Fix broken whitespace. I'd apologize for the compile times if it was my fault :D
[ardour.git] / libs / ardour / midi_model.cc
index 5926d403c36ffe0b48cc54e31cac9ca6797fda3c..b6500563ba46604a376bd43548cf42baba6efb5a 100644 (file)
@@ -1,24 +1,23 @@
 /*
-    Copyright (C) 2007 Paul Davis
-    Author: Dave Robillard
+  Copyright (C) 2007 Paul Davis
+  Author: David Robillard
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
 
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
 */
 
-#define __STDC_LIMIT_MACROS 1
 #include <set>
 #include <iostream>
 #include <algorithm>
@@ -26,6 +25,7 @@
 #include <stdint.h>
 #include "pbd/error.h"
 #include "pbd/enumwriter.h"
+#include "pbd/compose.h"
 #include "midi++/events.h"
 
 #include "ardour/midi_model.h"
 #include "ardour/smf_source.h"
 #include "ardour/types.h"
 #include "ardour/session.h"
+#include "ardour/midi_automation_list_binder.h"
+
+#include "i18n.h"
 
 using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-MidiModel::MidiModel(MidiSource* s)
+MidiModel::MidiModel (boost::shared_ptr<MidiSource> s)
        : AutomatableSequence<TimeType>(s->session())
-       , _midi_source(s)
 {
+       set_midi_source (s);
 }
 
-/** Start a new Diff command.
+/** Start a new NoteDiff command.
  *
  * This has no side-effects on the model or Session, the returned command
  * can be held on to for as long as the caller wishes, or discarded without
  * formality, until apply_command is called and ownership is taken.
  */
-MidiModel::DiffCommand*
-MidiModel::new_diff_command(const string name)
+MidiModel::NoteDiffCommand*
+MidiModel::new_note_diff_command (const string name)
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       return new NoteDiffCommand (ms->model(), name);
+}
+
+/** Start a new SysExDiff command */
+MidiModel::SysExDiffCommand*
+MidiModel::new_sysex_diff_command (const string name)
 {
-       DiffCommand* cmd = new DiffCommand(_midi_source->model(), name);
-       return cmd;
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       return new SysExDiffCommand (ms->model(), name);
 }
 
+/** Start a new PatchChangeDiff command */
+MidiModel::PatchChangeDiffCommand*
+MidiModel::new_patch_change_diff_command (const string name)
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       return new PatchChangeDiffCommand (ms->model(), name);
+}
+
+
 /** Apply a command.
  *
  * Ownership of cmd is taken, it must not be deleted by the caller.
@@ -87,1029 +113,1853 @@ MidiModel::apply_command_as_subcommand(Session& session, Command* cmd)
 
 /************** DIFF COMMAND ********************/
 
-#define DIFF_COMMAND_ELEMENT "DiffCommand"
+#define NOTE_DIFF_COMMAND_ELEMENT "NoteDiffCommand"
 #define DIFF_NOTES_ELEMENT "ChangedNotes"
 #define ADDED_NOTES_ELEMENT "AddedNotes"
 #define REMOVED_NOTES_ELEMENT "RemovedNotes"
 #define SIDE_EFFECT_REMOVALS_ELEMENT "SideEffectRemovals"
+#define SYSEX_DIFF_COMMAND_ELEMENT "SysExDiffCommand"
+#define DIFF_SYSEXES_ELEMENT "ChangedSysExes"
+#define PATCH_CHANGE_DIFF_COMMAND_ELEMENT "PatchChangeDiffCommand"
+#define ADDED_PATCH_CHANGES_ELEMENT "AddedPatchChanges"
+#define REMOVED_PATCH_CHANGES_ELEMENT "RemovedPatchChanges"
+#define DIFF_PATCH_CHANGES_ELEMENT "ChangedPatchChanges"
 
 MidiModel::DiffCommand::DiffCommand(boost::shared_ptr<MidiModel> m, const std::string& name)
-       : Command(name)
-       , _model(m)
-       , _name(name)
+       : Command (name)
+       , _model (m)
+       , _name (name)
 {
        assert(_model);
 }
 
-MidiModel::DiffCommand::DiffCommand(boost::shared_ptr<MidiModel> m, const XMLNode& node)
-       : _model(m)
+MidiModel::NoteDiffCommand::NoteDiffCommand (boost::shared_ptr<MidiModel> m, const XMLNode& node)
+       : DiffCommand (m, "")
 {
-       assert(_model);
-       set_state(node, Stateful::loading_state_version);
+       assert (_model);
+       set_state (node, Stateful::loading_state_version);
 }
 
 void
-MidiModel::DiffCommand::add(const NotePtr note)
+MidiModel::NoteDiffCommand::add (const NotePtr note)
 {
        _removed_notes.remove(note);
        _added_notes.push_back(note);
 }
 
 void
-MidiModel::DiffCommand::remove(const NotePtr note)
+MidiModel::NoteDiffCommand::remove (const NotePtr note)
 {
        _added_notes.remove(note);
        _removed_notes.push_back(note);
 }
 
 void
-MidiModel::DiffCommand::side_effect_remove(const NotePtr note)
+MidiModel::NoteDiffCommand::side_effect_remove (const NotePtr note)
 {
        side_effect_removals.insert (note);
 }
 
- void
- MidiModel::DiffCommand::change(const NotePtr note, Property prop,
-                                uint8_t new_value)
- {
-         NoteChange change;
-
-         switch (prop) {
-         case NoteNumber:
-                 if (new_value == note->note()) {
-                         return;
-                 }
-                 change.old_value = note->note();
-                 break;
-         case Velocity:
-                 if (new_value == note->velocity()) {
-                         return;
-                 }
-                 change.old_value = note->velocity();
-                 break;
-         case Channel:
-                 if (new_value == note->channel()) {
-                         return;
-                 }
-                 change.old_value = note->channel();
-                 break;
-
-
-         case StartTime:
-                 fatal << "MidiModel::DiffCommand::change() with integer argument called for start time" << endmsg;
-                 /*NOTREACHED*/
-                 break;
-         case Length:
-                 fatal << "MidiModel::DiffCommand::change() with integer argument called for length" << endmsg;
-                 /*NOTREACHED*/
-                 break;
-         }
-
-         change.note = note;
-         change.property = prop;
-         change.new_value = new_value;
-
-         _changes.push_back (change);
- }
-
- void
- MidiModel::DiffCommand::change(const NotePtr note, Property prop,
-                                TimeType new_time)
- {
-         NoteChange change;
-
-         switch (prop) {
-         case NoteNumber:
-         case Channel:
-         case Velocity:
-                 fatal << "MidiModel::DiffCommand::change() with time argument called for note, channel or velocity" << endmsg;
-                 break;
-
-         case StartTime:
-                 if (Evoral::musical_time_equal (note->time(), new_time)) {
-                         return;
-                 }
-                 change.old_time = note->time();
-                 break;
-         case Length:
-                 if (Evoral::musical_time_equal (note->length(), new_time)) {
-                         return;
-                 }
-                 change.old_time = note->length();
-                 break;
-         }
-
-         change.note = note;
-         change.property = prop;
-         change.new_time = new_time;
-
-         _changes.push_back (change);
- }
-
- MidiModel::DiffCommand&
- MidiModel::DiffCommand::operator+= (const DiffCommand& other)
- {
-         if (this == &other) {
-                 return *this;
-         }
-
-         if (_model != other._model) {
-                 return *this;
-         }
-
-         _added_notes.insert (_added_notes.end(), other._added_notes.begin(), other._added_notes.end());
-         _removed_notes.insert (_removed_notes.end(), other._removed_notes.begin(), other._removed_notes.end());
-         side_effect_removals.insert (other.side_effect_removals.begin(), other.side_effect_removals.end());
-         _changes.insert (_changes.end(), other._changes.begin(), other._changes.end());
-
-         return *this;
- }
-
- void
- MidiModel::DiffCommand::operator()()
- {
-         {
-                 MidiModel::WriteLock lock(_model->edit_lock());
-
-                 for (NoteList::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i) {
-                         if (!_model->add_note_unlocked(*i)) {
-                                 /* failed to add it, so don't leave it in the removed list, to
-                                    avoid apparent errors on undo.
-                                  */
-                                 _removed_notes.remove (*i);
-                         }
-                 }
-
-                 for (NoteList::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i) {
-                         _model->remove_note_unlocked(*i);
-                 }
-
-                 /* notes we modify in a way that requires remove-then-add to maintain ordering */
-                 set<NotePtr> temporary_removals;
-
-                 for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
-                         Property prop = i->property;
-                         switch (prop) {
-                         case NoteNumber:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-                                 }
-                                 i->note->set_note (i->new_value);
-                                 break;
-
-                         case StartTime:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-
-                                 }
-                                 i->note->set_time (i->new_time);
-                                 break;
-
-                         case Channel:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-                                 }
-                                 i->note->set_channel (i->new_value);
-                                 break;
-
-                         /* no remove-then-add required for these properties, since we do not index them
-                          */
-
-                         case Velocity:
-                                 i->note->set_velocity (i->new_value);
-                                 break;
-
-                         case Length:
-                                 i->note->set_length (i->new_time);
-                                 break;
-
-                         }
-                 }
-
-
-                 for (set<NotePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
-                         DiffCommand side_effects (model(), "side effects");
-                         _model->add_note_unlocked (*i, &side_effects);
-                         *this += side_effects;
-                 }
-
-                 if (!side_effect_removals.empty()) {
-                         cerr << "SER: \n";
-                         for (set<NotePtr>::iterator i = side_effect_removals.begin(); i != side_effect_removals.end(); ++i) {
-                                 cerr << "\t" << *i << ' ' << **i << endl;
-                         }
-                 }
-         }
-
-         _model->ContentsChanged(); /* EMIT SIGNAL */
- }
-
- void
- MidiModel::DiffCommand::undo()
- {
-         {
-                 MidiModel::WriteLock lock(_model->edit_lock());
-
-                 for (NoteList::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i) {
-                         _model->remove_note_unlocked(*i);
-                 }
-
-                 for (NoteList::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i) {
-                         _model->add_note_unlocked(*i);
-                 }
-
-                 /* notes we modify in a way that requires remove-then-add to maintain ordering */
-                 set<NotePtr> temporary_removals;
-
-                 for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
-                         Property prop = i->property;
-                         switch (prop) {
-                         case NoteNumber:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-                                 }
-                                 i->note->set_note (i->old_value);
-                                 break;
-                         case Velocity:
-                                 i->note->set_velocity (i->old_value);
-                                 break;
-                         case StartTime:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-                                 }
-                                 i->note->set_time (i->old_time);
-                                 break;
-                         case Length:
-                                 i->note->set_length (i->old_time);
-                                 break;
-                         case Channel:
-                                 if (temporary_removals.find (i->note) == temporary_removals.end()) {
-                                         _model->remove_note_unlocked (i->note);
-                                         temporary_removals.insert (i->note);
-                                 }
-                                 i->note->set_channel (i->old_value);
-                                 break;
-                         }
-                 }
-
-                 for (set<NotePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
-                         _model->add_note_unlocked (*i);
-                 }
-
-                 /* finally add back notes that were removed by the "do". we don't care
-                    about side effects here since the model should be back to its original
-                    state once this is done.
