change note colors on the fly, to permit user-definition of colors more easily; remov...
[ardour.git] / libs / ardour / midi_model.cc
index d2e24bafb73ab833e8268a612629a77d71f25633..57cbb70cfdd587831b69773d99e0e05bd9f64d6d 100644 (file)
@@ -1,6 +1,6 @@
 /*
-    Copyright (C) 2007 Paul Davis 
-       Written by Dave Robillard, 2007
+    Copyright (C) 2007 Paul Davis
+    Author: Dave 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
 */
 
 #define __STDC_LIMIT_MACROS 1
-
+#include <set>
 #include <iostream>
 #include <algorithm>
 #include <stdexcept>
 #include <stdint.h>
-#include <pbd/enumwriter.h>
-#include <midi++/events.h>
+#include "pbd/error.h"
+#include "pbd/enumwriter.h"
+#include "midi++/events.h"
 
-#include <ardour/midi_model.h>
-#include <ardour/midi_source.h>
-#include <ardour/types.h>
-#include <ardour/session.h>
+#include "ardour/midi_model.h"
+#include "ardour/midi_source.h"
+#include "ardour/midi_state_tracker.h"
+#include "ardour/smf_source.h"
+#include "ardour/types.h"
+#include "ardour/session.h"
 
 using namespace std;
 using namespace ARDOUR;
+using namespace PBD;
 
