FloatingActionButton Animator

FABAnimator

package com.companionfree.tracker.bjj.util;

import android.animation.Animator;
import android.animation.ObjectAnimator;
import android.support.v7.widget.RecyclerView;
import android.view.ViewGroup;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;

import com.getbase.floatingactionbutton.FloatingActionButton;


/**
 * Simple Animator for Futuresimple's FloatingActionButton listed here: https://github.com/futuresimple/android-floating-action-button
 */
public class FABAnimator {

    private static final int TRANSLATE_DURATION_MILLIS = 400;

    private boolean fabTransitioning;
    private boolean fabVisible;
    private FloatingActionButton fab;
    private RecyclerView recyclerView;

    public void attachToRecyclerView(final FloatingActionButton fab, RecyclerView recyclerView) {
        this.fab = fab;
        fabVisible = true;
        fabTransitioning = false;
        this.recyclerView = recyclerView;

        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                if (!fabTransitioning) {
                    if (dy > 20) {
                        fabTransitioning = true;
                        hide(true);
                    } else if (dy < -20) {
                        fabTransitioning = true;
                        show(true);
                    }
                }
            }
        });
    }
    public void removeAllListeners() {
        recyclerView.clearOnScrollListeners();
    }

    public void hide(boolean animate) {
        toggle(false, animate, false);
    }
    public void show(boolean animate) {
        toggle(true, animate, false);
    }

    private void toggle(final boolean visible, final boolean animate, boolean force) {
        if (fabVisible != visible || force) {
            fabVisible = visible;
            int height = fab.getHeight();

            int translationY = visible ? 0 : height + getMarginBottom();
            ObjectAnimator fabAnim = ObjectAnimator.ofFloat(fab, "translationY", translationY);
            fabAnim.setDuration(TRANSLATE_DURATION_MILLIS);

            if (animate) {
                fabAnim.setInterpolator(new DecelerateInterpolator());
            } else {
                fabAnim.setInterpolator(new AccelerateInterpolator());
            }

            fabAnim.addListener(new Animator.AnimatorListener() {
                @Override
                public void onAnimationStart(Animator animation) {
                }
                @Override
                public void onAnimationEnd(Animator animation) {
                    fabTransitioning = false;
                }
                @Override
                public void onAnimationCancel(Animator animation) {
                    fabTransitioning = false;
                }
                @Override
                public void onAnimationRepeat(Animator animation) {
                }
            });

            fabAnim.start();

        }
    }
    private int getMarginBottom() {
        int marginBottom = 0;
        final ViewGroup.LayoutParams layoutParams = fab.getLayoutParams();
        if (layoutParams instanceof ViewGroup.MarginLayoutParams) {
            marginBottom = ((ViewGroup.MarginLayoutParams) layoutParams).bottomMargin;
        }
        return marginBottom;
    }

}