-                  */
-
-                 for (set<NotePtr>::iterator i = side_effect_removals.begin(); i != side_effect_removals.end(); ++i) {
-                         _model->add_note_unlocked (*i);
-                 }
-         }
-
-         _model->ContentsChanged(); /* EMIT SIGNAL */
- }
-
- XMLNode&
- MidiModel::DiffCommand::marshal_note(const NotePtr note)
- {
-         XMLNode* xml_note = new XMLNode("note");
-
-         cerr << "Marshalling note: " << *note << endl;
-
-         ostringstream note_str(ios::ate);
-         note_str << int(note->note());
-         xml_note->add_property("note", note_str.str());
-
-         ostringstream channel_str(ios::ate);
-         channel_str << int(note->channel());
-         xml_note->add_property("channel", channel_str.str());
-
-         ostringstream time_str(ios::ate);
-         time_str << note->time();
-         xml_note->add_property("time", time_str.str());
-
-         ostringstream length_str(ios::ate);
-         length_str << note->length();
-         xml_note->add_property("length", length_str.str());
-
-         ostringstream velocity_str(ios::ate);
-         velocity_str << (unsigned int) note->velocity();
-         xml_note->add_property("velocity", velocity_str.str());
-
-         return *xml_note;
- }
-
- Evoral::Sequence<MidiModel::TimeType>::NotePtr
- MidiModel::DiffCommand::unmarshal_note(XMLNode *xml_note)
- {
-         unsigned int note;
-         XMLProperty* prop;
-         unsigned int channel;
-         unsigned int time;
-         unsigned int length;
-         unsigned int velocity;
-
-         if ((prop = xml_note->property("note")) != 0) {
-                 istringstream note_str(prop->value());
-                 note_str >> note;
-         } else {
-                 warning << "note information missing note value" << endmsg;
-                 note = 127;
-         }
-
-         if ((prop = xml_note->property("channel")) != 0) {
-                 istringstream channel_str(prop->value());
-                 channel_str >> channel;
-         } else {
-                 warning << "note information missing channel" << endmsg;
-                 channel = 0;
-         }
-
-         if ((prop = xml_note->property("time")) != 0) {
-                 istringstream time_str(prop->value());
-                 time_str >> time;
-         } else {
-                 warning << "note information missing time" << endmsg;
-                 time = 0;
-         }
-
-         if ((prop = xml_note->property("length")) != 0) {
-                 istringstream length_str(prop->value());
-                 length_str >> length;
-         } else {
-                 warning << "note information missing length" << endmsg;
-                 length = 1;
-         }
-
-         if ((prop = xml_note->property("velocity")) != 0) {
-                 istringstream velocity_str(prop->value());
-                 velocity_str >> velocity;
-         } else {
-                 warning << "note information missing velocity" << endmsg;
-                 velocity = 127;
-         }
-
-         NotePtr note_ptr(new Evoral::Note<TimeType>(channel, time, length, note, velocity));
-
-         return note_ptr;
- }
-
- XMLNode&
- MidiModel::DiffCommand::marshal_change(const NoteChange& change)
- {
-         XMLNode* xml_change = new XMLNode("change");
-
-         /* first, the change itself */
-
-         xml_change->add_property ("property", enum_2_string (change.property));
-
-         {
-                 ostringstream old_value_str (ios::ate);
-                 if (change.property == StartTime || change.property == Length) {
-                         old_value_str << change.old_time;
-                 } else {
-                         old_value_str << (unsigned int) change.old_value;
-                 }
-                 xml_change->add_property ("old", old_value_str.str());
-         }
-
-         {
-                 ostringstream new_value_str (ios::ate);
-                 if (change.property == StartTime || change.property == Length) {
-                         new_value_str << change.new_time;
-                 } else {
-                         new_value_str << (unsigned int) change.new_value;
-                 }
-                 xml_change->add_property ("new", new_value_str.str());
-         }
-
-         /* now the rest of the note */
-
-         const SMFSource* smf = dynamic_cast<const SMFSource*> (_model->midi_source());
-
-         if (change.property != NoteNumber) {
-                 ostringstream note_str;
-                 note_str << int(change.note->note());
-                 xml_change->add_property("note", note_str.str());
-         }
-
-         if (change.property != Channel) {
-                 ostringstream channel_str;
-                 channel_str << int(change.note->channel());
-                 xml_change->add_property("channel", channel_str.str());
-         }
-
-         if (change.property != StartTime) {
-                 ostringstream time_str;
-                 if (smf) {
-                         time_str << smf->round_to_file_precision (change.note->time());
-                 } else {
-                         time_str << change.note->time();
-                 }
-                 xml_change->add_property("time", time_str.str());
-         }
-
-         if (change.property != Length) {
-                 ostringstream length_str;
-                 if (smf) {
-                         length_str << smf->round_to_file_precision (change.note->length());
-                 } else {
-                         length_str << change.note->length();
-                 }
-                 xml_change->add_property ("length", length_str.str());
-         }
-
-         if (change.property != Velocity) {
-                 ostringstream velocity_str;
-                 velocity_str << int (change.note->velocity());
-                 xml_change->add_property("velocity", velocity_str.str());
-         }
-
-         /* and now notes that were remove as a side-effect */
-
-         return *xml_change;
- }
-
- MidiModel::DiffCommand::NoteChange
- MidiModel::DiffCommand::unmarshal_change(XMLNode *xml_change)
- {
-         XMLProperty* prop;
-         NoteChange change;
-         unsigned int note;
-         unsigned int channel;
-         unsigned int velocity;
-         Evoral::MusicalTime time;
-         Evoral::MusicalTime length;
-
-         if ((prop = xml_change->property("property")) != 0) {
-                 change.property = (Property) string_2_enum (prop->value(), change.property);
-         } else {
-                 fatal << "!!!" << endmsg;
-                 /*NOTREACHED*/
-         }
-
-         if ((prop = xml_change->property ("old")) != 0) {
-                 istringstream old_str (prop->value());
-                 if (change.property == StartTime || change.property == Length) {
-                         old_str >> change.old_time;
-                 } else {
-                         int integer_value_so_that_istream_does_the_right_thing;
-                         old_str >> integer_value_so_that_istream_does_the_right_thing;
-                         change.old_value = integer_value_so_that_istream_does_the_right_thing;
-                 }
-         } else {
-                 fatal << "!!!" << endmsg;
-                 /*NOTREACHED*/
-         }
-
-         if ((prop = xml_change->property ("new")) != 0) {
-                 istringstream new_str (prop->value());
-                 if (change.property == StartTime || change.property == Length) {
-                         new_str >> change.new_time;
-                 } else {
-                         int integer_value_so_that_istream_does_the_right_thing;
-                         new_str >> integer_value_so_that_istream_does_the_right_thing;
-                         change.new_value = integer_value_so_that_istream_does_the_right_thing;
-                 }
-         } else {
-                 fatal << "!!!" << endmsg;
-                 /*NOTREACHED*/
-         }
-
-         if (change.property != NoteNumber) {
-                 if ((prop = xml_change->property("note")) != 0) {
-                         istringstream note_str(prop->value());
-                         note_str >> note;
-                 } else {
-                         warning << "note information missing note value" << endmsg;
-                         note = 127;
-                 }
-         } else {
-                 note = change.new_value;
-         }
-
-         if (change.property != Channel) {
-                 if ((prop = xml_change->property("channel")) != 0) {
-                         istringstream channel_str(prop->value());
-                         channel_str >> channel;
-                 } else {
-                         warning << "note information missing channel" << endmsg;
-                         channel = 0;
-                 }
-         } else {
-                 channel = change.new_value;
-         }
-
-         if (change.property != StartTime) {
-                 if ((prop = xml_change->property("time")) != 0) {
-                         istringstream time_str(prop->value());
-                         time_str >> time;
-                 } else {
-                         warning << "note information missing time" << endmsg;
-                         time = 0;
-                 }
-         } else {
-                 time = change.new_time;
-         }
-
-         if (change.property != Length) {
-                 if ((prop = xml_change->property("length")) != 0) {
-                         istringstream length_str(prop->value());
-                         length_str >> length;
-                 } else {
-                         warning << "note information missing length" << endmsg;
-                         length = 1;
-                 }
-         } else {
-                 length = change.new_time;
-         }
-
-         if (change.property != Velocity) {
-                 if ((prop = xml_change->property("velocity")) != 0) {
-                         istringstream velocity_str(prop->value());
-                         velocity_str >> velocity;
-                 } else {
-                         warning << "note information missing velocity" << endmsg;
-                         velocity = 127;
-                 }
-         } else {
-                 velocity = change.new_value;
-         }
-
-         /* we must point at the instance of the note that is actually in the model.
-            so go look for it ...
-         */
-
-         NotePtr new_note (new Evoral::Note<TimeType> (channel, time, length, note, velocity));
-
-         change.note = _model->find_note (new_note);
-
-         if (!change.note) {
-                 warning << "MIDI note " << *new_note << " not found in model - programmers should investigate this" << endmsg;
-                 /* use the actual new note */
-                 change.note = new_note;
-         }
-
-         return change;
- }
-
- int
- MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
- {
-         if (diff_command.name() != string(DIFF_COMMAND_ELEMENT)) {
-                 return 1;
-         }
-
-         /* additions */
-
-         _added_notes.clear();
-         XMLNode* added_notes = diff_command.child(ADDED_NOTES_ELEMENT);
-         if (added_notes) {
-                 XMLNodeList notes = added_notes->children();
-                 transform(notes.begin(), notes.end(), back_inserter(_added_notes),
-                           boost::bind (&DiffCommand::unmarshal_note, this, _1));
-         }
-
-
-         /* removals */
-
-         _removed_notes.clear();
-         XMLNode* removed_notes = diff_command.child(REMOVED_NOTES_ELEMENT);
-         if (removed_notes) {
-                 XMLNodeList notes = removed_notes->children();
-                 transform(notes.begin(), notes.end(), back_inserter(_removed_notes),
-                           boost::bind (&DiffCommand::unmarshal_note, this, _1));
-         }
-
-
-         /* changes */
-
-         _changes.clear();
-
-         XMLNode* changed_notes = diff_command.child(DIFF_NOTES_ELEMENT);
-
-         if (changed_notes) {
-                 XMLNodeList notes = changed_notes->children();
-                 transform (notes.begin(), notes.end(), back_inserter(_changes),
-                            boost::bind (&DiffCommand::unmarshal_change, this, _1));
-
-         }
-
-         /* side effect removals caused by changes */
-
-         side_effect_removals.clear();
-
-         XMLNode* side_effect_notes = diff_command.child(SIDE_EFFECT_REMOVALS_ELEMENT);
-
-         if (side_effect_notes) {
-                 XMLNodeList notes = side_effect_notes->children();
-                 for (XMLNodeList::iterator n = notes.begin(); n != notes.end(); ++n) {
-                         side_effect_removals.insert (unmarshal_note (*n));
-                 }
-         }
-
-         return 0;
- }
-
- XMLNode&
- MidiModel::DiffCommand::get_state ()
- {
-         XMLNode* diff_command = new XMLNode(DIFF_COMMAND_ELEMENT);
-         diff_command->add_property("midi-source", _model->midi_source()->id().to_s());
-
-         XMLNode* changes = diff_command->add_child(DIFF_NOTES_ELEMENT);
-         for_each(_changes.begin(), _changes.end(), 
-                  boost::bind (
-                          boost::bind (&XMLNode::add_child_nocopy, changes, _1),
-                          boost::bind (&DiffCommand::marshal_change, this, _1)));
-
-         XMLNode* added_notes = diff_command->add_child(ADDED_NOTES_ELEMENT);
-         for_each(_added_notes.begin(), _added_notes.end(), 
-                  boost::bind(
-                          boost::bind (&XMLNode::add_child_nocopy, added_notes, _1),
-                          boost::bind (&DiffCommand::marshal_note, this, _1)));
-
-         XMLNode* removed_notes = diff_command->add_child(REMOVED_NOTES_ELEMENT);
-         for_each(_removed_notes.begin(), _removed_notes.end(), 
-                  boost::bind (
-                          boost::bind (&XMLNode::add_child_nocopy, removed_notes, _1),
-                          boost::bind (&DiffCommand::marshal_note, this, _1)));
-
-         /* if this command had side-effects, store that state too 
-          */
-
-         if (!side_effect_removals.empty()) {
-                 XMLNode* side_effect_notes = diff_command->add_child(SIDE_EFFECT_REMOVALS_ELEMENT);
-                 for_each(side_effect_removals.begin(), side_effect_removals.end(), 
-                          boost::bind (
-                                  boost::bind (&XMLNode::add_child_nocopy, side_effect_notes, _1),
-                                  boost::bind (&DiffCommand::marshal_note, this, _1)));
-         }
-
-         return *diff_command;
- }
-
- /** Write all of the model to a MidiSource (i.e. save the model).
