From 01c7e14c6e35976afd38bb712e30c5fa1bd35263 Mon Sep 17 00:00:00 2001
From: Ben Loftis <ben@harrisonconsoles.com>
Date: Thu, 10 Nov 2022 09:04:01 -0600
Subject: [PATCH] MixerScenes: highlight momentarily recalled scenes by using
 libardour 'undo'

* also moves 'momentary' into libardour so it can be accessed by other UIs
---
 gtk2_ardour/mixer_ui.cc | 20 ++++++++++----------
 gtk2_ardour/mixer_ui.h  |  2 +-
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index ccab3e5513..5ea33f54a5 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -125,7 +125,6 @@ Mixer_UI::instance ()
 Mixer_UI::Mixer_UI ()
 	: Tabbable (_content, _("Mixer"), X_("mixer"))
 	, plugin_search_clear_button (Stock::CLEAR)
-	, _mixer_scene_release (0)
 	, no_track_list_redisplay (false)
 	, in_group_row_change (false)
 	, track_menu (0)
@@ -447,7 +446,6 @@ Mixer_UI::~Mixer_UI ()
 	delete _plugin_selector;
 	delete track_menu;
 	delete _group_tabs;
-	delete _mixer_scene_release;
 }
 
 struct MixerStripSorter {
@@ -4115,16 +4113,16 @@ Mixer_UI::scene_button_press (GdkEventButton* ev, int idx)
 		return false;
 	}
 
+	_mixer_scene_momentary = false;
+
 	if (Keyboard::is_context_menu_event (ev)) {
 		popup_scene_menu (ev, idx);
 	} else if (Keyboard::is_delete_event (ev)) {
 		clear_mixer_scene (idx, true);
 	} else if (Keyboard::is_momentary_push_event (ev)) {
 		/* momentary */
-		delete _mixer_scene_release; // .. or keep existing?
-		_mixer_scene_release = new MixerScene (*_session);
-		_mixer_scene_release->snapshot (); // TODO; prevent changed signal
-		recall_mixer_scene (idx, false);
+		_mixer_scene_momentary = true;
+		recall_mixer_scene(idx, false);
 		return false;
 	} else if (ev->button == 1) {
 		return false;
@@ -4136,10 +4134,12 @@ Mixer_UI::scene_button_press (GdkEventButton* ev, int idx)
 bool
 Mixer_UI::scene_button_release (GdkEventButton* ev, int idx)
 {
-	if (_mixer_scene_release) {
-		_mixer_scene_release->apply ();
-		delete _mixer_scene_release;
-		_mixer_scene_release = 0;
+	if (!_session) {
+		return false;
+	}
+	if (_mixer_scene_momentary) {
+		_session->apply_mixer_scene_undo();
+		_mixer_scene_momentary = false;
 	} else if (ev->button == 1) {
 		recall_mixer_scene (idx);
 	}
diff --git a/gtk2_ardour/mixer_ui.h b/gtk2_ardour/mixer_ui.h
index b05f2181ad..fed44c4555 100644
--- a/gtk2_ardour/mixer_ui.h
+++ b/gtk2_ardour/mixer_ui.h
@@ -215,7 +215,7 @@ private:
 
 	std::vector<ArdourWidgets::ArdourButton*> _mixer_scene_buttons;
 	std::vector<Gtk::Label*>                  _mixer_scene_labels;
-	ARDOUR::MixerScene*                       _mixer_scene_release;
+	bool                                      _mixer_scene_momentary;
 
 	void popup_scene_menu (GdkEventButton* ev, int);
 	bool scene_button_press (GdkEventButton*, int);