Merge "Expose API for using SurfaceControl with ViewRootImpl" into sc-dev

core/api/current.txt

@@ -48712,6 +48712,7 @@ package android.view {
     method @Nullable public android.graphics.drawable.Drawable getVerticalScrollbarThumbDrawable();
     method @Nullable public android.graphics.drawable.Drawable getVerticalScrollbarTrackDrawable();
     method public int getVerticalScrollbarWidth();
+    method @Nullable public android.view.ViewRoot getViewRoot();
     method @Nullable public android.view.translation.ViewTranslationCallback getViewTranslationCallback();
     method public android.view.ViewTreeObserver getViewTreeObserver();
     method public int getVisibility();
@@ -49788,6 +49789,11 @@ package android.view {
     method public android.view.ViewPropertyAnimator zBy(float);
   }
 
+  @UiThread public interface ViewRoot {
+    method public boolean applyTransactionOnDraw(@NonNull android.view.SurfaceControl.Transaction);
+    method @Nullable public android.view.SurfaceControl.Transaction buildReparentTransaction(@NonNull android.view.SurfaceControl);
+  }
+
   public abstract class ViewStructure {
     ctor public ViewStructure();
     method public abstract int addChildCount(int);
@@ -49983,6 +49989,7 @@ package android.view {
     method @NonNull public java.util.List<android.graphics.Rect> getSystemGestureExclusionRects();
     method public long getTransitionBackgroundFadeDuration();
     method public android.transition.TransitionManager getTransitionManager();
+    method @Nullable public android.view.ViewRoot getViewRoot();
     method public abstract int getVolumeControlStream();
     method public android.view.WindowManager getWindowManager();
     method public final android.content.res.TypedArray getWindowStyle();

core/java/android/view/View.java

@@ -29543,6 +29543,10 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
             return mScrollCaptureInternal;
         }
 
+        ViewRoot getViewRoot() {
+            return mViewRootImpl;
+        }
+
         public void dump(String prefix, PrintWriter writer) {
             String innerPrefix = prefix + "  ";
             writer.println(prefix + "AttachInfo:");
@@ -30930,4 +30934,20 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
             callback.onDisplayHashError(DISPLAY_HASH_ERROR_UNKNOWN);
         }
     }
+
+    /**
+     * @return The {@link android.view.ViewRoot} interface for this View. This will only
+     * return a non-null value when called between {@link #onAttachedToWindow} and
+     * {@link #onDetachedFromWindow}.
+     *
+     * The ViewRoot itself is not a View, it is just the interface to the windowing-system
+     * object that contains the entire view hierarchy. For the root View of a given hierarchy
+     * see {@link #getRootView}.
+     */
+    public @Nullable ViewRoot getViewRoot() {
+        if (mAttachInfo != null) {
+            return mAttachInfo.getViewRoot();
+        }
+        return null;
+    }
 }

core/java/android/view/ViewRoot.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2021 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;
+
+/**
+ * Provides an interface to the root-Surface of a View Hierarchy or Window. This
+ * is used in combination with the {@link android.view.SurfaceControl} API to enable
+ * attaching app created SurfaceControl to the ViewRoot's surface hierarchy, and enable
+ * SurfaceTransactions to be performed in sync with the ViewRoot drawing. This object
+ * is obtained from {@link android.view.View#getViewRoot} and
+ * {@link android.view.Window#getViewRoot}. It must be used from the UI thread of
+ * the object it was obtained from.
+ */
+@UiThread
+public interface ViewRoot {
+    /**
+     * Create a transaction which will reparent {@param child} to the ViewRoot. See
+     * {@link SurfaceControl.Transaction#reparent}. This transacton must be applied
+     * or merged in to another transaction by the caller, otherwise it will have
+     * no effect.
+     *
+     * @param child The SurfaceControl to reparent.
+     * @return A new transaction which performs the reparent operation when applied.
+     */
+    @Nullable SurfaceControl.Transaction buildReparentTransaction(@NonNull SurfaceControl child);
+
+    /**
+     * Consume the passed in transaction, and request the ViewRoot to apply it with the
+     * next draw. This transaction will be merged with the buffer transaction from the ViewRoot
+     * and they will show up on-screen atomically synced.
+     *
+     * This will not cause a draw to be scheduled, and if there are no other changes
+     * to the View hierarchy you may need to call {@link android.view.View#invalidate}
+     */
+    boolean applyTransactionOnDraw(@NonNull SurfaceControl.Transaction t);
+}

core/java/android/view/ViewRootImpl.java

@@ -224,7 +224,7 @@ import java.util.concurrent.CountDownLatch;
  */
 @SuppressWarnings({"EmptyCatchBlock", "PointlessBooleanExpression"})
 public final class ViewRootImpl implements ViewParent,
-        View.AttachInfo.Callbacks, ThreadedRenderer.DrawCallbacks {
+        View.AttachInfo.Callbacks, ThreadedRenderer.DrawCallbacks, ViewRoot {
     private static final String TAG = "ViewRootImpl";
     private static final boolean DBG = false;
     private static final boolean LOCAL_LOGV = false;
@@ -10249,4 +10249,21 @@ public final class ViewRootImpl implements ViewParent,
             t.apply();
         }
     }
+
+    @Override
+    @Nullable public SurfaceControl.Transaction buildReparentTransaction(
+        @NonNull SurfaceControl child) {
+        if (mSurfaceControl.isValid()) {
+            return new SurfaceControl.Transaction().reparent(child, mSurfaceControl);
+        }
+        return null;
+    }
+
+    @Override
+    public boolean applyTransactionOnDraw(@NonNull SurfaceControl.Transaction t) {
+        registerRtFrameCallback(frame -> {
+            mergeWithNextTransaction(t, frame);
+        });
+        return true;
+    }
 }

core/java/android/view/Window.java

@@ -2717,4 +2717,14 @@ public abstract class Window {
     public @Nullable WindowInsetsController getInsetsController() {
         return null;
     }
+
+    /**
+     * This will be null before a content view is added, e.g. via
+     * {@link #setContentView} or {@link #addContentView}.
+     *
+     * @return The {@link android.view.ViewRoot} interface for this Window
+     */
+    public @Nullable ViewRoot getViewRoot() {
+        return null;
+    }
 }

core/java/com/android/internal/policy/PhoneWindow.java

@@ -75,6 +75,7 @@ import android.util.Log;
 import android.util.Pair;
 import android.util.SparseArray;
 import android.util.TypedValue;
+import android.view.ViewRoot;
 import android.view.ContextThemeWrapper;
 import android.view.CrossWindowBlurListeners;
 import android.view.Gravity;
@@ -3981,4 +3982,9 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
     public View getNavigationBarBackgroundView() {
         return mDecor != null ? mDecor.getNavigationBarBackgroundView() : null;
     }
+
+    @Override
+    public ViewRoot getViewRoot() {
+        return getViewRootImplOrNull();
+    }
 }