From 1e6694f41af3ba3b25fb19ed802f6806b0b6f0ef Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sat, 25 Feb 2012 20:43:14 +0000
Subject: [PATCH] Use FastScreenUpdate for UI message updating, and only if
 plugin has message output ports.

git-svn-id: svn://localhost/ardour2/branches/3.0@11521 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 gtk2_ardour/lv2_plugin_ui.cc    |  9 +++++----
 gtk2_ardour/lv2_plugin_ui.h     |  2 +-
 libs/ardour/ardour/lv2_plugin.h |  1 +
 libs/ardour/lv2_plugin.cc       | 11 +++++++++++
 4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/gtk2_ardour/lv2_plugin_ui.cc b/gtk2_ardour/lv2_plugin_ui.cc
index 7cf230e4ec..7524b6b5de 100644
--- a/gtk2_ardour/lv2_plugin_ui.cc
+++ b/gtk2_ardour/lv2_plugin_ui.cc
@@ -73,11 +73,10 @@ LV2PluginUI::write_to_ui(void*       controller,
 	                         port_index, buffer_size, format, buffer);
 }
 
-bool
+void
 LV2PluginUI::update_timeout()
 {
 	_lv2->emit_to_ui(this, &LV2PluginUI::write_to_ui);
-	return true;
 }
 
 void
@@ -267,8 +266,10 @@ LV2PluginUI::lv2ui_instantiate(const std::string& title)
 		}
 	}
 
-	Glib::signal_timeout().connect(
-		sigc::mem_fun(*this, &LV2PluginUI::update_timeout), 500);
+	if (_lv2->has_message_output()) {
+		ARDOUR_UI::instance()->RapidScreenUpdate.connect(
+			sigc::mem_fun(*this, &LV2PluginUI::update_timeout));
+	}
 }
 
 void
diff --git a/gtk2_ardour/lv2_plugin_ui.h b/gtk2_ardour/lv2_plugin_ui.h
index 071ad2a1dc..7284f82128 100644
--- a/gtk2_ardour/lv2_plugin_ui.h
+++ b/gtk2_ardour/lv2_plugin_ui.h
@@ -90,7 +90,7 @@ class LV2PluginUI : public PlugUIBase, public Gtk::VBox
 	                        uint32_t    format,
 	                        const void* buffer);
 
-	bool update_timeout();
+	void update_timeout();
 
 	void lv2ui_instantiate(const std::string& title);
 	void lv2ui_free();
diff --git a/libs/ardour/ardour/lv2_plugin.h b/libs/ardour/ardour/lv2_plugin.h
index 65b63269e1..cf764b34d2 100644
--- a/libs/ardour/ardour/lv2_plugin.h
+++ b/libs/ardour/ardour/lv2_plugin.h
@@ -113,6 +113,7 @@ class LV2Plugin : public ARDOUR::Plugin
 	std::string current_preset () const;
 
 	bool has_editor () const;
+	bool has_message_output () const;
 
 	uint32_t atom_eventTransfer() const;
 
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index 2907c2f904..d74d23acc2 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -763,6 +763,17 @@ LV2Plugin::has_editor() const
 	return _impl->ui != NULL;
 }
 
+bool
+LV2Plugin::has_message_output() const
+{
+	for (uint32_t i = 0; i < num_ports(); ++i) {
+		if ((_port_flags[i] & PORT_MESSAGE) && _port_flags[i] & PORT_OUTPUT) {
+			return true;
+		}
+	}
+	return false;
+}
+
 uint32_t
 LV2Plugin::atom_eventTransfer() const
 {