-  * This is different from manually using read to write to a source in that
-  * note off events are written regardless of the track mode.  This is so the
-  * user can switch a recorded track (with note durations from some instrument)
-  * to percussive, save, reload, then switch it back to sustained without
-  * destroying the original note durations.
-  */
- bool
- MidiModel::write_to (boost::shared_ptr<MidiSource> source)
- {
-         ReadLock lock(read_lock());
-
-         const bool old_percussive = percussive();
-         set_percussive(false);
-
-         source->drop_model();
-         source->mark_streaming_midi_write_started(note_mode(), _midi_source->timeline_position());
-
-         for (Evoral::Sequence<TimeType>::const_iterator i = begin(); i != end(); ++i) {
-                 source->append_event_unlocked_beats(*i);
-         }
-
-         set_percussive(old_percussive);
-         source->mark_streaming_write_completed();
-
-         set_edited(false);
-        
-         return true;
- }
-
- /** Write part or all of the model to a MidiSource (i.e. save the model).
-  * This is different from manually using read to write to a source in that
-  * note off events are written regardless of the track mode.  This is so the
-  * user can switch a recorded track (with note durations from some instrument)
-  * to percussive, save, reload, then switch it back to sustained without
-  * destroying the original note durations.
-  */
- bool
- MidiModel::write_section_to (boost::shared_ptr<MidiSource> source, Evoral::MusicalTime begin_time, Evoral::MusicalTime end_time)
- {
-         ReadLock lock(read_lock());
-         MidiStateTracker mst;
-         Evoral::MusicalTime extra_note_on_time = end_time;
-
-         const bool old_percussive = percussive();
-         set_percussive(false);
-
-         source->drop_model();
-         source->mark_streaming_midi_write_started(note_mode(), _midi_source->timeline_position());
-
-         for (Evoral::Sequence<TimeType>::const_iterator i = begin(); i != end(); ++i) {
-                 const Evoral::Event<Evoral::MusicalTime>& ev (*i);
-
-                 if (ev.time() >= begin_time && ev.time() < end_time) {
-
-                         const Evoral::MIDIEvent<Evoral::MusicalTime>* mev = 
-                                 static_cast<const Evoral::MIDIEvent<Evoral::MusicalTime>* > (&ev);
-
-                         if (!mev) {
-                                 continue;
-                         }
-
-
-                         if (mev->is_note_off()) {
-
-                                 if (!mst.active (mev->note(), mev->channel())) {
-
-                                         /* add a note-on at the start of the range we're writing
-                                            to the file. velocity is just an arbitary reasonable value.
-                                         */
-
-                                         Evoral::MIDIEvent<Evoral::MusicalTime> on (mev->event_type(), extra_note_on_time, 3, 0, true);
-                                         on.set_type (mev->type());
-                                         on.set_note (mev->note());
-                                         on.set_channel (mev->channel());
-                                         on.set_velocity (mev->velocity());
-
-                                         cerr << "Add note on for odd note off, note = " << (int) on.note() << endl;
-                                         source->append_event_unlocked_beats (on);
-                                         mst.add (on.note(), on.channel());
-                                         mst.dump (cerr);
-                                         extra_note_on_time += 1.0/128.0;
-                                 }
-
-                                 cerr << "MIDI Note off (note = " << (int) mev->note() << endl;
-                                 source->append_event_unlocked_beats (*i);
-                                 mst.remove (mev->note(), mev->channel());
-                                 mst.dump (cerr);
-
-                         } else if (mev->is_note_on()) {
-                                 cerr << "MIDI Note on (note = " << (int) mev->note() << endl;
-                                 mst.add (mev->note(), mev->channel());
-                                 source->append_event_unlocked_beats(*i);
-                                 mst.dump (cerr);
-                         } else {
-                                 cerr << "MIDI other event type\n";
-                                 source->append_event_unlocked_beats(*i);
-                         }
-                 }
-         }
-
-         mst.resolve_notes (*source, end_time);
-
-         set_percussive(old_percussive);
-         source->mark_streaming_write_completed();
-
-         set_edited(false);
-
-         return true;
- }
-
- XMLNode&
- MidiModel::get_state()
- {
-         XMLNode *node = new XMLNode("MidiModel");
-         return *node;
- }
-
- Evoral::Sequence<MidiModel::TimeType>::NotePtr
- MidiModel::find_note (NotePtr other)
- {
-         Notes::iterator l = notes().lower_bound(other);
-
-         if (l != notes().end()) {
-                 for (; (*l)->time() == other->time(); ++l) {
-                         /* NB: compare note contents, not note pointers.
-                            If "other" was a ptr to a note already in
-                            the model, we wouldn't be looking for it,
-                            would we now?
-                          */
-                         if (**l == *other) {
-                                 return *l;
-                         }
-                 }
-         }
-
-         return NotePtr();
- }
-
- /** Lock and invalidate the source.
-  * This should be used by commands and editing things
-  */
- MidiModel::WriteLock
- MidiModel::edit_lock()
- {
-         Glib::Mutex::Lock* source_lock = new Glib::Mutex::Lock(_midi_source->mutex());
-         _midi_source->invalidate(); // Release cached iterator's read lock on model
-         return WriteLock(new WriteLockImpl(source_lock, _lock, _control_lock));
- }
-
- /** Lock just the model, the source lock must already be held.
-  * This should only be called from libardour/evoral places
-  */
- MidiModel::WriteLock
- MidiModel::write_lock()
- {
-         assert(!_midi_source->mutex().trylock());
-         return WriteLock(new WriteLockImpl(NULL, _lock, _control_lock));
- }
-
- int
- MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
- {
-         using namespace Evoral;
-
-         if (_writing || insert_merge_policy() == InsertMergeRelax) {
-                 return 0;
-         }
-
-         DiffCommand* cmd = static_cast<DiffCommand*>(arg);
-
-         TimeType sa = note->time();
-         TimeType ea  = note->end_time();
-
-         const Pitches& p (pitches (note->channel()));
-         NotePtr search_note(new Note<TimeType>(0, 0, 0, note->note()));
-         set<NotePtr> to_be_deleted;
-         bool set_note_length = false;
-         bool set_note_time = false;
-         TimeType note_time = note->time();
-         TimeType note_length = note->length();
-
-         for (Pitches::const_iterator i = p.lower_bound (search_note); 
-              i != p.end() && (*i)->note() == note->note(); ++i) {
-
-                 TimeType sb = (*i)->time();
-                 TimeType eb = (*i)->end_time();
-                 OverlapType overlap = OverlapNone;
-
-                 if ((sb > sa) && (eb <= ea)) {
-                         overlap = OverlapInternal;
-                 } else if ((eb >= sa) && (eb <= ea)) {
-                         overlap = OverlapStart;
-                 } else if ((sb > sa) && (sb <= ea)) {
-                         overlap = OverlapEnd;
-                 } else if ((sa >= sb) && (sa <= eb) && (ea <= eb)) {
-                         overlap = OverlapExternal;
-                 } else {
-                         /* no overlap */
-                         continue;
-                 }
-
-                 if (insert_merge_policy() == InsertMergeReject) {
-                         return -1;
-                 }
-
-                 switch (overlap) {
-                 case OverlapStart:
-                         cerr << "OverlapStart\n";
-                         /* existing note covers start of new note */
-                         switch (insert_merge_policy()) {
-                         case InsertMergeReplace:
-                                 to_be_deleted.insert (*i);
-                                 break;
-                         case InsertMergeTruncateExisting:
-                                 if (cmd) {
-                                         cmd->change (*i, DiffCommand::Length, (note->time() - (*i)->time()));
-                                 }
-                                 (*i)->set_length (note->time() - (*i)->time());
-                                 break;
-                         case InsertMergeTruncateAddition:
-                                 set_note_time = true;
-                                 set_note_length = true;
-                                 note_time = (*i)->time() + (*i)->length();
-                                 note_length = min (note_length, (*i)->length() - ((*i)->end_time() - note->time()));
-                                 break;
-                         case InsertMergeExtend:
-                                 if (cmd) {
-                                         cmd->change ((*i), DiffCommand::Length, note->end_time() - (*i)->time());
-                                 } 
-                                 (*i)->set_length (note->end_time() - (*i)->time());
-                                 return -1; /* do not add the new note */
-                                 break;
-                         default:
-                                 /*NOTREACHED*/
-                                 /* stupid gcc */
-                                 break;
-                         }
-                         break;
-
-                 case OverlapEnd:
-                         cerr << "OverlapEnd\n";
-                         /* existing note covers end of new note */
-                         switch (insert_merge_policy()) {
-                         case InsertMergeReplace:
-                                 to_be_deleted.insert (*i);
-                                 break;
-
-                         case InsertMergeTruncateExisting:
-                                 /* resetting the start time of the existing note
-                                    is a problem because of time ordering.
