From 67f733bb9768e60fe7108613b3f9335675c7d08d Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sat, 1 Sep 2018 21:32:57 +0200
Subject: [PATCH] Restore mixer scroll offset after spill

---
 gtk2_ardour/mixer_ui.cc | 11 +++++++++++
 gtk2_ardour/mixer_ui.h  |  1 +
 2 files changed, 12 insertions(+)

diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index b9b9eccaca..4f029e9b4b 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -106,6 +106,7 @@ Mixer_UI::Mixer_UI ()
 	, _monitor_section (0)
 	, _plugin_selector (0)
 	, _strip_width (UIConfiguration::instance().get_default_narrow_ms() ? Narrow : Wide)
+	, _spill_scroll_position (0)
 	, ignore_reorder (false)
 	, _in_group_rebuild_or_clear (false)
 	, _route_deletion_in_progress (false)
@@ -1450,6 +1451,9 @@ Mixer_UI::redisplay_track_list ()
 	if (ss) {
 		boost::shared_ptr<VCA> sv = boost::dynamic_pointer_cast<VCA> (ss);
 		if (sv) {
+			if (_spill_scroll_position <= 0 && scroller.get_hscrollbar()) {
+				_spill_scroll_position = scroller.get_hscrollbar()->get_adjustment()->get_value();
+			}
 			spill_redisplay (sv);
 			return;
 		}
@@ -1541,6 +1545,13 @@ Mixer_UI::redisplay_track_list ()
 	}
 
 	_group_tabs->set_dirty ();
+
+	if (_spill_scroll_position > 0 && scroller.get_hscrollbar()) {
+		Adjustment* adj = scroller.get_hscrollbar()->get_adjustment();
+		adj->set_value (max (adj->get_lower(), min (adj->get_upper(), _spill_scroll_position)));
+	}
+	_spill_scroll_position = 0;
+
 }
 
 void
diff --git a/gtk2_ardour/mixer_ui.h b/gtk2_ardour/mixer_ui.h
index 2469f74503..1315f74f5d 100644
--- a/gtk2_ardour/mixer_ui.h
+++ b/gtk2_ardour/mixer_ui.h
@@ -348,6 +348,7 @@ private:
 	bool vca_button_release_event (GdkEventButton*, VCAMasterStrip*);
 
 	Width _strip_width;
+	double _spill_scroll_position;
 
 	void presentation_info_changed (PBD::PropertyChange const &);
 	void sync_treeview_from_presentation_info (PBD::PropertyChange const &);