tabs selection

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

 import com.reactnativenavigation.utils.CompatUtils;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 
 public class BottomTabsController extends ParentController implements BottomNavigationView.OnNavigationItemSelectedListener {
 	private BottomNavigationView bottomNavigationView;
-	private int selectedIndex = 0;
 	private List<ViewController> tabs = new ArrayList<>();
+	private int selectedIndex = 0;
 
 	public BottomTabsController(final Activity activity, final String id) {
 		super(activity, id);
 
 	@Override
 	public boolean onNavigationItemSelected(@NonNull final MenuItem item) {
+		selectTabAtIndex(item.getItemId());
+		return true;
+	}
+
+	public void selectTabAtIndex(final int newIndex) {
 		tabs.get(selectedIndex).getView().setVisibility(View.GONE);
-		selectedIndex = item.getItemId();
+		selectedIndex = newIndex;
 		tabs.get(selectedIndex).getView().setVisibility(View.VISIBLE);
-		return true;
 	}
 
 	public void setTabs(final List<ViewController> tabs) {
 		this.tabs = tabs;
 		getView();
 		for (int i = 0; i < tabs.size(); i++) {
-			ViewController tab = tabs.get(i);
-			bottomNavigationView.getMenu().add(0, i, Menu.NONE, String.valueOf(i));
-			RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT);
-			params.addRule(ABOVE, bottomNavigationView.getId());
-			getView().addView(tab.getView(), params);
-			if (i > 0) {
-				tab.getView().setVisibility(View.GONE);
-			}
+			String title = String.valueOf(i);
+			createTab(tabs.get(i), i, title);
 		}
+		selectTabAtIndex(0);
+	}
+
+	private void createTab(ViewController tab, final int index, final String title) {
+		bottomNavigationView.getMenu().add(0, index, Menu.NONE, title);
+		RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT);
+		params.addRule(ABOVE, bottomNavigationView.getId());
+		tab.getView().setVisibility(View.GONE);
+		getView().addView(tab.getView(), params);
 	}
 
 	public int getSelectedIndex() {
 	}
 
 	@Override
-	public Iterable<ViewController> getChildControllers() {
+	public Collection<ViewController> getChildControllers() {
 		return tabs;
 	}
 }

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

 
 import android.app.Activity;
 
+import java.util.Collection;
+
 public abstract class ParentController extends ViewController {
 	public ParentController(final Activity activity, final String id) {
 		super(activity, id);
 	}
 
-	public abstract Iterable<ViewController> getChildControllers();
+	public abstract Collection<ViewController> getChildControllers();
 
 	public ViewController findControllerById(final String id) {
 		ViewController fromSuper = super.findControllerById(id);

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

 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
+import java.util.Collection;
+
 public class StackController extends ParentController {
 	private final IndexedStack<ViewController> stack = new IndexedStack<>();
 
 	}
 
 	@Override
-	public Iterable<ViewController> getChildControllers() {
+	public Collection<ViewController> getChildControllers() {
 		return stack.values();
 	}
 }

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

 import android.app.Activity;
 import android.support.annotation.NonNull;
 import android.support.design.widget.BottomNavigationView;
-import android.view.MenuItem;
 import android.view.View;
 import android.widget.RelativeLayout;
 
 import com.reactnativenavigation.BaseTest;
 import com.reactnativenavigation.mocks.SimpleViewController;
 
-import org.assertj.core.api.Condition;
+import org.assertj.core.api.iterable.Extractor;
 import org.junit.Test;
 
 import java.util.Arrays;
 import java.util.List;
 
 import static org.assertj.core.api.Java6Assertions.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 public class BottomTabsControllerTest extends BaseTest {
 
 		List<ViewController> tabs = createTabs();
 		uut.setTabs(tabs);
 		assertThat(uut.getView().getChildCount()).isEqualTo(6);
-		assertThat(uut.getView().getChildAt(1).getVisibility()).isEqualTo(View.VISIBLE);
-		assertThat(uut.getView().getChildAt(2).getVisibility()).isEqualTo(View.GONE);
-		assertThat(uut.getView().getChildAt(3).getVisibility()).isEqualTo(View.GONE);
-		assertThat(uut.getView().getChildAt(4).getVisibility()).isEqualTo(View.GONE);
-		assertThat(uut.getView().getChildAt(5).getVisibility()).isEqualTo(View.GONE);
+		assertThat(uut.getChildControllers()).extracting(new Extractor<ViewController, Integer>() {
+			@Override
+			public Integer extract(final ViewController input) {
+				return input.getView().getVisibility();
+			}
+		}).containsExactly(View.VISIBLE, View.GONE, View.GONE, View.GONE, View.GONE);
 	}
 
 	@Test
-	public void onTabSelected_SelectsTab() throws Exception {
+	public void selectTabAtIndex() throws Exception {
 		uut.setTabs(createTabs());
 		assertThat(uut.getSelectedIndex()).isZero();
 
-		MenuItem menuItem = mock(MenuItem.class);
-		when(menuItem.getItemId()).thenReturn(3);
-		assertThat(uut.onNavigationItemSelected(menuItem)).isTrue();
+		uut.selectTabAtIndex(3);
 
 		assertThat(uut.getSelectedIndex()).isEqualTo(3);
-		assertThat(uut.getChildControllers()).areExactly(1, new Condition<ViewController>() {
+		assertThat(uut.getChildControllers()).extracting(new Extractor<ViewController, Integer>() {
 			@Override
-			public boolean matches(final ViewController value) {
-				return value.getView().getVisibility() == View.VISIBLE;
+			public Integer extract(final ViewController input) {
+				return input.getView().getVisibility();
 			}
-		});
-//		assertThat(uut.getView().getChildAt(1).getVisibility()).isEqualTo(View.GONE);
-//		assertThat(uut.getView().getChildAt(2).getVisibility()).isEqualTo(View.GONE);
-//		assertThat(uut.getView().getChildAt(3).getVisibility()).isEqualTo(View.GONE);
-//		assertThat(uut.getView().getChildAt(4).getVisibility()).isEqualTo(View.VISIBLE);
-//		assertThat(uut.getView().getChildAt(5).getVisibility()).isEqualTo(View.GONE);
+		}).containsExactly(View.GONE, View.GONE, View.GONE, View.VISIBLE, View.GONE);
 	}
 
 	@Test

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

 import org.junit.Test;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 
 import static org.assertj.core.api.Java6Assertions.assertThat;
 	public void findControllerById_ReturnsSelfIfSameId() throws Exception {
 		ParentController uut = new ParentController(activity, "uut") {
 			@Override
-			public Iterable<ViewController> getChildControllers() {
+			public Collection<ViewController> getChildControllers() {
 				return Collections.emptyList();
 			}
 
 
 		ParentController uut = new ParentController(activity, "uut") {
 			@Override
-			public Iterable<ViewController> getChildControllers() {
+			public Collection<ViewController> getChildControllers() {
 				return Arrays.<ViewController>asList(someInnerStack);
 			}