- /* CHANGE_PENDING and CHANGE_CANCELLED may be emitted from any thread; CHANGE_DONE always from GUI thread */
- boost::signals2::signal<void (ChangeType, boost::weak_ptr<Content>, int, bool)> Change;
+ virtual bool can_be_played () const {
+ return true;
+ }
+
+ /* ChangeType::PENDING and ChangeType::CANCELLED may be emitted from any thread; ChangeType::DONE always from GUI thread */
+ boost::signals2::signal<void (ChangeType, std::weak_ptr<Content>, int, bool)> Change;