Support setting custom react view dynamically

android/app/src/main/java/com/reactnativenavigation/params/NavigationParams.java

 import android.os.Bundle;
 
 public class NavigationParams {
+    public static final NavigationParams EMPTY = new NavigationParams(Bundle.EMPTY);
+
     private static final String SCREEN_INSTANCE_ID = "screenInstanceID";
     private static final String NAVIGATOR_ID = "navigatorID";
     private static final String NAVIGATOR_EVENT_ID = "navigatorEventID";

android/app/src/main/java/com/reactnativenavigation/params/StyleParams.java

     public Color topBarColor;
     public String topBarReactView;
     public String topBarReactViewAlignment;
+    public Bundle topBarReactViewInitialProps;
     public CollapsingTopBarParams collapsingTopBarParams;
     public boolean topBarCollapseOnScroll;
     public boolean topBarElevationShadowEnabled;

android/app/src/main/java/com/reactnativenavigation/params/parsers/StyleParamsParser.java

         result.topBarColor = getColor("topBarColor", getDefaultTopBarColor());
         result.topBarReactView = params.getString("topBarReactView");
         result.topBarReactViewAlignment = params.getString("topBarReactViewAlignment");
+        result.topBarReactViewInitialProps = getBundle("topBarReactViewInitialProps");
         result.titleBarHideOnScroll = getBoolean("titleBarHideOnScroll", getDefaultTitleBarHideOnScroll());
         result.topBarTransparent = getBoolean("topBarTransparent", getDefaultTopBarHidden());
         result.topBarCollapseOnScroll = getBoolean("topBarCollapseOnScroll", false);
     private int getInt(String key, int defaultValue) {
         return params.containsKey(key) ? params.getInt(key) : defaultValue;
     }
+
+    private Bundle getBundle(String key) {
+        return params.containsKey(key) ? params.getBundle(key) : Bundle.EMPTY;
+    }
 }

android/app/src/main/java/com/reactnativenavigation/screens/Screen.java

     private void createTitleBar() {
         addTitleBarButtons();
         if (screenParams.styleParams.hasTopBarCustomComponent()) {
-            topBar.setReactView(screenParams.styleParams.topBarReactView, screenParams.styleParams.topBarReactViewAlignment);
+            topBar.setReactView(screenParams.styleParams);
         } else {
             topBar.setTitle(screenParams.title);
             topBar.setSubtitle(screenParams.subtitle);

android/app/src/main/java/com/reactnativenavigation/views/ContentView.java

 package com.reactnativenavigation.views;
 
 import android.content.Context;
+import android.os.Bundle;
 import android.view.View;
 
 import com.facebook.react.ReactRootView;
 public class ContentView extends ReactRootView {
     private final String screenId;
     private final NavigationParams navigationParams;
+    private Bundle initialProps;
 
     boolean isContentVisible = false;
     private SingleScreen.OnDisplayListener onDisplayListener;
     }
 
     public ContentView(Context context, String screenId, NavigationParams navigationParams) {
+        this(context, screenId, navigationParams, Bundle.EMPTY);
+    }
+
+    public ContentView(Context context, String screenId, NavigationParams navigationParams, Bundle initialProps) {
         super(context);
         this.screenId = screenId;
         this.navigationParams = navigationParams;
+        this.initialProps = initialProps;
         attachToJS();
         viewMeasurer = new ViewMeasurer();
     }
     }
 
     private void attachToJS() {
-        startReactApplication(NavigationApplication.instance.getReactGateway().getReactInstanceManager(), screenId,
-                navigationParams.toBundle());
+        navigationParams.toBundle().putAll(initialProps);
+        startReactApplication(NavigationApplication.instance.getReactGateway().getReactInstanceManager(),
+                screenId,
+                createInitialParams()
+        );
+    }
+
+    private Bundle createInitialParams() {
+        final Bundle params = new Bundle();
+        params.putAll(navigationParams.toBundle());
+        params.putAll(initialProps);
+        return params;
     }
 
     public String getNavigatorEventId() {

android/app/src/main/java/com/reactnativenavigation/views/TitleBar.java

                 if (params.titleBarTitleTextCentered) {
                     titleView.setX(ViewUtils.getWindowWidth(getActivity()) / 2 - titleView.getWidth() / 2);
                 }
-                
             }
         });
     }

android/app/src/main/java/com/reactnativenavigation/views/TopBar.java

 import android.content.Context;
 import android.graphics.Color;
 import android.os.Build;
-import android.os.Bundle;
 import android.support.design.widget.AppBarLayout;
 import android.support.v7.app.ActionBar;
 import android.text.TextUtils;
         titleBar.setSubtitle(subtitle);
     }
 
-    public void setReactView(String topBarReactView, String alignment) {
-        if (!TextUtils.isEmpty(topBarReactView)) {
-            final ContentView view = new ContentView(getContext(), topBarReactView, new NavigationParams(Bundle.EMPTY));
-            if ("fill".equals(alignment)) {
+    public void setReactView(StyleParams styleParams) {
+        if (!TextUtils.isEmpty(styleParams.topBarReactView)) {
+            final ContentView view = new ContentView(getContext(),
+                    styleParams.topBarReactView,
+                    NavigationParams.EMPTY,
+                    styleParams.topBarReactViewInitialProps
+            );
+            if ("fill".equals(styleParams.topBarReactViewAlignment)) {
                 addReactViewFill(view);
             } else {
                 addCenteredReactView(view);
             setTransparent();
         }
         titleBar.setStyle(styleParams);
+        setReactView(styleParams);
         setTopTabsStyle(styleParams);
         if (!styleParams.topBarElevationShadowEnabled) {
             disableElevationShadow();

src/deprecated/platformSpecificDeprecated.android.js

     statusBarColor: processColor(originalStyleObject.statusBarColor),
     topBarReactView: originalStyleObject.navBarCustomView,
     topBarReactViewAlignment: originalStyleObject.navBarComponentAlignment,
+    topBarReactViewInitialProps: originalStyleObject.navBarCustomViewInitialProps,
     topBarColor: processColor(originalStyleObject.navBarBackgroundColor),
     topBarTransparent: originalStyleObject.navBarTransparent,
     topBarTranslucent: originalStyleObject.navBarTranslucent,