Use ObjectAnimator to hide/show BottomNavigation

android/app/src/main/java/com/reactnativenavigation/views/BottomNavigation.java

 package com.reactnativenavigation.views;
 
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ObjectAnimator;
 import android.content.Context;
+import android.support.v4.view.animation.LinearOutSlowInInterpolator;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.view.View;
 
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
  * Created by guyc on 10/07/16.
  */
 public class BottomNavigation extends AHBottomNavigation {
-
+    private static final String TAG = "BottomNavigation";
     public static final int SCROLL_DIRECTION_UP = 0;
     public static final int SCROLL_DIRECTION_DOWN = 1;
 
+    private static final int STATE_HIDDEN = 0;
+    private static final int STATE_ANIMATE_HIDE = 1;
+    private static final int STATE_SHOWN = 2;
+    private static final int STATE_ANIMATE_SHOW = 3;
+    public static final int DURATION = 300;
+
+    private int mState = STATE_SHOWN;
+    private ObjectAnimator mHideAnimator;
+    private ObjectAnimator mShowAnimator;
+
+
     public BottomNavigation(Context context) {
         super(context);
     }
         super(context, attrs, defStyleAttr);
     }
 
-    // TODO: support animated = false -guyca
     public void toggleTabs(boolean hide, boolean animated) {
         if (hide) {
-            hide();
+            hide(animated);
         } else {
-            show();
+            show(animated);
         }
     }
 
-    private void hide() {
-        // mBottomNavigation.hideBottomNavigation(animated);
-        setVisibility(View.GONE);
+    private void hide(boolean animated) {
+        if (animated) {
+            hideAnimated();
+        } else {
+            setVisibility(View.GONE);
+        }
     }
 
-    private void show() {
-        setVisibility(View.VISIBLE);
-        // mBottomNavigation.restoreBottomNavigation(animated);
+    private void hideAnimated() {
+        if (mHideAnimator == null) {
+            mHideAnimator = createHideAnimator();
+        }
+
+        mHideAnimator.start();
+    }
+
+    private ObjectAnimator createHideAnimator() {
+        ObjectAnimator hideAnimator = ObjectAnimator.ofFloat(this, "translationY", getHeight());
+        hideAnimator.setDuration(DURATION);
+        hideAnimator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animation) {
+                mState = STATE_ANIMATE_HIDE;
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mState = STATE_HIDDEN;
+            }
+        });
+        hideAnimator.setInterpolator(new LinearOutSlowInInterpolator());
+        return hideAnimator;
+
     }
 
+    private void show(boolean animated) {
+        if (animated) {
+            showAnimated();
+        } else {
+            setVisibility(View.VISIBLE);
+        }
+    }
+
+    private void showAnimated() {
+        if (mShowAnimator == null) {
+            mShowAnimator = createShowAnimator();
+        }
+
+        mShowAnimator.start();
+    }
+
+    private ObjectAnimator createShowAnimator() {
+        ObjectAnimator showAnimator = ObjectAnimator.ofFloat(this, "translationY", 0);
+        showAnimator.setDuration(DURATION);
+        showAnimator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animation) {
+                mState = STATE_ANIMATE_SHOW;
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mState = STATE_SHOWN;
+            }
+        });
+        showAnimator.setInterpolator(new LinearOutSlowInInterpolator());
+        return showAnimator;
+    }
+
+
     public void onScroll(int direction) {
-        if (direction == SCROLL_DIRECTION_DOWN) {
-            hideBottomNavigation(true);
-        } else if (direction == SCROLL_DIRECTION_UP) {
-            restoreBottomNavigation(true);
+        Log.d(TAG, "onScroll() called with: " + "direction = [" + direction + "]");
+        if (direction == SCROLL_DIRECTION_DOWN && mState == STATE_SHOWN) {
+            hide(true);
+
+        } else if (direction == SCROLL_DIRECTION_UP && mState == STATE_HIDDEN) {
+            show(true);
         }
     }
 }