onTap property Null safety

GestureTapCallback? onTap

Called when the user taps on the render object.

Implementation

GestureTapCallback? get onTap => _onTap;
void onTap=(GestureTapCallback? value)

Implementation

set onTap(GestureTapCallback? value) {
  if (_onTap == value)
    return;
  final bool hadHandler = _onTap != null;
  _onTap = value;
  if ((value != null) != hadHandler)
    markNeedsSemanticsUpdate();
}