More tinkering with State<>. Use some StateDiffCommands instead of

MementoCommand<Region>.  More use of State<> for Region members.


git-svn-id: svn://localhost/ardour2/branches/3.0@6675 d708f5d6-7413-0410-9779-e7cbd77b26cf

22 files changed, 195 insertions, 177 deletions

diff --git a/libs/ardour/ardour/ardour.h b/libs/ardour/ardour/ardour.h
index a7b3bcafd0..403cf21007 100644
--- a/libs/ardour/ardour/ardour.h
+++ b/libs/ardour/ardour/ardour.h
@@ -70,6 +70,7 @@ namespace ARDOUR {
 	extern PBD::Change PositionChanged;
 	extern PBD::Change NameChanged;
 	extern PBD::Change BoundsChanged;
+	extern PBD::Change FlagsChanged;
 
 	static const double SHUTTLE_FRACT_SPEED1=0.48412291827; /* derived from A1,A2 */
 
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index 414a1723f9..9c78285a09 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -314,21 +314,21 @@ class Region
 	virtual void recompute_at_end () = 0;
 
 	DataType                _type;
-	Flag                    _flags;
+	PBD::EnumState<Flag>    _flags;
 	PBD::State<nframes_t>   _start;
-	nframes_t               _length;
+	PBD::State<nframes_t>   _length;
 	nframes_t               _last_length;
 	PBD::State<nframes_t>   _position;
 	nframes_t               _last_position;
 	PositionLockStyle       _positional_lock_style;
-	nframes_t               _sync_position;
+	PBD::State<nframes_t>   _sync_position;
 	PBD::State<layer_t>     _layer;
 	mutable RegionEditState _first_edit;
 	int                     _frozen;
-	nframes64_t             _ancestral_start;
-	nframes64_t             _ancestral_length;
-	float                   _stretch;
-	float                   _shift;
+	PBD::State<nframes64_t> _ancestral_start;
+	PBD::State<nframes64_t> _ancestral_length;
+	PBD::State<float>       _stretch;
+	PBD::State<float>       _shift;
 	BBT_Time                _bbt_time;
 	AnalysisFeatureList     _transients;
 	bool                    _valid_transients;
diff --git a/libs/ardour/ardour/session_object.h b/libs/ardour/ardour/session_object.h
index 47caab5475..cf9ccbb3a7 100644
--- a/libs/ardour/ardour/session_object.h
+++ b/libs/ardour/ardour/session_object.h
@@ -26,6 +26,8 @@
 
 #include "ardour/session_handle.h"
 
+#include "i18n.h"
+
 namespace ARDOUR {
 
 class Session;
@@ -39,11 +41,13 @@ class SessionObject : public SessionHandleRef, public PBD::StatefulDestructible
   public:
 	SessionObject (Session& session, const std::string& name)
 		: SessionHandleRef (session)
-		, _name(name)
-	{}
+		, _name (X_("name"), PBD::Change (0), "")
+	{
+		add_state (_name);
+	}
 	
-	Session&           session() const { return _session; }
-	const std::string& name()    const { return _name; }
+	Session&    session() const { return _session; }
+	std::string name()    const { return _name; }
 
 	virtual bool set_name (const std::string& str) {
 		if (_name != str) {
@@ -56,7 +60,7 @@ class SessionObject : public SessionHandleRef, public PBD::StatefulDestructible
 	PBD::Signal0<void> NameChanged;
 
   protected:
-	std::string _name;
+	PBD::State<std::string> _name;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index db1a343d17..ef209fad3a 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -1433,7 +1433,7 @@ AudioDiskstream::transport_stopped (struct tm& when, time_t twhen, bool abort_ca
 		if (s) {
 			srcs.push_back (s);
 			s->update_header (capture_info.front()->start, when, twhen);
-			s->set_captured_for (_name);
+			s->set_captured_for (_name.get());
 			s->mark_immutable ();
 			if (Config->get_auto_analyse_audio()) {
 				Analyser::queue_source_for_analysis (s, true);
@@ -1970,7 +1970,7 @@ AudioDiskstream::rename_write_sources ()
 
