+ double lower() const { return parameter().min(); }
+ double upper() const { return parameter().max(); }
+
+ const ARDOUR::Session& session() const { return _session; }
+
+ /** Convert user values to UI values. See pbd/controllable.h */
+ virtual double user_to_ui (double val) const {
+ return val;
+ }
+
+ /** Convert UI values to user values. See pbd/controllable.h */
+ virtual double ui_to_user (double val) const {
+ return val;
+ }