pop and popTo

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

 	}
 
 	public void push(final String fromId, final ViewController viewController) {
-		StackController parentStackController = findParentStackControllerForChildId(fromId);
-		if (parentStackController != null) {
-			parentStackController.push(viewController);
+		ViewController from = findControllerById(fromId);
+		if (from != null) {
+			StackController parentStackController = from.getParentStackController();
+			if (parentStackController != null) {
+				parentStackController.push(viewController);
+			}
 		}
 	}
 
 	public void pop(final String fromId) {
-		StackController parentStackController = findParentStackControllerForChildId(fromId);
-		if (parentStackController != null) {
-			parentStackController.pop();
+		ViewController from = findControllerById(fromId);
+		if (from != null) {
+			StackController parentStackController = from.getParentStackController();
+			if (parentStackController != null) {
+				parentStackController.pop(from);
+			}
 		}
 	}
 
 	public void popTo(final String fromId, final String toId) {
-		StackController parentStackController = findParentStackControllerForChildId(fromId);
-		if (parentStackController != null) {
-			parentStackController.popTo(findControllerById(toId));
+		ViewController from = findControllerById(fromId);
+		ViewController to = findControllerById(toId);
+		if (from != null && to != null) {
+			StackController parentStackController = from.getParentStackController();
+			if (parentStackController != null) {
+				parentStackController.popTo(to);
+			}
 		}
 	}
 }

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

 import java.util.Collection;
 
 public abstract class ParentController extends ViewController {
+
 	public ParentController(final Activity activity, final String id) {
 		super(activity, id);
 	}
 	@Override
 	protected abstract ViewGroup createView();
 
+	@NonNull
 	public abstract Collection<ViewController> getChildControllers();
 
 	@Nullable
+	@Override
 	public ViewController findControllerById(final String id) {
 		ViewController fromSuper = super.findControllerById(id);
-		if (fromSuper != null) {
-			return fromSuper;
-		}
+		if (fromSuper != null) return fromSuper;
 
 		for (ViewController child : getChildControllers()) {
-			ViewController found = child.findControllerById(id);
-			if (found != null) return found;
+			ViewController fromChild = child.findControllerById(id);
+			if (fromChild != null) return fromChild;
 		}
 
 		return null;
 	}
-
-	@Nullable
-	public StackController findParentStackControllerForChildId(final String childId) {
-		ViewController found = findControllerById(childId);
-		return found != null ? found.getParentStackController() : null;
-	}
 }

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

 		return stack.containsId(id);
 	}
 
+	@NonNull
 	@Override
 	public Collection<ViewController> getChildControllers() {
 		return stack.values();

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

 import com.reactnativenavigation.utils.StringUtils;
 
 public abstract class ViewController {
+
 	private final Activity activity;
 	private final String id;
 	private View view;
 		return id;
 	}
 
-	public ViewController findControllerById(final String id) {
-		return StringUtils.isEqual(this.id, id) ? this : null;
+	public boolean isSameId(final String id) {
+		return StringUtils.isEqual(this.id, id);
+	}
+
+	@Nullable
+	public ViewController findControllerById(String id) {
+		return isSameId(id) ? this : null;
 	}
 }

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

 		bottomTabsController.setTabs(Arrays.<ViewController>asList(stack1, stack2));
 		uut.setRoot(bottomTabsController);
 
-		uut.pop(child2.getId());
+		uut.pop("child4");
 
 		assertThat(stack2.getChildControllers()).containsOnly(child2, child3);
 	}

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

 
 import org.junit.Test;
 
-import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
+import java.util.List;
 
 import static org.assertj.core.api.Java6Assertions.assertThat;
 
 public class ParentControllerTest extends BaseTest {
 
 	private Activity activity;
+	private List<ViewController> children;
+	private ParentController uut;
 
 	@Override
 	public void beforeEach() {
 		super.beforeEach();
 		activity = newActivity();
-	}
-
-	@Test
-	public void holdsViewGroup() throws Exception {
-		ParentController uut = new ParentController(activity, "uut") {
-			@Override
-			public Collection<ViewController> getChildControllers() {
-				return Collections.emptyList();
-			}
+		children = new ArrayList<>();
+		uut = new ParentController(activity, "uut") {
 