-
-void 
-MidiModel::write_lock()        
-{ 
-       _lock.writer_lock(); 
-       _automation_lock.lock(); 
-}
-
-void 
-MidiModel::write_unlock()      
-{ 
-       _lock.writer_unlock(); 
-       _automation_lock.unlock(); 
-}
-
-void 
-MidiModel::read_lock()   const 
-{ 
-       _lock.reader_lock(); 
-       /*_automation_lock.lock();*/ 
-}
-
-void 
-MidiModel::read_unlock() const 
-{ 
-       _lock.reader_unlock(); 
-       /*_automation_lock.unlock();*/ 
-}
-
-// Read iterator (const_iterator)
-
-MidiModel::const_iterator::const_iterator(const MidiModel& model, double t)
-       : _model(&model)
-       , _is_end( (t == DBL_MAX) || model.empty())
-       , _locked( ! _is_end)
-{
-       //cerr << "Created MIDI iterator @ " << t << " (is end: " << _is_end << ")" << endl;
-       
-       if (_is_end)
-               return;
-
-       model.read_lock();
-       
-       _note_iter = model.notes().end();
-       // find first note which begins after t
-       for (MidiModel::Notes::const_iterator i = model.notes().begin(); i != model.notes().end(); ++i) {
-               if ((*i)->time() >= t) {
-                       _note_iter = i;
-                       break;
-               }
-       }
-                       
-       /* TODO: Disabled for stablility reasons
-       MidiControlIterator earliest_control(boost::shared_ptr<AutomationList>(), DBL_MAX, 0.0);
-
-       _control_iters.reserve(model.controls().size());
-       for (Automatable::Controls::const_iterator i = model.controls().begin();
-                       i != model.controls().end(); ++i) {
-
-               assert(i->first.type() == MidiCCAutomation);
-
-               double x, y;
-               bool ret = i->second->list()->rt_safe_earliest_event_unlocked(t, DBL_MAX, x, y);
-               if (!ret) {
-                       //cerr << "MIDI Iterator: CC " << i->first.id() << " (size " << i->second->list()->size()
-                       //      << ") has no events past " << t << endl;
-                       continue;
-               } 
-
-               assert(x >= 0);
-               assert(y >= 0);
-               assert(y <= UINT8_MAX);
-               
-               const MidiControlIterator new_iter(i->second->list(), x, y);
-               
-               //cerr << "MIDI Iterator: CC " << i->first.id() << " added (" << x << ", " << y << ")" << endl;
-               _control_iters.push_back(new_iter);
-
-               if (x < earliest_control.x) {
-                       earliest_control = new_iter;
-                       _control_iter = _control_iters.end();
-                       --_control_iter;
-               }
-       }
-       */
-       
-
-       if (_note_iter != model.notes().end()) {
-               _event = MIDI::Event((*_note_iter)->on_event(), false);
-               _active_notes.push(*_note_iter);
-               //cerr << " new const iterator: size active notes: " << _active_notes.size() << " is empty: " << _active_notes.empty() << endl;
-               ++_note_iter;
-       }
-
-       /** TODO: Disabled for stability reasons
-       if (earliest_control.automation_list && earliest_control.x < _event.time())
-               model.control_to_midi_event(_event, earliest_control);
-       else
-               _control_iter = _control_iters.end();
-        */
-
-       _pgm_change_iter = model.pgm_changes().end();
-       // find first program change which begins after t
-       for (PgmChanges::const_iterator i = model.pgm_changes().begin(); i != model.pgm_changes().end(); ++i) {
-               if ((*i)->time() >= t) {
-                       _pgm_change_iter = i;
-                       break;
-               }
-       }
-       
-       if(_pgm_change_iter != model.pgm_changes().end()) {
-               if((*_pgm_change_iter)->time() <= _event.time()) {
-                       _event = MIDI::Event(*(*_pgm_change_iter), false);
-               }
-       }
-       
-       if (_event.size() == 0) {
-               //cerr << "Created MIDI iterator @ " << t << " is at end." << endl;
-               _is_end = true;
-               
-               // FIXME: possible race condition here....
-               if(_locked) {
-                       _model->read_unlock();
-                       _locked = false;
-               }
-       } else {
-               printf("MIDI Iterator = %X @ %lf\n", _event.type(), _event.time());
-       }
-}
-
-
-MidiModel::const_iterator::~const_iterator()
-{
-       if (_locked) {
-               _model->read_unlock();
-}
-}
-
-const MidiModel::const_iterator&
-MidiModel::const_iterator::operator++()
-{
-       if (_is_end)
-               throw std::logic_error("Attempt to iterate past end of MidiModel");
-
-       cerr << "const_iterator::operator++: _event type:" << hex << "0x" << int(_event.type()) 
-            << "   buffer: 0x" << int(_event.buffer()[0]) << " 0x" << int(_event.buffer()[1]) 
-            << " 0x" << int(_event.buffer()[2]) << endl;
-
-       if(! (_event.is_note() || _event.is_cc() || _event.is_pgm_change())) {
-               cerr << "FAILED pgm change vector size: " << _model->pgm_changes().size() << endl;
-               cerr << "FAILED event buffer: " << hex << int(_event.buffer()[0]) << int(_event.buffer()[1]) << int(_event.buffer()[2]) << endl;
-       }
-       assert(_event.is_note() || _event.is_cc() || _event.is_pgm_change());
-
-       // TODO: This code crashes at the marked section
-       /*
-       // Increment past current control event
-       if (_control_iter != _control_iters.end() && _control_iter->automation_list && _event.is_cc()) {