-                                 */
-                                 break;
-
-                         case InsertMergeTruncateAddition:
-                                 set_note_length = true;
-                                 note_length = min (note_length, ((*i)->time() - note->time()));
-                                 break;
-
-                         case InsertMergeExtend:
-                                 /* we can't reset the time of the existing note because
-                                    that will corrupt time ordering. So remove the
-                                    existing note and change the position/length
-                                    of the new note (which has not been added yet)
-                                 */
-                                 to_be_deleted.insert (*i);
-                                 set_note_length = true;
-                                 note_length = min (note_length, (*i)->end_time() - note->time());
-                                 break;
-                         default:
-                                 /*NOTREACHED*/
-                                 /* stupid gcc */
-                                 break;
-                         }
-                         break;
-
-                 case OverlapExternal:
-                         cerr << "OverlapExt\n";
-                         /* existing note overlaps all the new note */
-                         switch (insert_merge_policy()) {
-                         case InsertMergeReplace:
-                                 to_be_deleted.insert (*i);
-                                 break;
-                         case InsertMergeTruncateExisting:
-                         case InsertMergeTruncateAddition:
-                         case InsertMergeExtend:
-                                 /* cannot add in this case */
-                                 return -1;
-                         default:
-                                 /*NOTREACHED*/
-                                 /* stupid gcc */
-                                 break;
-                         }
-                         break;
-
-                 case OverlapInternal:
-                         cerr << "OverlapInt\n";
-                         /* new note fully overlaps an existing note */
-                         switch (insert_merge_policy()) {
-                         case InsertMergeReplace:
-                         case InsertMergeTruncateExisting:
-                         case InsertMergeTruncateAddition:
-                         case InsertMergeExtend:
-                                 /* delete the existing note, the new one will cover it */
-                                 to_be_deleted.insert (*i);
-                                 break;
-                         default:
-                                 /*NOTREACHED*/
-                                 /* stupid gcc */
-                                 break;
-                         }
-                         break;
-
-                 default:
-                         /*NOTREACHED*/
-                         /* stupid gcc */
-                         break;
-                 }
-         }
-
-         for (set<NotePtr>::iterator i = to_be_deleted.begin(); i != to_be_deleted.end(); ++i) {
-                 remove_note_unlocked (*i);
-
-                 if (cmd) {
-                         cmd->side_effect_remove (*i);
-                 }
-         }
-
-         if (set_note_time) {
-                 if (cmd) {
-                         cmd->change (note, DiffCommand::StartTime, note_time);
-                 } 
-                 note->set_time (note_time);
-         }
-
-         if (set_note_length) {
-                 if (cmd) {
-                         cmd->change (note, DiffCommand::Length, note_length);
-                 } 
-                 note->set_length (note_length);
-         }
-
-         return 0;
- }
-
- InsertMergePolicy
- MidiModel::insert_merge_policy () const 
- {
-         /* XXX ultimately this should be a per-track or even per-model policy */
-
-         return _midi_source->session().config.get_insert_merge_policy();
-}
-                        
 void
-MidiModel::set_midi_source (MidiSource* s)
+MidiModel::NoteDiffCommand::change (const NotePtr note, Property prop,
+                                    uint8_t new_value)
+{
+       assert (note);
+
+       NoteChange change;
+
+       switch (prop) {
+       case NoteNumber:
+               if (new_value == note->note()) {
+                       return;
+               }
+               change.old_value = note->note();
+               break;
+       case Velocity:
+               if (new_value == note->velocity()) {
+                       return;
+               }
+               change.old_value = note->velocity();
+               break;
+       case Channel:
+               if (new_value == note->channel()) {
+                       return;
+               }
+               change.old_value = note->channel();
+               break;
+
+
+       case StartTime:
+               fatal << "MidiModel::DiffCommand::change() with integer argument called for start time" << endmsg;
+               /*NOTREACHED*/
+               break;
+       case Length:
+               fatal << "MidiModel::DiffCommand::change() with integer argument called for length" << endmsg;
+               /*NOTREACHED*/
+               break;
+       }
+
+       change.note = note;
+       change.property = prop;
+       change.new_value = new_value;
+
+       _changes.push_back (change);
+}
+
+void
+MidiModel::NoteDiffCommand::change (const NotePtr note, Property prop,
+                                    TimeType new_time)
+{
+       assert (note);
+
+       NoteChange change;
+
+       switch (prop) {
+       case NoteNumber:
+       case Channel:
+       case Velocity:
+               fatal << "MidiModel::NoteDiffCommand::change() with time argument called for note, channel or velocity" << endmsg;
+               break;
+
+       case StartTime:
+               if (Evoral::musical_time_equal (note->time(), new_time)) {
+                       return;
+               }
+               change.old_time = note->time();
+               break;
+       case Length:
+               if (Evoral::musical_time_equal (note->length(), new_time)) {
+                       return;
+               }
+               change.old_time = note->length();
+               break;
+       }
+
+       change.note = note;
+       change.property = prop;
+       change.new_time = new_time;
+
+       _changes.push_back (change);
+}
+
+MidiModel::NoteDiffCommand &
+MidiModel::NoteDiffCommand::operator+= (const NoteDiffCommand& other)
+{
+       if (this == &other) {
+               return *this;
+       }
+
+       if (_model != other._model) {
+               return *this;
+       }
+
+       _added_notes.insert (_added_notes.end(), other._added_notes.begin(), other._added_notes.end());
+       _removed_notes.insert (_removed_notes.end(), other._removed_notes.begin(), other._removed_notes.end());
+       side_effect_removals.insert (other.side_effect_removals.begin(), other.side_effect_removals.end());
+       _changes.insert (_changes.end(), other._changes.begin(), other._changes.end());
+
+       return *this;
+}
+
+void
+MidiModel::NoteDiffCommand::operator() ()
+{
+       {
+               MidiModel::WriteLock lock(_model->edit_lock());
+
+               for (NoteList::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i) {
+                       if (!_model->add_note_unlocked(*i)) {
+                               /* failed to add it, so don't leave it in the removed list, to
+                                  avoid apparent errors on undo.
+                               */
+                               _removed_notes.remove (*i);
+                       }
+               }
+
+               for (NoteList::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i) {
+                       _model->remove_note_unlocked(*i);
+               }
+
+               /* notes we modify in a way that requires remove-then-add to maintain ordering */
+               set<NotePtr> temporary_removals;
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       Property prop = i->property;
+                       switch (prop) {
+                       case NoteNumber:
+                               if (temporary_removals.find (i->note) == temporary_removals.end()) {
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_note (i->new_value);
+                               break;
+
+                       case StartTime:
+                               if (temporary_removals.find (i->note) == temporary_removals.end()) {
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_time (i->new_time);
+                               break;
+
+                       case Channel:
+                               if (temporary_removals.find (i->note) == temporary_removals.end()) {
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_channel (i->new_value);
+                               break;
+
+                               /* no remove-then-add required for these properties, since we do not index them
+                                */
+
+                       case Velocity:
+                               i->note->set_velocity (i->new_value);
+                               break;
+
+                       case Length:
+                               i->note->set_length (i->new_time);
+                               break;
+
+                       }
+               }
+
+               for (set<NotePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
+                       NoteDiffCommand side_effects (model(), "side effects");
+                       if (_model->add_note_unlocked (*i, &side_effects)) {
+                               /* The note was re-added ok */
+                               *this += side_effects;
+                       } else {
+                               /* The note that we removed earlier could not be re-added.  This change record
+                                  must say that the note was removed.  We'll keep the changes we made, though,
+                                  as if the note is re-added by the undo the changes must also be undone.
+                               */
+                               _removed_notes.push_back (*i);
+                       }
+               }
+
+               if (!side_effect_removals.empty()) {
+                       cerr << "SER: \n";
+                       for (set<NotePtr>::iterator i = side_effect_removals.begin(); i != side_effect_removals.end(); ++i) {
+                               cerr << "\t" << *i << ' ' << **i << endl;
+                       }
+               }
+       }
+
+       _model->ContentsChanged(); /* EMIT SIGNAL */
+}
+
+void
+MidiModel::NoteDiffCommand::undo ()
+{
+       {
+               MidiModel::WriteLock lock(_model->edit_lock());
+
+               for (NoteList::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i) {
+                       _model->remove_note_unlocked(*i);
+               }
+
+               /* Apply changes first; this is important in the case of a note change which
+                  resulted in the note being removed by the overlap checker.  If the overlap
+                  checker removes a note, it will be in _removed_notes.  We are going to re-add
+                  it below, but first we must undo the changes we made so that the overlap
+                  checker doesn't refuse the re-add.
+               */
+
+               /* notes we modify in a way that requires remove-then-add to maintain ordering */
+               set<NotePtr> temporary_removals;
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       Property prop = i->property;
+                       switch (prop) {
+
+                       case NoteNumber:
+                               if (
+                                       temporary_removals.find (i->note) == temporary_removals.end() &&
+                                       find (_removed_notes.begin(), _removed_notes.end(), i->note) == _removed_notes.end()
+                                       ) {
+
+                                       /* We only need to mark this note for re-add if (a) we haven't
+                                          already marked it and (b) it isn't on the _removed_notes
+                                          list (which means that it has already been removed and it
+                                          will be re-added anyway)
+                                       */
+
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_note (i->old_value);
+                               break;
+
+                       case StartTime:
+                               if (
+                                       temporary_removals.find (i->note) == temporary_removals.end() &&
+                                       find (_removed_notes.begin(), _removed_notes.end(), i->note) == _removed_notes.end()
+                                       ) {
+
+                                       /* See above ... */
+
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_time (i->old_time);
+                               break;
+
+                       case Channel:
+                               if (
+                                       temporary_removals.find (i->note) == temporary_removals.end() &&
+                                       find (_removed_notes.begin(), _removed_notes.end(), i->note) == _removed_notes.end()
+                                       ) {
+
+                                       /* See above ... */
+
+                                       _model->remove_note_unlocked (i->note);
+                                       temporary_removals.insert (i->note);
+                               }
+                               i->note->set_channel (i->old_value);
+                               break;
+
+                               /* no remove-then-add required for these properties, since we do not index them
+                                */
+
+                       case Velocity:
+                               i->note->set_velocity (i->old_value);
+                               break;
+
+                       case Length:
+                               i->note->set_length (i->old_time);
+                               break;
+                       }
+               }
+
+               for (NoteList::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i) {
+                       _model->add_note_unlocked(*i);
+               }
+
+               for (set<NotePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
+                       _model->add_note_unlocked (*i);
+               }
+
+               /* finally add back notes that were removed by the "do". we don't care
+                  about side effects here since the model should be back to its original
+                  state once this is done.
