15 virtual void set_text(const std::string& text) = 0;
16 virtual void set_font(const std::string& fontname) = 0;
17 virtual void fade_in(float fadetime) = 0;
18 virtual void fade_out(float fadetime) = 0;
19 virtual void set_visible(bool visible) = 0;
20 virtual void set_centered(bool centered) = 0;