-               double x, y;
-               cerr << "control_iter x:" << _control_iter->x << " y:" << _control_iter->y << endl;
-               // v--- this crashes because of a null pointer in the stl containers linked list chain
-               //      the crash occurs in _control_iter->automation_list->size();
-               const bool ret = _control_iter->automation_list->rt_safe_earliest_event_unlocked(
-                                    _control_iter->x, DBL_MAX, x, y, false);
-
-               if (ret) {
-                       //cerr << "Incremented " << _control_iter->automation_list->parameter().id() << " to " << x << endl;
-                       _control_iter->x = x;
-                       _control_iter->x = y;
-               } else {
-                       //cerr << "Hit end of " << _control_iter->automation_list->parameter().id() << endl;
-                       _control_iter->automation_list.reset();
-                       _control_iter->x = DBL_MAX;
-               }
-       }
-
-       // Now find and point at the earliest event
-
-       _control_iter = _control_iters.begin();
-
-       for (std::vector<MidiControlIterator>::iterator i = _control_iters.begin();
-                       i != _control_iters.end(); ++i) {
-               if (i->x < _control_iter->x) {
-                       _control_iter = i;
-               }
-       }
-       
-       */
-       
-       enum Type { NIL, NOTE_ON, NOTE_OFF, CC, PGM_CHANGE, PITCH_BENDER };
-       
-       Type   type = NIL;
-       double t    = 0;
-
-       // Next earliest note on
-       if (_note_iter != _model->notes().end()) {
-               type = NOTE_ON;
-               t = (*_note_iter)->time();
-       }
-       
-       // Use the next earliest note off iff it's earlier than the note on
-       if (_model->note_mode() == Sustained && (! _active_notes.empty())) {
-               if (type == NIL || _active_notes.top()->end_time() <= (*_note_iter)->time()) {
-                       type = NOTE_OFF;
-                       t = _active_notes.top()->end_time();
-               }
-       }
-       
-       /* disabled for above mentioned reason, this loops endlessly otherwise
-       // Use the next earliest controller iff it's earlier than the note event
-       if (_control_iter != _control_iters.end() && _control_iter->x != DBL_MAX)
-               if (type == NIL || _control_iter->x < t)
-                       type = CC;
-       */
-       if(_pgm_change_iter != _model->pgm_changes().end()) {
-               if((*_pgm_change_iter)->time() <= t) {
-                       type = PGM_CHANGE;
-                       t = (*_pgm_change_iter)->time();
-                       cerr << "operator++ got PGM CHANGE with time " << t << " and type " << hex
-                       << int((*_pgm_change_iter)->type()) << " and channel " << int((*_pgm_change_iter)->channel()) 
-                       << " and program " << int((*_pgm_change_iter)->pgm_number()) << endl;
-               }
-       }
-
-       if (type == NOTE_ON) {
-               cerr << "********** MIDI Iterator = note on" << endl;
-               _event = MIDI::Event((*_note_iter)->on_event(), false);
-               _active_notes.push(*_note_iter);
-               ++_note_iter;
-       } else if (type == NOTE_OFF) {
-               cerr << "********** MIDI Iterator = note off" << endl;
-               _event = MIDI::Event(_active_notes.top()->off_event(), false);
-               _active_notes.pop();
-       } else if (type == CC) {
-               cerr << "********** MIDI Iterator = CC" << endl;
-               _model->control_to_midi_event(_event, *_control_iter);
-       } else if (type == PGM_CHANGE) {
-               cerr << "********** MIDI Iterator = program change" << endl;
-               _event = MIDI::Event(*(*_pgm_change_iter), false);
-               ++_pgm_change_iter;
-       } else {
-               cerr << "********** MIDI Iterator = END" << endl;
-               _is_end = true;
-       }
-
-       assert(_is_end || _event.size() > 0);
-
-       return *this;
-}
-               
-
-bool
-MidiModel::const_iterator::operator==(const const_iterator& other) const
-{
-       if (_is_end || other._is_end)
-               return (_is_end == other._is_end);
-       else
-               return (_event == other._event);
-}
-               
-
-MidiModel::const_iterator&
-MidiModel::const_iterator::operator=(const const_iterator& other)
-{
-       if (_locked && _model != other._model)
-               _model->read_unlock();
-
-       assert( ! other._event.owns_buffer());
-
-       _model = other._model;
-       _event = other._event;
-       _active_notes = other._active_notes;
-       _is_end = other._is_end;
-       _locked = other._locked;
-       _note_iter = other._note_iter;
-       _control_iters = other._control_iters;
-       _control_iter = other._control_iter;
-       _pgm_change_iter = other._pgm_change_iter;
-       
-       assert( ! _event.owns_buffer());
-       
-       return *this;
-}
-
-       
-// MidiModel
-
-MidiModel::MidiModel(MidiSource *s, size_t size)
-       : Automatable(s->session(), "midi model")
-       , _notes(size)
-       , _note_mode(Sustained)
-       , _writing(false)
-       , _edited(false)
-       , _end_iter(*this, DBL_MAX)
-       , _next_read(UINT32_MAX)
-       , _read_iter(*this, DBL_MAX)
+MidiModel::MidiModel(MidiSource* s)
+       : AutomatableSequence<TimeType>(s->session())
        , _midi_source(s)
 {
-       assert(_end_iter._is_end);
-       assert( ! _end_iter._locked);
 }
 
