Change the height of a layout with ValueAnimator

Animation.java

private RelativeLayout mCalendarView;    
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private void expandLayout() {
    final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    mCalendarView.measure(widthSpec, heightSpec);

    ValueAnimator animator = slideAnimator(0, 750);
    nimator.start();
}

private void collapseLayout() {
    int finalHeight = mCalendarView.getHeight();

    ValueAnimator animator = slideAnimator(finalHeight, 0);
    animator.start();
}

private ValueAnimator slideAnimator(int start, int end) {
    ValueAnimator animator = ValueAnimator.ofInt(start, end);
    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            int value = (Integer) valueAnimator.getAnimatedValue();
            ViewGroup.LayoutParams layoutParams = mCalendarView.getLayoutParams();
            layoutParams.height = value;
            mCalendarView.setLayoutParams(layoutParams);
        }
    });
    return animator;
}