fabUseShape property

Use shape theming on Floating Action Button (FAB).

When fabUseShape is false, default since FCS version 5.2.0, no custom shape theme is used on FABs, it keeps its un-themed defaults. The fabRadius properties has no effect when fabUseShape is false.

If ThemeData.useMaterial3 is false the FAB is circular. If it is true, the FAB uses M3 shapes as defined by https://m3.material.io/components/floating-action-button/specs

Defaults to false.

The default opinionated style was changed from true to false, in version 5.2.0. This is a style break with previous versions where it was true. The opinionated style change was done to use a style that by default matches M3 style, when ThemeData.useMaterial3 is true.

To make make circular FAB when ThemeData.useMaterial3 is true, set fabUseShape to true and fabRadius to a high values, like 60.