-/** Read events in frame range \a start .. \a start+cnt into \a dst,
- * adding \a stamp_offset to each event's timestamp.
- * \return number of events written to \a dst
- */
-size_t
-MidiModel::read(MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
-{
-       //cerr << this << " MM::read @ " << start << " frames: " << nframes << " -> " << stamp_offset << endl;
-       //cerr << this << " MM # notes: " << n_notes() << endl;
-
-       size_t read_events = 0;
-
-       if (start != _next_read) {
-               _read_iter = const_iterator(*this, (double)start);
-               //cerr << "Repositioning iterator from " << _next_read << " to " << start << endl;
-       } else {
-               //cerr << "Using cached iterator at " << _next_read << endl;
-       }
-
-       _next_read = start + nframes;
-
-       while (_read_iter != end() && _read_iter->time() < start + nframes) {
-               assert(_read_iter->size() > 0);
-               dst.write(_read_iter->time() + stamp_offset - negative_stamp_offset, _read_iter->size(), _read_iter->buffer());
-               
-               cerr << this << " MidiModel::read event @ " << _read_iter->time()  
-                    << " type: " << hex << int(_read_iter->type()) << dec 
-                    << " note: " << int(_read_iter->note()) 
-                    << " velocity: " << int(_read_iter->velocity()) 
-                    << endl;
-               
-               ++_read_iter;
-               ++read_events;
-       }
-
-       return read_events;
-}
-       
-
-bool
-MidiModel::control_to_midi_event(MIDI::Event& ev, const MidiControlIterator& iter) const
-{
-       if (iter.automation_list->parameter().type() == MidiCCAutomation) {
-               if (ev.size() < 3)
-                       ev.set_buffer((Byte*)malloc(3), true);
-
-               assert(iter.automation_list);
-               assert(iter.automation_list->parameter().channel() < 16);
-               assert(iter.automation_list->parameter().id() <= INT8_MAX);
-               assert(iter.y <= INT8_MAX);
-               ev.buffer()[0] = MIDI_CMD_CONTROL + iter.automation_list->parameter().channel();
-               ev.buffer()[1] = (Byte)iter.automation_list->parameter().id();
-               ev.buffer()[2] = (Byte)iter.y;
-               ev.time() = iter.x;
-               ev.size() = 3;
-               return true;
-       } else {
-               return false;
-       }
-}
-
-       
-/** Begin a write of events to the model.
+/** Start a new Diff command.
  *
- * If \a mode is Sustained, complete notes with duration are constructed as note
- * on/off events are received.  Otherwise (Percussive), only note on events are
- * stored; note off events are discarded entirely and all contained notes will
- * have duration 0.
- */
-void
-MidiModel::start_write()
-{
-       //cerr << "MM " << this << " START WRITE, MODE = " << enum_2_string(_note_mode) << endl;
-       write_lock();
-       _writing = true;
-       for (int i = 0; i < 16; ++i)
-               _write_notes[i].clear();
-       write_unlock();
-}
-
-
-
-/** Finish a write of events to the model.
- *
- * If \a delete_stuck is true and the current mode is Sustained, note on events
- * that were never resolved with a corresonding note off will be deleted.
- * Otherwise they will remain as notes with duration 0.
+ * 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.
  */
-void
-MidiModel::end_write(bool delete_stuck)
+MidiModel::DiffCommand*
+MidiModel::new_diff_command(const string name)
 {
-       write_lock();
-       assert(_writing);
-       
-       //cerr << "MM " << this << " END WRITE: " << _notes.size() << " NOTES\n";
-
-       if (_note_mode == Sustained && delete_stuck) {
-               for (Notes::iterator n = _notes.begin(); n != _notes.end() ; ) {
-                       if ((*n)->duration() == 0) {
-                               cerr << "WARNING: Stuck note lost: " << (*n)->note() << endl;
-                               n = _notes.erase(n);
-                               // we have to break here because erase invalidates the iterator
-                               break;
-                       } else {
-                               ++n;
-                       }
-               }
-       }
-
-       for (int i = 0; i < 16; ++i) {
-               if (!_write_notes[i].empty()) {
-                       cerr << "WARNING: MidiModel::end_write: Channel " << i << " has "
-                                       << _write_notes[i].size() << " stuck notes" << endl;
-               }
-               _write_notes[i].clear();
-       }
-       
-       _writing = false;
-       write_unlock();
+       DiffCommand* cmd = new DiffCommand(_midi_source->model(), name);
+       return cmd;
 }
 
