Provide default implementation of ViewManager#getDelegate (#48664)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/48664

Simplify ViewManager base-class by making `ViewManager`'s delegate non-nullable and using a single path for updating properties.

The ViewManagerDelegate API can map back to the original ViewManagerSetter API transparently, allowing us to remove the codepath from `ViewManagerPropertyUpdater`.

Changelog: [Android][Removed] `ViewManagerPropertyUpdater.updateProps` is deprected, use the related ViewManager APIs instead

Reviewed By: mdvacca, rshest

Differential Revision: D68120420

fbshipit-source-id: cd8b906dc36d4803dbe09ee0283654285eb81fd4

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManager.java

@@ -27,6 +27,7 @@ import com.facebook.react.uimanager.annotations.ReactPropGroup;
 import com.facebook.react.uimanager.annotations.ReactPropertyHolder;
 import com.facebook.yoga.YogaMeasureMode;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Stack;
 
@@ -41,7 +42,6 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode>
 
   private static final String NAME = ViewManager.class.getSimpleName();
 
-  private boolean mIsDelegateLoaded = false;
   private @Nullable ViewManagerDelegate<T> mDelegate = null;
 
   /**
@@ -91,11 +91,11 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode>
    * @param props {@link ReactStylesDiffMap} props to update the view with
    */
   public void updateProperties(@NonNull T viewToUpdate, ReactStylesDiffMap props) {
-    final ViewManagerDelegate<T> delegate = getOrCreateViewManagerDelegate();
-    if (delegate != null) {
-      ViewManagerPropertyUpdater.updateProps(delegate, viewToUpdate, props);
-    } else {
-      ViewManagerPropertyUpdater.updateProps(this, viewToUpdate, props);
+    ViewManagerDelegate<T> delegate = getOrCreateViewManagerDelegate();
+    Iterator<Map.Entry<String, Object>> iterator = props.mBackingMap.getEntryIterator();
+    while (iterator.hasNext()) {
+      Map.Entry<String, Object> entry = iterator.next();
+      delegate.setProperty(viewToUpdate, entry.getKey(), entry.getValue());
     }
     onAfterUpdateTransaction(viewToUpdate);
   }
@@ -106,22 +106,23 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode>
    * then get calls to {@link ViewManagerDelegate#setProperty(View, String, Object)} for every prop
    * that must be updated and it's the delegate's responsibility to apply these values to the view.
    *
-   * <p>By default this method returns {@code null}, which means that the view manager doesn't have
-   * a delegate and the view props should be set internally by the view manager itself.
+   * <p>By default, this methods returns a generic {@link ViewManagerDelegate} which uses {@link
+   * ViewManagerSetter} to apply property updates.
    *
    * @return an instance of {@link ViewManagerDelegate} if the props of the view managed by this
    *     view manager should be set via this delegate
    */
-  protected @Nullable ViewManagerDelegate<T> getDelegate() {
-    return null;
+  protected ViewManagerDelegate<T> getDelegate() {
+    return new ViewManagerPropertyUpdater.GenericViewManagerDelegate(this);
   }
 
-  private @Nullable ViewManagerDelegate<T> getOrCreateViewManagerDelegate() {
-    if (!mIsDelegateLoaded) {
-      mDelegate = getDelegate();
-      mIsDelegateLoaded = true;
+  private ViewManagerDelegate<T> getOrCreateViewManagerDelegate() {
+    ViewManagerDelegate<T> delegate = mDelegate;
+    if (delegate == null) {
+      delegate = getDelegate();
+      mDelegate = delegate;
     }
-    return mDelegate;
+    return delegate;
   }
 
   /** Creates a view with knowledge of props and state. */
@@ -316,10 +317,7 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode>
    * @param args optional arguments for the command
    */
   public void receiveCommand(@NonNull T root, String commandId, @Nullable ReadableArray args) {
-    final ViewManagerDelegate<T> delegate = getOrCreateViewManagerDelegate();
-    if (delegate != null) {
-      delegate.receiveCommand(root, commandId, args);
-    }
+    getOrCreateViewManagerDelegate().receiveCommand(root, commandId, args);
   }
 
   /**

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManagerPropertyUpdater.kt

@@ -9,6 +9,8 @@ package com.facebook.react.uimanager
 
 import android.view.View
 import com.facebook.common.logging.FLog
+import com.facebook.react.bridge.ReadableArray
+import com.facebook.react.common.annotations.DeprecatedInNewArchitecture
 import com.facebook.react.uimanager.ViewManagersPropertyCache.PropSetter
 import java.util.HashMap
 
@@ -40,6 +42,7 @@ public object ViewManagerPropertyUpdater {
   }
 
   @JvmStatic
+  @Deprecated("Use ViewManager#updateProperties to update a view's properties")
   public fun <T : ViewManagerDelegate<V>, V : View> updateProps(
       delegate: T,
       view: V,
@@ -53,6 +56,7 @@ public object ViewManagerPropertyUpdater {
   }
 
   @JvmStatic
+  @Deprecated("Use ViewManager#updateProperties to update a view's properties")
   public fun <V : View> updateProps(
       manager: ViewManager<V, *>,
       view: V,
@@ -66,6 +70,7 @@ public object ViewManagerPropertyUpdater {
     }
   }
 
+  @DeprecatedInNewArchitecture
   @JvmStatic
   public fun <T : ReactShadowNode<T>> updateProps(node: T, props: ReactStylesDiffMap) {
     val setter = findNodeSetter(node.javaClass)
@@ -168,4 +173,17 @@ public object ViewManagerPropertyUpdater {
       }
     }
   }
+
+  internal class GenericViewManagerDelegate<T : View>(private val manager: ViewManager<T, *>) :
+      ViewManagerDelegate<T> {
+    private val setter = findManagerSetter(manager.javaClass)
+
+    @Suppress("ACCIDENTAL_OVERRIDE")
+    override fun setProperty(view: T, propName: String, value: Any?): Unit {
+      setter.setProperty(manager, view, propName, value)
+    }
+
+    @Suppress("ACCIDENTAL_OVERRIDE")
+    override fun receiveCommand(view: T, commandName: String, args: ReadableArray?) = Unit
+  }
 }