isSelected property

bool isSelected

Whether the owning RenderObject is selected (true) or not (false).

This is different from having accessibility focus. The element that is accessibility focused may or may not be selected; e.g. a ListTile can have accessibility focus but have its ListTile.selected property set to false, in which case it will not be flagged as selected.

Implementation 

bool get isSelected => _hasFlag(SemanticsFlag.isSelected);
void isSelected= (bool value)

Implementation 

set isSelected(bool value) {
  _setFlag(SemanticsFlag.isSelected, value);
}