refactor MenuBackgrund base class

changed on_show, on_finish and deconstructor to optional implementations
with empty implementations instead of pure virtual functions in base class

1 files changed, 5 insertions, 5 deletions

diff --git a/src/menu/menuBackground.hpp b/src/menu/menuBackground.hpp
index e242080e..9f3e76fa 100644
--- a/src/menu/menuBackground.hpp
+++ b/src/menu/menuBackground.hpp
@@ -36,13 +36,13 @@ namespace usdx
 	class MenuBackground
 	{
 	public:
-		// all members are pure virtual
-		virtual ~MenuBackground() = 0;
+		virtual void draw(void) = 0;
 
-		virtual void on_show(void) = 0;
-		virtual void on_finish(void) = 0;
+		// optional methods
+		virtual ~MenuBackground() {}
 
-		virtual void draw(void) = 0;
+		virtual void on_show(void) {}
+		virtual void on_finish(void) {}
 
 	protected:
 		// no copy and no assignment