+               */
+
+               for (set<NotePtr>::iterator i = side_effect_removals.begin(); i != side_effect_removals.end(); ++i) {
+                       _model->add_note_unlocked (*i);
+               }
+       }
+
+       _model->ContentsChanged(); /* EMIT SIGNAL */
+}
+
+XMLNode&
+MidiModel::NoteDiffCommand::marshal_note(const NotePtr note)
+{
+       XMLNode* xml_note = new XMLNode("note");
+
+       {
+               ostringstream id_str(ios::ate);
+               id_str << int(note->id());
+               xml_note->add_property("id", id_str.str());
+       }
+
+       {
+               ostringstream note_str(ios::ate);
+               note_str << int(note->note());
+               xml_note->add_property("note", note_str.str());
+       }
+
+       {
+               ostringstream channel_str(ios::ate);
+               channel_str << int(note->channel());
+               xml_note->add_property("channel", channel_str.str());
+       }
+
+       {
+               ostringstream time_str(ios::ate);
+               time_str << note->time();
+               xml_note->add_property("time", time_str.str());
+       }
+
+       {
+               ostringstream length_str(ios::ate);
+               length_str << note->length();
+               xml_note->add_property("length", length_str.str());
+       }
+
+       {
+               ostringstream velocity_str(ios::ate);
+               velocity_str << (unsigned int) note->velocity();
+               xml_note->add_property("velocity", velocity_str.str());
+       }
+
+       return *xml_note;
+}
+
+Evoral::Sequence<MidiModel::TimeType>::NotePtr
+MidiModel::NoteDiffCommand::unmarshal_note (XMLNode *xml_note)
+{
+       unsigned int note;
+       XMLProperty* prop;
+       unsigned int channel;
+       unsigned int time;
+       unsigned int length;
+       unsigned int velocity;
+       gint id;
+
+       if ((prop = xml_note->property("id")) != 0) {
+               istringstream id_str(prop->value());
+               id_str >> id;
+       } else {
+               error << "note information missing ID value" << endmsg;
+               id = -1;
+       }
+
+       if ((prop = xml_note->property("note")) != 0) {
+               istringstream note_str(prop->value());
+               note_str >> note;
+       } else {
+               warning << "note information missing note value" << endmsg;
+               note = 127;
+       }
+
+       if ((prop = xml_note->property("channel")) != 0) {
+               istringstream channel_str(prop->value());
+               channel_str >> channel;
+       } else {
+               warning << "note information missing channel" << endmsg;
+               channel = 0;
+       }
+
+       if ((prop = xml_note->property("time")) != 0) {
+               istringstream time_str(prop->value());
+               time_str >> time;
+       } else {
+               warning << "note information missing time" << endmsg;
+               time = 0;
+       }
+
+       if ((prop = xml_note->property("length")) != 0) {
+               istringstream length_str(prop->value());
+               length_str >> length;
+       } else {
+               warning << "note information missing length" << endmsg;
+               length = 1;
+       }
+
+       if ((prop = xml_note->property("velocity")) != 0) {
+               istringstream velocity_str(prop->value());
+               velocity_str >> velocity;
+       } else {
+               warning << "note information missing velocity" << endmsg;
+               velocity = 127;
+       }
+
+       NotePtr note_ptr(new Evoral::Note<TimeType>(channel, time, length, note, velocity));
+       note_ptr->set_id (id);
+
+       return note_ptr;
+}
+
+XMLNode&
+MidiModel::NoteDiffCommand::marshal_change (const NoteChange& change)
+{
+       XMLNode* xml_change = new XMLNode("Change");
+
+       /* first, the change itself */
+
+       xml_change->add_property ("property", enum_2_string (change.property));
+
+       {
+               ostringstream old_value_str (ios::ate);
+               if (change.property == StartTime || change.property == Length) {
+                       old_value_str << change.old_time;
+               } else {
+                       old_value_str << (unsigned int) change.old_value;
+               }
+               xml_change->add_property ("old", old_value_str.str());
+       }
+
+       {
+               ostringstream new_value_str (ios::ate);
+               if (change.property == StartTime || change.property == Length) {
+                       new_value_str << change.new_time;
+               } else {
+                       new_value_str << (unsigned int) change.new_value;
+               }
+               xml_change->add_property ("new", new_value_str.str());
+       }
+
+       ostringstream id_str;
+       id_str << change.note->id();
+       xml_change->add_property ("id", id_str.str());
+
+       return *xml_change;
+}
+
+MidiModel::NoteDiffCommand::NoteChange
+MidiModel::NoteDiffCommand::unmarshal_change (XMLNode *xml_change)
+{
+       XMLProperty* prop;
+       NoteChange change;
+
+       if ((prop = xml_change->property("property")) != 0) {
+               change.property = (Property) string_2_enum (prop->value(), change.property);
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       if ((prop = xml_change->property ("id")) == 0) {
+               error << _("No NoteID found for note property change - ignored") << endmsg;
+               return change;
+       }
+
+       gint note_id = atoi (prop->value().c_str());
+
+       if ((prop = xml_change->property ("old")) != 0) {
+               istringstream old_str (prop->value());
+               if (change.property == StartTime || change.property == Length) {
+                       old_str >> change.old_time;
+               } else {
+                       int integer_value_so_that_istream_does_the_right_thing;
+                       old_str >> integer_value_so_that_istream_does_the_right_thing;
+                       change.old_value = integer_value_so_that_istream_does_the_right_thing;
+               }
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       if ((prop = xml_change->property ("new")) != 0) {
+               istringstream new_str (prop->value());
+               if (change.property == StartTime || change.property == Length) {
+                       new_str >> change.new_time;
+               } else {
+                       int integer_value_so_that_istream_does_the_right_thing;
+                       new_str >> integer_value_so_that_istream_does_the_right_thing;
+                       change.new_value = integer_value_so_that_istream_does_the_right_thing;
+               }
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       /* we must point at the instance of the note that is actually in the model.
+          so go look for it ...
+       */
+
+       change.note = _model->find_note (note_id);
+
+       if (!change.note) {
+               warning << "MIDI note #" << note_id << " not found in model - programmers should investigate this" << endmsg;
+               return change;
+       }
+
+       return change;
+}
+
+int
+MidiModel::NoteDiffCommand::set_state (const XMLNode& diff_command, int /*version*/)
+{
+       if (diff_command.name() != string (NOTE_DIFF_COMMAND_ELEMENT)) {
+               return 1;
+       }
+
+       /* additions */
+
+       _added_notes.clear();
+       XMLNode* added_notes = diff_command.child(ADDED_NOTES_ELEMENT);
+       if (added_notes) {
+               XMLNodeList notes = added_notes->children();
+               transform(notes.begin(), notes.end(), back_inserter(_added_notes),
+                         boost::bind (&NoteDiffCommand::unmarshal_note, this, _1));
+       }
+
+
+       /* removals */
+
+       _removed_notes.clear();
+       XMLNode* removed_notes = diff_command.child(REMOVED_NOTES_ELEMENT);
+       if (removed_notes) {
+               XMLNodeList notes = removed_notes->children();
+               transform(notes.begin(), notes.end(), back_inserter(_removed_notes),
+                         boost::bind (&NoteDiffCommand::unmarshal_note, this, _1));
+       }
+
+
+       /* changes */
+
+       _changes.clear();
+
+       XMLNode* changed_notes = diff_command.child(DIFF_NOTES_ELEMENT);
+
+       if (changed_notes) {
+               XMLNodeList notes = changed_notes->children();
+               transform (notes.begin(), notes.end(), back_inserter(_changes),
+                          boost::bind (&NoteDiffCommand::unmarshal_change, this, _1));
+
+       }
+
+       /* side effect removals caused by changes */
+
+       side_effect_removals.clear();
+
+       XMLNode* side_effect_notes = diff_command.child(SIDE_EFFECT_REMOVALS_ELEMENT);
+
+       if (side_effect_notes) {
+               XMLNodeList notes = side_effect_notes->children();
+               for (XMLNodeList::iterator n = notes.begin(); n != notes.end(); ++n) {
+                       side_effect_removals.insert (unmarshal_note (*n));
+               }
+       }
+
+       return 0;
+}
+
+XMLNode&
+MidiModel::NoteDiffCommand::get_state ()
+{
+       XMLNode* diff_command = new XMLNode (NOTE_DIFF_COMMAND_ELEMENT);
+       diff_command->add_property("midi-source", _model->midi_source()->id().to_s());
+
+       XMLNode* changes = diff_command->add_child(DIFF_NOTES_ELEMENT);
+       for_each(_changes.begin(), _changes.end(),
+                boost::bind (
+                        boost::bind (&XMLNode::add_child_nocopy, changes, _1),
+                        boost::bind (&NoteDiffCommand::marshal_change, this, _1)));
+
+       XMLNode* added_notes = diff_command->add_child(ADDED_NOTES_ELEMENT);
+       for_each(_added_notes.begin(), _added_notes.end(),
+                boost::bind(
+                        boost::bind (&XMLNode::add_child_nocopy, added_notes, _1),
+                        boost::bind (&NoteDiffCommand::marshal_note, this, _1)));
+
+       XMLNode* removed_notes = diff_command->add_child(REMOVED_NOTES_ELEMENT);
+       for_each(_removed_notes.begin(), _removed_notes.end(),
+                boost::bind (
+                        boost::bind (&XMLNode::add_child_nocopy, removed_notes, _1),
+                        boost::bind (&NoteDiffCommand::marshal_note, this, _1)));
+
+       /* if this command had side-effects, store that state too
+        */
+
+       if (!side_effect_removals.empty()) {
+               XMLNode* side_effect_notes = diff_command->add_child(SIDE_EFFECT_REMOVALS_ELEMENT);
+               for_each(side_effect_removals.begin(), side_effect_removals.end(),
+                        boost::bind (
+                                boost::bind (&XMLNode::add_child_nocopy, side_effect_notes, _1),
+                                boost::bind (&NoteDiffCommand::marshal_note, this, _1)));
+       }
+
+       return *diff_command;
+}
+
+MidiModel::SysExDiffCommand::SysExDiffCommand (boost::shared_ptr<MidiModel> m, const XMLNode& node)
+       : DiffCommand (m, "")
+{
+       assert (_model);
+       set_state (node, Stateful::loading_state_version);
+}
+
+void
+MidiModel::SysExDiffCommand::change (boost::shared_ptr<Evoral::Event<TimeType> > s, TimeType new_time)
+{
+       Change change;
+
+       change.sysex = s;
+       change.property = Time;
+       change.old_time = s->time ();
+       change.new_time = new_time;
+
+       _changes.push_back (change);
+}
+
+void
+MidiModel::SysExDiffCommand::operator() ()
 {
-       _midi_source->invalidate ();
+       {
+               MidiModel::WriteLock lock (_model->edit_lock ());
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       switch (i->property) {
+                       case Time:
+                               i->sysex->set_time (i->new_time);
+                       }
+               }
+       }
+
+       _model->ContentsChanged (); /* EMIT SIGNAL */
+}
+
+void
+MidiModel::SysExDiffCommand::undo ()
+{
+       {
+               MidiModel::WriteLock lock (_model->edit_lock ());
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       switch (i->property) {
+                       case Time:
+                               i->sysex->set_time (i->old_time);
+                               break;
+                       }
+               }
+
+       }
+
+       _model->ContentsChanged(); /* EMIT SIGNAL */
+}
+
+XMLNode&
+MidiModel::SysExDiffCommand::marshal_change (const Change& change)
+{
+       XMLNode* xml_change = new XMLNode ("Change");
+
+       /* first, the change itself */
+
+       xml_change->add_property ("property", enum_2_string (change.property));
+
+       {
+               ostringstream old_value_str (ios::ate);
+               old_value_str << change.old_time;
+               xml_change->add_property ("old", old_value_str.str());
+       }
+
+       {
+               ostringstream new_value_str (ios::ate);
+               new_value_str << change.new_time;
+               xml_change->add_property ("new", new_value_str.str());
+       }
+
+       ostringstream id_str;
+       id_str << change.sysex->id();
+       xml_change->add_property ("id", id_str.str());
+
+       return *xml_change;
+}
+
+MidiModel::SysExDiffCommand::Change
+MidiModel::SysExDiffCommand::unmarshal_change (XMLNode *xml_change)
+{
+       XMLProperty* prop;
+       Change change;
+
+       if ((prop = xml_change->property ("property")) != 0) {
+               change.property = (Property) string_2_enum (prop->value(), change.property);
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       if ((prop = xml_change->property ("id")) == 0) {
+               error << _("No SysExID found for sys-ex property change - ignored") << endmsg;
+               return change;
+       }
+
+       gint sysex_id = atoi (prop->value().c_str());
+
+       if ((prop = xml_change->property ("old")) != 0) {
+               istringstream old_str (prop->value());
+               old_str >> change.old_time;
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       if ((prop = xml_change->property ("new")) != 0) {
+               istringstream new_str (prop->value());
+               new_str >> change.new_time;
+       } else {
+               fatal << "!!!" << endmsg;
+               /*NOTREACHED*/
+       }
+
+       /* we must point at the instance of the sysex that is actually in the model.
