library/src/main/java/de/mrapp/android/view/FloatingActionButton.java
@SuppressLint("NewApi")
    private void adaptImageButtonBackground() {
        Drawable background = createStateListBackgroundDrawable();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Drawable rippleDrawable = new RippleDrawable(
                    new ColorStateList(new int[][]{{}}, new int[]{getPressedColor()}), background,
                    null);
            ViewUtil.setBackground(imageButton, rippleDrawable);
        } else {
            ViewUtil.setBackground(imageButton, background);
        }
    }
@SuppressLint("NewApi")
    private void adaptImageButtonBackground() {
        Drawable background = createStateListBackgroundDrawable();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Drawable rippleDrawable = new RippleDrawable(
                    new ColorStateList(new int[][]{{}}, new int[]{getPressedColor()}), background,
                    null);
            ViewUtil.setBackground(imageButton, rippleDrawable);
        } else {
            ViewUtil.setBackground(imageButton, background);
        }
    }
Adapts the background of the image button, which is used to show the floating image button's
background and icon, depending on the floating button's colors.