Doesn't build on darwin and probably other platforms.
GsWidget.H:26:3: error: 'Atom' does not name a type; did you mean 'tm'?
Atom atoms[5];
^~~~
tm
GsWidget.cxx: In member function 'void GsWidget::setProps()':
GsWidget.cxx:47:2: error: 'atoms' was not declared in this scope
atoms[0] = XInternAtom(fl_display,"GHOSTVIEW" , false);
^~~~~
/cc ZHF #45961
cd78d0cc3f