view groups

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/BottomTabsController.java

@@ -43,12 +43,6 @@ public class BottomTabsController extends ParentController implements BottomNavi
 		return root;
 	}
 
-	@NonNull
-	@Override
-	public RelativeLayout getView() {
-		return (RelativeLayout) super.getView();
-	}
-
 	@Override
 	public boolean onNavigationItemSelected(@NonNull final MenuItem item) {
 		selectTabAtIndex(item.getItemId());

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/ParentController.java

@@ -1,6 +1,9 @@
 package com.reactnativenavigation.viewcontrollers;
 
 import android.app.Activity;
+import android.support.annotation.NonNull;
+import android.view.View;
+import android.view.ViewGroup;
 
 import java.util.Collection;
 
@@ -9,6 +12,16 @@ public abstract class ParentController extends ViewController {
 		super(activity, id);
 	}
 
+	@NonNull
+	@Override
+	public ViewGroup getView() {
+		return (ViewGroup) super.getView();
+	}
+
+	@NonNull
+	@Override
+	protected abstract View createView();
+
 	public abstract Collection<ViewController> getChildControllers();
 
 	public ViewController findControllerById(final String id) {

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/StackController.java

@@ -72,12 +72,6 @@ public class StackController extends ParentController {
 		}
 	}
 
-	@NonNull
-	@Override
-	public ViewGroup getView() {
-		return (ViewGroup) super.getView();
-	}
-
 	@NonNull
 	@Override
 	protected ViewGroup createView() {

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/ParentControllerTest.java

@@ -3,6 +3,7 @@ package com.reactnativenavigation.viewcontrollers;
 import android.app.Activity;
 import android.support.annotation.NonNull;
 import android.view.View;
+import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
 import com.reactnativenavigation.BaseTest;
@@ -26,6 +27,23 @@ public class ParentControllerTest extends BaseTest {
 		activity = newActivity();
 	}
 
+	@Test
+	public void holdsViewGroup() throws Exception {
+		ParentController uut = new ParentController(activity, "uut") {
+			@Override
+			public Collection<ViewController> getChildControllers() {
+				return Collections.emptyList();
+			}
+
+			@NonNull
+			@Override
+			protected View createView() {
+				return new FrameLayout(activity);
+			}
+		};
+
+		assertThat(uut.getView()).isInstanceOf(ViewGroup.class);
+	}
 
 	@Test
 	public void findControllerById_ReturnsSelfIfSameId() throws Exception {