push pop android animations

lib/android/app/src/main/java/com/reactnativenavigation/anim/StackAnimator.java

@@ -1,33 +1,57 @@
 package com.reactnativenavigation.anim;
 
-import android.animation.Animator;
-import android.animation.AnimatorListenerAdapter;
-import android.animation.AnimatorSet;
-import android.animation.ObjectAnimator;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.support.annotation.Nullable;
 import android.view.View;
-import android.view.animation.DecelerateInterpolator;
+import android.view.animation.Animation;
+import android.view.animation.AnimationUtils;
 
+@SuppressWarnings("ResourceType")
 public class StackAnimator {
-	public void animatePush(final View target, final Runnable onComplete) {
-		target.setAlpha(0);
-		target.setTranslationY(0.08f * ((View) target.getParent()).getHeight());
-
-		ObjectAnimator alpha = ObjectAnimator.ofFloat(target, View.ALPHA, 1);
-		alpha.setInterpolator(new DecelerateInterpolator());
-		alpha.setDuration(200);
-
-		ObjectAnimator translationY = ObjectAnimator.ofFloat(target, View.TRANSLATION_Y, 0);
-		translationY.setInterpolator(new DecelerateInterpolator());
-		translationY.setDuration(350);
-
-		AnimatorSet set = new AnimatorSet();
-		set.playTogether(translationY, alpha);
-		set.addListener(new AnimatorListenerAdapter() {
-			@Override
-			public void onAnimationEnd(final Animator animation) {
-				if (onComplete != null) onComplete.run();
-			}
-		});
-		set.start();
+
+	private static int androidOpenEnterAnimResId;
+	private static int androidOpenExitAnimResId;
+	private static int androidCloseEnterAnimResId;
+	private static int androidCloseExitAnimResId;
+	private final Context context;
+
+	public StackAnimator(Context context) {
+		this.context = context;
+		loadResIfNeeded(context);
+	}
+
+	private void loadResIfNeeded(Context context) {
+		if (androidOpenEnterAnimResId > 0) return;
+
+		int[] attrs = {android.R.attr.activityOpenEnterAnimation, android.R.attr.activityOpenExitAnimation, android.R.attr.activityCloseEnterAnimation, android.R.attr.activityCloseExitAnimation};
+		TypedArray typedArray = context.obtainStyledAttributes(android.R.style.Animation_Activity, attrs);
+		androidOpenEnterAnimResId = typedArray.getResourceId(0, -1);
+		androidOpenExitAnimResId = typedArray.getResourceId(1, -1);
+		androidCloseEnterAnimResId = typedArray.getResourceId(2, -1);
+		androidCloseExitAnimResId = typedArray.getResourceId(3, -1);
+		typedArray.recycle();
+	}
+
+	public void animatePush(final View enteringView, final View exitingView, @Nullable final Runnable onComplete) {
+		Animation enterAnim = AnimationUtils.loadAnimation(context, androidOpenEnterAnimResId);
+		Animation exitAnim = AnimationUtils.loadAnimation(context, androidOpenExitAnimResId);
+
+		new ViewAnimationSetBuilder()
+				.withEndListener(onComplete)
+				.add(enteringView, enterAnim)
+				.add(exitingView, exitAnim)
+				.start();
+	}
+
+	public void animatePop(final View enteringView, final View exitingView, @Nullable final Runnable onComplete) {
+		Animation enterAnim = AnimationUtils.loadAnimation(context, androidCloseEnterAnimResId);
+		Animation exitAnim = AnimationUtils.loadAnimation(context, androidCloseExitAnimResId);
+
+		new ViewAnimationSetBuilder()
+				.withEndListener(onComplete)
+				.add(enteringView, enterAnim)
+				.add(exitingView, exitAnim)
+				.start();
 	}
 }

lib/android/app/src/main/java/com/reactnativenavigation/anim/ViewAnimationSetBuilder.java

@@ -0,0 +1,60 @@
+package com.reactnativenavigation.anim;
+
+import android.view.View;
+import android.view.animation.Animation;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ViewAnimationSetBuilder implements Animation.AnimationListener {
+
+	private Runnable onComplete;
+	private List<View> views = new ArrayList<>();
+	private List<Animation> pendingAnimations = new ArrayList<>();
+	private boolean started = false;
+
+	public ViewAnimationSetBuilder withEndListener(Runnable onComplete) {
+		this.onComplete = onComplete;
+		return this;
+	}
+
+	public ViewAnimationSetBuilder add(View view, Animation animation) {
+		views.add(view);
+		pendingAnimations.add(animation);
+		animation.setAnimationListener(this);
+		view.setAnimation(animation);
+		return this;
+	}
+
+	public void start() {
+		for (Animation animation : pendingAnimations) {
+			animation.start();
+		}
+		started = true;
+		if (pendingAnimations.isEmpty()) finish();
+	}
+
+	@Override
+	public void onAnimationStart(final Animation animation) {
+		// nothing
+	}
+
+	@Override
+	public void onAnimationEnd(final Animation animation) {
+		pendingAnimations.remove(animation);
+		if (started && pendingAnimations.isEmpty()) finish();
+	}
+
+	@Override
+	public void onAnimationRepeat(final Animation animation) {
+		// nothing
+	}
+
+	private void finish() {
+		for (View view : views) {
+			view.clearAnimation();
+		}
+		views.clear();
+		if (onComplete != null) onComplete.run();
+	}
+}

