Extend UIManagerHelper class to retrieve EventDispatcher associated with a ReactContext

Summary:
This diff extends the UIManagerHelper class to expose the EventDispatcher associated to a tag / UImanagerType

Changelog: [internal]

Reviewed By: JoshuaGross

Differential Revision: D18862863

fbshipit-source-id: 14ce7a6a33f20a94a6296320924dbe3544eadd85

ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerHelper.java

@@ -9,14 +9,14 @@ package com.facebook.react.uimanager;
 
 import static com.facebook.react.uimanager.common.UIManagerType.FABRIC;
 import static com.facebook.react.uimanager.common.ViewUtil.getUIManagerType;
-
-import androidx.annotation.Nullable;
 import com.facebook.react.bridge.CatalystInstance;
+import androidx.annotation.Nullable;
 import com.facebook.react.bridge.JSIModuleType;
 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.bridge.ReactSoftException;
 import com.facebook.react.bridge.UIManager;
 import com.facebook.react.uimanager.common.UIManagerType;
+import com.facebook.react.uimanager.events.EventDispatcher;
 
 /** Helper class for {@link UIManager}. */
 public class UIManagerHelper {
@@ -30,15 +30,39 @@ public class UIManagerHelper {
   /** @return a {@link UIManager} that can handle the react tag received by parameter. */
   @Nullable
   public static UIManager getUIManager(ReactContext context, @UIManagerType int uiManagerType) {
-    if (!context.hasActiveCatalystInstance()) {
-      ReactSoftException.logSoftException(
-          "UIManagerHelper",
-          new RuntimeException("Cannot get UIManager: no active Catalyst instance"));
-      return null;
+    if (context.isBridgeless()) {
+      return (UIManager) context.getJSIModule(JSIModuleType.UIManager);
+    } else {
+      if (!context.hasActiveCatalystInstance()) {
+        ReactSoftException.logSoftException(
+            "UIManagerHelper",
+            new RuntimeException("Cannot get UIManager: no active Catalyst instance"));
+        return null;
+      }
+      CatalystInstance catalystInstance = context.getCatalystInstance();
+      return uiManagerType == FABRIC
+          ? (UIManager) catalystInstance.getJSIModule(JSIModuleType.UIManager)
+          : catalystInstance.getNativeModule(UIManagerModule.class);
     }
-    CatalystInstance catalystInstance = context.getCatalystInstance();
-    return uiManagerType == FABRIC
-        ? (UIManager) catalystInstance.getJSIModule(JSIModuleType.UIManager)
-        : catalystInstance.getNativeModule(UIManagerModule.class);
+  }
+
+  /**
+   * @return the {@link EventDispatcher} that handles events for the reactTag received as a
+   *     parameter.
+   */
+  @Nullable
+  public static EventDispatcher getEventDispatcherForReactTag(ReactContext context, int reactTag) {
+    return getEventDispatcher(context, getUIManagerType(reactTag));
+  }
+
+  /**
+   * @return the {@link EventDispatcher} that handles events for the {@link UIManagerType} received
+   *     as a parameter.
+   */
+  @Nullable
+  public static EventDispatcher getEventDispatcher(
+      ReactContext context, @UIManagerType int uiManagerType) {
+    UIManager uiManager = getUIManager(context, uiManagerType);
+    return uiManager == null ? null : (EventDispatcher) uiManager.getEventDispatcher();
   }
 }