 			@NonNull
 			@Override
 			protected ViewGroup createView() {
 				return new FrameLayout(activity);
 			}
-		};
-
-		assertThat(uut.getView()).isInstanceOf(ViewGroup.class);
-	}
-
-	@Test
-	public void findControllerById_ReturnsSelfIfSameId() throws Exception {
-		ParentController uut = new ParentController(activity, "uut") {
-			@Override
-			public Collection<ViewController> getChildControllers() {
-				return Collections.emptyList();
-			}
 
 			@NonNull
 			@Override
-			protected ViewGroup createView() {
-				return new FrameLayout(activity);
+			public Collection<ViewController> getChildControllers() {
+				return children;
 			}
 		};
-
-		assertThat(uut.findControllerById("123")).isNull();
-		assertThat(uut.findControllerById(uut.getId())).isEqualTo(uut);
 	}
 
 	@Test
-	public void findControllerById_DeeplyInOneOfTheChildren() throws Exception {
-		ViewController child1 = new SimpleViewController(activity, "child1");
-		ViewController child2 = new SimpleViewController(activity, "child2");
-
-		final StackController someInnerStack = new StackController(activity, "stack1");
-		someInnerStack.push(child1);
-		someInnerStack.push(child2);
+	public void holdsViewGroup() throws Exception {
+		assertThat(uut.getView()).isInstanceOf(ViewGroup.class);
+	}
 
-		ParentController uut = new ParentController(activity, "uut") {
-			@Override
-			public Collection<ViewController> getChildControllers() {
-				return Arrays.<ViewController>asList(someInnerStack);
-			}
+	@Test
+	public void mustHaveChildControllers() throws Exception {
+		assertThat(uut.getChildControllers()).isNotNull();
+	}
 
-			@NonNull
-			@Override
-			protected ViewGroup createView() {
-				return new FrameLayout(activity);
-			}
-		};
+	@Test
+	public void findControllerById_ChildById() throws Exception {
+		SimpleViewController child1 = new SimpleViewController(activity, "child1");
+		SimpleViewController child2 = new SimpleViewController(activity, "child2");
+		children.add(child1);
+		children.add(child2);
 
-		assertThat(uut.findControllerById("stack1")).isEqualTo(someInnerStack);
+		assertThat(uut.findControllerById("uut")).isEqualTo(uut);
 		assertThat(uut.findControllerById("child1")).isEqualTo(child1);
-		assertThat(uut.findControllerById("child2")).isEqualTo(child2);
 	}
 
 	@Test
-	public void findParentStackControllerForChildId() throws Exception {
-		ViewController child1 = new SimpleViewController(activity, "child1");
-		ViewController child2 = new SimpleViewController(activity, "child2");
-
-		final StackController someInnerStack = new StackController(activity, "stack1");
-		someInnerStack.push(child1);
-		someInnerStack.push(child2);
+	public void findControllerById_Recursive() throws Exception {
+		StackController stackController = new StackController(activity, "stack");
+		SimpleViewController child1 = new SimpleViewController(activity, "child1");
+		SimpleViewController child2 = new SimpleViewController(activity, "child2");
+		stackController.push(child1);
+		stackController.push(child2);
+		children.add(stackController);
 
-		ParentController uut = new ParentController(activity, "uut") {
-			@Override
-			public Collection<ViewController> getChildControllers() {
-				return Arrays.<ViewController>asList(someInnerStack);
-			}
-
-			@NonNull
-			@Override
-			protected ViewGroup createView() {
-				return new FrameLayout(activity);
-			}
-		};
-
-		assertThat(uut.findParentStackControllerForChildId("not existing child")).isNull();
-		assertThat(uut.findParentStackControllerForChildId("child2")).isEqualTo(someInnerStack);
+		assertThat(uut.findControllerById("child2")).isEqualTo(child2);
 	}
 }

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

 	}
 
 	@Test
-	public void findControllerById_ReturnsSelfIfSameId() throws Exception {
-		assertThat(uut.findControllerById("123")).isNull();
-		assertThat(uut.findControllerById(uut.getId())).isEqualTo(uut);
+	public void isSameId() throws Exception {
+		assertThat(uut.isSameId("")).isFalse();
+		assertThat(uut.isSameId(null)).isFalse();
+		assertThat(uut.isSameId("uut")).isTrue();
+	}
+
+	@Test
+	public void findControllerById_SelfOrNull() throws Exception {
+		assertThat(uut.findControllerById("456")).isNull();
+		assertThat(uut.findControllerById("uut")).isEqualTo(uut);
 	}
 }