startDocked constant
Start-aligned FloatingActionButton, floating over the Scaffold.bottomNavigationBar so that the center of the floating action button lines up with the top of the bottom navigation bar.
To align a floating action button with CircleAvatars in the ListTile.leading slots of ListTiles in a ListView in the Scaffold.body, use miniStartDocked and set FloatingActionButton.mini to true.
If the value of Scaffold.bottomNavigationBar is a BottomAppBar, the bottom app bar can include a "notch" in its shape that accommodates the overlapping floating action button.
This is unlikely to be a useful location for apps that lack a bottom navigation bar.
Implementation
static const FloatingActionButtonLocation startDocked = _StartDockedFabLocation();