From ad9a3ae1039d326ad70250ebf912347018bfa63b Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sun, 14 Apr 2024 19:37:09 +0200
Subject: [PATCH] Fix region-gain envelope auto-enable when dragging

When using freehand drawing of automation, the line itself
is not notified (no ::start_drag(), ::end_drag() calls).

This adds a end_draw() call which allows the AutomatioLine
to perform additional actions.
---
 gtk2_ardour/automation_line.h   |  1 +
 gtk2_ardour/mergeable_line.cc   |  2 ++
 gtk2_ardour/region_gain_line.cc | 34 +++++++++++++++++++++++++++++++++
 gtk2_ardour/region_gain_line.h  |  3 +++
 4 files changed, 40 insertions(+)

diff --git a/gtk2_ardour/automation_line.h b/gtk2_ardour/automation_line.h
index 8aac3799f2..efa557851b 100644
--- a/gtk2_ardour/automation_line.h
+++ b/gtk2_ardour/automation_line.h
@@ -94,6 +94,7 @@ public:
 	virtual void start_drag_multiple (std::list<ControlPoint*>, float, XMLNode *);
 	virtual std::pair<float, float> drag_motion (Temporal::timecnt_t const &, float, bool, bool with_push, uint32_t& final_index);
 	virtual void end_drag (bool with_push, uint32_t final_index);
+	virtual void end_draw_merge () {}
 
 	ControlPoint* nth (uint32_t);
 	ControlPoint const * nth (uint32_t) const;
diff --git a/gtk2_ardour/mergeable_line.cc b/gtk2_ardour/mergeable_line.cc
index d554b05133..6a39644ac7 100644
--- a/gtk2_ardour/mergeable_line.cc
+++ b/gtk2_ardour/mergeable_line.cc
@@ -103,6 +103,8 @@ MergeableLine::merge_drawn_line (Editor& e, Session& s, Evoral::ControlList::Ord
 	e.begin_reversible_command (_("draw automation"));
 	s.add_command (new MementoCommand<ARDOUR::AutomationList> (*list.get (), &before, &after));
 
+	_line->end_draw_merge ();
+
 	_line->get_selectables (earliest, latest, 0.0, 1.0, results);
 	e.get_selection ().set (results);
 
diff --git a/gtk2_ardour/region_gain_line.cc b/gtk2_ardour/region_gain_line.cc
index cc7bff9b4b..14830e95f9 100644
--- a/gtk2_ardour/region_gain_line.cc
+++ b/gtk2_ardour/region_gain_line.cc
@@ -77,6 +77,28 @@ AudioRegionGainLine::start_drag_single (ControlPoint* cp, double x, float fracti
 	}
 }
 
+void
+AudioRegionGainLine::start_drag_line (uint32_t i1, uint32_t i2, float fraction)
+{
+	AutomationLine::start_drag_line (i1, i2, fraction);
+
+	if (!rv.audio_region()->envelope_active()) {
+		trackview.session()->add_command(new MementoCommand<AudioRegion>(*(rv.audio_region().get()), &rv.audio_region()->get_state(), 0));
+		rv.audio_region()->set_envelope_active(false);
+	}
+}
+
+void
+AudioRegionGainLine::start_drag_multiple (list<ControlPoint*> cp, float fraction, XMLNode* state)
+{
+	AutomationLine::start_drag_multiple (cp, fraction, state);
+
+	if (!rv.audio_region()->envelope_active()) {
+		trackview.session()->add_command(new MementoCommand<AudioRegion>(*(rv.audio_region().get()), &rv.audio_region()->get_state(), 0));
+		rv.audio_region()->set_envelope_active(false);
+	}
+}
+
 // This is an extended copy from AutomationList
 void
 AudioRegionGainLine::remove_point (ControlPoint& cp)
@@ -109,6 +131,18 @@ AudioRegionGainLine::end_drag (bool with_push, uint32_t final_index)
 	AutomationLine::end_drag (with_push, final_index);
 }
 
+void
+AudioRegionGainLine::end_draw_merge ()
+{
+	if (!rv.audio_region()->envelope_active()) {
+		XMLNode& before = rv.audio_region()->get_state();
+		rv.audio_region()->set_envelope_active(true);
+		trackview.session()->add_command(new MementoCommand<AudioRegion>(*(rv.audio_region().get()), &before, &rv.audio_region()->get_state()));
+	}
+
+	AutomationLine::end_draw_merge ();
+}
+
 void
 AudioRegionGainLine::region_changed (const PropertyChange& what_changed)
 {
diff --git a/gtk2_ardour/region_gain_line.h b/gtk2_ardour/region_gain_line.h
index 2959357f61..9a2daccb91 100644
--- a/gtk2_ardour/region_gain_line.h
+++ b/gtk2_ardour/region_gain_line.h
@@ -45,7 +45,10 @@ public:
 	Temporal::timepos_t get_origin() const;
 
 	void start_drag_single (ControlPoint*, double, float);
+	void start_drag_line (uint32_t, uint32_t, float);
+	void start_drag_multiple (std::list<ControlPoint*>, float, XMLNode*);
 	void end_drag (bool with_push, uint32_t final_index);
+	void end_draw_merge ();
 
 	void remove_point (ControlPoint&);
 	AudioRegionView& region_view () { return rv; }