+ wxListCtrl* _content;
+ wxButton* _content_add;
+ wxButton* _content_remove;
+ wxButton* _content_properties;
+ wxButton* _content_earlier;
+ wxButton* _content_later;
+ wxButton* _content_timeline;
+ wxTextCtrl* _content_information;
+ wxCheckBox* _loop_content;
+ wxSpinCtrl* _loop_count;