midi_list_editor.cc

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/*
    Copyright (C) 2009 Paul Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <cmath>
#include <map>

#include <gtkmm/cellrenderercombo.h>

#include "evoral/midi_util.h"
#include "evoral/Note.hpp"

#include "ardour/beats_frames_converter.h"
#include "ardour/midi_model.h"
#include "ardour/midi_region.h"
#include "ardour/midi_source.h"
#include "ardour/session.h"
#include "ardour/tempo.h"

#include "gtkmm2ext/gui_thread.h"
#include "gtkmm2ext/keyboard.h"
#include "gtkmm2ext/actions.h"

#include "ardour_ui.h"
#include "midi_list_editor.h"
#include "note_player.h"

#include "i18n.h"

using namespace std;
using namespace Gtk;
using namespace Gtkmm2ext;
using namespace Glib;
using namespace ARDOUR;
using Timecode::BBT_Time;

static map<int,std::string> note_length_map;

static void 
fill_note_length_map ()
{
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat, _("Whole")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/2, _("Half")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/3, _("Triplet")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/4, _("Quarter")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/8, _("Eighth")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/16, _("Sixteenth")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/32, _("Thirty-second")));
        note_length_map.insert (make_pair<int,string> (BBT_Time::ticks_per_beat/64, _("Sixty-fourth")));
}

MidiListEditor::MidiListEditor (Session* s, boost::shared_ptr<MidiRegion> r, boost::shared_ptr<MidiTrack> tr)
        : ArdourWindow (r->name())
        , buttons (1, 1)
        , region (r)
        , track (tr)
{
        if (note_length_map.empty()) {
                fill_note_length_map ();
        }
        
        /* We do not handle nested sources/regions. Caller should have tackled this */

        if (r->max_source_level() > 0) {
                throw failed_constructor();
        }

        set_session (s);

        edit_column = -1;
        editing_renderer = 0;
        editing_editable = 0;

        model = ListStore::create (columns);
        view.set_model (model);

        note_length_model = ListStore::create (note_length_columns);
        TreeModel::Row row;
        
        for (std::map<int,string>::iterator i = note_length_map.begin(); i != note_length_map.end(); ++i) {
                row = *(note_length_model->append());
                row[note_length_columns.ticks] = i->first;
                row[note_length_columns.name] = i->second;
        }

        view.signal_key_press_event().connect (sigc::mem_fun (*this, &MidiListEditor::key_press), false);
        view.signal_key_release_event().connect (sigc::mem_fun (*this, &MidiListEditor::key_release), false);
        view.signal_scroll_event().connect (sigc::mem_fun (*this, &MidiListEditor::scroll_event), false);

        view.append_column (_("Start"), columns.start);
        view.append_column (_("Channel"), columns.channel);
        view.append_column (_("Num"), columns.note);
        view.append_column (_("Name"), columns.note_name);
        view.append_column (_("Vel"), columns.velocity);

        /* use a combo renderer for length, so that we can offer a selection
           of pre-defined note lengths. we still allow edited values with
           arbitrary length (in ticks).
         */

        Gtk::TreeViewColumn* lenCol = Gtk::manage (new Gtk::TreeViewColumn (_("Length")));
        Gtk::CellRendererCombo* comboCell = Gtk::manage(new Gtk::CellRendererCombo);
        lenCol->pack_start(*comboCell);
        lenCol->add_attribute (comboCell->property_text(), columns.length);

        comboCell->property_model() = note_length_model;
        comboCell->property_text_column() = 1;
        comboCell->property_has_entry() = false;

        view.append_column (*lenCol);

        view.set_headers_visible (true);
        view.set_rules_hint (true);
        view.get_selection()->set_mode (SELECTION_MULTIPLE);
        view.get_selection()->signal_changed().connect (sigc::mem_fun (*this, &MidiListEditor::selection_changed));

        for (int i = 0; i < 6; ++i) {
                CellRendererText* renderer = dynamic_cast<CellRendererText*>(view.get_column_cell_renderer (i));

