onAnimationEnd is not getting called, onAnimationStart works fine

Question

I've a ScrollView in the PopupWindow. I'm animating ScrollView contents using TranslateAnimation.

When animation starts, the onAnimationStart listener is called but the onAnimationEnd is not getting called. Any ideas ?

Layout :

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:background="@drawable/popup_window_bg"
   android:layout_width="match_parent"
   android:layout_height="wrap_content">
  <View
     android:layout_width="@dimen/toolbar_padding_left"
     android:layout_height="@dimen/toolbar_height"/>
  <ScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+web/toolbar"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:scrollbars="none"
     android:visibility="invisible">
    <LinearLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="vertical">

       ...

    </LinearLayout>
  </ScrollView>
</LinearLayout>

Animation code :

mToolbar = mPopupContents.findViewById( R.web.toolbar );
TranslateAnimation anim =
    new TranslateAnimation(0, 0, -60, 0);
anim.setDuration(1000);
anim.setAnimationListener(new Animation.AnimationListener() {
        public void onAnimationStart(Animation a) {
            Log.d(LOGTAG, "---- animation start listener called"  );
        }
        public void onAnimationRepeat(Animation a) {}
        public void onAnimationEnd(Animation a) {
            Log.d(LOGTAG, "---- animation end listener called"  );
        }
    });
mToolbar.startAnimation(anim);

Update : I verified that the onAnimationEnd is called but it is called after some delay (provided you don't start the new animation during that time).

Answer 1

AnimationEnd is not reliable. If you don't want to rewrite your code with custom views that override OnAnimationEnd, use postDelayed.

Here's some example code:

final FadeUpAnimation anim = new FadeUpAnimation(v);
anim.setInterpolator(new AccelerateInterpolator());
anim.setDuration(1000);
anim.setFillAfter(true);
new Handler().postDelayed(new Runnable() {
    public void run() {
        v.clearAnimation();
        //Extra work goes here
    }
}, anim.getDuration());
v.startAnimation(anim);

While it MAY seem ugly, I can guarantee it's very reliable. I use it for ListViews that are inserting new rows while removing with animation to other rows. Stress testing a listener with AnimationEnd proved unreliable. Sometimes AnimationEnd was never triggered. You might want to reapply any transformation in the postDelayed function in case the animation didn't fully finish, but that really depends on what type of animation you're using.