protected ObjectAnimator animateY(
final View view, final float oldY, final float newY, final float durationUnit) {
final int duration = getDuration(oldY, newY, durationUnit);
final ObjectAnimator anim =
ObjectAnimator.ofFloat(AnimatorProxy.wrap(view), "translationY", oldY - newY, 0);
final int finalDuration = Math.min(Math.max(duration, MIN_ANIM_DURATION), MAX_ANIM_DURATION);
anim.setDuration((long) (finalDuration * animationDurationFactor));
anim.setInterpolator(translateInterpolater);
return anim;
}
/** Animate items that are deleted entirely and items that move out of bounds. */
private void animatePreLayout(
final float durationUnit, final Animator.AnimatorListener listener) {
final AnimatorSet animatorSet = new AnimatorSet();
final int firstVisiblePosition = getFirstVisiblePosition();
final int childCount = getChildCount();
for (final Iterator<Entry<Long, Float>> iter = yMap.entrySet().iterator(); iter.hasNext(); ) {
final Entry<Long, Float> entry = iter.next();
final long id = entry.getKey();
final int oldPos = positionMap.get(id);
final View child = getChildAt(oldPos - firstVisiblePosition);
final int newPos = getPositionForId(id);
// fade out items that disappear
if (newPos == -1) {
final ObjectAnimator anim = animateAlpha(child, false);
animatorSet.play(anim);
iter.remove();
positionMap.remove(id);
continue;
}
// translate items that move out of bounds
if (newPos < firstVisiblePosition || newPos > firstVisiblePosition + childCount) {
final float offset;
if (newPos < firstVisiblePosition) {
offset = -getHeight();
} else {
offset = getHeight();
}
final AnimatorProxy proxy = AnimatorProxy.wrap(child);
final ObjectAnimator anim = ObjectAnimator.ofFloat(proxy, "translationY", 0f, offset);
final int finalDuration = getDuration(0, getHeight() / 2, durationUnit);
anim.setInterpolator(new AccelerateInterpolator());
anim.setDuration((long) (finalDuration * animationDurationFactor));
animatorSet.addListener(
new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(final Animator animation) {
child.post(
new Runnable() {
@Override
public void run() {
proxy.setTranslationY(0f);
}
});
}
});
animatorSet.play(anim);
iter.remove();
positionMap.remove(id);
continue;
}
}
if (!animatorSet.getChildAnimations().isEmpty()) {
animatorSet.addListener(listener);
animatorSet.start();
} else {
listener.onAnimationEnd(animatorSet);
}
}