keyboardDismissBehavior property
The ScrollViewKeyboardDismissBehavior defines how this ScrollView will
dismiss the keyboard automatically.
If keyboardDismissBehavior is null then it will fallback to
scrollBehavior. If that is also null, the inherited
ScrollBehavior.getKeyboardDismissBehavior will be used.
Implementation
final ScrollViewKeyboardDismissBehavior? keyboardDismissBehavior;