android FloatingActionButton

<android.support.design.widget.FloatingActionButton    android:id="@+id/fab"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_margin="16dp"    android:src="@mipmap/ic_launcher"    app:backgroundTint="#30469b"    app:borderWidth="0dp"    app:elevation="6dp"    app:fabSize="normal"    app:layout_anchor="@+id/btn"    app:layout_anchorGravity="bottom|right"    app:pressedTranslationZ="12dp"    app:rippleColor="#a6a6a6" />