Android Design Library: Floating Action Button

A floating action button is a round button denoting a primary action on your interface. The Design library’s FloatingActionButton gives you a single consistent implementation, by default colored using the colorAccent from your theme.

In addition to the normal size floating action button, it also supports the mini size (fabSize="mini") when visual continuity with other elements is critical. As FloatingActionButton extends ImageView, you’ll use android:src or any of the methods such as setImageDrawable() to control the icon shown within the FloatingActionButton.