Add possibility to use generic version to the animation sample

Add menu item to switch to the generic version when using the sample on
a platform where a native version is available (i.e. wxGTK) in order to
allow testing it there easily.

samples/animate/anitest.h

@@ -36,17 +36,20 @@ public:
     void OnSetBgColor(wxCommandEvent& event);
     void OnStop(wxCommandEvent& event);
 
+#ifdef wxHAS_NATIVE_ANIMATIONCTRL
+    void OnUseGeneric(wxCommandEvent& event);
+#endif // wxHAS_NATIVE_ANIMATIONCTRL
+
     void OnUpdateUI(wxUpdateUIEvent& event);
 
 #if wxUSE_FILEDLG
     void OnOpen(wxCommandEvent& event);
 #endif // wxUSE_FILEDLG
 
-    wxAnimationCtrl* GetAnimationCtrl() const { return m_animationCtrl; }
-
-protected:
-    wxAnimationCtrl*    m_animationCtrl;
-
 private:
+    void RecreateAnimation(long style);
+
+    wxAnimationCtrlBase* m_animationCtrl;
+
     wxDECLARE_EVENT_TABLE();
 };