Add a null check to ports when loading an export channel from xml + fix indentation...
[ardour.git] / libs / ardour / midi_model.cc
index c93993aef8c78e13d1e49401115a92f934eccfd3..be8e97b055b757856fa8fcb9858ff069bbdbc1ac 100644 (file)
@@ -18,7 +18,6 @@
 
 */
 
-#define __STDC_LIMIT_MACROS 1
 #include <set>
 #include <iostream>
 #include <algorithm>
 #include "ardour/smf_source.h"
 #include "ardour/types.h"
 #include "ardour/session.h"
+#include "ardour/midi_automation_list_binder.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 (0)
 {
        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)
 {
-       DiffCommand* cmd = new DiffCommand(_midi_source->model(), name);
-       return cmd;
+       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)
+{
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+       
+       return new SysExDiffCommand (ms->model(), name);
+}
+
+
 /** Apply a command.
  *
  * Ownership of cmd is taken, it must not be deleted by the caller.
@@ -88,51 +100,55 @@ 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"
 
 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)
+MidiModel::NoteDiffCommand::change (const NotePtr note, Property prop,
+                                   uint8_t new_value)
 {
+       assert (note);
+       
         NoteChange change;
         
         switch (prop) {
@@ -174,16 +190,18 @@ MidiModel::DiffCommand::change(const NotePtr note, Property prop,
 }
 
 void
-MidiModel::DiffCommand::change(const NotePtr note, Property prop,
-                               TimeType new_time)
+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::DiffCommand::change() with time argument called for note, channel or velocity" << endmsg;
+                fatal << "MidiModel::NoteDiffCommand::change() with time argument called for note, channel or velocity" << endmsg;
                 break;
 
         case StartTime:
@@ -207,8 +225,8 @@ MidiModel::DiffCommand::change(const NotePtr note, Property prop,
         _changes.push_back (change);
 }
 
-MidiModel::DiffCommand&
-MidiModel::DiffCommand::operator+= (const DiffCommand& other)
+MidiModel::NoteDiffCommand &
+MidiModel::NoteDiffCommand::operator+= (const NoteDiffCommand& other)
 {
         if (this == &other) {
                 return *this;
@@ -227,7 +245,7 @@ MidiModel::DiffCommand::operator+= (const DiffCommand& other)
 }
 
 void
-MidiModel::DiffCommand::operator()()
+MidiModel::NoteDiffCommand::operator() ()
 {
         {
                 MidiModel::WriteLock lock(_model->edit_lock());
@@ -292,9 +310,31 @@ MidiModel::DiffCommand::operator()()
 
 
                 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;
+                        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.  It is an un-note.
+                               */
+
+                               /* We didn't change it... */
+                               for (ChangeList::iterator j = _changes.begin(); j != _changes.end(); ) {
+
+                                       ChangeList::iterator k = j;
+                                       ++k;
+                                       
+                                       if (*i == j->note) {
+                                               _changes.erase (j);
+                                       }
+
+                                       j = k;
+                               }
+
+                               /* ...in fact, we removed it */
+                               _removed_notes.push_back (*i);
+                       }
                 }
 
                 if (!side_effect_removals.empty()) {
@@ -309,7 +349,7 @@ MidiModel::DiffCommand::operator()()
 }
 
 void
-MidiModel::DiffCommand::undo()
+MidiModel::NoteDiffCommand::undo ()
 {
         {
                 MidiModel::WriteLock lock(_model->edit_lock());
@@ -376,12 +416,10 @@ MidiModel::DiffCommand::undo()
 }
 
 XMLNode&
-MidiModel::DiffCommand::marshal_note(const NotePtr note)
+MidiModel::NoteDiffCommand::marshal_note(const NotePtr note)
 {
         XMLNode* xml_note = new XMLNode("note");
 
-        cerr << "Marshalling note: " << *note << endl;
-
         {
                 ostringstream id_str(ios::ate);
                 id_str << int(note->id());
@@ -422,7 +460,7 @@ MidiModel::DiffCommand::marshal_note(const NotePtr note)
 }
 
 Evoral::Sequence<MidiModel::TimeType>::NotePtr
-MidiModel::DiffCommand::unmarshal_note(XMLNode *xml_note)
+MidiModel::NoteDiffCommand::unmarshal_note (XMLNode *xml_note)
 {
         unsigned int note;
         XMLProperty* prop;
@@ -487,7 +525,7 @@ MidiModel::DiffCommand::unmarshal_note(XMLNode *xml_note)
 }
 
 XMLNode&
-MidiModel::DiffCommand::marshal_change(const NoteChange& change)
+MidiModel::NoteDiffCommand::marshal_change (const NoteChange& change)
 {
         XMLNode* xml_change = new XMLNode("Change");
 
