handleBack

lib/android/app/src/main/java/com/reactnativenavigation/layout/Layout.java

 
 import com.reactnativenavigation.layout.impl.StackLayout;
 
+//TODO delete
 public interface Layout {
 	void setParentStackLayout(StackLayout stackLayout);
 

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

 	}
 
 	public void push(final ViewController child) {
-		childControllers.push(child);
 		child.setNavigationController(this);
+		childControllers.push(child);
 	}
 
 	public void pop() {
 	public boolean isEmpty() {
 		return childControllers.isEmpty();
 	}
+
+	@Override
+	public boolean handleBack() {
+		if (size() > 1) {
+			pop();
+			return true;
+		} else {
+			return false;
+		}
+	}
 }

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

 	void setNavigationController(final NavigationController navigationController) {
 		this.navigationController = navigationController;
 	}
+
+	public boolean handleBack() {
+		return false;
+	}
 }

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

 		NavigationController anotherNavController = new NavigationController(child2);
 		assertThat(child2.getNavigationController()).isEqualTo(anotherNavController);
 	}
+
+	@Test
+	public void handleBack_PopsUnlessSingleChild() throws Exception {
+		assertThat(uut.isEmpty()).isTrue();
+		assertThat(uut.handleBack()).isFalse();
+
+		uut.push(child1);
+		assertThat(uut.size()).isEqualTo(1);
+		assertThat(uut.handleBack()).isFalse();
+
+		uut.push(child2);
+		assertThat(uut.size()).isEqualTo(2);
+		assertThat(uut.handleBack()).isTrue();
+		assertThat(uut.size()).isEqualTo(1);
+	}
 }

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

 		NavigationController nav = new NavigationController(uut);
 		assertThat(uut.getNavigationController()).isEqualTo(nav);
 	}
+
+	@Test
+	public void handleBackDefaultFalse() throws Exception {
+		assertThat(uut.handleBack()).isFalse();
+	}
 }