualDisplayDevice(IBinder displayToken, IBinder appToken,
                 int ownerUid, String ownerPackageName, Surface surface, int flags,
@@ -253,6 +256,7 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
             mUniqueIndex = uniqueIndex;
             mIsDisplayOn = surface != null;
             mDisplayIdToMirror = virtualDisplayConfig.getDisplayIdToMirror();
+            mWindowTokenClientToMirror = virtualDisplayConfig.getWindowTokenClientToMirror();
         }
 
         @Override
@@ -282,6 +286,26 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
             return mDisplayIdToMirror;
         }
 
+        @Override
+        @Nullable
+        public IBinder getWindowTokenClientToMirrorLocked() {
+            return mWindowTokenClientToMirror;
+        }
+
+        @Override
+        public void setWindowTokenClientToMirrorLocked(IBinder windowToken) {
+            if (mWindowTokenClientToMirror != windowToken) {
+                mWindowTokenClientToMirror = windowToken;
+                sendDisplayDeviceEventLocked(this, DISPLAY_DEVICE_EVENT_CHANGED);
+                sendTraversalRequestLocked();
+            }
+        }
+
+        @Override
+        public Point getDisplaySurfaceDefaultSize() {
+            return mSurface.getDefaultSize();
+        }
+
         @VisibleForTesting
         Surface getSurfaceLocked() {
             return mSurface;
@@ -362,6 +386,7 @@ public class VirtualDisplayAdapter extends DisplayAdapter {
             pw.println("mDisplayState=" + Display.stateToString(mDisplayState));
             pw.println("mStopped=" + mStopped);
             pw.println("mDisplayIdToMirror=" + mDisplayIdToMirror);
+            pw.println("mWindowTokenClientToMirror=" + mWindowTokenClientToMirror);
         }
 
 

services/core/java/com/android/server/wm/DisplayContent.java

@@ -298,6 +298,22 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
      */
     private final SurfaceControl mWindowingLayer;
 
+    /**
+     * The window token of the layer of the hierarchy to mirror, or null if this DisplayContent
+     * is not being used for layer mirroring.
+     */
+    @VisibleForTesting IBinder mTokenToMirror = null;
+
+    /**
+     * The surface for mirroring the contents of this hierarchy.
+     */
+    private SurfaceControl mMirroredSurface = null;
+
+    /**
+     * The last bounds of the DisplayArea to mirror.
+     */
+    private Rect mLastMirroredDisplayAreaBounds = null;
+
     // Contains all IME window containers. Note that the z-ordering of the IME windows will depend
     // on the IME target. We mainly have this container grouping so we can keep track of all the IME
     // window containers together and move them in-sync if/when needed. We use a subclass of
@@ -1126,6 +1142,10 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
         if (DEBUG_DISPLAY) Slog.v(TAG_WM, "Creating display=" + display);
 
         mWmService.mDisplayWindowSettings.applySettingsToDisplayLocked(this);
+
+        // Check if this DisplayContent is for a new VirtualDisplay, that should use layer mirroring
+        // to capture the contents of a DisplayArea.
+        startMirrorIfNeeded();
     }
 
     boolean isReady() {
@@ -2480,6 +2500,25 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
         // Update IME parent if needed.
         updateImeParent();
 
+        // Update mirroring surface for MediaProjection, if this DisplayContent is being used
+        // for layer mirroring.
+        if (mMirroredSurface != null) {
+            // Retrieve the size of the DisplayArea to mirror, and continue with the update if the
+            // bounds have changed.
+            final WindowContainer wc = mWmService.mWindowContextListenerController.getContainer(
+                    mTokenToMirror);
+            if (wc != null && mLastMirroredDisplayAreaBounds != null) {
+                // Retrieve the size of the DisplayArea to mirror, and continue with the update
+                // if the bounds or orientation has changed.
+                final Rect displayAreaBounds = wc.getDisplayContent().getBounds();
+                int displayAreaOrientation = wc.getDisplayContent().getOrientation();
+                if (!mLastMirroredDisplayAreaBounds.equals(displayAreaBounds)
+                        || lastOrientation != displayAreaOrientation) {
+                    updateMirroredSurface(mWmService.mTransactionFactory.get(), displayAreaBounds);
+                }
+            }
+        }
+
         if (lastOrientation != getConfiguration().orientation) {
             getMetricsLogger().write(
                     new LogMaker(MetricsEvent.ACTION_PHONE_ORIENTATION_CHANGED)
@@ -4338,6 +4377,7 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
                     mTmpApplySurfaceChangesTransactionState.preferMinimalPostProcessing,
                     true /* inTraversal, must call performTraversalInTrans... below */);
         }
+        updateMirroring();
 
         final boolean wallpaperVisible = mWallpaperController.isWallpaperVisible();
         if (wallpaperVisible != mLastWallpaperVisible) {
@@ -5901,6 +5941,133 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
         return mSandboxDisplayApis;
     }
 
