+ typedef std::map<uint32_t, ParameterDescriptor> PropertyDescriptors;
+
+ /** Get a descrption of all properties supported by this plugin.
+ *
+ * Properties are distinct from parameters in that they are potentially
+ * dynamic, referred to by key, and do not correspond 1:1 with ports.
+ *
+ * For LV2 plugins, properties are implemented by sending/receiving set/get
+ * messages to/from the plugin via event ports.
+ */
+ virtual const PropertyDescriptors& get_supported_properties() const {
+ static const PropertyDescriptors nothing;
+ return nothing;
+ }
+
+ virtual const ParameterDescriptor& get_property_descriptor(uint32_t id) const {
+ static const ParameterDescriptor nothing;
+ return nothing;
+ }
+
+ /** Set a property from the UI.
+ *
+ * This is not UI-specific, but may only be used by one thread. If the
+ * Ardour UI is present, that is the UI thread, but otherwise, any thread
+ * except the audio thread may call this function as long as it is not
+ * called concurrently.
+ */
+ virtual void set_property(uint32_t key, const Variant& value) {}
+
+ /** Emit PropertyChanged for all current property values. */
+ virtual void announce_property_values() {}
+
+ /** Emitted when a property is changed in the plugin. */
+ PBD::Signal2<void, uint32_t, Variant> PropertyChanged;
+
+ PBD::Signal1<void,uint32_t> StartTouch;
+ PBD::Signal1<void,uint32_t> EndTouch;