-
-/** Append \a in_event to model.  NOT realtime safe.
+/** Apply a command.
  *
- * Timestamps of events in \a buf are expected to be relative to
- * the start of this model (t=0) and MUST be monotonically increasing
- * and MUST be >= the latest event currently in the model.
+ * Ownership of cmd is taken, it must not be deleted by the caller.
+ * The command will constitute one item on the undo stack.
  */
 void
-MidiModel::append(const MIDI::Event& ev)
+MidiModel::apply_command(Session& session, Command* cmd)
 {
-       write_lock();
-       _edited = true;
-       
-       cerr << "MidiModel::append event type: " << hex << "0x" << int(ev.type()) << endl;
-
-       assert(_notes.empty() || ev.time() >= _notes.back()->time());
-       assert(_writing);
-
-       if (ev.is_note_on()) {
-               append_note_on_unlocked(ev.channel(), ev.time(), ev.note(), ev.velocity());
-       } else if (ev.is_note_off()) {
-               append_note_off_unlocked(ev.channel(), ev.time(), ev.note());
-       } else if (ev.is_cc()) {
-               append_cc_unlocked(ev.channel(), ev.time(), ev.cc_number(), ev.cc_value());
-       } else if (ev.is_pgm_change()) {
-               append_pgm_change_unlocked(ev.channel(), ev.time(), ev.pgm_number());
-       } else { 
-               printf("MM Unknown event type %X\n", ev.type());
-       }
-       
-       write_unlock();
-}
-
-
-void
-MidiModel::append_note_on_unlocked(uint8_t chan, double time, uint8_t note_num, uint8_t velocity)
-{
-       /*cerr << "MidiModel " << this << " chan " << (int)chan <<
-                       " note " << (int)note_num << " on @ " << time << endl;*/
-
-       assert(chan < 16);
-       assert(_writing);
-       _edited = true;
-
-       _notes.push_back(boost::shared_ptr<Note>(new Note(chan, time, 0, note_num, velocity)));
-       if (_note_mode == Sustained) {
-               //cerr << "MM Sustained: Appending active note on " << (unsigned)(uint8_t)note_num << endl;
-               _write_notes[chan].push_back(_notes.size() - 1);
-       }/* else {
-               cerr << "MM Percussive: NOT appending active note on" << endl;
-       }*/
-}
-
-
-void
-MidiModel::append_note_off_unlocked(uint8_t chan, double time, uint8_t note_num)
-{
-       /*cerr << "MidiModel " << this << " chan " << (int)chan <<
-                       " note " << (int)note_num << " off @ " << time << endl;*/
-
-       assert(chan < 16);
-       assert(_writing);
-       _edited = true;
-
-       if (_note_mode == Percussive) {
-               cerr << "MidiModel Ignoring note off (percussive mode)" << endl;
-               return;
-       }
-
-       /* FIXME: make _write_notes fixed size (127 noted) for speed */
-       
-       /* FIXME: note off velocity for that one guy out there who actually has
-        * keys that send it */
-
-       bool resolved = false;
-
-       for (WriteNotes::iterator n = _write_notes[chan].begin(); n != _write_notes[chan].end(); ++n) {
-               Note& note = *_notes[*n].get();
-               //cerr << (unsigned)(uint8_t)note.note() << " ? " << (unsigned)note_num << endl;
-               if (note.note() == note_num) {
-                       assert(time >= note.time());
-                       note.set_duration(time - note.time());
-                       _write_notes[chan].erase(n);
-                       //cerr << "MM resolved note, duration: " << note.duration() << endl;
-                       resolved = true;
-                       break;
-               }
-       }
-
-       if (!resolved)
-               cerr << "MidiModel " << this << " spurious note off chan " << (int)chan
-                       << ", note " << (int)note_num << " @ " << time << endl;
-}
-
-
-void
-MidiModel::append_cc_unlocked(uint8_t chan, double time, uint8_t number, uint8_t value)
-{
-       //cerr << "MidiModel " << this << " chan " << (int)chan <<
-       //              " CC " << (int)number << " = " << (int)value << " @ " << time << endl;
-       
-       assert(chan < 16);
-       assert(_writing);
-       /** TODO: disabled for now until debugged....
-       _edited = true;
-       
-       Parameter param(MidiCCAutomation, number, chan);
-       boost::shared_ptr<AutomationControl> control = Automatable::control(param, true);
-       control->list()->fast_simple_add(time, (double)value);
-       */
-}
-
-void
-MidiModel::append_pgm_change_unlocked(uint8_t chan, double time, uint8_t number) 
-{
-       cerr << "MidiModel::append_pgm_change_unlocked: channel " << int(chan) << " time: " << time << " program number: " << int(number) <<endl; 
-       assert(chan < 16);
-       assert(_writing);
-       _edited = true;
-       
-       boost::shared_ptr<MIDI::Event> event_ptr(new MIDI::Event(time, 3, 0, true));
-       event_ptr->set_type(MIDI_CMD_PGM_CHANGE);
-       event_ptr->set_channel(chan);
-       event_ptr->set_pgm_number(number);
-       _pgm_changes.push_back(event_ptr);
-}
-
-void
-MidiModel::add_note_unlocked(const boost::shared_ptr<Note> note)
-{
-       //cerr << "MidiModel " << this << " add note " << (int)note.note() << " @ " << note.time() << endl;
-       _edited = true;
-       Notes::iterator i = upper_bound(_notes.begin(), _notes.end(), note, note_time_comparator);
-       _notes.insert(i, note);
-}
-
-
-void
-MidiModel::remove_note_unlocked(const boost::shared_ptr<const Note> note)
-{
-       _edited = true;
-       //cerr << "MidiModel " << this << " remove note " << (int)note.note() << " @ " << note.time() << endl;
-       for(Notes::iterator n = _notes.begin(); n != _notes.end(); ++n) {
-               Note& _n = *(*n);
-               const Note& _note = *note;
-               cerr << "======================================= " << endl;
-               cerr << int(_n.note()) << "@" << int(_n.time()) << "[" << int(_n.channel()) << "] --" << int(_n.duration()) << "-- #" << int(_n.velocity())  << endl;
-               cerr << int(_note.note()) << "@" << int(_note.time()) << "[" << int(_note.channel()) << "] --" << int(_note.duration()) << "-- #" << int(_note.velocity())  << endl;
-               cerr << "Equal: " << bool(_n == _note) << endl;
-               cerr << endl << endl;
-               if(_n == _note) {
-                       _notes.erase(n);
-                       // we have to break here, because erase invalidates all iterators, ie. n itself
-                       break;
-               }               
-       }
-}
-
-/** Slow!  for debugging only. */
-#ifndef NDEBUG
-bool
-MidiModel::is_sorted() const
-{
-       bool t = 0;
-       for (Notes::const_iterator n = _notes.begin(); n != _notes.end(); ++n)
-               if ((*n)->time() < t)
-                       return false;
-               else
-                       t = (*n)->time();
-
-       return true;
-}
-#endif
-
-/** Start a new 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::DeltaCommand*
-MidiModel::new_delta_command(const string name)
-{
-       DeltaCommand* cmd =  new DeltaCommand(_midi_source->model(), name);
-       return cmd;
+       session.begin_reversible_command(cmd->name());
+       (*cmd)();
+       session.commit_reversible_command(cmd);
+       set_edited(true);
 }
 
