Minor refactor to Animators

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

 
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
+import android.animation.TimeInterpolator;
 import android.content.Context;
 import android.support.annotation.NonNull;
 import android.view.View;
-import android.view.animation.AccelerateInterpolator;
+import android.view.animation.AccelerateDecelerateInterpolator;
 import android.view.animation.DecelerateInterpolator;
 
 import com.reactnativenavigation.parse.AnimationsOptions;
 import com.reactnativenavigation.utils.UiUtils;
 
+import static android.view.View.ALPHA;
+import static android.view.View.TRANSLATION_Y;
+
 class BaseAnimator {
 
     private static final int DURATION = 300;
-    private static final DecelerateInterpolator DECELERATE_INTERPOLATOR = new DecelerateInterpolator();
-    private static final AccelerateInterpolator ACCELERATE_INTERPOLATOR = new AccelerateInterpolator();
+    private static final TimeInterpolator DECELERATE = new DecelerateInterpolator();
+    private static final TimeInterpolator ACCELERATE_DECELERATE = new AccelerateDecelerateInterpolator();
 
     protected AnimationsOptions options = new AnimationsOptions();
 
 
     @NonNull
     AnimatorSet getDefaultPushAnimation(View view) {
-        ObjectAnimator alpha = ObjectAnimator.ofFloat(view, View.ALPHA, 0, 1);
-        alpha.setInterpolator(DECELERATE_INTERPOLATOR);
-
         AnimatorSet set = new AnimatorSet();
-        ObjectAnimator translationY = ObjectAnimator.ofFloat(view, View.TRANSLATION_Y, this.translationY, 0);
-        set.setInterpolator(DECELERATE_INTERPOLATOR);
+        set.setInterpolator(DECELERATE);
         set.setDuration(DURATION);
+        ObjectAnimator translationY = ObjectAnimator.ofFloat(view, TRANSLATION_Y, this.translationY, 0);
+        ObjectAnimator alpha = ObjectAnimator.ofFloat(view, ALPHA, 0, 1);
         set.playTogether(translationY, alpha);
         return set;
     }
     @NonNull
     AnimatorSet getDefaultPopAnimation(View view) {
         AnimatorSet set = new AnimatorSet();
-
-        ObjectAnimator alpha = ObjectAnimator.ofFloat(view, View.ALPHA, 1, 0);
-        alpha.setInterpolator(ACCELERATE_INTERPOLATOR);
-
-        ObjectAnimator translationY = ObjectAnimator.ofFloat(view, View.TRANSLATION_Y, 0, this.translationY);
-        translationY.setInterpolator(ACCELERATE_INTERPOLATOR);
-        translationY.setDuration(DURATION);
-        alpha.setDuration(DURATION);
+        set.setInterpolator(ACCELERATE_DECELERATE);
+        set.setDuration(DURATION);
+        ObjectAnimator translationY = ObjectAnimator.ofFloat(view, TRANSLATION_Y, 0, this.translationY);
+        ObjectAnimator alpha = ObjectAnimator.ofFloat(view, ALPHA, 1, 0);
         set.playTogether(translationY, alpha);
         return set;
     }

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

 import android.animation.ObjectAnimator;
 import android.animation.TimeInterpolator;
 import android.view.View;
+import android.view.animation.AccelerateDecelerateInterpolator;
 import android.view.animation.DecelerateInterpolator;
 import android.view.animation.LinearInterpolator;
 
 
 import javax.annotation.Nullable;
 
+import static android.view.View.TRANSLATION_Y;
+
 public class TopBarAnimator {
 
     private static final int DEFAULT_COLLAPSE_DURATION = 100;
-    private static final int DURATION_TOPBAR = 300;
-    private final DecelerateInterpolator decelerateInterpolator = new DecelerateInterpolator();
-    private final LinearInterpolator linearInterpolator = new LinearInterpolator();
+    private static final int DURATION = 300;
+    private static final TimeInterpolator DECELERATE = new DecelerateInterpolator();
+    private static final TimeInterpolator LINEAR = new LinearInterpolator();
+    private static final TimeInterpolator ACCELERATE_DECELERATE = new AccelerateDecelerateInterpolator();
 
     private TopBar topBar;
     private String stackId;
         if (options.hasValue() && (!options.id.hasValue() || options.id.get().equals(stackId))) {
             showAnimator = options.getAnimation(topBar);
         } else {
-            showAnimator = getDefaultShowAnimator(-1 * topBar.getMeasuredHeight(), decelerateInterpolator, DURATION_TOPBAR);
+            showAnimator = getDefaultShowAnimator(-1 * topBar.getMeasuredHeight(), DECELERATE, DURATION);
         }
         show();
     }
 
     public void show(float startTranslation) {
-        showAnimator = getDefaultShowAnimator(startTranslation, linearInterpolator, DEFAULT_COLLAPSE_DURATION);
+        showAnimator = getDefaultShowAnimator(startTranslation, LINEAR, DEFAULT_COLLAPSE_DURATION);
         show();
     }
 
     }
 
     private AnimatorSet getDefaultShowAnimator(float startTranslation, TimeInterpolator interpolator, int duration) {
-        ObjectAnimator showAnimator = ObjectAnimator.ofFloat(topBar, View.TRANSLATION_Y, startTranslation, 0);
+        ObjectAnimator showAnimator = ObjectAnimator.ofFloat(topBar, TRANSLATION_Y, startTranslation, 0);
         showAnimator.setInterpolator(interpolator);
         showAnimator.setDuration(duration);
         AnimatorSet set = new AnimatorSet();
         if (options.hasValue() && (!options.id.hasValue() || options.id.get().equals(stackId))) {
             hideAnimator = options.getAnimation(topBar);
         } else {
-            hideAnimator = getDefaultHideAnimator(0, linearInterpolator, DURATION_TOPBAR);
+            hideAnimator = getDefaultHideAnimator(0, ACCELERATE_DECELERATE, DURATION);
         }
         hide(onAnimationEnd);
     }
 
     void hide(float startTranslation) {
-        hideAnimator = getDefaultHideAnimator(startTranslation, linearInterpolator, DEFAULT_COLLAPSE_DURATION);
+        hideAnimator = getDefaultHideAnimator(startTranslation, LINEAR, DEFAULT_COLLAPSE_DURATION);
         hide(() -> {});
     }
 
     }
 
     private Animator getDefaultHideAnimator(float startTranslation, TimeInterpolator interpolator, int duration) {
-        ObjectAnimator hideAnimator = ObjectAnimator.ofFloat(topBar, View.TRANSLATION_Y, startTranslation, -1 * topBar.getMeasuredHeight());
+        ObjectAnimator hideAnimator = ObjectAnimator.ofFloat(topBar, TRANSLATION_Y, startTranslation, -1 * topBar.getMeasuredHeight());
         hideAnimator.setInterpolator(interpolator);
         hideAnimator.setDuration(duration);
         return hideAnimator;