From cbb59ddbce3f53798e83f5a88b3f38fa3a713592 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Wed, 18 Feb 2009 23:54:41 +0000
Subject: [PATCH] Fix 'sticky' sliders when MIDI control feedback is enabled.

git-svn-id: svn://localhost/ardour2/branches/3.0@4628 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 gtk2_ardour/gain_meter.cc                      | 4 ++--
 libs/ardour/ardour/automation_control.h        | 2 ++
 libs/pbd/controllable.cc                       | 1 +
 libs/pbd/pbd/controllable.h                    | 6 +++++-
 libs/surfaces/generic_midi/midicontrollable.cc | 4 ++++
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/gtk2_ardour/gain_meter.cc b/gtk2_ardour/gain_meter.cc
index 429331178c..85562bac0e 100644
--- a/gtk2_ardour/gain_meter.cc
+++ b/gtk2_ardour/gain_meter.cc
@@ -569,14 +569,14 @@ GainMeterBase::meter_point_clicked ()
 gint
 GainMeterBase::start_gain_touch (GdkEventButton* ev)
 {
-	_io->gain_control()->alist()->start_touch ();
+	_io->gain_control()->start_touch ();
 	return FALSE;
 }
 
 gint
 GainMeterBase::end_gain_touch (GdkEventButton* ev)
 {
-	_io->gain_control()->alist()->stop_touch ();
+	_io->gain_control()->stop_touch ();
 	return FALSE;
 }
 
diff --git a/libs/ardour/ardour/automation_control.h b/libs/ardour/ardour/automation_control.h
index d3a220efbc..e4b024a290 100644
--- a/libs/ardour/ardour/automation_control.h
+++ b/libs/ardour/ardour/automation_control.h
@@ -65,10 +65,12 @@ public:
 	}
 	
 	inline void start_touch() {
+		set_touching (true);
 		return ((ARDOUR::AutomationList*)_list.get())->start_touch();
 	}
 	
 	inline void stop_touch() {
+		set_touching (false);
 		return ((ARDOUR::AutomationList*)_list.get())->stop_touch();
 	}
 
diff --git a/libs/pbd/controllable.cc b/libs/pbd/controllable.cc
index c79e0cb3d8..4788965c97 100644
--- a/libs/pbd/controllable.cc
+++ b/libs/pbd/controllable.cc
@@ -36,6 +36,7 @@ Controllable::Controllables Controllable::registry;
 
 Controllable::Controllable (std::string name)
 	: _name (name)
+	, _touching (false)
 {
 	if (registry_lock == 0) {
 		registry_lock = new Glib::Mutex;
diff --git a/libs/pbd/pbd/controllable.h b/libs/pbd/pbd/controllable.h
index 9fa374ebc6..6d37464419 100644
--- a/libs/pbd/pbd/controllable.h
+++ b/libs/pbd/pbd/controllable.h
@@ -54,13 +54,17 @@ class Controllable : public PBD::StatefulDestructible {
 	int set_state (const XMLNode&);
 	XMLNode& get_state ();
 
-	std::string name() const { return _name; }
+	std::string name()      const { return _name; }
+	bool        touching () const { return _touching; }
+	
+	void set_touching (bool yn) { _touching = yn; }
 
 	static Controllable* by_id (const PBD::ID&);
 	static Controllable* by_name (const std::string&);
 
   private:
 	std::string _name;
+	bool        _touching;
 
 	void add ();
 	void remove ();
diff --git a/libs/surfaces/generic_midi/midicontrollable.cc b/libs/surfaces/generic_midi/midicontrollable.cc
index 08f90165bc..204332fc4b 100644
--- a/libs/surfaces/generic_midi/midicontrollable.cc
+++ b/libs/surfaces/generic_midi/midicontrollable.cc
@@ -182,6 +182,10 @@ MIDIControllable::midi_sense_note (Parser &p, EventTwoBytes *msg, bool is_on)
 void
 MIDIControllable::midi_sense_controller (Parser &, EventTwoBytes *msg)
 {
+	if (controllable.touching()) {
+		return; // to prevent feedback fights when e.g. dragging a UI slider
+	}
+
 	if (control_additional == msg->controller_number) {
 		if (!bistate) {
 			controllable.set_value (midi_to_control(msg->value));