-
-/** Apply a command.
+/** Apply a command as part of a larger reversible transaction
  *
  * Ownership of cmd is taken, it must not be deleted by the caller.
  * The command will constitute one item on the undo stack.
  */
 void
-MidiModel::apply_command(Command* cmd)
+MidiModel::apply_command_as_subcommand(Session& session, Command* cmd)
 {
-       _session.begin_reversible_command(cmd->name());
        (*cmd)();
-       assert(is_sorted());
-       _session.commit_reversible_command(cmd);
-       _edited = true;
+       session.add_command(cmd);
+       set_edited(true);
 }
 
+/************** DIFF COMMAND ********************/
 
-// MidiEditCommand
+#define DIFF_COMMAND_ELEMENT "DiffCommand"
+#define DIFF_NOTES_ELEMENT "ChangedNotes"
+#define ADDED_NOTES_ELEMENT "AddedNotes"
+#define REMOVED_NOTES_ELEMENT "RemovedNotes"
+#define SIDE_EFFECT_REMOVALS_ELEMENT "SideEffectRemovals"
 
-MidiModel::DeltaCommand::DeltaCommand(boost::shared_ptr<MidiModel> m, const std::string& name)
-       : Command(name), _model(m), _name(name) 
+MidiModel::DiffCommand::DiffCommand(boost::shared_ptr<MidiModel> m, const std::string& name)
+       : Command(name)
+       , _model(m)
+       , _name(name)
 {
-       
+       assert(_model);
 }
 
-MidiModel::DeltaCommand::DeltaCommand(boost::shared_ptr<MidiModel> m, const XMLNode& node)
+MidiModel::DiffCommand::DiffCommand(boost::shared_ptr<MidiModel> m, const XMLNode& node)
        : _model(m)
 {
-       set_state(node);
+       assert(_model);
+       set_state(node, Stateful::loading_state_version);
 }
 
 void
-MidiModel::DeltaCommand::add(const boost::shared_ptr<Note> note)
+MidiModel::DiffCommand::add(const NotePtr note)
 {
-       //cerr << "MEC: apply" << endl;
-
        _removed_notes.remove(note);
        _added_notes.push_back(note);
 }
 
-
 void
-MidiModel::DeltaCommand::remove(const boost::shared_ptr<Note> note)
+MidiModel::DiffCommand::remove(const NotePtr note)
 {
-       //cerr << "MEC: remove" << endl;
-
        _added_notes.remove(note);
        _removed_notes.push_back(note);
 }
 