 	for (chan = c->begin(), n = 0; chan != c->end(); ++chan, ++n) {
 		if ((*chan)->write_source != 0) {
-			(*chan)->write_source->set_source_name (_name, destructive());
+			(*chan)->write_source->set_source_name (_name.get(), destructive());
 			/* XXX what to do if one of them fails ? */
 		}
 	}
@@ -2178,7 +2178,7 @@ AudioDiskstream::use_pending_capture_data (XMLNode& node)
 				first_fs = fs;
 			}
 
-			fs->set_captured_for (_name);
+			fs->set_captured_for (_name.get());
 		}
 	}
 
diff --git a/libs/ardour/audio_region_importer.cc b/libs/ardour/audio_region_importer.cc
index c9203435d5..289af0b4d8 100644
--- a/libs/ardour/audio_region_importer.cc
+++ b/libs/ardour/audio_region_importer.cc
@@ -252,7 +252,7 @@ AudioRegionImporter::parse_source_xml ()
 		return false;
 	}
 
-	channels = atoi (prop->value());
+	channels = atoi (prop->value().c_str());
 	for (uint32_t i = 0; i < channels; ++i) {
 		bool source_found = false;
 
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 7485ac6913..c96f7119b8 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -305,12 +305,9 @@ void
 AudioRegion::set_envelope_active (bool yn)
 {
 	if (envelope_active() != yn) {
-		char buf[64];
 		if (yn) {
-			snprintf (buf, sizeof (buf), "envelope active");
 			_flags = Flag (_flags|EnvelopeActive);
 		} else {
-			snprintf (buf, sizeof (buf), "envelope off");
 			_flags = Flag (_flags & ~EnvelopeActive);
 		}
 		send_change (EnvelopeActiveChanged);
diff --git a/libs/ardour/crossfade.cc b/libs/ardour/crossfade.cc
index fd59982f62..a79dae5f07 100644
--- a/libs/ardour/crossfade.cc
+++ b/libs/ardour/crossfade.cc
@@ -314,7 +314,7 @@ Crossfade::read_at (Sample *buf, Sample *mixdown_buffer,
 
 		start = _position;
 		buf += offset;
-		to_write = min (_length, cnt);
+		to_write = min (_length.get(), cnt);
 
 	} else {
 
@@ -679,7 +679,7 @@ Crossfade::get_state ()
 	node->add_property ("active", (_active ? "yes" : "no"));
 	node->add_property ("follow-overlap", (_follow_overlap ? "yes" : "no"));
 	node->add_property ("fixed", (_fixed ? "yes" : "no"));
-	snprintf (buf, sizeof(buf), "%" PRIu32, _length);
+	snprintf (buf, sizeof(buf), "%" PRIu32, _length.get());
 	node->add_property ("length", buf);
 	snprintf (buf, sizeof(buf), "%" PRIu32, (uint32_t) _anchor_point);
 	node->add_property ("anchor-point", buf);
diff --git a/libs/ardour/diskstream.cc b/libs/ardour/diskstream.cc
index a4f8c22e28..264dd3e79f 100644
--- a/libs/ardour/diskstream.cc
+++ b/libs/ardour/diskstream.cc
@@ -396,7 +396,7 @@ Diskstream::playlist_deleted (boost::weak_ptr<Playlist> wpl)
 bool
 Diskstream::set_name (const string& str)
 {
-	if (str != _name) {
+	if (_name != str) {
 		assert(playlist());
 		playlist()->set_name (str);
 