+          so go look for it ...
+       */
+
+       change.sysex = _model->find_sysex (sysex_id);
+
+       if (!change.sysex) {
+               warning << "Sys-ex #" << sysex_id << " not found in model - programmers should investigate this" << endmsg;
+               return change;
+       }
+
+       return change;
+}
+
+int
+MidiModel::SysExDiffCommand::set_state (const XMLNode& diff_command, int /*version*/)
+{
+       if (diff_command.name() != string (SYSEX_DIFF_COMMAND_ELEMENT)) {
+               return 1;
+       }
+
+       /* changes */
+
+       _changes.clear();
+
+       XMLNode* changed_sysexes = diff_command.child (DIFF_SYSEXES_ELEMENT);
+
+       if (changed_sysexes) {
+               XMLNodeList sysexes = changed_sysexes->children();
+               transform (sysexes.begin(), sysexes.end(), back_inserter (_changes),
+                          boost::bind (&SysExDiffCommand::unmarshal_change, this, _1));
+
+       }
+
+       return 0;
+}
+
+XMLNode&
+MidiModel::SysExDiffCommand::get_state ()
+{
+       XMLNode* diff_command = new XMLNode (SYSEX_DIFF_COMMAND_ELEMENT);
+       diff_command->add_property ("midi-source", _model->midi_source()->id().to_s());
+
+       XMLNode* changes = diff_command->add_child(DIFF_SYSEXES_ELEMENT);
+       for_each (_changes.begin(), _changes.end(),
+                 boost::bind (
+                         boost::bind (&XMLNode::add_child_nocopy, changes, _1),
+                         boost::bind (&SysExDiffCommand::marshal_change, this, _1)));
+
+       return *diff_command;
+}
+
+MidiModel::PatchChangeDiffCommand::PatchChangeDiffCommand (boost::shared_ptr<MidiModel> m, const string& name)
+       : DiffCommand (m, name)
+{
+       assert (_model);
+}
+
+MidiModel::PatchChangeDiffCommand::PatchChangeDiffCommand (boost::shared_ptr<MidiModel> m, const XMLNode & node)
+       : DiffCommand (m, "")
+{
+       assert (_model);
+       set_state (node, Stateful::loading_state_version);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::add (PatchChangePtr p)
+{
+       _added.push_back (p);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::remove (PatchChangePtr p)
+{
+       _removed.push_back (p);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::change_time (PatchChangePtr patch, TimeType t)
+{
+       Change c;
+       c.property = Time;
+       c.patch = patch;
+       c.old_time = patch->time ();
+       c.new_time = t;
+
+       _changes.push_back (c);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::change_channel (PatchChangePtr patch, uint8_t channel)
+{
+       Change c;
+       c.property = Channel;
+       c.patch = patch;
+       c.old_channel = patch->channel ();
+       c.new_channel = channel;
+
+       _changes.push_back (c);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::change_program (PatchChangePtr patch, uint8_t program)
+{
+       Change c;
+       c.property = Program;
+       c.patch = patch;
+       c.old_program = patch->program ();
+       c.new_program = program;
+
+       _changes.push_back (c);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::change_bank (PatchChangePtr patch, int bank)
+{
+       Change c;
+       c.property = Bank;
+       c.patch = patch;
+       c.old_bank = patch->bank ();
+       c.new_bank = bank;
+
+       _changes.push_back (c);
+}
+
+void
+MidiModel::PatchChangeDiffCommand::operator() ()
+{
+       {
+               MidiModel::WriteLock lock (_model->edit_lock ());
+
+               for (list<PatchChangePtr>::iterator i = _added.begin(); i != _added.end(); ++i) {
+                       _model->add_patch_change_unlocked (*i);
+               }
+
+               for (list<PatchChangePtr>::iterator i = _removed.begin(); i != _removed.end(); ++i) {
+                       _model->remove_patch_change_unlocked (*i);
+               }
+
+               set<PatchChangePtr> temporary_removals;
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       switch (i->property) {
+                       case Time:
+                               if (temporary_removals.find (i->patch) == temporary_removals.end()) {
+                                       _model->remove_patch_change_unlocked (i->patch);
+                                       temporary_removals.insert (i->patch);
+                               }
+                               i->patch->set_time (i->new_time);
+                               break;
+
+                       case Channel:
+                               i->patch->set_channel (i->new_channel);
+                               break;
+
+                       case Program:
+                               i->patch->set_program (i->new_program);
+                               break;
+
+                       case Bank:
+                               i->patch->set_bank (i->new_bank);
+                               break;
+                       }
+               }
+
+               for (set<PatchChangePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
+                       _model->add_patch_change_unlocked (*i);
+               }
+       }
+
+       _model->ContentsChanged (); /* EMIT SIGNAL */
+}
+
+void
+MidiModel::PatchChangeDiffCommand::undo ()
+{
+       {
+               MidiModel::WriteLock lock (_model->edit_lock());
+
+               for (list<PatchChangePtr>::iterator i = _added.begin(); i != _added.end(); ++i) {
+                       _model->remove_patch_change_unlocked (*i);
+               }
+
+               for (list<PatchChangePtr>::iterator i = _removed.begin(); i != _removed.end(); ++i) {
+                       _model->add_patch_change_unlocked (*i);
+               }
+
+               set<PatchChangePtr> temporary_removals;
+
+               for (ChangeList::iterator i = _changes.begin(); i != _changes.end(); ++i) {
+                       switch (i->property) {
+                       case Time:
+                               if (temporary_removals.find (i->patch) == temporary_removals.end()) {
+                                       _model->remove_patch_change_unlocked (i->patch);
+                                       temporary_removals.insert (i->patch);
+                               }
+                               i->patch->set_time (i->old_time);
+                               break;
+
+                       case Channel:
+                               i->patch->set_channel (i->old_channel);
+                               break;
+
+                       case Program:
+                               i->patch->set_program (i->old_program);
+                               break;
+
+                       case Bank:
+                               i->patch->set_bank (i->old_bank);
+                               break;
+                       }
+               }
+
+               for (set<PatchChangePtr>::iterator i = temporary_removals.begin(); i != temporary_removals.end(); ++i) {
+                       _model->add_patch_change_unlocked (*i);
+               }
+
+       }
+
+       _model->ContentsChanged (); /* EMIT SIGNAL */
+}
+
+XMLNode &
+MidiModel::PatchChangeDiffCommand::marshal_patch_change (constPatchChangePtr p)
+{
+       XMLNode* n = new XMLNode ("patch-change");
+
+       {
+               ostringstream s (ios::ate);
+               s << int (p->id ());
+               n->add_property ("id", s.str());
+       }
+
+       {
+               ostringstream s (ios::ate);
+               s << p->time ();
+               n->add_property ("time", s.str ());
+       }
+
+       {
+               ostringstream s (ios::ate);
+               s << int (p->channel ());
+               n->add_property ("channel", s.str ());
+       }
+
+       {
+               ostringstream s (ios::ate);
+               s << int (p->program ());
+               n->add_property ("program", s.str ());
+       }
+
+       {
+               ostringstream s (ios::ate);
+               s << int (p->bank ());
+               n->add_property ("bank", s.str ());
+       }
+
+       return *n;
+}
+
+XMLNode&
+MidiModel::PatchChangeDiffCommand::marshal_change (const Change& c)
+{
+       XMLNode* n = new XMLNode (X_("Change"));
+
+       n->add_property (X_("property"), enum_2_string (c.property));
+
+       {
+               ostringstream s (ios::ate);
+               if (c.property == Time) {
+                       s << c.old_time;
+               } else if (c.property == Channel) {
+                       s << c.old_channel;
+               } else if (c.property == Program) {
+                       s << int (c.old_program);
+               } else if (c.property == Bank) {
+                       s << c.old_bank;
+               }
+
+               n->add_property (X_("old"), s.str ());
+       }
+
+       {
+               ostringstream s (ios::ate);
+
+               if (c.property == Time) {
+                       s << c.new_time;
+               } else if (c.property == Channel) {
+                       s << c.new_channel;
+               } else if (c.property == Program) {
+                       s << int (c.new_program);
+               } else if (c.property == Bank) {
+                       s << c.new_bank;
+               }
+
+               n->add_property (X_("new"), s.str ());
+       }
+
+       {
+               ostringstream s;
+               s << c.patch->id ();
+               n->add_property ("id", s.str ());
+       }
+
+       return *n;
+}
+
+MidiModel::PatchChangePtr
+MidiModel::PatchChangeDiffCommand::unmarshal_patch_change (XMLNode* n)
+{
+       XMLProperty* prop;
+       Evoral::event_id_t id;
+       Evoral::MusicalTime time = 0;
+       uint8_t channel = 0;
+       uint8_t program = 0;
+       int bank = 0;
+
+       if ((prop = n->property ("id")) != 0) {
+               istringstream s (prop->value());
+               s >> id;
+       }
+
+       if ((prop = n->property ("time")) != 0) {
+               istringstream s (prop->value ());
+               s >> time;
+       }
+
+       if ((prop = n->property ("channel")) != 0) {
+               istringstream s (prop->value ());
+               s >> channel;
+       }
+
+       if ((prop = n->property ("program")) != 0) {
+               istringstream s (prop->value ());
+               s >> program;
+       }
+
+       if ((prop = n->property ("bank")) != 0) {
+               istringstream s (prop->value ());
+               s >> bank;
+       }
+
+       PatchChangePtr p (new Evoral::PatchChange<TimeType> (time, channel, program, bank));
+       p->set_id (id);
+       return p;
+}
+
+MidiModel::PatchChangeDiffCommand::Change
+MidiModel::PatchChangeDiffCommand::unmarshal_change (XMLNode* n)
+{
+       XMLProperty* prop;
+       Change c;
+
+       prop = n->property ("property");
+       assert (prop);
+       c.property = (Property) string_2_enum (prop->value(), c.property);
+
+       prop = n->property ("id");
+       assert (prop);
+       Evoral::event_id_t const id = atoi (prop->value().c_str());
+
+       prop = n->property ("old");
+       assert (prop);
+       {
+               istringstream s (prop->value ());
+               if (c.property == Time) {
+                       s >> c.old_time;
+               } else if (c.property == Channel) {
+                       s >> c.old_channel;
+               } else if (c.property == Program) {
+                       s >> c.old_program;
+               } else if (c.property == Bank) {
+                       s >> c.old_bank;
+               }
+       }
+
+       prop = n->property ("new");
+       assert (prop);
+       {
+               istringstream s (prop->value ());
+               if (c.property == Time) {
+                       s >> c.new_time;
+               } else if (c.property == Channel) {
+                       s >> c.new_channel;
+               } else if (c.property == Program) {
+                       s >> c.new_program;
+               } else if (c.property == Bank) {
+                       s >> c.new_bank;
+               }
+       }
+
+       c.patch = _model->find_patch_change (id);
+       assert (c.patch);
+
+       return c;
+}
+
+int
+MidiModel::PatchChangeDiffCommand::set_state (const XMLNode& diff_command, int /*version*/)
+{
+       if (diff_command.name() != PATCH_CHANGE_DIFF_COMMAND_ELEMENT) {
+               return 1;
+       }
+
+       _added.clear ();
+       XMLNode* added = diff_command.child (ADDED_PATCH_CHANGES_ELEMENT);
+       if (added) {
+               XMLNodeList p = added->children ();
+               transform (p.begin(), p.end(), back_inserter (_added), boost::bind (&PatchChangeDiffCommand::unmarshal_patch_change, this, _1));
+       }
+
+       _removed.clear ();
+       XMLNode* removed = diff_command.child (REMOVED_PATCH_CHANGES_ELEMENT);
+       if (removed) {
+               XMLNodeList p = removed->children ();
+               transform (p.begin(), p.end(), back_inserter (_removed), boost::bind (&PatchChangeDiffCommand::unmarshal_patch_change, this, _1));
+       }
+
+       _changes.clear ();
+       XMLNode* changed = diff_command.child (DIFF_PATCH_CHANGES_ELEMENT);
+       if (changed) {
+               XMLNodeList p = changed->children ();
+               transform (p.begin(), p.end(), back_inserter (_changes), boost::bind (&PatchChangeDiffCommand::unmarshal_change, this, _1));
+       }
+
+       return 0;
+}
+
+XMLNode &
+MidiModel::PatchChangeDiffCommand::get_state ()
+{
+       XMLNode* diff_command = new XMLNode (PATCH_CHANGE_DIFF_COMMAND_ELEMENT);
+       diff_command->add_property("midi-source", _model->midi_source()->id().to_s());
+
+       XMLNode* added = diff_command->add_child (ADDED_PATCH_CHANGES_ELEMENT);
+       for_each (_added.begin(), _added.end(),
+                 boost::bind (
+                         boost::bind (&XMLNode::add_child_nocopy, added, _1),
+                         boost::bind (&PatchChangeDiffCommand::marshal_patch_change, this, _1)
+                         )
+               );
+
+       XMLNode* removed = diff_command->add_child (REMOVED_PATCH_CHANGES_ELEMENT);
+       for_each (_removed.begin(), _removed.end(),
+                 boost::bind (
+                         boost::bind (&XMLNode::add_child_nocopy, removed, _1),
+                         boost::bind (&PatchChangeDiffCommand::marshal_patch_change, this, _1)
+                         )
+               );
+
+       XMLNode* changes = diff_command->add_child (DIFF_PATCH_CHANGES_ELEMENT);
+       for_each (_changes.begin(), _changes.end(),
+                 boost::bind (
+                         boost::bind (&XMLNode::add_child_nocopy, changes, _1),
+                         boost::bind (&PatchChangeDiffCommand::marshal_change, this, _1)
+                         )
+               );
+
+       return *diff_command;
+}
+
+/** Write all of the model to a MidiSource (i.e. save the model).
