show/hide static box when the wxStaticBoxSizer is shown/hidden (replaces patch 897020)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@26817 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/sizer.h

@@ -313,7 +313,7 @@ public:
     bool IsShown( size_t index ) const;
 
     // Recursively call wxWindow::Show () on all sizer items.
-    void ShowItems (bool show);
+    virtual void ShowItems (bool show);
 
 protected:
     wxSize              m_size;
@@ -505,6 +505,9 @@ public:
     wxStaticBox *GetStaticBox() const
         { return m_staticBox; }
 
+    // override to hide/show the static box as well
+    virtual void ShowItems (bool show);
+
 protected:
     wxStaticBox   *m_staticBox;