-               
-void 
-MidiModel::DeltaCommand::operator()()
-{
-       // This could be made much faster by using a priority_queue for added and
-       // removed notes (or sort here), and doing a single iteration over _model
-       
-       // Need to reset iterator to drop the read lock it holds, or we'll deadlock
-       const bool   reset_iter = (_model->_read_iter.locked());
-       const double iter_time  = _model->_read_iter->time();
-
-       if (reset_iter)
-               _model->_read_iter = _model->end(); // drop read lock
-
-       assert( ! _model->_read_iter.locked());
-
-       _model->write_lock();
-       
-       for (std::list< boost::shared_ptr<Note> >::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i)
-               _model->add_note_unlocked(*i);
-       
-       for (std::list< boost::shared_ptr<Note> >::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i)
-               _model->remove_note_unlocked(*i);
-       
-       _model->write_unlock();
-
-       if (reset_iter)
-               _model->_read_iter = const_iterator(*_model.get(), iter_time);
-       
-       _model->ContentsChanged(); /* EMIT SIGNAL */
-}
-
-
 void
-MidiModel::DeltaCommand::undo()
-{
-       // This could be made much faster by using a priority_queue for added and
-       // removed notes (or sort here), and doing a single iteration over _model
-       
-       // Need to reset iterator to drop the read lock it holds, or we'll deadlock
-       const bool   reset_iter = (_model->_read_iter.locked());
-       const double iter_time  = _model->_read_iter->time();
-
-       if (reset_iter)
-               _model->_read_iter = _model->end(); // drop read lock
-       
-       assert( ! _model->_read_iter.locked());
-
-       _model->write_lock();
-
-       for (std::list< boost::shared_ptr<Note> >::iterator i = _added_notes.begin(); i != _added_notes.end(); ++i)
-               _model->remove_note_unlocked(*i);
-       
-       for (std::list< boost::shared_ptr<Note> >::iterator i = _removed_notes.begin(); i != _removed_notes.end(); ++i)
-               _model->add_note_unlocked(*i);
-       
-       _model->write_unlock();
-       
-       if (reset_iter)
-               _model->_read_iter = const_iterator(*_model.get(), iter_time);
-       
-       _model->ContentsChanged(); /* EMIT SIGNAL */
-}
-
-XMLNode &
-MidiModel::DeltaCommand::marshal_note(const boost::shared_ptr<Note> note)
-{
-       XMLNode *xml_note = new XMLNode("note");
-       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 << int(note->time());
-       xml_note->add_property("time", time_str.str());
-
-       ostringstream duration_str(ios::ate);
-       duration_str <<(unsigned int) note->duration();
-       xml_note->add_property("duration", duration_str.str());
-
-       ostringstream velocity_str(ios::ate);
-       velocity_str << (unsigned int) note->velocity();
-       xml_note->add_property("velocity", velocity_str.str());
-       
-       return *xml_note;
-}
-
-boost::shared_ptr<Note> 
-MidiModel::DeltaCommand::unmarshal_note(XMLNode *xml_note) 
+MidiModel::DiffCommand::side_effect_remove(const NotePtr note)
 {
-       unsigned int note;
-       istringstream note_str(xml_note->property("note")->value());
-       note_str >> note;
-
-       unsigned int channel;
-       istringstream channel_str(xml_note->property("channel")->value());
-       channel_str >> channel;
-
-       unsigned int time;
-       istringstream time_str(xml_note->property("time")->value());
-       time_str >> time;
-
-       unsigned int duration;
-       istringstream duration_str(xml_note->property("duration")->value());
-       duration_str >> duration;
-
-       unsigned int velocity;
-       istringstream velocity_str(xml_note->property("velocity")->value());
-       velocity_str >> velocity;
-       
-       boost::shared_ptr<Note> note_ptr(new Note(channel, time, duration, note, velocity));
-       return note_ptr;
+       side_effect_removals.insert (note);
 }
 
-#define ADDED_NOTES_ELEMENT "added_notes"
-#define REMOVED_NOTES_ELEMENT "removed_notes"
-#define DELTA_COMMAND_ELEMENT "DeltaCommand"
+ 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)));
 
-int 
-MidiModel::DeltaCommand::set_state (const XMLNode& delta_command)
-{
-       if(delta_command.name() != string(DELTA_COMMAND_ELEMENT)) {
-               return 1;
-       }
-       
-       _added_notes.clear();
-       XMLNode *added_notes = delta_command.child(ADDED_NOTES_ELEMENT);
-       XMLNodeList notes = added_notes->children();
-       transform(notes.begin(), notes.end(), back_inserter(_added_notes), 
-                 sigc::mem_fun(*this, &DeltaCommand::unmarshal_note));
-       
-       _removed_notes.clear();
-       XMLNode *removed_notes = delta_command.child(REMOVED_NOTES_ELEMENT);
-       notes = removed_notes->children();
-       transform(notes.begin(), notes.end(), back_inserter(_removed_notes), 
-                       sigc::mem_fun(*this, &DeltaCommand::unmarshal_note));
-       
-       return 0;
-}
+         /* if this command had side-effects, store that state too 
+          */
 
