Activity lifecycle send DidAppear & Disappear

lib/android/app/src/main/java/com/reactnativenavigation/react/NavigationModule.java

@@ -53,6 +53,12 @@ public NavigationModule(ReactApplicationContext reactContext, ReactInstanceManag
         this.jsonParser = jsonParser;
         this.layoutFactory = layoutFactory;
         reactContext.addLifecycleEventListener(new LifecycleEventListenerAdapter() {
+            @Override
+            public void onHostPause() {
+                super.onHostPause();
+                navigator().onHostPause();
+            }
+
             @Override
             public void onHostResume() {
                 eventEmitter = new EventEmitter(reactContext);
@@ -63,6 +69,7 @@ public void onHostResume() {
                         navigator().getChildRegistry(),
                         ((NavigationApplication) activity().getApplication()).getExternalComponents()
                 );
+                navigator().onHostResume();
             }
         });
     }

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

@@ -256,4 +256,11 @@ CoordinatorLayout getModalsLayout() {
     CoordinatorLayout getOverlaysLayout() {
         return overlaysLayout;
     }
+
+    public void onHostPause() {
+        super.onViewDisappear();
+    }
+    public void onHostResume(){
+        super.onViewDidAppear();
+    }
 }

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

@@ -45,7 +45,16 @@ public void setDefaultOptions(Options defaultOptions) {
 
     @Override
     public void onViewDidAppear() {
-        getCurrentChild().onViewDidAppear();
+        super.onViewDidAppear();
+        ViewController currentChild = getCurrentChild();
+        if (currentChild != null) currentChild.onViewDidAppear();
+    }
+
+    @Override
+    public void onViewDisappear() {
+        super.onViewDisappear();
+        ViewController currentChild = getCurrentChild();
+        if (currentChild != null) currentChild.onViewDisappear();
     }
 
     @Override

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

@@ -142,6 +142,22 @@ public void bindViews() {
         verify(modalStack).setModalsLayout(uut.getModalsLayout());
     }
 
+    @Test
+    public void shouldCallOnViewDidAppearWhenHostResumes() {
+        SimpleViewController child1 = spy(this.child1);
+        uut.setRoot(child1, new CommandListenerAdapter(), reactInstanceManager);
+        uut.onHostResume();
+        verify(child1,times(2)).onViewDidAppear();
+    }
+
+    @Test
+    public void shouldCallOnViewDisappearWhenHostPauses() {
+        SimpleViewController child1 = spy(this.child1);
+        uut.setRoot(child1, new CommandListenerAdapter(), reactInstanceManager);
+        uut.onHostPause();
+        verify(child1).onViewDidAppear();
+    }
+
     @Test
     public void setDefaultOptions() {
         uut.setDefaultOptions(new Options());
@@ -160,12 +176,11 @@ public void setRoot_delegatesToRootPresenter() {
         CommandListenerAdapter listener = new CommandListenerAdapter();
         uut.setRoot(child1, listener, reactInstanceManager);
         ArgumentCaptor<CommandListenerAdapter> captor = ArgumentCaptor.forClass(CommandListenerAdapter.class);
-        verify(rootPresenter).setRoot(eq(child1), eq(null),eq(uut.getDefaultOptions()), captor.capture(), eq(reactInstanceManager));
+        verify(rootPresenter).setRoot(eq(child1), eq(null), eq(uut.getDefaultOptions()), captor.capture(), eq(reactInstanceManager));
         assertThat(captor.getValue().getListener()).isEqualTo(listener);
     }
 
 
-
     @Test
     public void setRoot_clearsSplashLayout() {
         FrameLayout content = activity.findViewById(android.R.id.content);

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

@@ -30,6 +30,7 @@
 import static org.assertj.core.api.Java6Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -83,6 +84,31 @@ public Collection<ViewController> getChildControllers() {
         });
     }
 
+    @Test
+    public void onViewDidAppearShouldCallCurrentChildDidAppear(){
+        SimpleViewController child1 = spy(new SimpleViewController(activity, childRegistry, "child1", new Options()));
+        SimpleViewController child2 = spy(new SimpleViewController(activity, childRegistry, "child2", new Options()));
+        children.add(child1);
+        children.add(child2);
+
+        uut.onViewDidAppear();
+
+        verify(child1).onViewDidAppear();
+        verify(child2,never()).onViewDidAppear();
+    }
+
+    @Test
+    public void onViewDisappearShouldCallCurrentChildDisAppear(){
+        SimpleViewController child1 = spy(new SimpleViewController(activity, childRegistry, "child1", new Options()));
+        SimpleViewController child2 = spy(new SimpleViewController(activity, childRegistry, "child2", new Options()));
+        children.add(child1);
+        children.add(child2);
+
+        uut.onViewDisappear();
+
+        verify(child1).onViewDisappear();
+        verify(child2,never()).onViewDisappear();
+    }
     @Test
     public void holdsViewGroup() {
         assertThat(uut.getView()).isInstanceOf(ViewGroup.class);