SDLPP: Visitor pattern

sdlpp/sdlpp_renderobject.cpp

@@ -237,4 +237,7 @@ void RenderObject::setAnimationSpeed( const double fps ) {
     animation_fps = fps;
     animation_next_frame = animation_next_frame_base = 1000 / fps;
 }
+void RenderObject::visit( Visitor &visitor ) {
+    visitor.visit( *this );
+}
 } // namespace SDLPP

sdlpp/sdlpp_renderobject.hpp

@@ -6,6 +6,7 @@
 #include "sdlpp_renderer.hpp"
 #include "sdlpp_texture.hpp"
 #include "sdlpp_vector.hpp"
+#include "sdlpp_visitor.hpp"
 
 #include <memory>
 #include <vector>
@@ -101,6 +102,7 @@ public:
     void resumeAnimation();
     void removeAnimation();
     void animate( int ticks );
+    void visit( Visitor &visitor );
 
 protected:
     virtual void copyTo( std::shared_ptr< RenderObject > other );

sdlpp/sdlpp_visitor.hpp

@@ -0,0 +1,18 @@
+#ifndef SDLPP_HPP_VISITOR
+#define SDLPP_HPP_VISITOR
+
+#include "sdlpp_common.hpp"
+
+namespace SDLPP {
+
+class SDLPPSCOPE RenderObject;
+
+class SDLPPSCOPE Visitor {
+public:
+    Visitor() {}
+    virtual void visit( const RenderObject &obj );
+};
+
+} // namespace SDLPP
+
+#endif