-XMLNode& 
-MidiModel::DeltaCommand::get_state () 
-{
-       XMLNode *delta_command = new XMLNode(DELTA_COMMAND_ELEMENT);
-       delta_command->add_property("midi_source", _model->midi_source()->id().to_s());
-       
-       XMLNode *added_notes   = delta_command->add_child(ADDED_NOTES_ELEMENT);
-       for_each(_added_notes.begin(), _added_notes.end(), 
-               sigc::compose(sigc::mem_fun(*added_notes, &XMLNode::add_child_nocopy),
-                             sigc::mem_fun(*this, &DeltaCommand::marshal_note))); 
-       
-       XMLNode *removed_notes   = delta_command->add_child(REMOVED_NOTES_ELEMENT);
-       for_each(_removed_notes.begin(), _removed_notes.end(), 
-               sigc::compose(sigc::mem_fun(*removed_notes, &XMLNode::add_child_nocopy),
-                             sigc::mem_fun(*this, &DeltaCommand::marshal_note))); 
-
-       return *delta_command;
+         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();
 }
-
-
-struct EventTimeComparator {
-       typedef const MIDI::Event* value_type;
-       inline bool operator()(const MIDI::Event* a,
-                              const MIDI::Event* b) const { 
-               return a->time() >= b->time();
-       }
-};
-
-bool
-MidiModel::write_to(boost::shared_ptr<MidiSource> source)
-{
-       cerr << "Writing model to " << source->name() << endl;
-
-       /* This could be done using a temporary MidiRingBuffer and using
-        * MidiModel::read and MidiSource::write, but this is more efficient
-        * and doesn't require any buffer size assumptions (ie it's worth
-        * the code duplication).
-        *
-        * This is also different from read 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 preserving the original
-        * note durations.
-        */
-
-       /* Percussive 
-       for (Notes::const_iterator n = _notes.begin(); n != _notes.end(); ++n) {
-               const MIDI::Event& ev = n->on_event();
-               source->append_event_unlocked(ev);
-       }*/
-
-       read_lock();
-
-       //LaterNoteEndComparator cmp;
-       //ActiveNotes active_notes(cmp);
-       
-       EventTimeComparator comp;
-       typedef std::priority_queue<
-                               MIDI::Event*, 
-                               std::deque<MIDI::Event*>,
-                               EventTimeComparator> MidiEvents;
-       
-       MidiEvents events(comp);
-       
-
-       for (Notes::const_iterator n = _notes.begin(); n != _notes.end(); ++n) {
-               events.push(&(*n)->on_event());
-               events.push(&(*n)->off_event());
-       }
-       
-       for (PgmChanges::const_iterator p = _pgm_changes.begin(); p != _pgm_changes.end(); ++p) {
-               events.push((*p).get());                
-       }
-
-       while(!events.empty()) {
-               source->append_event_unlocked(Frames, *events.top());
-               cerr << "MidiModel::write_to appending event with time:" << dec << int(events.top()->time()) << hex 
-                    << "   buffer: 0x" << int(events.top()->buffer()[0]) << " 0x" << int(events.top()->buffer()[1]) 
-                    << " 0x" << int(events.top()->buffer()[2]) << endl;
-               events.pop();
-       }
-       
-               
-       /* Why sort manyally, when a priority queue does the job for us,
-        * or am I missing something???
-        * 
-       // Foreach note
-       for (Notes::const_iterator n = _notes.begin(); n != _notes.end(); ++n) {
-
-               // Write any pending note offs earlier than this note on
-               while ( ! active_notes.empty() ) {
-                       const boost::shared_ptr<const Note> earliest_off = active_notes.top();
-                       const MIDI::Event& off_ev = earliest_off->off_event();
-                       if (off_ev.time() <= (*n)->time()) {
-                               source->append_event_unlocked(Frames, off_ev);
-                               active_notes.pop();
-                       } else {
-                               break;
-                       }
-               }
-               
-               // Write program changes preceding this note on
-               if(p != _pgm_changes.end() && ((*p)->time() <= (*n)->time())) {
-                       const MIDI::Event& pgm_change_event = *(*p);
-                       source->append_event_unlocked(Frames, pgm_change_event);
-                       ++p;
-               }
-
-               // Write this note on
-               source->append_event_unlocked(Frames, (*n)->on_event());
-               if ((*n)->duration() > 0)
-                       active_notes.push(*n);
-       }
-               
-       // Write any trailing note offs
-       while ( ! active_notes.empty() ) {
-               source->append_event_unlocked(Frames, active_notes.top()->off_event());
-               active_notes.pop();
-       }
-       */
-       
-       _edited = false;
-       
-       read_unlock();
-
-       return true;
-}
-
-XMLNode&
-MidiModel::get_state()
+                        
+void
+MidiModel::set_midi_source (MidiSource* s)
 {
-       XMLNode *node = new XMLNode("MidiModel");
-       return *node;
+       _midi_source->invalidate ();
+       _midi_source = s;
 }
-
-const MidiSource * 
-MidiModel::midi_source() const
-{ 
-       return _midi_source; 
-}
-
-void 
-MidiModel::set_midi_source(MidiSource *source) 
-{ 
-       _midi_source = source; 
-}