+ * This is different from manually using read to write to a source in that
+ * note off events are written regardless of the track mode.  This is so the
+ * user can switch a recorded track (with note durations from some instrument)
+ * to percussive, save, reload, then switch it back to sustained without
+ * destroying the original note durations.
+ *
+ * Similarly, control events are written without interpolation (as with the
+ * `Discrete' mode).
+ */
+bool
+MidiModel::write_to (boost::shared_ptr<MidiSource> source)
+{
+       ReadLock lock(read_lock());
+
+       const bool old_percussive = percussive();
+       set_percussive(false);
+
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       source->drop_model();
+       source->mark_streaming_midi_write_started (note_mode());
+
+       for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
+               source->append_event_unlocked_beats(*i);
+       }
+
+       set_percussive(old_percussive);
+       source->mark_streaming_write_completed();
+
+       set_edited(false);
+
+       return true;
+}
+
+/** very similar to ::write_to() but writes to the model's own
+    existing midi_source, without making it call MidiSource::drop_model().
+    the caller is a MidiSource that needs to catch up with the state
+    of the model.
+*/
+bool
+MidiModel::sync_to_source ()
+{
+       ReadLock lock(read_lock());
+
+       const bool old_percussive = percussive();
+       set_percussive(false);
+
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       ms->mark_streaming_midi_write_started (note_mode());
+
+       for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
+               ms->append_event_unlocked_beats(*i);
+       }
+
+       set_percussive (old_percussive);
+       ms->mark_streaming_write_completed ();
+
+       set_edited (false);
+
+       return true;
+}
+
+/** Write part or all of the model to a MidiSource (i.e. save the model).
+ * This is different from manually using read to write to a source in that
+ * note off events are written regardless of the track mode.  This is so the
+ * user can switch a recorded track (with note durations from some instrument)
+ * to percussive, save, reload, then switch it back to sustained without
+ * destroying the original note durations.
+ */
+bool
+MidiModel::write_section_to (boost::shared_ptr<MidiSource> source, Evoral::MusicalTime begin_time, Evoral::MusicalTime end_time)
+{
+       ReadLock lock(read_lock());
+       MidiStateTracker mst;
+       Evoral::MusicalTime extra_note_on_time = end_time;
+
+       const bool old_percussive = percussive();
+       set_percussive(false);
+
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       source->drop_model();
+       source->mark_streaming_midi_write_started (note_mode());
+
+       for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
+               const Evoral::Event<Evoral::MusicalTime>& ev (*i);
+
+               if (ev.time() >= begin_time && ev.time() < end_time) {
+
+                       const Evoral::MIDIEvent<Evoral::MusicalTime>* mev =
+                               static_cast<const Evoral::MIDIEvent<Evoral::MusicalTime>* > (&ev);
+
+                       if (!mev) {
+                               continue;
+                       }
+
+
+                       if (mev->is_note_off()) {
+
+                               if (!mst.active (mev->note(), mev->channel())) {
+
+                                       /* add a note-on at the start of the range we're writing
+                                          to the file. velocity is just an arbitary reasonable value.
+                                       */
+
+                                       Evoral::MIDIEvent<Evoral::MusicalTime> on (mev->event_type(), extra_note_on_time, 3, 0, true);
+                                       on.set_type (mev->type());
+                                       on.set_note (mev->note());
+                                       on.set_channel (mev->channel());
+                                       on.set_velocity (mev->velocity());
+
+                                       cerr << "Add note on for odd note off, note = " << (int) on.note() << endl;
+                                       source->append_event_unlocked_beats (on);
+                                       mst.add (on.note(), on.channel());
+                                       mst.dump (cerr);
+                                       extra_note_on_time += 1.0/128.0;
+                               }
+
+                               cerr << "MIDI Note off (note = " << (int) mev->note() << endl;
+                               source->append_event_unlocked_beats (*i);
+                               mst.remove (mev->note(), mev->channel());
+                               mst.dump (cerr);
+
+                       } else if (mev->is_note_on()) {
+                               cerr << "MIDI Note on (note = " << (int) mev->note() << endl;
+                               mst.add (mev->note(), mev->channel());
+                               source->append_event_unlocked_beats(*i);
+                               mst.dump (cerr);
+                       } else {
+                               cerr << "MIDI other event type\n";
+                               source->append_event_unlocked_beats(*i);
+                       }
+               }
+       }
+
+       mst.resolve_notes (*source, end_time);
+
+       set_percussive(old_percussive);
+       source->mark_streaming_write_completed();
+
+       set_edited(false);
+
+       return true;
+}
+
+XMLNode&
+MidiModel::get_state()
+{
+       XMLNode *node = new XMLNode("MidiModel");
+       return *node;
+}
+
+Evoral::Sequence<MidiModel::TimeType>::NotePtr
+MidiModel::find_note (NotePtr other)
+{
+       Notes::iterator l = notes().lower_bound(other);
+
+       if (l != notes().end()) {
+               for (; (*l)->time() == other->time(); ++l) {
+                       /* NB: compare note contents, not note pointers.
+                          If "other" was a ptr to a note already in
+                          the model, we wouldn't be looking for it,
+                          would we now?
+                       */
+                       if (**l == *other) {
+                               return *l;
+                       }
+               }
+       }
+
+       return NotePtr();
+}
+
+Evoral::Sequence<MidiModel::TimeType>::NotePtr
+MidiModel::find_note (gint note_id)
+{
+       /* used only for looking up notes when reloading history from disk,
+          so we don't care about performance *too* much.
+       */
+
+       for (Notes::iterator l = notes().begin(); l != notes().end(); ++l) {
+               if ((*l)->id() == note_id) {
+                       return *l;
+               }
+       }
+
+       return NotePtr();
+}
+
+MidiModel::PatchChangePtr
+MidiModel::find_patch_change (Evoral::event_id_t id)
+{
+       for (PatchChanges::iterator i = patch_changes().begin(); i != patch_changes().end(); ++i) {
+               if ((*i)->id() == id) {
+                       return *i;
+               }
+       }
+
+       return PatchChangePtr ();
+}
+
+boost::shared_ptr<Evoral::Event<MidiModel::TimeType> >
+MidiModel::find_sysex (gint sysex_id)
+{
+       /* used only for looking up notes when reloading history from disk,
+          so we don't care about performance *too* much.
+       */
+
+       for (SysExes::iterator l = sysexes().begin(); l != sysexes().end(); ++l) {
+               if ((*l)->id() == sysex_id) {
+                       return *l;
+               }
+       }
+
+       return boost::shared_ptr<Evoral::Event<TimeType> > ();
+}
+
+/** Lock and invalidate the source.
+ * This should be used by commands and editing things
+ */
+MidiModel::WriteLock
+MidiModel::edit_lock()
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       Glib::Mutex::Lock* source_lock = new Glib::Mutex::Lock (ms->mutex());
+       ms->invalidate(); // Release cached iterator's read lock on model
+       return WriteLock(new WriteLockImpl(source_lock, _lock, _control_lock));
+}
+
+/** Lock just the model, the source lock must already be held.