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 7536ee5932..3f3c35f739 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -104,6 +104,7 @@ PBD::Change ARDOUR::LengthChanged = PBD::new_change ();
 PBD::Change ARDOUR::PositionChanged = PBD::new_change ();
 PBD::Change ARDOUR::NameChanged = PBD::new_change ();
 PBD::Change ARDOUR::BoundsChanged = Change (0); // see init(), below
+PBD::Change ARDOUR::FlagsChanged = PBD::new_change ();
 
 compute_peak_t          ARDOUR::compute_peak = 0;
 find_peaks_t            ARDOUR::find_peaks = 0;
diff --git a/libs/ardour/io.cc b/libs/ardour/io.cc
index c9d3f6be08..34f624f2d2 100644
--- a/libs/ardour/io.cc
+++ b/libs/ardour/io.cc
@@ -1086,7 +1086,7 @@ IO::set_name (const string& requested_name)
 {
 	string name = requested_name;
 
-	if (name == _name) {
+	if (_name == name) {
 		return true;
 	}
 
@@ -1098,7 +1098,7 @@ IO::set_name (const string& requested_name)
 
 	for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
 		string current_name = i->name();
-		current_name.replace (current_name.find (_name), _name.length(), name);
+		current_name.replace (current_name.find (_name), _name.get().length(), name);
 		i->set_name (current_name);
 	}
 
@@ -1267,7 +1267,7 @@ IO::build_legal_port_name (DataType type)
 	char buf1[name_size+1];
 	char buf2[name_size+1];
 
-	snprintf (buf1, name_size+1, ("%.*s/%s"), limit, _name.c_str(), suffix.c_str());
+	snprintf (buf1, name_size+1, ("%.*s/%s"), limit, _name.get().c_str(), suffix.c_str());
 
 	int port_number = find_port_hole (buf1);
 	snprintf (buf2, name_size+1, "%s %d", buf1, port_number);
@@ -1342,9 +1342,9 @@ IO::setup_bundle ()
 	_bundle->remove_channels ();
 
 	if (_direction == Input) {
-		snprintf(buf, sizeof (buf), _("%s in"), _name.c_str());
+		snprintf(buf, sizeof (buf), _("%s in"), _name.get().c_str());
 	} else {
-		snprintf(buf, sizeof (buf), _("%s out"), _name.c_str());
+		snprintf(buf, sizeof (buf), _("%s out"), _name.get().c_str());
 	}
         _bundle->set_name (buf);
 	uint32_t const ni = _ports.num_ports();
diff --git a/libs/ardour/io_processor.cc b/libs/ardour/io_processor.cc
index 91247d5082..d1b7e9c232 100644
--- a/libs/ardour/io_processor.cc
+++ b/libs/ardour/io_processor.cc
@@ -170,7 +170,7 @@ IOProcessor::set_state (const XMLNode& node, int version)
 		for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 			const XMLProperty* prop;
 			if ((prop = (*niter)->property ("name")) != 0) {
-				if (prop->value() == _name) {
+				if (_name == prop->value()) {
 					if ((prop = (*niter)->property ("direction")) != 0) {
 						if (prop->value() == instr) {
 							io_node = (*niter);
@@ -200,7 +200,7 @@ IOProcessor::set_state (const XMLNode& node, int version)
 			if ((*niter)->name() == "IO") {
 				const XMLProperty* prop;
 				if ((prop = (*niter)->property ("name")) != 0) {
-					if (prop->value() == _name) {
+					if (_name == prop->value()) {
 						if ((prop = (*niter)->property ("direction")) != 0) {
 							if (prop->value() == outstr) {
 								io_node = (*niter);
diff --git a/libs/ardour/midi_diskstream.cc b/libs/ardour/midi_diskstream.cc
index 18d3bc5ce3..790891a72d 100644
--- a/libs/ardour/midi_diskstream.cc
+++ b/libs/ardour/midi_diskstream.cc
@@ -1388,7 +1388,7 @@ int
 MidiDiskstream::rename_write_sources ()
 {
 	if (_write_source != 0) {
-		_write_source->set_source_name (_name, destructive());
+		_write_source->set_source_name (_name.get(), destructive());
 		/* XXX what to do if this fails ? */
 	}
 	return 0;
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 7bb995337f..fb7a7e082f 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -51,7 +51,7 @@ using namespace PBD;
 MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length)
 	: Region (src, start, length, PBD::basename_nosuffix(src->name()), DataType::MIDI, 0,  Region::Flag(Region::DefaultFlags|Region::External))
 {
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
@@ -59,7 +59,7 @@ MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nfra
 MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
 	: Region (src, start, length, name, DataType::MIDI, layer, flags)
 {
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
@@ -67,7 +67,7 @@ MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nfra
 MidiRegion::MidiRegion (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
 	: Region (srcs, start, length, name, DataType::MIDI, layer, flags)
 {
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
@@ -76,14 +76,14 @@ MidiRegion::MidiRegion (const SourceList& srcs, nframes_t start, nframes_t lengt
 MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
 	: Region (other, offset, length, name, layer, flags)
 {
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
 MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other)
 	: Region (other)
 {
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
@@ -95,7 +95,7 @@ MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, const XMLNode& node)
 	}
 
