feat(Android): Implement direct communication between Android code and JS (#1203)

android/src/main/java/com/reactnativecommunity/webview/RNCWebViewManager.java

 import com.facebook.react.views.scroll.ScrollEventType;
 import com.facebook.react.views.scroll.OnScrollDispatchHelper;
 import com.facebook.react.bridge.Arguments;
+import com.facebook.react.bridge.CatalystInstance;
 import com.facebook.react.bridge.LifecycleEventListener;
 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.bridge.ReadableMapKeySetIterator;
 import com.facebook.react.bridge.WritableMap;
+import com.facebook.react.bridge.WritableNativeArray;
+import com.facebook.react.bridge.WritableNativeMap;
 import com.facebook.react.common.MapBuilder;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.module.annotations.ReactModule;
     protected boolean messagingEnabled = false;
     protected @Nullable
     RNCWebViewClient mRNCWebViewClient;
+    protected @Nullable
+    CatalystInstance mCatalystInstance;
     protected boolean sendContentSizeChangeEvents = false;
     private OnScrollDispatchHelper mOnScrollDispatchHelper;
     protected boolean hasScrollEvent = false;
       return new RNCWebViewBridge(webView);
     }
 
+    protected void createCatalystInstance() {
+      ReactContext reactContext = (ReactContext) this.getContext();
+
+      if (reactContext != null) {
+        mCatalystInstance = reactContext.getCatalystInstance();
+      }
+    }
+
     @SuppressLint("AddJavascriptInterface")
     public void setMessagingEnabled(boolean enabled) {
       if (messagingEnabled == enabled) {
 
       if (enabled) {
         addJavascriptInterface(createRNCWebViewBridge(this), JAVASCRIPT_INTERFACE);
+        this.createCatalystInstance();
       } else {
         removeJavascriptInterface(JAVASCRIPT_INTERFACE);
       }
     }
 
     public void onMessage(String message) {
+      ReactContext reactContext = (ReactContext) this.getContext();
+      RNCWebView mContext = this;
+
       if (mRNCWebViewClient != null) {
         WebView webView = this;
         webView.post(new Runnable() {
             }
             WritableMap data = mRNCWebViewClient.createWebViewEvent(webView, webView.getUrl());
             data.putString("data", message);
-            dispatchEvent(webView, new TopMessageEvent(webView.getId(), data));
+
+            if (mCatalystInstance != null) {
+              mContext.sendDirectMessage(data);
+            } else {
+              dispatchEvent(webView, new TopMessageEvent(webView.getId(), data));
+            }
           }
         });
       } else {
         WritableMap eventData = Arguments.createMap();
         eventData.putString("data", message);
-        dispatchEvent(this, new TopMessageEvent(this.getId(), eventData));
+
+        if (mCatalystInstance != null) {
+          this.sendDirectMessage(eventData);
+        } else {
+          dispatchEvent(this, new TopMessageEvent(this.getId(), eventData));
+        }
       }
     }
 
+    protected void sendDirectMessage(WritableMap data) {
+      WritableNativeMap event = new WritableNativeMap();
+      event.putMap("nativeEvent", data);
+
+      WritableNativeArray params = new WritableNativeArray();
+      params.pushMap(event);
+
+      mCatalystInstance.callFunction("WebViewMessageHandler", "onMessage", params);
+    }
+
     protected void onScrollChanged(int x, int y, int oldX, int oldY) {
       super.onScrollChanged(x, y, oldX, oldY);
 

src/WebView.android.tsx

   findNodeHandle,
 } from 'react-native';
 
+import BatchedBridge from 'react-native/Libraries/BatchedBridge/BatchedBridge';
+
 import invariant from 'invariant';
 
 import {
 
   webViewRef = React.createRef<NativeWebViewAndroid>();
 
+  componentDidMount = () => {
+    BatchedBridge.registerCallableModule('WebViewMessageHandler', this);
+  }
+
   getCommands = () => UIManager.getViewManagerConfig('RNCWebView').Commands;
 
   goForward = () => {