@@ -522,8 +560,8 @@ MidiModel::DiffCommand::marshal_change(const NoteChange& change)
         return *xml_change;
 }
 
-MidiModel::DiffCommand::NoteChange
-MidiModel::DiffCommand::unmarshal_change(XMLNode *xml_change)
+MidiModel::NoteDiffCommand::NoteChange
+MidiModel::NoteDiffCommand::unmarshal_change (XMLNode *xml_change)
 {
         XMLProperty* prop;
         NoteChange change;
@@ -585,9 +623,9 @@ MidiModel::DiffCommand::unmarshal_change(XMLNode *xml_change)
 }
 
 int
-MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
+MidiModel::NoteDiffCommand::set_state (const XMLNode& diff_command, int /*version*/)
 {
-        if (diff_command.name() != string(DIFF_COMMAND_ELEMENT)) {
+        if (diff_command.name() != string (NOTE_DIFF_COMMAND_ELEMENT)) {
                 return 1;
         }
 
@@ -598,7 +636,7 @@ MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
         if (added_notes) {
                 XMLNodeList notes = added_notes->children();
                 transform(notes.begin(), notes.end(), back_inserter(_added_notes),
-                          boost::bind (&DiffCommand::unmarshal_note, this, _1));
+                          boost::bind (&NoteDiffCommand::unmarshal_note, this, _1));
         }
 
 
@@ -609,7 +647,7 @@ MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
         if (removed_notes) {
                 XMLNodeList notes = removed_notes->children();
                 transform(notes.begin(), notes.end(), back_inserter(_removed_notes),
-                          boost::bind (&DiffCommand::unmarshal_note, this, _1));
+                          boost::bind (&NoteDiffCommand::unmarshal_note, this, _1));
         }
 
 
@@ -622,7 +660,7 @@ MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
         if (changed_notes) {
                 XMLNodeList notes = changed_notes->children();
                 transform (notes.begin(), notes.end(), back_inserter(_changes),
-                           boost::bind (&DiffCommand::unmarshal_change, this, _1));
+                           boost::bind (&NoteDiffCommand::unmarshal_change, this, _1));
 
         }
 
@@ -643,28 +681,28 @@ MidiModel::DiffCommand::set_state(const XMLNode& diff_command, int /*version*/)
 }
 
 XMLNode&
-MidiModel::DiffCommand::get_state ()
+MidiModel::NoteDiffCommand::get_state ()
 {
-        XMLNode* diff_command = new XMLNode(DIFF_COMMAND_ELEMENT);
+        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 (&DiffCommand::marshal_change, this, _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 (&DiffCommand::marshal_note, this, _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 (&DiffCommand::marshal_note, this, _1)));
+                         boost::bind (&NoteDiffCommand::marshal_note, this, _1)));
 
         /* if this command had side-effects, store that state too 
          */
@@ -674,12 +712,183 @@ MidiModel::DiffCommand::get_state ()
                 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)));
+                                 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() ()
+{
+       {
+               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;
+}
 
 /** 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
@@ -699,8 +908,11 @@ MidiModel::write_to (boost::shared_ptr<MidiSource> source)
         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(), _midi_source->timeline_position());
+        source->mark_streaming_midi_write_started (note_mode(), ms->timeline_position ());
 
         for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
                 source->append_event_unlocked_beats(*i);
@@ -727,14 +939,17 @@ MidiModel::sync_to_source ()
         const bool old_percussive = percussive();
         set_percussive(false);
 
-        _midi_source->mark_streaming_midi_write_started(note_mode(), _midi_source->timeline_position());
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+       
+        ms->mark_streaming_midi_write_started (note_mode(), ms->timeline_position());
 
         for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
-                _midi_source->append_event_unlocked_beats(*i);
+                ms->append_event_unlocked_beats(*i);
         }
 
         set_percussive (old_percussive);
-        _midi_source->mark_streaming_write_completed ();
+        ms->mark_streaming_write_completed ();
 
         set_edited (false);
         
@@ -758,8 +973,11 @@ MidiModel::write_section_to (boost::shared_ptr<MidiSource> source, Evoral::Music
         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(), _midi_source->timeline_position());
+        source->mark_streaming_midi_write_started (note_mode(), ms->timeline_position());
 
         for (Evoral::Sequence<TimeType>::const_iterator i = begin(0, true); i != end(); ++i) {
                 const Evoral::Event<Evoral::MusicalTime>& ev (*i);
@@ -866,14 +1084,33 @@ MidiModel::find_note (gint note_id)
         return NotePtr();
 }
 
+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()
 {
-        Glib::Mutex::Lock* source_lock = new Glib::Mutex::Lock(_midi_source->mutex());
-        _midi_source->invalidate(); // Release cached iterator's read lock on model
+       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));
 }
 