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	assert(_type == DataType::MIDI);
 }
 
@@ -107,7 +107,7 @@ MidiRegion::MidiRegion (const SourceList& srcs, const XMLNode& node)
 	}
 
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
-	assert(_name.find("/") == string::npos);
+	assert(_name.get().find("/") == string::npos);
 	assert(_type == DataType::MIDI);
 }
 
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index 1e890170c4..ce58d4f585 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -230,7 +230,7 @@ MidiSource::session_saved()
 
 	if (_model && _model->edited()) {
 		string newname;
-		const string basename = PBD::basename_nosuffix(_name);
+		const string basename = PBD::basename_nosuffix(_name.get());
 		string::size_type last_dash = basename.find_last_of("-");
 		if (last_dash == string::npos || last_dash == basename.find_first_of("-")) {
 			newname = basename + "-1";
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 2fe0616973..aab7431cc1 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -19,6 +19,7 @@
 #include "pbd/error.h"
 
 #include "pbd/enumwriter.h"
+#include "pbd/convert.h"
 #include "midi++/events.h"
 #include "evoral/midi_util.h"
 
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 52137f9af2..03d90bcf09 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -60,29 +60,36 @@ void
 Region::register_states ()
 {
 	_xml_node_name = X_("Region");
+	add_state (_flags);
 	add_state (_start);
+	add_state (_length);
 	add_state (_position);
+	add_state (_sync_position);
 	add_state (_layer);
+	add_state (_ancestral_start);
+	add_state (_ancestral_length);
+	add_state (_stretch);
+	add_state (_shift);
 }
 
 /* derived-from-derived constructor (no sources in constructor) */
 Region::Region (Session& s, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(s, name)
 	, _type(type)
-	, _flags(Flag (flags|DoNotSendPropertyChanges))
+	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, start)
-	, _length(length)
+	, _length (X_("length"), LengthChanged, length)
 	, _position (X_("position"), PositionChanged, 0)
-	, _last_position(0)
+	, _last_position (0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position(_start)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
 	, _layer (X_("layer"), LayerChanged, layer)
 	, _first_edit(EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (0)
-	, _ancestral_length (0)
-	, _stretch(1.0)
-	, _shift(1.0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _read_data_count(0)
 	, _pending_changed(Change (0))
 	, _last_layer_op(0)
@@ -97,20 +104,20 @@ Region::Region (Session& s, nframes_t start, nframes_t length, const string& nam
 Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(src->session(), name)
 	, _type(type)
-	, _flags(Flag (flags|DoNotSendPropertyChanges))
+	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, start)
-	, _length(length)
+	, _length (X_("length"), LengthChanged, length)
 	, _position (X_("position"), PositionChanged, 0)
 	, _last_position(0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position(_start)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
 	, _layer (X_("layer"), LayerChanged, layer)
 	, _first_edit(EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (0)
-	, _ancestral_length (0)
-	, _stretch (1.0)
-	, _shift (1.0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _valid_transients(false)
 	, _read_data_count(0)
 	, _pending_changed(Change (0))
@@ -132,20 +139,20 @@ Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length
 Region::Region (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
 	: SessionObject(srcs.front()->session(), name)
 	, _type(type)
-	, _flags(Flag (flags|DoNotSendPropertyChanges))
+	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, start)
-	, _length(length)
+	, _length (X_("length"), LengthChanged, length)
 	, _position (X_("position"), PositionChanged, 0)
 	, _last_position(0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position(_start)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
 	, _layer (X_("layer"), LayerChanged, layer)
 	, _first_edit(EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (0)
-	, _ancestral_length (0)
-	, _stretch(1.0)
-	, _shift(1.0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _read_data_count(0)
 	, _pending_changed(Change (0))
 	, _last_layer_op(0)
@@ -161,9 +168,16 @@ Region::Region (const SourceList& srcs, nframes_t start, nframes_t length, const
 Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
 	: SessionObject(other->session(), name)
 	, _type (other->data_type())
+	, _flags (X_("flags"), FlagsChanged, Flag (flags | DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, 0)
+	, _length (X_("length"), LengthChanged, 0)
 	, _position (X_("position"), PositionChanged, 0)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, 0)
 	, _layer (X_("layer"), LayerChanged, 0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _pending_explicit_relayer (false)
 
