From 5e3d35c1021c3b93abc01d4cea202a3c622eedec Mon Sep 17 00:00:00 2001
From: Brian Isganitis <brianji@google.com>
Date: Mon, 18 Oct 2021 19:15:24 -0400
Subject: [PATCH] Expose mirror of wallpaper surface in WindowManagerGlobal.

Test: Manual
Bug: 188222480
Change-Id: I92302053a797de76aec3c2a25e5d895cfc85e6d5
---
 core/java/android/view/IWindowManager.aidl           |  8 ++++++++
 core/java/android/view/WindowManagerGlobal.java      | 11 +++++++++++
 .../com/android/server/wm/WallpaperController.java   | 12 ++++++++++++
 .../com/android/server/wm/WindowManagerService.java  |  8 ++++++++
 4 files changed, 39 insertions(+)

diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index 8e149a98af0eb..1791d3a731f74 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -346,6 +346,14 @@ interface IWindowManager
      */
     Bitmap screenshotWallpaper();
 
+    /**
+     * Mirrors the wallpaper for the given display.
+     *
+     * @param displayId ID of the display for the wallpaper.
+     * @return A SurfaceControl for the parent of the mirrored wallpaper.
+     */
+    SurfaceControl mirrorWallpaperSurface(int displayId);
+
     /**
      * Registers a wallpaper visibility listener.
      * @return Current visibility.
diff --git a/core/java/android/view/WindowManagerGlobal.java b/core/java/android/view/WindowManagerGlobal.java
index 18013e815d134..c92a3a086a8bf 100644
--- a/core/java/android/view/WindowManagerGlobal.java
+++ b/core/java/android/view/WindowManagerGlobal.java
@@ -18,6 +18,7 @@ package android.view;
 
 import android.animation.ValueAnimator;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.app.ActivityManager;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.ComponentCallbacks2;
@@ -709,6 +710,16 @@ public final class WindowManagerGlobal {
             }
         }
     }
+
+    /** @hide */
+    @Nullable
+    public SurfaceControl mirrorWallpaperSurface(int displayId) {
+        try {
+            return getWindowManagerService().mirrorWallpaperSurface(displayId);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }
 
 final class WindowLeaked extends AndroidRuntimeException {
diff --git a/services/core/java/com/android/server/wm/WallpaperController.java b/services/core/java/com/android/server/wm/WallpaperController.java
index a92e0883db379..d93b649b390af 100644
--- a/services/core/java/com/android/server/wm/WallpaperController.java
+++ b/services/core/java/com/android/server/wm/WallpaperController.java
@@ -801,6 +801,18 @@ class WallpaperController {
                 wallpaperBuffer.getHardwareBuffer(), wallpaperBuffer.getColorSpace());
     }
 
+    /**
+     * Mirrors the visible wallpaper if it's available.
+     *
+     * @return A SurfaceControl for the parent of the mirrored wallpaper.
+     */
+    SurfaceControl mirrorWallpaperSurface() {
+        final WindowState wallpaperWindowState = getTopVisibleWallpaper();
+        return wallpaperWindowState != null
+                ? SurfaceControl.mirrorSurface(wallpaperWindowState.getSurfaceControl())
+                : null;
+    }
+
     WindowState getTopVisibleWallpaper() {
         mTmpTopWallpaper = null;
 
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index ff3919b2c07c0..afa3552e940c6 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -3791,6 +3791,14 @@ public class WindowManagerService extends IWindowManager.Stub
         }
     }
 
+    @Override
+    public SurfaceControl mirrorWallpaperSurface(int displayId) {
+        synchronized (mGlobalLock) {
+            final DisplayContent dc = mRoot.getDisplayContent(displayId);
+            return dc.mWallpaperController.mirrorWallpaperSurface();
+        }
+    }
+
     /**
      * Takes a snapshot of the screen.  In landscape mode this grabs the whole screen.
      * In portrait mode, it grabs the upper region of the screen based on the vertical dimension