+ * This should only be called from libardour/evoral places
+ */
+MidiModel::WriteLock
+MidiModel::write_lock()
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       assert (!ms->mutex().trylock ());
+       return WriteLock(new WriteLockImpl(NULL, _lock, _control_lock));
+}
+
+int
+MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
+{
+       using namespace Evoral;
+
+       if (_writing || insert_merge_policy() == InsertMergeRelax) {
+               return 0;
+       }
+
+       NoteDiffCommand* cmd = static_cast<NoteDiffCommand*>(arg);
+
+       TimeType sa = note->time();
+       TimeType ea  = note->end_time();
+
+       const Pitches& p (pitches (note->channel()));
+       NotePtr search_note(new Note<TimeType>(0, 0, 0, note->note()));
+       set<NotePtr> to_be_deleted;
+       bool set_note_length = false;
+       bool set_note_time = false;
+       TimeType note_time = note->time();
+       TimeType note_length = note->length();
+
+       DEBUG_TRACE (DEBUG::Sequence, string_compose ("%1 checking overlaps for note %2 @ %3\n", this, (int)note->note(), note->time()));
+
+       for (Pitches::const_iterator i = p.lower_bound (search_note);
+            i != p.end() && (*i)->note() == note->note(); ++i) {
+
+               TimeType sb = (*i)->time();
+               TimeType eb = (*i)->end_time();
+               OverlapType overlap = OverlapNone;
+
+               if ((sb > sa) && (eb <= ea)) {
+                       overlap = OverlapInternal;
+               } else if ((eb >= sa) && (eb <= ea)) {
+                       overlap = OverlapStart;
+               } else if ((sb > sa) && (sb <= ea)) {
+                       overlap = OverlapEnd;
+               } else if ((sa >= sb) && (sa <= eb) && (ea <= eb)) {
+                       overlap = OverlapExternal;
+               } else {
+                       /* no overlap */
+                       continue;
+               }
+
+               DEBUG_TRACE (DEBUG::Sequence, string_compose (
+                                    "\toverlap is %1 for (%2,%3) vs (%4,%5)\n",
+                                    enum_2_string(overlap), sa, ea, sb, eb));
+
+               if (insert_merge_policy() == InsertMergeReject) {
+                       DEBUG_TRACE (DEBUG::Sequence, string_compose ("%1 just reject\n", this));
+                       return -1;
+               }
+
+               switch (overlap) {
+               case OverlapStart:
+                       cerr << "OverlapStart\n";
+                       /* existing note covers start of new note */
+                       switch (insert_merge_policy()) {
+                       case InsertMergeReplace:
+                               to_be_deleted.insert (*i);
+                               break;
+                       case InsertMergeTruncateExisting:
+                               if (cmd) {
+                                       cmd->change (*i, NoteDiffCommand::Length, (note->time() - (*i)->time()));
+                               }
+                               (*i)->set_length (note->time() - (*i)->time());
+                               break;
+                       case InsertMergeTruncateAddition:
+                               set_note_time = true;
+                               set_note_length = true;
+                               note_time = (*i)->time() + (*i)->length();
+                               note_length = min (note_length, (*i)->length() - ((*i)->end_time() - note->time()));
+                               break;
+                       case InsertMergeExtend:
+                               if (cmd) {
+                                       cmd->change ((*i), NoteDiffCommand::Length, note->end_time() - (*i)->time());
+                               }
+                               (*i)->set_length (note->end_time() - (*i)->time());
+                               return -1; /* do not add the new note */
+                               break;
+                       default:
+                               /*NOTREACHED*/
+                               /* stupid gcc */
+                               break;
+                       }
+                       break;
+
+               case OverlapEnd:
+                       cerr << "OverlapEnd\n";
+                       /* existing note covers end of new note */
+                       switch (insert_merge_policy()) {
+                       case InsertMergeReplace:
+                               to_be_deleted.insert (*i);
+                               break;
+
+                       case InsertMergeTruncateExisting:
+                               /* resetting the start time of the existing note
+                                  is a problem because of time ordering.
+                               */
+                               break;
+
+                       case InsertMergeTruncateAddition:
+                               set_note_length = true;
+                               note_length = min (note_length, ((*i)->time() - note->time()));
+                               break;
+
+                       case InsertMergeExtend:
+                               /* we can't reset the time of the existing note because
+                                  that will corrupt time ordering. So remove the
+                                  existing note and change the position/length
+                                  of the new note (which has not been added yet)
+                               */
+                               to_be_deleted.insert (*i);
+                               set_note_length = true;
+                               note_length = min (note_length, (*i)->end_time() - note->time());
+                               break;
+                       default:
+                               /*NOTREACHED*/
+                               /* stupid gcc */
+                               break;
+                       }
+                       break;
+
+               case OverlapExternal:
+                       cerr << "OverlapExt\n";
+                       /* existing note overlaps all the new note */
+                       switch (insert_merge_policy()) {
+                       case InsertMergeReplace:
+                               to_be_deleted.insert (*i);
+                               break;
+                       case InsertMergeTruncateExisting:
+                       case InsertMergeTruncateAddition:
+                       case InsertMergeExtend:
+                               /* cannot add in this case */
+                               return -1;
+                       default:
+                               /*NOTREACHED*/
+                               /* stupid gcc */
+                               break;
+                       }
+                       break;
+
+               case OverlapInternal:
+                       cerr << "OverlapInt\n";
+                       /* new note fully overlaps an existing note */
+                       switch (insert_merge_policy()) {
+                       case InsertMergeReplace:
+                       case InsertMergeTruncateExisting:
+                       case InsertMergeTruncateAddition:
+                       case InsertMergeExtend:
+                               /* delete the existing note, the new one will cover it */
+                               to_be_deleted.insert (*i);
+                               break;
+                       default:
+                               /*NOTREACHED*/
+                               /* stupid gcc */
+                               break;
+                       }
+                       break;
+
+               default:
+                       /*NOTREACHED*/
+                       /* stupid gcc */
+                       break;
+               }
+       }
+
+       for (set<NotePtr>::iterator i = to_be_deleted.begin(); i != to_be_deleted.end(); ++i) {
+               remove_note_unlocked (*i);
+
+               if (cmd) {
+                       cmd->side_effect_remove (*i);
+               }
+       }
+
+       if (set_note_time) {
+               if (cmd) {
+                       cmd->change (note, NoteDiffCommand::StartTime, note_time);
+               }
+               note->set_time (note_time);
+       }
+
+       if (set_note_length) {
+               if (cmd) {
+                       cmd->change (note, NoteDiffCommand::Length, note_length);
+               }
+               note->set_length (note_length);
+       }
+
+       return 0;
+}
+
+InsertMergePolicy
+MidiModel::insert_merge_policy () const
+{
+       /* XXX ultimately this should be a per-track or even per-model policy */
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       return ms->session().config.get_insert_merge_policy ();
+}
+
+void
+MidiModel::set_midi_source (boost::shared_ptr<MidiSource> s)
+{
+       boost::shared_ptr<MidiSource> old = _midi_source.lock ();
+
+       if (old) {
+               old->invalidate ();
+       }
+
+       _midi_source_connections.drop_connections ();
+
        _midi_source = s;
+
+       s->InterpolationChanged.connect_same_thread (
+               _midi_source_connections, boost::bind (&MidiModel::source_interpolation_changed, this, _1, _2)
+               );
+
+       s->AutomationStateChanged.connect_same_thread (
+               _midi_source_connections, boost::bind (&MidiModel::source_automation_state_changed, this, _1, _2)
+               );
+}
+
+/** The source has signalled that the interpolation style for a parameter has changed.  In order to
+ *  keep MidiSource and ControlList interpolation state the same, we pass this change onto the
+ *  appropriate ControlList.
+ *
+ *  The idea is that MidiSource and the MidiModel's ControlList states are kept in sync, and one
+ *  or the other is listened to by the GUI.
+ */
+void
+MidiModel::source_interpolation_changed (Evoral::Parameter p, Evoral::ControlList::InterpolationStyle s)
+{
+       Glib::Mutex::Lock lm (_control_lock);
+       control(p)->list()->set_interpolation (s);
+}
+
+/** A ControlList has signalled that its interpolation style has changed.  Again, in order to keep
+ *  MidiSource and ControlList interpolation state in sync, we pass this change onto our MidiSource.
+ */
+void
+MidiModel::control_list_interpolation_changed (Evoral::Parameter p, Evoral::ControlList::InterpolationStyle s)
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       ms->set_interpolation_of (p, s);
+}
+
+void
+MidiModel::source_automation_state_changed (Evoral::Parameter p, AutoState s)
+{
+       Glib::Mutex::Lock lm (_control_lock);
+       boost::shared_ptr<AutomationList> al = boost::dynamic_pointer_cast<AutomationList> (control(p)->list ());
+       al->set_automation_state (s);
+}
+
+void
+MidiModel::automation_list_automation_state_changed (Evoral::Parameter p, AutoState s)
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+       ms->set_automation_state_of (p, s);
+}
+
+boost::shared_ptr<Evoral::Control>
+MidiModel::control_factory (Evoral::Parameter const & p)
+{
+       boost::shared_ptr<Evoral::Control> c = Automatable::control_factory (p);
+
+       /* Set up newly created control's lists to the appropriate interpolation and
+          automation state from our source.
+       */
+
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       c->list()->set_interpolation (ms->interpolation_of (p));
+
+       boost::shared_ptr<AutomationList> al = boost::dynamic_pointer_cast<AutomationList> (c->list ());
+       assert (al);
+
+       al->set_automation_state (ms->automation_state_of (p));
+
+       return c;
+}
+
+boost::shared_ptr<const MidiSource>
+MidiModel::midi_source ()
+{
+       return _midi_source.lock ();
+}
+
+/** Moves notes, controllers and sys-ex to insert silence at the start of the model.
+ *  Adds commands to the session's current undo stack to reflect the movements.
+ */
+void
+MidiModel::insert_silence_at_start (TimeType t)
+{
+       boost::shared_ptr<MidiSource> s = _midi_source.lock ();
+       assert (s);
+
+       /* Notes */
+
+       if (!notes().empty ()) {
+               NoteDiffCommand* c = new_note_diff_command ("insert silence");
+
+               for (Notes::const_iterator i = notes().begin(); i != notes().end(); ++i) {
+                       c->change (*i, NoteDiffCommand::StartTime, (*i)->time() + t);
+               }
+
+               apply_command_as_subcommand (s->session(), c);
+       }
+
+       /* Controllers */
+
+       for (Controls::iterator i = controls().begin(); i != controls().end(); ++i) {
+               boost::shared_ptr<AutomationControl> ac = boost::dynamic_pointer_cast<AutomationControl> (i->second);
+               XMLNode& before = ac->alist()->get_state ();
+               i->second->list()->shift (0, t);
+               XMLNode& after = ac->alist()->get_state ();
+               s->session().add_command (new MementoCommand<AutomationList> (new MidiAutomationListBinder (s, i->first), &before, &after));
+       }
+
+       /* Sys-ex */
+
+       if (!sysexes().empty()) {
+               SysExDiffCommand* c = new_sysex_diff_command ("insert silence");
+
+               for (SysExes::iterator i = sysexes().begin(); i != sysexes().end(); ++i) {
+                       c->change (*i, (*i)->time() + t);
+               }
+
+               apply_command_as_subcommand (s->session(), c);
+       }
+}
+
+/** Transpose notes in a time range by a given number of semitones.  Notes
+ *  will be clamped at 0 and 127 if the transposition would make them exceed
+ *  that range.
+ *
+ *  @param from Start time.
+ *  @param end End time.
+ *  @param semitones Number of semitones to transpose by (+ve is higher, -ve is lower).
+ */
+void
+MidiModel::transpose (TimeType from, TimeType to, int semitones)
+{
+       boost::shared_ptr<const MidiSource> s = midi_source ();
+
+       NoteDiffCommand* c = new_note_diff_command (_("transpose"));
+
+       for (Notes::iterator i = notes().begin(); i != notes().end(); ++i) {
+
+               if ((*i)->time() >= to) {
+
+                       /* finished */
+                       break;
+
+               } else if ((*i)->time() >= from) {
+
+                       int new_note = (*i)->note() + semitones;
+
+                       if (new_note < 0) {
+                               new_note = 0;
+                       } else if (new_note > 127) {
+                               new_note = 127;
+                       }
+
+                       c->change (*i, NoteDiffCommand::NoteNumber, (uint8_t) new_note);
+
+               }
+       }
+
+       apply_command (s->session (), c);
 }