Allow Qt graphics callbacks to work again (bug #56857) * Object.h, Object.cc (Object::do_connections): New virtual method. Do connections that were previously done in qt_graphics_toolkit::create_object * qt_graphics_toolkit.cc (qt_graphics_toolkit::create_object): Let Object::do_connections do the signal/slot connections. * Figure.h, Figure.cc (Figure::do_connection): Overload Object::do_connections to also make connections on peer Canvas object. * Panel.h, Panel.cc (Panel::do_connection): Overload Object::do_connections to also make connections on peer Canvas object.

--- a/libgui/graphics/Figure.cc	Thu Sep 05 17:42:07 2019 -0400
+++ b/libgui/graphics/Figure.cc	Thu Sep 05 10:13:39 2019 +0200
@@ -588,6 +588,13 @@
                                 .arg (pt(1), 0, 'g', 5));
   }
 
+  void
+  Figure::do_connections (const QObject *receiver, const QObject* /* emitter */)
+  {
+    Object::do_connections (receiver);
+    Object::do_connections (receiver, m_container->canvas (m_handle));
+  }
+
   QWidget*
   Figure::menu (void)
   {