Android support library FloatingActionButton - padding on pre-lollipop devices?

Question

This is my FAB definition:

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/button_capture_action_show_options"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:layout_margin="16dp"
        android:focusable="true"
        android:src="@drawable/c"

It seems that there's some extra padding when rendered on pre-lollipop devices and I can't seem to be able to remove it.

Lollipop rendering:

Pre-lollipop rendering:

Any suggestions much appreciated..

Answer 1

This is because of the way padding is implemented in the FAB on pre-Lollipop devices.

There's no way I know of to remove it on pre-Lollipop, but you can make it consistent (i.e. increase the padding on Lollipop and up) by setting app:useCompatPadding="true" on the FAB in the layout definition, or by using setUseCompatPadding.

It behaves this way because of the way shadows are drawn.