@@ -883,7 +1120,10 @@ MidiModel::edit_lock()
 MidiModel::WriteLock
 MidiModel::write_lock()
 {
-        assert(!_midi_source->mutex().trylock());
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+        assert (!ms->mutex().trylock ());
         return WriteLock(new WriteLockImpl(NULL, _lock, _control_lock));
 }
 
@@ -896,7 +1136,7 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
                 return 0;
         }
 
-        DiffCommand* cmd = static_cast<DiffCommand*>(arg);
+        NoteDiffCommand* cmd = static_cast<NoteDiffCommand*>(arg);
 
         TimeType sa = note->time();
         TimeType ea  = note->end_time();
@@ -910,7 +1150,7 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
         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) {
 
@@ -918,7 +1158,6 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
                 TimeType eb = (*i)->end_time();
                 OverlapType overlap = OverlapNone;
 
-
                 if ((sb > sa) && (eb <= ea)) {
                         overlap = OverlapInternal;
                 } else if ((eb >= sa) && (eb <= ea)) {
@@ -932,7 +1171,7 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
                         continue;
                 }
 
-                DEBUG_TRACE (DEBUG::Sequence, string_compose ("\toverlap is %1 for (%2,%3) vs (%4,%5)\n", enum_2_string(overlap), 
+               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) {
@@ -950,7 +1189,7 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
                                 break;
                         case InsertMergeTruncateExisting:
                                 if (cmd) {
-                                        cmd->change (*i, DiffCommand::Length, (note->time() - (*i)->time()));
+                                        cmd->change (*i, NoteDiffCommand::Length, (note->time() - (*i)->time()));
                                 }
                                 (*i)->set_length (note->time() - (*i)->time());
                                 break;
@@ -962,7 +1201,7 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
                                 break;
                         case InsertMergeExtend:
                                 if (cmd) {
-                                        cmd->change ((*i), DiffCommand::Length, note->end_time() - (*i)->time());
+                                        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 */
@@ -1064,14 +1303,14 @@ MidiModel::resolve_overlaps_unlocked (const NotePtr note, void* arg)
 
         if (set_note_time) {
                 if (cmd) {
-                        cmd->change (note, DiffCommand::StartTime, note_time);
+                        cmd->change (note, NoteDiffCommand::StartTime, note_time);
                 } 
                 note->set_time (note_time);
         }
 
         if (set_note_length) {
                 if (cmd) {
-                        cmd->change (note, DiffCommand::Length, note_length);
+                        cmd->change (note, NoteDiffCommand::Length, note_length);
                 } 
                 note->set_length (note_length);
         }
@@ -1083,26 +1322,30 @@ 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 _midi_source->session().config.get_insert_merge_policy();
+        return ms->session().config.get_insert_merge_policy ();
 }
                         
 void
-MidiModel::set_midi_source (MidiSource* s)
+MidiModel::set_midi_source (boost::shared_ptr<MidiSource> s)
 {
-       if (_midi_source) {
-               _midi_source->invalidate ();
+       boost::shared_ptr<MidiSource> old = _midi_source.lock ();
+       
+       if (old) {
+               old->invalidate ();
        }
 
        _midi_source_connections.drop_connections ();
 
        _midi_source = s;
 
-       _midi_source->InterpolationChanged.connect_same_thread (
+       s->InterpolationChanged.connect_same_thread (
                _midi_source_connections, boost::bind (&MidiModel::source_interpolation_changed, this, _1, _2)
                );
 
-       _midi_source->AutomationStateChanged.connect_same_thread (
+       s->AutomationStateChanged.connect_same_thread (
                _midi_source_connections, boost::bind (&MidiModel::source_automation_state_changed, this, _1, _2)
                );
 }
@@ -1127,7 +1370,10 @@ MidiModel::source_interpolation_changed (Evoral::Parameter p, Evoral::ControlLis
 void
 MidiModel::control_list_interpolation_changed (Evoral::Parameter p, Evoral::ControlList::InterpolationStyle s)
 {
-       _midi_source->set_interpolation_of (p, s);
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+
+       ms->set_interpolation_of (p, s);
 }
 
 void
@@ -1141,7 +1387,9 @@ MidiModel::source_automation_state_changed (Evoral::Parameter p, AutoState s)
 void
 MidiModel::automation_list_automation_state_changed (Evoral::Parameter p, AutoState s)
 {
-       _midi_source->set_automation_state_of (p, s);
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
+       ms->set_automation_state_of (p, s);
 }
 
 boost::shared_ptr<Evoral::Control>
@@ -1153,14 +1401,65 @@ MidiModel::control_factory (Evoral::Parameter const & p)
           automation state from our source.
        */
 
-       assert (_midi_source);
+       boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
+       assert (ms);
 
-       c->list()->set_interpolation (_midi_source->interpolation_of (p));
+       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 (_midi_source->automation_state_of (p));
+       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);
+       }
+}