GestureTapCallback onTap

Called when the user taps on the render object.

Source 

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

Source 

set onTap(GestureTapCallback value) {
  if (_onTap == value)
    return;
  bool wasSemanticBoundary = isSemanticBoundary;
  bool hadHandler = _onTap != null;
  _onTap = value;
  if ((value != null) != hadHandler)
    markNeedsSemanticsUpdate(onlyChanges: isSemanticBoundary == wasSemanticBoundary);
}