 {
@@ -172,8 +186,6 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes
 	_start = other->_start + offset;
 	copy_stuff (other, offset, length, name, layer, flags);
 
-	_flags = Flag (_flags | DoNotSendPropertyChanges);
-
 	/* if the other region had a distinct sync point
 	   set, then continue to use it as best we can.
 	   otherwise, reset sync point back to start.
@@ -206,9 +218,16 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes
 Region::Region (boost::shared_ptr<const Region> other, nframes_t length, const string& name, layer_t layer, Flag flags)
 	: SessionObject(other->session(), name)
 	, _type (other->data_type())
+	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, 0)
+	, _length (X_("length"), LengthChanged, 0)
 	, _position (X_("position"), PositionChanged, 0)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, 0)
 	, _layer (X_("layer"), LayerChanged, 0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _pending_explicit_relayer (false)
 {
 	register_states ();
@@ -266,7 +285,7 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t length, const s
 Region::Region (boost::shared_ptr<const Region> other)
 	: SessionObject(other->session(), other->name())
 	, _type(other->data_type())
-	, _flags(Flag(other->_flags & ~(Locked|PositionLocked)))
+	, _flags (other->_flags)
 	, _start(other->_start)
 	, _length(other->_length)
 	, _position(other->_position)
@@ -288,6 +307,7 @@ Region::Region (boost::shared_ptr<const Region> other)
 {
 	register_states ();
 
+	_flags = Flag (_flags & ~ (Locked | PositionLocked));
 	_flags = Flag (_flags | DoNotSendPropertyChanges);
 
 	other->_first_edit = EditChangesName;
@@ -305,18 +325,20 @@ Region::Region (boost::shared_ptr<const Region> other)
 Region::Region (const SourceList& srcs, const XMLNode& node)
 	: SessionObject(srcs.front()->session(), X_("error: XML did not reset this"))
 	, _type(DataType::NIL) // to be loaded from XML
-	, _flags(DoNotSendPropertyChanges)
+	, _flags (X_("flags"), FlagsChanged, Flag (DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, 0)
-	, _length(0)
+	, _length (X_("length"), LengthChanged, 0)
 	, _position (X_("position"), PositionChanged, 0)
 	, _last_position(0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position(_start)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
 	, _layer (X_("layer"), LayerChanged, 0)
 	, _first_edit(EditChangesNothing)
 	, _frozen(0)
-	, _stretch(1.0)
-	, _shift(1.0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _read_data_count(0)
 	, _pending_changed(Change(0))
 	, _last_layer_op(0)
@@ -337,18 +359,20 @@ Region::Region (const SourceList& srcs, const XMLNode& node)
 Region::Region (boost::shared_ptr<Source> src, const XMLNode& node)
 	: SessionObject(src->session(), X_("error: XML did not reset this"))
 	, _type(DataType::NIL)
-	, _flags(DoNotSendPropertyChanges)
+	, _flags (X_("flags"), FlagsChanged, Flag (DoNotSendPropertyChanges))
 	, _start (X_("start"), StartChanged, 0)
-	, _length(0)
+	, _length (X_("length"), LengthChanged, 0)
 	, _position (X_("position"), PositionChanged, 0)
 	, _last_position(0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position(_start)
+	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
 	, _layer (X_("layer"), LayerChanged, 0)
 	, _first_edit(EditChangesNothing)
 	, _frozen(0)
-	, _stretch(1.0)
-	, _shift(1.0)
+	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
+	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
+	, _stretch (X_("stretch"), Change (0), 1.0)
+	, _shift (X_("shift"), Change (0), 1.0)
 	, _read_data_count(0)
 	, _pending_changed(Change(0))
 	, _last_layer_op(0)
@@ -1096,18 +1120,7 @@ Region::state (bool /*full_state*/)
 
