maintainFocusability property
final
Whether to allow the widget to receive focus when hidden. Only in effect if visible is false.
To set this to true, maintainState must also be set to true.
By default, with maintainFocusability set to false, focus events cannot reach the child when this widget is not visible because an ExcludeFocus widget is used to exclude the child subtree from the focus tree. If this flag is set to true, then focus events will reach the child subtree.
Implementation
final bool maintainFocusability;