From 48fdfbab53d728b37a368e0f4585558358e9ae9b Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Thu, 19 May 2022 06:00:39 +0200
Subject: [PATCH] Implement Session support for Mixer Scenes

---
 libs/ardour/ardour/session.h | 11 +++++++
 libs/ardour/session.cc       | 57 ++++++++++++++++++++++++++++++++++++
 libs/ardour/session_state.cc | 43 +++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index c27b135c98..de4ec87871 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -153,6 +153,7 @@ class MidiPort;
 class MidiRegion;
 class MidiSource;
 class MidiTrack;
+class MixerScene;
 class Playlist;
 class PluginInsert;
 class PluginInfo;
@@ -1228,6 +1229,13 @@ public:
 	boost::shared_ptr<PBD::Controllable> solo_cut_control() const;
 	boost::shared_ptr<PBD::Controllable> recently_touched_controllable () const;
 
+	bool apply_nth_mixer_scene (size_t);
+	void store_nth_mixer_scene (size_t);
+	bool nth_mixer_scene_valid (size_t) const;
+
+	boost::shared_ptr<MixerScene>              nth_mixer_scene (size_t, bool create_if_missing = false);
+	std::vector<boost::shared_ptr<MixerScene>> mixer_scenes () const;
+
 	SessionConfiguration config;
 
 	SessionConfiguration* cfg () { return &config; }
@@ -1635,6 +1643,9 @@ private:
 
 	SerializedRCUManager<IOPlugList> _io_plugins;
 
+	std::vector<boost::shared_ptr<MixerScene>> _mixer_scenes;
+	mutable Glib::Threads::RWLock              _mixer_scenes_lock;
+
 	Butler* _butler;
 
 	TransportFSM* _transport_fsm;
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index b0482c8550..9ac9b1f2f0 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -88,6 +88,7 @@
 #include "ardour/midi_patch_manager.h"
 #include "ardour/midi_track.h"
 #include "ardour/midi_ui.h"
+#include "ardour/mixer_scene.h"
 #include "ardour/operations.h"
 #include "ardour/playlist.h"
 #include "ardour/playlist_factory.h"
@@ -7482,3 +7483,59 @@ Session::had_destructive_tracks() const
 	return _had_destructive_tracks;
 }
 
+bool
+Session::nth_mixer_scene_valid (size_t nth) const
+{
+	Glib::Threads::RWLock::ReaderLock lm (_mixer_scenes_lock);
+	if (_mixer_scenes.size () <= nth) {
+		return false;
+	}
+	if (!_mixer_scenes[nth]) {
+		return false;
+	}
+	return !_mixer_scenes[nth]->empty ();
+}
+
+bool
+Session::apply_nth_mixer_scene (size_t nth)
+{
+	Glib::Threads::RWLock::ReaderLock lm (_mixer_scenes_lock);
+	if (_mixer_scenes.size () <= nth) {
+		return false;
+	}
+	if (!_mixer_scenes[nth]) {
+		return false;
+	}
+	return _mixer_scenes[nth]->apply ();
+}
+
+void
+Session::store_nth_mixer_scene (size_t nth)
+{
+	nth_mixer_scene (nth, true)->snapshot ();
+}
+
+boost::shared_ptr<MixerScene>
+Session::nth_mixer_scene (size_t nth, bool create_if_missing)
+{
+	Glib::Threads::RWLock::ReaderLock lm (_mixer_scenes_lock);
+	if (create_if_missing && _mixer_scenes.size () <= nth) {
+		lm.release ();
+		Glib::Threads::RWLock::WriterLock lw (_mixer_scenes_lock);
+		_mixer_scenes.resize (nth + 1);
+		_mixer_scenes[nth] = boost::shared_ptr<MixerScene> (new MixerScene (*this));
+		set_dirty ();
+		return _mixer_scenes[nth];
+	}
+	if (_mixer_scenes.size () <= nth) {
+		return boost::shared_ptr<MixerScene> ();
+	}
+	return _mixer_scenes[nth];
+}
+
+std::vector<boost::shared_ptr<MixerScene>>
+Session::mixer_scenes () const
+{
+	Glib::Threads::RWLock::ReaderLock lm (_mixer_scenes_lock);
+	return _mixer_scenes;
+}
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index c821365541..c016d7c1ec 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -112,6 +112,7 @@
 #include "ardour/midi_scene_changer.h"
 #include "ardour/midi_source.h"
 #include "ardour/midi_track.h"
+#include "ardour/mixer_scene.h"
 #include "ardour/playlist_factory.h"
 #include "ardour/playlist_source.h"
 #include "ardour/port.h"
@@ -1483,6 +1484,34 @@ Session::state (bool save_template, snapshot_t snapshot_type, bool only_used_ass
 		node->add_child_nocopy (*script_node);
 	}
 
+	{
+		Glib::Threads::RWLock::ReaderLock lm (_mixer_scenes_lock);
+		size_t idx = 0;
+		size_t last = 0;
+		for (auto const& i : _mixer_scenes) {
+			++idx;
+			if (i && !i->empty ()) {
+				last = idx;
+			}
+		}
+		if (last > 0) {
+			idx = 0;
+			XMLNode* ms_node = new XMLNode (X_("MixerScenes"));
+			ms_node->set_property ("n_scenes", _mixer_scenes.size ());
+			for (auto const& i : _mixer_scenes) {
+				if (i && !i->empty ()) {
+					XMLNode& ms_state (i->get_state ());
+					ms_state.set_property ("index", idx);
+					ms_node->add_child_nocopy (ms_state);
+				}
+				if (++idx >= last) {
+					break;
+				}
+			}
+			node->add_child_nocopy (*ms_node);
+		}
+	}
+
 	{
 		boost::shared_ptr<IOPlugList> iop (_io_plugins.reader ());
 		XMLNode* iop_node = new XMLNode (X_("IOPlugins"));
@@ -1881,6 +1910,20 @@ Session::set_state (const XMLNode& node, int version)
 		}
 	}
 
+	if ((child = find_named_node (node, "MixerScenes"))) {
+		Glib::Threads::RWLock::WriterLock lm (_mixer_scenes_lock);
+		size_t n_scenes = 0;
+		child->get_property("n_scenes", n_scenes);
+		_mixer_scenes.resize (n_scenes);
+		for (auto const n : child->children () ) {
+			size_t index = 0;
+			if (n->get_property("index", index)) {
+				_mixer_scenes[index] = boost::shared_ptr<MixerScene> (new MixerScene (*this));
+				_mixer_scenes[index]->set_state (*n, version);
+			}
+		}
+	}
+
 	if ((child = find_named_node (node, "IOPlugins"))) {
 		RCUWriter<IOPlugList> writer (_io_plugins);
 		boost::shared_ptr<IOPlugList> iopl = writer.get_copy ();