 	_id.print (buf, sizeof (buf));
 	node->add_property ("id", buf);
-	node->add_property ("name", _name);
 	node->add_property ("type", _type.to_string());
-	snprintf (buf, sizeof (buf), "%u", _length);
-	node->add_property ("length", buf);
-	snprintf (buf, sizeof (buf), "%" PRIi64, _ancestral_start);
-	node->add_property ("ancestral-start", buf);
-	snprintf (buf, sizeof (buf), "%" PRIi64, _ancestral_length);
-	node->add_property ("ancestral-length", buf);
-	snprintf (buf, sizeof (buf), "%.12g", _stretch);
-	node->add_property ("stretch", buf);
-	snprintf (buf, sizeof (buf), "%.12g", _shift);
-	node->add_property ("shift", buf);
 
 	switch (_first_edit) {
 	case EditChangesNothing:
@@ -1128,9 +1141,6 @@ Region::state (bool /*full_state*/)
 
 	/* note: flags are stored by derived classes */
 
-	snprintf (buf, sizeof (buf), "%" PRIu32, _sync_position);
-	node->add_property ("sync-position", buf);
-
 	if (_positional_lock_style != AudioTime) {
 		node->add_property ("positional-lock-style", enum_2_string (_positional_lock_style));
 		stringstream str;
@@ -1152,41 +1162,17 @@ Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_chang
 {
 	const XMLNodeList& nlist = node.children();
 	const XMLProperty *prop;
-	nframes_t val;
 
 	/* this is responsible for setting those aspects of Region state
 	   that are mutable after construction.
 	*/
 
-	if ((prop = node.property ("name"))) {
-		_name = prop->value();
-	}
-
 	if ((prop = node.property ("type")) == 0) {
 		_type = DataType::AUDIO;
 	} else {
 		_type = DataType(prop->value());
 	}
 
-	if ((prop = node.property ("length")) != 0) {
-		sscanf (prop->value().c_str(), "%" PRIu32, &val);
-		if (val != _length) {
-			what_changed = Change (what_changed|LengthChanged);
-			cerr << _name << " length changed\n";
-			_last_length = _length;
-			_length = val;
-		}
-	}
-
-	if ((prop = node.property ("sync-position")) != 0) {
-		sscanf (prop->value().c_str(), "%" PRIu32, &val);
-		if (val != _sync_position) {
-			what_changed = Change (what_changed|SyncOffsetChanged);
-			cerr << _name << " sync changed\n";
-			_sync_position = val;
-		}
-	}
-
 	if ((prop = node.property ("positional-lock-style")) != 0) {
 		_positional_lock_style = PositionLockStyle (string_2_enum (prop->value(), _positional_lock_style));
 
@@ -1208,47 +1194,17 @@ Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_chang
 
