rename Plugin::ParameterChanged to ParameterChangedExternally to reflect its intent, and clean up the libardour side of result.

The signal exists to notify listeners that something outside of the host's control (e.g. a plugin's own GUI for AU or VST)
has modified a plugin parameter. Previous code had strange feedback loops and ambiguous semantics.

2 files changed, 21 insertions, 5 deletions

diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index 2554a6816c..7bef40ab88 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -208,10 +208,17 @@ class LIBARDOUR_API Plugin : public PBD::StatefulDestructible, public Latent
 	/** Emitted when a preset has been loaded */
 	PBD::Signal0<void> PresetLoaded;
 
+	/** Emitted when a parameter is altered in a way that may have
+	 *  changed the settings with respect to any loaded preset.
+	 */
+	PBD::Signal0<void> PresetDirty;
+
 	virtual bool has_editor () const = 0;
 
-	/** Emitted when any parameter changes */
-	PBD::Signal2<void, uint32_t, float> ParameterChanged;
+	/** Emitted when a parameter is altered by something outside of our
+	 * control, most typically a Plugin GUI/editor
+	 */
+	PBD::Signal2<void, uint32_t, float> ParameterChangedExternally;
 
 	virtual bool configure_io (ChanCount /*in*/, ChanCount /*out*/) { return true; }
 
@@ -272,9 +279,18 @@ class LIBARDOUR_API Plugin : public PBD::StatefulDestructible, public Latent
 protected:
 
 	friend class PluginInsert;
+	friend class Session;
 
+	/* Called when a parameter of the plugin is changed outside of this
+	 * host's control (typical via a plugin's own GUI/editor)
+	 */
+	void parameter_changed_externally (uint32_t which, float val);
+
+	/* should be overridden by plugin API specific derived types to
+	 * actually implement changing the parameter. The derived type should
+	 * call this after the change is made.
+	 */
 	virtual void set_parameter (uint32_t which, float val);
-	virtual void set_parameter_automated (uint32_t which, float val);
 
 	/** Do the actual saving of the current plugin settings to a preset of the provided name.
 	 *  Should return a URI on success, or an empty string on failure.
diff --git a/libs/ardour/ardour/plugin_insert.h b/libs/ardour/ardour/plugin_insert.h
index 8788778a3a..d4d9adb54d 100644
--- a/libs/ardour/ardour/plugin_insert.h
+++ b/libs/ardour/ardour/plugin_insert.h
@@ -96,6 +96,7 @@ class LIBARDOUR_API PluginInsert : public Processor
 
 		void set_value (double val);
 		double get_value (void) const;
+		void catch_up_with_external_value (double val);
 		XMLNode& get_state();
 
 	private:
@@ -164,10 +165,9 @@ class LIBARDOUR_API PluginInsert : public Processor
 	/* disallow copy construction */
 	PluginInsert (const PluginInsert&);
 
-	void parameter_changed (uint32_t, float);
+	void parameter_changed_externally (uint32_t, float);
 
 	void  set_parameter (Evoral::Parameter param, float val);
-	float get_parameter (Evoral::Parameter param);
 
 	float default_parameter_value (const Evoral::Parameter& param);