FAB.java

 //开始旋转
    public void turnLeft(View v) {
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(v, "rotation", 0, -155, -135);
        objectAnimator.setDuration(300);
        objectAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
        objectAnimator.start();
        hide.setVisibility(View.VISIBLE);
        AlphaAnimation alphaAnimation = new AlphaAnimation(0, 0.75f);
        alphaAnimation.setDuration(300);
        alphaAnimation.setFillAfter(true);
        hide.startAnimation(alphaAnimation);
        hide.setClickable(true);
        isOpen = true;
    }

    //回到起始位置
    public void turnRight(View v) {
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(v, "rotation", -135, 20, 0);
        objectAnimator.setDuration(300);
        objectAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
        objectAnimator.start();
        hide.setVisibility(View.GONE);
        AlphaAnimation alphaAnimation = new AlphaAnimation(0.75f, 0);
        alphaAnimation.setDuration(300);
        alphaAnimation.setFillAfter(true);
        hide.startAnimation(alphaAnimation);
        hide.setClickable(false);
        isOpen = false;
    }
//注:hide就是TextView控件(蒙版)




public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
    //先慢后快再慢
    private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
    private boolean mIsAnimatingOut = false;

    public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
        super();
    }

    //初始条件
    @Override
    public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
                                       final View directTargetChild, final View target, final int nestedScrollAxes) {
        //垂直滚动
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
    }

    @Override
    public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
                               final View target, final int dxConsumed, final int dyConsumed,
                               final int dxUnconsumed, final int dyUnconsumed) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        if (dyConsumed > 0 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            animateOut(child);
        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            animateIn(child);
        }
    }

    // Same animation that FloatingActionButton.Behavior uses to hide the FAB when the AppBarLayout exits
    private void animateOut(final FloatingActionButton button) {
        if (Build.VERSION.SDK_INT >= 14) {
            //withLayer()使动画中的某些操作变得更顺畅,加速渲染,API 14以后
            ViewCompat.animate(button).translationY(button.getHeight() + getMarginBottom(button)).setInterpolator(INTERPOLATOR).withLayer()
                    .setListener(new ViewPropertyAnimatorListener() {
                        public void onAnimationStart(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
                        }

                        public void onAnimationCancel(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                        }

                        public void onAnimationEnd(View view) {
                            ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                            view.setVisibility(View.GONE);
                        }
                    }).start();
        } else {

        }
    }

    // Same animation that FloatingActionButton.Behavior uses to show the FAB when the AppBarLayout enters
    private void animateIn(FloatingActionButton button) {
        button.setVisibility(View.VISIBLE);
        if (Build.VERSION.SDK_INT >= 14) {
            ViewCompat.animate(button).translationY(0)
                    .setInterpolator(INTERPOLATOR).withLayer().setListener(null)
                    .start();
        } else {

        }
    }

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