detach tab after attaching new tab (#2658)

* detach tab after attaching new tab

* Fix tests

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

 import android.graphics.Color;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.NonNull;
-import android.view.View;
 import android.view.ViewGroup;
 import android.widget.RelativeLayout;
 
 public class BottomTabsController extends ParentController implements AHBottomNavigation.OnTabSelectedListener, NavigationOptionsListener {
 	private BottomTabs bottomTabs;
 	private List<ViewController> tabs = new ArrayList<>();
-	private int selectedIndex = 0;
     private ImageLoader imageLoader;
 
     public BottomTabsController(final Activity activity, ImageLoader imageLoader, final String id, Options initialOptions) {
 
 	@Override
 	public boolean handleBack() {
-		return !tabs.isEmpty() && tabs.get(selectedIndex).handleBack();
+		return !tabs.isEmpty() && tabs.get(bottomTabs.getCurrentItem()).handleBack();
 	}
 
     @Override
     public boolean onTabSelected(int index, boolean wasSelected) {
+        if (wasSelected) return false;
         selectTabAtIndex(index);
         return true;
     }
 
-	void selectTabAtIndex(final int newIndex) {
-		tabs.get(selectedIndex).getView().setVisibility(View.GONE);
-		selectedIndex = newIndex;
-		tabs.get(selectedIndex).getView().setVisibility(View.VISIBLE);
-	}
-
 	public void setTabs(final List<ViewController> tabs) {
 		if (tabs.size() > 5) {
 			throw new RuntimeException("Too many tabs!");
 		this.tabs = tabs;
 		getView();
 		for (int i = 0; i < tabs.size(); i++) {
-			createTab(i, tabs.get(i), tabs.get(i).options.bottomTabOptions, tabs.get(i).options.bottomTabsOptions);
+			createTab(i, tabs.get(i).options.bottomTabOptions, tabs.get(i).options.bottomTabsOptions);
 		}
 		selectTabAtIndex(0);
 	}
 
-	private void createTab(int index, ViewController tab, final BottomTabOptions tabOptions, final BottomTabsOptions bottomTabsOptions) {
+	private void createTab(int index, final BottomTabOptions tabOptions, final BottomTabsOptions bottomTabsOptions) {
 	    if (!tabOptions.icon.hasValue()) {
             throw new RuntimeException("BottomTab must have an icon");
         }
 
         RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT);
         params.addRule(ABOVE, bottomTabs.getId());
-        tab.getView().setVisibility(View.GONE);
-        getView().addView(tab.getView(), params);
 	}
 
     private void setIconColor(Drawable drawable, BottomTabsOptions options) {
     }
 
     int getSelectedIndex() {
-		return selectedIndex;
+		return bottomTabs.getCurrentItem();
 	}
 
 	@NonNull
         }
     }
 
-	private boolean hasControlWithId(StackController controller, String id) {
+    void selectTabAtIndex(final int newIndex) {
+        getView().removeView(getCurrentView());
+        bottomTabs.setCurrentItem(newIndex, false);
+        getView().addView(getCurrentView());
+    }
+
+    @NonNull
+    private ViewGroup getCurrentView() {
+        return tabs.get(bottomTabs.getCurrentItem()).getView();
+    }
+
+    private boolean hasControlWithId(StackController controller, String id) {
 		for (ViewController child : controller.getChildControllers()) {
 			if (id.equals(child.getId())) {
 				return true;

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

 
 import android.app.Activity;
 import android.support.annotation.NonNull;
-import android.view.View;
 import android.widget.RelativeLayout;
 
 import com.reactnativenavigation.BaseTest;
 import com.reactnativenavigation.utils.OptionHelper;
 import com.reactnativenavigation.views.BottomTabs;
 
-import org.assertj.core.api.iterable.Extractor;
 import org.junit.Test;
 
 import java.util.Arrays;
     }
 
     @Test
-    public void setTabs_AddAllViewsAsGoneExceptFirst() throws Exception {
+    public void setTabs_AddAllViews() throws Exception {
         List<ViewController> tabs = createTabs();
         uut.setTabs(tabs);
-        assertThat(uut.getView().getChildCount()).isEqualTo(6);
-        assertThat(uut.getChildControllers()).extracting((Extractor<ViewController, Integer>) input -> input.getView().getVisibility()).containsExactly(View.VISIBLE, View.GONE, View.GONE, View.GONE, View.GONE);
+        assertThat(uut.getView().getChildCount()).isEqualTo(2);
+        assertThat(((ViewController) ((List) uut.getChildControllers()).get(0)).getView().getParent()).isNotNull();
     }
 
     @Test
         uut.selectTabAtIndex(3);
 
         assertThat(uut.getSelectedIndex()).isEqualTo(3);
-        assertThat(uut.getChildControllers()).extracting((Extractor<ViewController, Integer>) input -> input.getView().getVisibility()).containsExactly(View.GONE, View.GONE, View.GONE, View.VISIBLE, View.GONE);
+        assertThat(((ViewController) ((List) uut.getChildControllers()).get(0)).getView().getParent()).isNull();
     }
 
     @Test