+    /**
+     * Start mirroring to this DisplayContent if it does not have its own content. Captures the
+     * content of a WindowContainer indicated by a WindowToken. If unable to start mirroring, falls
+     * back to original MediaProjection approach.
+     */
+    private void startMirrorIfNeeded() {
+        // Only mirror if this display does not have its own content.
+        if (mLastHasContent) {
+            return;
+        }
+        // Given the WindowToken of the DisplayArea to mirror, retrieve the associated
+        // SurfaceControl.
+        IBinder tokenToMirror = mWmService.mDisplayManagerInternal.getWindowTokenClientToMirror(
+                mDisplayId);
+
+        if (tokenToMirror == null) {
+            // This DisplayContent instance is not involved in layer mirroring. If the display
+            // has been created for capturing, fall back to prior MediaProjection approach.
+            return;
+        }
+        final WindowContainer wc = mWmService.mWindowContextListenerController.getContainer(
+                tokenToMirror);
+        if (wc == null) {
+            // Un-set the window token to mirror for this VirtualDisplay, to fall back to the
+            // original MediaProjection approach.
+            mWmService.mDisplayManagerInternal.setWindowTokenClientToMirror(mDisplayId, null);
+            return;
+        }
+        SurfaceControl sc = wc.getDisplayContent().getSurfaceControl();
+
+        // Create a mirrored hierarchy for the SurfaceControl of the DisplayArea to capture.
+        mMirroredSurface = SurfaceControl.mirrorSurface(sc);
+        SurfaceControl.Transaction transaction = mWmService.mTransactionFactory.get()
+                // Set the mMirroredSurface's parent to the root SurfaceControl for this
+                // DisplayContent. This brings the new mirrored hierarchy under this DisplayContent,
+                // so SurfaceControl will write the layers of this hierarchy to the output surface
+                // provided by the app.
+                .reparent(mMirroredSurface, mSurfaceControl)
+                // Reparent the SurfaceControl of this DisplayContent to null, to prevent content
+                // being added to it. This ensures that no app launched explicitly on the
+                // VirtualDisplay will show up as part of the mirrored content.
+                .reparent(mWindowingLayer, null);
+        // Retrieve the size of the DisplayArea to mirror.
+        updateMirroredSurface(transaction, wc.getDisplayContent().getBounds());
+        mTokenToMirror = tokenToMirror;
+
+        // No need to clean up. In SurfaceFlinger, parents hold references to their children. The
+        // mirrored SurfaceControl is alive since the parent DisplayContent SurfaceControl is
+        // holding a reference to it. Therefore, the mirrored SurfaceControl will be cleaned up
+        // when the VirtualDisplay is destroyed - which will clean up this DisplayContent.
+    }
+
+    /**
+     * Start or stop mirroring if this DisplayContent now has content, or no longer has content.
+     */
+    private void updateMirroring() {
+        if (mLastHasContent && mMirroredSurface != null) {
+            // Display now has content, so stop mirroring to it.
+            mWmService.mTransactionFactory.get()
+                    // Remove the reference to mMirroredSurface, to clean up associated memory.
+                    .remove(mMirroredSurface)
+                    // Reparent the SurfaceControl of this DisplayContent back to mSurfaceControl,
+                    // to allow content to be added to it. This allows this DisplayContent to stop