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

@@ -15,7 +15,7 @@ public class StackController extends ParentController {
 	private StackAnimator animator;
 
 	public StackController(final Activity activity, String id) {
-		this(activity, id, new StackAnimator());
+		this(activity, id, new StackAnimator(activity));
 	}
 
 	public StackController(final Activity activity, String id, StackAnimator animator) {
@@ -32,7 +32,7 @@ public class StackController extends ParentController {
 		getView().addView(child.getView());
 
 		if (previousTop != null) {
-			animator.animatePush(child.getView(), new Runnable() {
+			animator.animatePush(child.getView(), previousTop.getView(), new Runnable() {
 				@Override
 				public void run() {
 					getView().removeView(previousTop.getView());
@@ -46,14 +46,19 @@ public class StackController extends ParentController {
 	}
 
 	public void pop() {
-		if (!canPop()) {
-			return;
-		}
-		ViewController poppedController = stack.pop();
-		getView().removeView(poppedController.getView());
+		if (!canPop()) return;
+
+		final ViewController poppedTop = stack.pop();
+		ViewController newTop = peek();
+
+		getView().addView(newTop.getView());
 
-		ViewController previousTop = peek();
-		getView().addView(previousTop.getView());
+		animator.animatePop(newTop.getView(), poppedTop.getView(), new Runnable() {
+			@Override
+			public void run() {
+				getView().removeView(poppedTop.getView());
+			}
+		});
 	}
 
 	public void popSpecific(final ViewController childController) {

lib/android/app/src/test/java/com/reactnativenavigation/anim/ViewAnimationSetBuilderTest.java

@@ -0,0 +1,85 @@
+package com.reactnativenavigation.anim;
+
+import android.view.View;
+import android.view.animation.AlphaAnimation;
+import android.view.animation.Animation;
+
+import com.reactnativenavigation.BaseTest;
+
+import org.junit.Test;
+import org.robolectric.shadow.api.Shadow;
+
+import static org.assertj.core.api.Java6Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+public class ViewAnimationSetBuilderTest extends BaseTest {
+
+	private Runnable mockListener;
+
+	@Override
+	public void beforeEach() {
+		super.beforeEach();
+		mockListener = mock(Runnable.class);
+	}
+
+	@Test
+	public void implementsViewAnimationListener() throws Exception {
+		assertThat(new ViewAnimationSetBuilder()).isInstanceOf(Animation.AnimationListener.class);
+	}
+
+	@Test
+	public void optionalCompletionListener() throws Exception {
+		new ViewAnimationSetBuilder()
+				.withEndListener(mockListener)
+				.add(someView(), someAnimation())
+				.start();
+		verify(mockListener, times(1)).run();
+	}
+
+	@Test
+	public void startsAllAnimations() throws Exception {
+		Animation anim1 = someAnimation();
+		Animation anim2 = someAnimation();
+		new ViewAnimationSetBuilder()
+				.withEndListener(mockListener)
+				.add(someView(), anim1)
+				.add(someView(), anim2)
+				.start();
+		assertThat(anim1.hasStarted()).isTrue();
+		assertThat(anim2.hasStarted()).isTrue();
+	}
+
+	@Test
+	public void callsEndListenerOnlyAfterAllAnimationsFinish() throws Exception {
+		Animation anim1 = someAnimation();
+		Animation anim2 = someAnimation();
+		ViewAnimationSetBuilder uut = new ViewAnimationSetBuilder();
+		uut.withEndListener(mockListener)
+				.add(someView(), anim1)
+				.add(someView(), anim2)
+				.start();
+		verify(mockListener, times(1)).run();
+	}
+
+	@Test
+	public void clearsAnimationFromViewsAfterFinished() throws Exception {
+		View v1 = someView();
+		View v2 = someView();
+		new ViewAnimationSetBuilder()
+				.withEndListener(mockListener)
+				.add(v1, someAnimation())
+				.start();
+		assertThat(v1.getAnimation()).isNull();
+		assertThat(v2.getAnimation()).isNull();
+	}
+
+	private Animation someAnimation() {
+		return Shadow.newInstanceOf(AlphaAnimation.class);
+	}
+
+	private View someView() {
+		return Shadow.newInstanceOf(View.class);
+	}
+}

lib/android/app/src/test/java/com/reactnativenavigation/mocks/TestStackAnimator.java

@@ -1,12 +1,25 @@
 package com.reactnativenavigation.mocks;
 
+import android.support.annotation.Nullable;
 import android.view.View;
 
 import com.reactnativenavigation.anim.StackAnimator;
 
+import org.robolectric.RuntimeEnvironment;
+
 public class TestStackAnimator extends StackAnimator {
+
+	public TestStackAnimator() {
+		super(RuntimeEnvironment.application);
+	}
+
+	@Override
+	public void animatePush(final View enteringView, final View exitingView, final Runnable onComplete) {
+		if (onComplete != null) onComplete.run();
+	}
+
 	@Override
-	public void animatePush(final View target, final Runnable onComplete) {
+	public void animatePop(final View enteringView, final View exitingView, @Nullable final Runnable onComplete) {
 		if (onComplete != null) onComplete.run();
 	}
 }

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

@@ -7,6 +7,7 @@ import android.widget.FrameLayout;
 
 import com.reactnativenavigation.BaseTest;
 import com.reactnativenavigation.mocks.SimpleViewController;
+import com.reactnativenavigation.mocks.TestStackAnimator;
 
 import org.junit.Test;
 
@@ -66,7 +67,7 @@ public class ParentControllerTest extends BaseTest {
 
 	@Test
 	public void findControllerById_Recursive() throws Exception {
-		StackController stackController = new StackController(activity, "stack");
+		StackController stackController = new StackController(activity, "stack", new TestStackAnimator());
 		SimpleViewController child1 = new SimpleViewController(activity, "child1");
 		SimpleViewController child2 = new SimpleViewController(activity, "child2");
 		stackController.push(child1);