example requires qt

Basic_viewer/examples/Basic_viewer/draw_several_windows.cpp

@@ -6,7 +6,10 @@
 #include <CGAL/draw_point_set_3.h>
 #include <CGAL/Graphics_scene_options.h>
 #include <CGAL/Qt/Basic_viewer.h>
+
+#ifdef CGAL_USE_BASIC_VIEWER
 #include <QMainWindow>
+#endif
 
 #include <vector>
 #include <iostream>
@@ -52,6 +55,7 @@ int main(void)
   CGAL::add_to_graphics_scene(output_mesh, scene2);
 
   /// (2) Qt code that create windows, add them in a layout, and create app.
+#ifdef CGAL_USE_BASIC_VIEWER
 
 #if defined(CGAL_TEST_SUITE)
   bool cgal_test_suite=true;
@@ -81,6 +85,7 @@ int main(void)
 
   mainWindow->show();
   app.exec();
+#endif
 
   return EXIT_SUCCESS;
 }