+                    // mirroring and show content normally.
+                    .reparent(mWindowingLayer, mSurfaceControl).apply();
+            // Stop mirroring by destroying the reference to the mirrored layer.
+            mMirroredSurface = null;
+            // Do not un-set the token, in case content is removed and mirroring should begin again.
+        } else if (!mLastHasContent && mMirroredSurface == null) {
+            // Display no longer has content, so start mirroring to it.
+            startMirrorIfNeeded();
+        }
+    }
+
+    /**
+     * Apply transformations to the mirrored surface to ensure the captured contents are scaled to
+     * fit and centred in the output surface.
+     *
+     * @param transaction            the transaction to include transformations of mMirroredSurface
+     *                               to. Transaction is not applied before returning.
+     * @param displayAreaBounds      bounds of the DisplayArea to mirror to the surface provided by
+     *                               the app.
+     */
+    @VisibleForTesting
+    void updateMirroredSurface(SurfaceControl.Transaction transaction,
+            Rect displayAreaBounds) {
+        // Retrieve the default size of the surface the app provided to
+        // MediaProjection#createVirtualDisplay. Note the app is the consumer of the surface,
+        // since it reads out buffers from the surface, and SurfaceFlinger is the producer since
+        // it writes the mirrored layers to the buffers.
+        final Point surfaceSize = mWmService.mDisplayManagerInternal.getDisplaySurfaceDefaultSize(
+                mDisplayId);
+
+        // Calculate the scale to apply to the root mirror SurfaceControl to fit the size of the
+        // output surface.
+        float scaleX = surfaceSize.x / (float) displayAreaBounds.width();
+        float scaleY = surfaceSize.y / (float) displayAreaBounds.height();
+        float scale = Math.min(scaleX, scaleY);
+        int scaledWidth = Math.round(scale * (float) displayAreaBounds.width());
+        int scaledHeight = Math.round(scale * (float) displayAreaBounds.height());
+
+        // Calculate the shift to apply to the root mirror SurfaceControl to centre the mirrored
+        // contents in the output surface.
+        int shiftedX = 0;
+        if (scaledWidth != surfaceSize.x) {
+            shiftedX = (surfaceSize.x - scaledWidth) / 2;
+        }
+        int shiftedY = 0;
+        if (scaledHeight != surfaceSize.y) {
+            shiftedY = (surfaceSize.y - scaledHeight) / 2;
+        }
+
+        transaction
+                // Crop the area to capture to exclude the 'extra' wallpaper that is used
+                // for parallax (b/189930234).
+                .setWindowCrop(mMirroredSurface, displayAreaBounds.width(),
+                        displayAreaBounds.height())
+                // Scale the root mirror SurfaceControl, based upon the size difference between the
+                // source (DisplayArea to capture) and output (surface the app reads images from).
+                .setMatrix(mMirroredSurface, scale, 0 /* dtdx */, 0 /* dtdy */, scale)
+                // Position needs to be updated when the mirrored DisplayArea has changed, since
+                // the content will no longer be centered in the output surface.
+                .setPosition(mMirroredSurface, shiftedX /* x */, shiftedY /* y */)
+                .apply();
+        mLastMirroredDisplayAreaBounds = new Rect(displayAreaBounds);
+    }
+
     /** The entry for proceeding to handle {@link #mFixedRotationLaunchingApp}. */
     class FixedRotationTransitionListener extends WindowManagerInternal.AppTransitionListener {
 