                TreeViewColumn* col = view.get_column (i);
                col->set_data (X_("colnum"), GUINT_TO_POINTER(i));

                renderer->property_editable() = true;

                renderer->signal_editing_started().connect (sigc::bind (sigc::mem_fun (*this, &MidiListEditor::editing_started), i));
                renderer->signal_editing_canceled().connect (sigc::mem_fun (*this, &MidiListEditor::editing_canceled));
                renderer->signal_edited().connect (sigc::mem_fun (*this, &MidiListEditor::edited));
        }

        scroller.add (view);
        scroller.set_policy (POLICY_NEVER, POLICY_AUTOMATIC);

        redisplay_model ();

        region->midi_source(0)->model()->ContentsChanged.connect (content_connection, invalidator (*this), 
                                                                  boost::bind (&MidiListEditor::redisplay_model, this), gui_context());

        buttons.attach (sound_notes_button, 0, 1, 0, 1);
        Glib::RefPtr<Gtk::Action> act = ActionManager::get_action ("Editor", "sound-midi-notes");
        if (act) {
                gtk_activatable_set_related_action (GTK_ACTIVATABLE (sound_notes_button.gobj()), act->gobj());  
        }

        view.show ();
        scroller.show ();
        buttons.show ();
        vbox.show ();
        sound_notes_button.show ();

        vbox.set_spacing (6);
        vbox.set_border_width (6);
        vbox.pack_start (buttons, false, false);
        vbox.pack_start (scroller, true, true);

        add (vbox);
        set_size_request (-1, 400);
}

MidiListEditor::~MidiListEditor ()
{
}

bool
MidiListEditor::scroll_event (GdkEventScroll* ev)
{
        TreeModel::Path path;
        TreeViewColumn* col;
        int cellx;
        int celly;
        int idelta = 0;
        double fdelta = 0;
        MidiModel::NoteDiffCommand::Property prop (MidiModel::NoteDiffCommand::NoteNumber);
        bool apply = false;
        bool was_selected = false;
        char const * opname;

        if (!view.get_path_at_pos (ev->x, ev->y, path, col, cellx, celly)) {
                return false;
        }
        
        if (view.get_selection()->count_selected_rows() == 0) {
                was_selected = false;
        } else if (view.get_selection()->is_selected (path)) {
                was_selected = true;
        } else {
                was_selected = false;
        }
        
        int colnum = GPOINTER_TO_UINT (col->get_data (X_("colnum")));

        switch (colnum) {
        case 0:
                if (Keyboard::modifier_state_equals (ev->state, Keyboard::SecondaryModifier)) {
                        fdelta = 1/64.0;
                } else {
                        fdelta = 1/4.0;
                }
                if (ev->direction == GDK_SCROLL_DOWN || ev->direction == GDK_SCROLL_LEFT) {
                        fdelta = -fdelta;
                }
                prop = MidiModel::NoteDiffCommand::StartTime;
                opname = _("edit note start");
                apply = true;
                break;
        case 1:
                idelta = 1;
                if (ev->direction == GDK_SCROLL_DOWN || ev->direction == GDK_SCROLL_LEFT) {
                        idelta = -idelta;
                }
                prop = MidiModel::NoteDiffCommand::Channel;
                opname = _("edit note channel");
                apply = true;
                break;
        case 2:
        case 3:
                idelta = 1;
                if (ev->direction == GDK_SCROLL_DOWN || ev->direction == GDK_SCROLL_LEFT) {
                        idelta = -idelta;
                }
                prop = MidiModel::NoteDiffCommand::NoteNumber;
                opname = _("edit note number");
                apply = true;
                break;

        case 4:
                idelta = 1;
                if (ev->direction == GDK_SCROLL_DOWN || ev->direction == GDK_SCROLL_LEFT) {
                        idelta = -idelta;
                }
                prop = MidiModel::NoteDiffCommand::Velocity;
                opname = _("edit note velocity");
                apply = true;
                break;

