Mario editor: use visitors

mario/edit_box.hpp

@@ -0,0 +1,14 @@
+#include "../sdlpp/sdlpp.hpp"
+#include "objectids.hpp"
+#include "blocks.hpp"
+#include "sprites.hpp"
+
+class EditBox : public SDLPP::RectangleRender {
+public:
+    EditBox(int x, int y, std::shared_ptr<SDLPP::Renderer> renderer);
+    SDLPP::Vec2D<int> getIndexes() const;
+    void visit( SDLPP::Visitor &visitor ) override;
+private:
+    int _x;
+    int _y;
+};