 	/* XXX FIRST EDIT !!! */
 
-	/* these 3 properties never change as a result of any editing */
-
-	if ((prop = node.property ("ancestral-start")) != 0) {
-		_ancestral_start = strtoll (prop->value().c_str(), 0, 10);
-	} else {
-		_ancestral_start = _start;
-	}
-
-	if ((prop = node.property ("ancestral-length")) != 0) {
-		_ancestral_length = strtoll (prop->value().c_str(), 0, 10);
-	} else {
-		_ancestral_length = _length;
-	}
-
-	if ((prop = node.property ("stretch")) != 0) {
-		_stretch = atof (prop->value());
-
-		/* fix problem with old sessions corrupted by an impossible
-		   value for _stretch
-		*/
-		if (_stretch == 0.0) {
-			_stretch = 1.0;
-		}
-	} else {
+	/* fix problems with old sessions corrupted by impossible
+	   values for _stretch or _shift
+	*/
+	if (_stretch == 0.0) {
 		_stretch = 1.0;
 	}
-
-	if ((prop = node.property ("shift")) != 0) {
-		_shift = atof (prop->value());
-
-		/* fix problem with old sessions corrupted by an impossible
-		   value for _shift
-		*/
-		if (_shift == 0.0) {
-			_shift = 1.0;
-		}
-	} else {
+	
+	if (_shift == 0.0) {
 		_shift = 1.0;
 	}
 
-
 	/* note: derived classes set flags */
 
 	for (XMLNodeConstIterator niter = nlist.begin(); niter != nlist.end(); ++niter) {
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index eb0707044a..02005fc269 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -26,6 +26,7 @@
 #include "pbd/enumwriter.h"
 #include "pbd/memento_command.h"
 #include "pbd/stacktrace.h"
+#include "pbd/convert.h"
 
 #include "evoral/Curve.hpp"
 
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index c7270e6ce9..8034f74033 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -41,6 +41,7 @@
 #include "pbd/basename.h"
 #include "pbd/stacktrace.h"
 #include "pbd/file_utils.h"
+#include "pbd/convert.h"
 
 #include "ardour/amp.h"
 #include "ardour/analyser.h"
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 45e35c91fd..93cf6b3791 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -64,6 +64,7 @@
 #include "pbd/pthread_utils.h"
 #include "pbd/search_path.h"
 #include "pbd/stacktrace.h"
+#include "pbd/convert.h"
 
 #include "ardour/amp.h"
 #include "ardour/audio_diskstream.h"
diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index d9d428a4cb..8f454d31ce 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -306,7 +306,7 @@ SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
 		if (sf_seek (sf, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
 			char errbuf[256];
 			sf_error_str (0, errbuf, sizeof (errbuf) - 1);
-			error << string_compose(_("SndFileSource: could not seek to frame %1 within %2 (%3)"), start, _name.substr (1), errbuf) << endmsg;
+			error << string_compose(_("SndFileSource: could not seek to frame %1 within %2 (%3)"), start, _name.get().substr (1), errbuf) << endmsg;
 			return 0;
 		}
 
@@ -316,7 +316,7 @@ SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
 			if (ret != file_cnt) {
 				char errbuf[256];
 				sf_error_str (0, errbuf, sizeof (errbuf) - 1);
-				cerr << string_compose(_("SndFileSource: @ %1 could not read %2 within %3 (%4) (len = %5)"), start, file_cnt, _name.substr (1), errbuf, _length) << endl;
+				cerr << string_compose(_("SndFileSource: @ %1 could not read %2 within %3 (%4) (len = %5)"), start, file_cnt, _name.get().substr (1), errbuf, _length) << endl;
 			}
 			return ret;
 		}
diff --git a/libs/pbd/i18n.h b/libs/pbd/i18n.h
index af1ac9d162..35516fab53 100644
--- a/libs/pbd/i18n.h
+++ b/libs/pbd/i18n.h
@@ -7,5 +7,6 @@
 #define _(Text) dgettext (PACKAGE, Text)
 #define N_(Text) gettext_noop (Text)
 #define X_(Text) (Text)
+#define I18N(Array) PBD::internationalize (PACKAGE, Array)
 
 #endif // __i18n_h__
diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index 80d7aa796a..5d3c98439c 100644
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -24,6 +24,7 @@
 #include <cassert>
 #include "pbd/id.h"
 #include "pbd/xml++.h"
+#include "pbd/enumwriter.h"
 
 class XMLNode;
 
