// 记录View移出动画是否执行完。
private boolean isOutExecute = false;

private ViewPropertyAnimatorListener outAnimatorListener = new ViewPropertyAnimatorListener() {
 @Override
 public void onAnimationStart(View view) {
 isOutExecute = true;
 }

 @Override
 public void onAnimationEnd(View view) {
 view.setVisibility(View.GONE);
 isOutExecute = false;
 }

 @Override
 public void onAnimationCancel(View view) {
 isOutExecute = false;
 }
};

public static class ListenerAnimatorEndBuild {
 // 记录View移出动画是否执行完。
 private boolean isOutExecute = false;

 private ViewPropertyAnimatorListener outAnimatorListener;

 public ListenerAnimatorEndBuild() {
 outAnimatorListener = new ViewPropertyAnimatorListener() {
 @Override
 public void onAnimationStart(View view) {
 isOutExecute = true;
 }
 @Override
 public void onAnimationEnd(View view) {
 view.setVisibility(View.GONE);
 isOutExecute = false;
 }

 @Override
 public void onAnimationCancel(View view) {
 isOutExecute = false;
 }
 };
 }

 // View移出动画是否执行完。
 public boolean isFinish() {
 return !isOutExecute;
 }

 // 返回ViewPropertyAnimatorListener。
 public ViewPropertyAnimatorListener build() {
 return outAnimatorListener;
 }
}

ListenerAnimatorEndBuild listenerAnimatorEndBuild = new ListenerAnimatorEndBuild();

// 判断是否执行完动画：
listenerAnimatorEndBuild.isFinish();

public class DefineBehavior extends BasicBehavior<View> {

 private ListenerAnimatorEndBuild listenerAnimatorEndBuild;

 public DefineBehavior(Context context, AttributeSet attrs) {
 super(context, attrs);
 listenerAnimatorEndBuild = new ListenerAnimatorEndBuild();
 }

 @Override
 public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {
 return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
 }

 @Override
 public void onNestedScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
// if (dyConsumed > 0 && dyUnconsumed == 0) {
// System.out.println("上滑中。。。");
// }
// if (dyConsumed == 0 && dyUnconsumed > 0) {
// System.out.println("到边界了还在上滑。。。");
// }
// if (dyConsumed < 0 && dyUnconsumed == 0) {
// System.out.println("下滑中。。。");
// }
// if (dyConsumed == 0 && dyUnconsumed < 0) {
// System.out.println("到边界了，还在下滑。。。");
// }

 // 这里可以写你的其他逻辑动画，这里只是举例子写了个缩放动画。
 if ((dyConsumed > 0 || dyUnconsumed > 0) && listenerAnimatorEndBuild.isFinish() && child.getVisibility() == View.VISIBLE) {//往下滑
 scaleHide(child, listenerAnimatorEndBuild.build());
 } else if ((dyConsumed < 0 || dyUnconsumed < 0) && child.getVisibility() != View.VISIBLE) {
 scaleShow(child, null);
 }
 }
}

<ImageView
 android:id="@+id/fab"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="bottom|end"
 android:layout_margin="16dp"
 android:src="@mipmap/ic_launcher"
 app:layout_behavior="@string/define_behavior"
 app:layout_scrollFlags="scroll|enterAlways|snap" />