From 5dd5bf0f706e5912383bf38fcd7635b42fc6ec4a Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 28 Oct 2015 04:06:14 +0100
Subject: [PATCH] notify LV2 GUIs about port-changes when loading presets

---
 gtk2_ardour/lv2_plugin_ui.cc | 15 +++++++++++++++
 gtk2_ardour/lv2_plugin_ui.h  |  1 +
 2 files changed, 16 insertions(+)

diff --git a/gtk2_ardour/lv2_plugin_ui.cc b/gtk2_ardour/lv2_plugin_ui.cc
index 572cdfb671..20f59b5e83 100644
--- a/gtk2_ardour/lv2_plugin_ui.cc
+++ b/gtk2_ardour/lv2_plugin_ui.cc
@@ -159,6 +159,19 @@ LV2PluginUI::stop_updating(GdkEventAny*)
 	return false;
 }
 
+void
+LV2PluginUI::queue_port_update()
+{
+	const uint32_t num_ports = _lv2->num_ports();
+	for (uint32_t i = 0; i < num_ports; ++i) {
+		bool     ok;
+		uint32_t port = _lv2->nth_parameter(i, ok);
+		if (ok) {
+			_updates.insert (port);
+		}
+	}
+}
+
 void
 LV2PluginUI::output_update()
 {
@@ -233,6 +246,8 @@ LV2PluginUI::LV2PluginUI(boost::shared_ptr<PluginInsert> pi,
 	_ardour_buttons_box.pack_end (add_button, false, false);
 	_ardour_buttons_box.pack_end (_preset_combo, false, false);
 	_ardour_buttons_box.pack_end (_preset_modified, false, false);
+
+	plugin->PresetLoaded.connect (*this, invalidator (*this), boost::bind (&LV2PluginUI::queue_port_update, this), gui_context ());
 }
 
 void
diff --git a/gtk2_ardour/lv2_plugin_ui.h b/gtk2_ardour/lv2_plugin_ui.h
index f7f2d99641..da6ffca957 100644
--- a/gtk2_ardour/lv2_plugin_ui.h
+++ b/gtk2_ardour/lv2_plugin_ui.h
@@ -118,6 +118,7 @@ class LV2PluginUI : public PlugUIBase, public Gtk::VBox
 	bool configure_handler (GdkEventConfigure*);
 	void save_plugin_setting ();
 	void output_update();
+	void queue_port_update();
 	bool is_update_wanted(uint32_t index);
 
 	virtual bool on_window_show(const std::string& title);