services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java

@@ -67,6 +67,7 @@ import static com.android.dx.mockito.inline.extended.ExtendedMockito.anyBoolean;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.doNothing;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.mock;
+import static com.android.dx.mockito.inline.extended.ExtendedMockito.mockitoSession;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.never;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.reset;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.same;
@@ -107,9 +108,12 @@ import android.app.WindowConfiguration;
 import android.app.servertransaction.FixedRotationAdjustmentsItem;
 import android.content.res.Configuration;
 import android.graphics.Insets;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.Region;
 import android.metrics.LogMaker;
+import android.os.Binder;
+import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.platform.test.annotations.Presubmit;
@@ -142,6 +146,8 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mockito;
+import org.mockito.MockitoSession;
+import org.mockito.quality.Strictness;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -2220,6 +2226,113 @@ public class DisplayContentTests extends WindowTestsBase {
         assertNotEquals(imeMenuDialog, mDisplayContent.findFocusedWindow());
     }
 
+    @Test
+    public void testVirtualDisplayContent() {
+        MockitoSession mockSession = mockitoSession()
+                .initMocks(this)
+                .spyStatic(SurfaceControl.class)
+                .strictness(Strictness.LENIENT)
+                .startMocking();
+
+        // GIVEN MediaProjection has already initialized the WindowToken of the DisplayArea to
+        // mirror.
+        final IBinder tokenToMirror = setUpDefaultTaskDisplayAreaWindowToken();
+
+        // GIVEN SurfaceControl can successfully mirror the provided surface.
+        Point surfaceSize = new Point(
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().width(),
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().height());
+        surfaceControlMirrors(surfaceSize);
+
+        // WHEN creating the DisplayContent for a new virtual display.
+        final DisplayContent virtualDisplay = new TestDisplayContent.Builder(mAtm,
+                mDisplayInfo).build();
+
+        // THEN mirroring is initiated for the default display's DisplayArea.
+        assertThat(virtualDisplay.mTokenToMirror).isEqualTo(tokenToMirror);
+
+        mockSession.finishMocking();
+    }
+
+    @Test
+    public void testVirtualDisplayContent_capturedAreaResized() {
+        MockitoSession mockSession = mockitoSession()
+                .initMocks(this)
+                .spyStatic(SurfaceControl.class)
+                .strictness(Strictness.LENIENT)
+                .startMocking();
+
+        // GIVEN MediaProjection has already initialized the WindowToken of the DisplayArea to
+        // mirror.
+        final IBinder tokenToMirror = setUpDefaultTaskDisplayAreaWindowToken();
+
+        // GIVEN SurfaceControl can successfully mirror the provided surface.
+        Point surfaceSize = new Point(
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().width(),
+                mDefaultDisplay.getDefaultTaskDisplayArea().getBounds().height());
+        SurfaceControl mirroredSurface = surfaceControlMirrors(surfaceSize);
+
+        // WHEN creating the DisplayContent for a new virtual display.
+        final DisplayContent virtualDisplay = new TestDisplayContent.Builder(mAtm,
+                mDisplayInfo).build();
+
+        // THEN mirroring is initiated for the default display's DisplayArea.
+        assertThat(virtualDisplay.mTokenToMirror).isEqualTo(tokenToMirror);
+
+        float xScale = 0.7f;
+        float yScale = 2f;
+        Rect displayAreaBounds = new Rect(0, 0, Math.round(surfaceSize.x * xScale),
+                Math.round(surfaceSize.y * yScale));
+        virtualDisplay.updateMirroredSurface(mTransaction, displayAreaBounds);
+
+        // THEN content in the captured DisplayArea is scaled to fit the surface size.
+        verify(mTransaction, atLeastOnce()).setMatrix(mirroredSurface, 1.0f / yScale, 0, 0,
+                1.0f / yScale);
+        // THEN captured content is positioned in the centre of the output surface.
+        float scaledWidth = displayAreaBounds.width() / xScale;
+        float xInset = (surfaceSize.x - scaledWidth) / 2;
+        verify(mTransaction, atLeastOnce()).setPosition(mirroredSurface, xInset, 0);
+
+        mockSession.finishMocking();
+    }
+
+    private class TestToken extends Binder {
+    }
+
+    /**
+     * Creates a WindowToken associated with the default task DisplayArea, in order for that
+     * DisplayArea to be mirrored.
+     */
+    private IBinder setUpDefaultTaskDisplayAreaWindowToken() {
+        // GIVEN MediaProjection has already initialized the WindowToken of the DisplayArea to
+        // mirror.
+        final IBinder tokenToMirror = new TestToken();
+        doReturn(tokenToMirror).when(mWm.mDisplayManagerInternal).getWindowTokenClientToMirror(
+                anyInt());
+
+        // GIVEN the default task display area is represented by the WindowToken.
+        spyOn(mWm.mWindowContextListenerController);
+        doReturn(mDefaultDisplay.getDefaultTaskDisplayArea()).when(
+                mWm.mWindowContextListenerController).getContainer(any());
+        return tokenToMirror;
+    }
+
+    /**
+     * SurfaceControl successfully creates a mirrored surface of the given size.
+     */
+    private SurfaceControl surfaceControlMirrors(Point surfaceSize) {
+        // Do not set the parent, since the mirrored surface is the root of a new surface hierarchy.
+        SurfaceControl mirroredSurface = new SurfaceControl.Builder()
+                .setName("mirroredSurface")
+                .setBufferSize(surfaceSize.x, surfaceSize.y)
+                .setCallsite("mirrorSurface")
+                .build();
+        doReturn(mirroredSurface).when(() -> SurfaceControl.mirrorSurface(any()));
+        doReturn(surfaceSize).when(mWm.mDisplayManagerInternal).getDisplaySurfaceDefaultSize(
+                anyInt());
+        return mirroredSurface;
+    }
+
     private void removeRootTaskTests(Runnable runnable) {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task rootTask1 = taskDisplayArea.createRootTask(WINDOWING_MODE_FULLSCREEN,