@@ -51,14 +52,6 @@ public:
 
 	}
 
-	StateBase (StateBase const & s)
-		: _have_old (s._have_old)
-		, _xml_property_name (s._xml_property_name)
-		, _change (s._change)
-	{
-
-	}
-
 	/** Forget about any old value for this state */
 	void clear_history () {
 		_have_old = false;
@@ -74,26 +67,19 @@ protected:
 	Change _change;
 };
 
-/** Class to represent a single piece of state in a Stateful object */
+/** Parent class for classes which represent a single piece of state in a Stateful object */
 template <class T>
-class State : public StateBase
+class StateTemplate : public StateBase
 {
 public:
-	State (std::string const & p, Change c, T const & v)
+	StateTemplate (std::string const & p, Change c, T const & v)
 		: StateBase (p, c)
 		, _current (v)
 	{
 
 	}
 
-	State (State<T> const & s)
-		: StateBase (s)
-	{
-		_current = s._current;
-		_old = s._old;
-	}		
-
-	State<T> & operator= (State<T> const & s) {
+	StateTemplate<T> & operator= (StateTemplate<T> const & s) {
 		/* XXX: isn't there a nicer place to do this? */
 		_have_old = s._have_old;
 		_xml_property_name = s._xml_property_name;
@@ -114,10 +100,18 @@ public:
 		return _current;
 	}
 
-	operator T () const {
+	bool operator== (std::string const & o) const {
+		return o == to_string (_current);
+	}
+
+	bool operator!= (std::string const & o) const {
+		return o != to_string (_current);
+	}
+
+	operator T const & () const {
 		return _current;
 	}
-	
+
 	T const & get () const {
 		return _current;
 	}
@@ -137,9 +131,7 @@ public:
 		XMLProperty const * p = node.property (_xml_property_name.c_str());
 
 		if (p) {
-			std::stringstream s (p->value ());
-			T v;
-			s >> v;
+			T const v = from_string (p->value ());
 
 			if (v == _current) {
 				return Change (0);
@@ -156,21 +148,83 @@ public:
 		node.add_property (_xml_property_name.c_str(), to_string (_current));
 	}
 
-private:
+protected:
 	void set (T const & v) {
 		_old = _current;
 		_have_old = true;
 		_current = v;
 	}
 
+	virtual std::string to_string (T const & v) const = 0;
+	virtual T from_string (std::string const & s) const = 0;
+		
+	T _current;
+	T _old;
+};
+
+template<class T>	
+std::ostream& operator<< (std::ostream& os, StateTemplate<T> const & s)
+{
+	os << s.get();
+	return os;
+}
+
+/** Representation of a single piece of state in a Stateful; for use
+ *  with types that can be written to / read from stringstreams.
+ */
+template <class T>
+class State : public StateTemplate<T>
+{
+public:
+	State (std::string const & p, Change c, T const & v)
+		: StateTemplate<T> (p, c, v)
+	{
+
+	}
+	
+	T & operator= (T const & v) {
+		this->set (v);
+		return this->_current;
+	}
+	
+private:	
 	std::string to_string (T const & v) const {
 		std::stringstream s;
 		s << v;
 		return s.str ();
 	}
-		
-	T _current;
-	T _old;
+
+	T from_string (std::string const & s) const {
+		std::stringstream t (s);
+		T v;
+		t >> v;
+		return v;
+	}
+};
+
+template <class T>
+class EnumState : public StateTemplate<T>
+{
+public:
+	EnumState (std::string const & p, Change c, T const & v)
+		: StateTemplate<T> (p, c, v)
+	{
+
+	}
+	
+	T & operator= (T const & v) {
+		this->set (v);
+		return this->_current;
+	}
+
+private:
+	std::string to_string (T const & v) const {
+		return enum_2_string (v);
+	}
+
+	T from_string (std::string const & v) const {
+		return T (string_2_enum (v, this->_current));
+	}
 };
 
 /** Base class for objects with saveable and undoable state */