        case 5:
                if (Keyboard::modifier_state_equals (ev->state, Keyboard::SecondaryModifier)) {
                        fdelta = 1/64.0;
                } else {
                        fdelta = 1/4.0;
                }
                if (ev->direction == GDK_SCROLL_DOWN || ev->direction == GDK_SCROLL_LEFT) {
                        fdelta = -fdelta;
                }
                prop = MidiModel::NoteDiffCommand::Length;
                opname = _("edit note length");
                apply = true;
                break;

        default:
                break;
        }


        if (apply) {

                boost::shared_ptr<MidiModel> m (region->midi_source(0)->model());
                MidiModel::NoteDiffCommand* cmd = m->new_note_diff_command (opname);
                vector<TreeModel::Path> previous_selection;

                if (was_selected) {

                        /* use selection */
                        
                        TreeView::Selection::ListHandle_Path rows = view.get_selection()->get_selected_rows ();
                        TreeModel::iterator iter;
                        boost::shared_ptr<NoteType> note;
                        
                        for (TreeView::Selection::ListHandle_Path::iterator i = rows.begin(); i != rows.end(); ++i) {

                                previous_selection.push_back (*i);

                                if ((iter = model->get_iter (*i))) {
                                        
                                        note = (*iter)[columns._note];          
                                        
                                        switch (prop) {
                                        case MidiModel::NoteDiffCommand::StartTime:
                                                if (note->time() + fdelta >= 0) {
                                                        cmd->change (note, prop, note->time() + fdelta);
                                                } else {
                                                        cmd->change (note, prop, Evoral::Beats());
                                                }
                                                break;
                                        case MidiModel::NoteDiffCommand::Velocity:
                                                cmd->change (note, prop, (uint8_t) (note->velocity() + idelta));
                                                break;
                                        case MidiModel::NoteDiffCommand::Length:
                                                if (note->length().to_double() + fdelta >=
                                                    Evoral::Beats::tick().to_double()) {
                                                        cmd->change (note, prop, note->length() + fdelta);
                                                } else {
                                                        cmd->change (note, prop, Evoral::Beats::tick());
                                                }
                                                break;
                                        case MidiModel::NoteDiffCommand::Channel:
                                                cmd->change (note, prop, (uint8_t) (note->channel() + idelta));
                                                break;
                                        case MidiModel::NoteDiffCommand::NoteNumber:
                                                cmd->change (note, prop, (uint8_t) (note->note() + idelta));
                                                break;
                                        default:
                                                continue;
                                        }
                                }
                        }

                } else {

                        /* just this row */
                        
                        TreeModel::iterator iter;
                        iter = model->get_iter (path);

                        previous_selection.push_back (path);

                        if (iter) {
                                boost::shared_ptr<NoteType> note = (*iter)[columns._note];
                                
                                switch (prop) {
                                case MidiModel::NoteDiffCommand::StartTime:
                                        if (note->time() + fdelta >= 0) {
                                                cmd->change (note, prop, note->time() + fdelta);
                                        } else {
                                                cmd->change (note, prop, Evoral::Beats());
                                        }
                                        break;
                                case MidiModel::NoteDiffCommand::Velocity:
                                        cmd->change (note, prop, (uint8_t) (note->velocity() + idelta));
                                        break;
                                case MidiModel::NoteDiffCommand::Length:
                                        if (note->length() + fdelta >=
                                            Evoral::Beats::tick().to_double()) {
                                                cmd->change (note, prop, note->length() + fdelta);
                                        } else {
                                                cmd->change (note, prop, Evoral::Beats::tick());
                                        }
                                        break;
                                case MidiModel::NoteDiffCommand::Channel:
                                        cmd->change (note, prop, (uint8_t) (note->channel() + idelta));
                                        break;
                                case MidiModel::NoteDiffCommand::NoteNumber:
                                        cmd->change (note, prop, (uint8_t) (note->note() + idelta));
                                        break;
                                default:
                                        break;
                                }
                        }
                }

                m->apply_command (*_session, cmd);

                /* reset selection to be as it was before we rebuilt */
                
                for (vector<TreeModel::Path>::iterator i = previous_selection.begin(); i != previous_selection.end(); ++i) {
                        view.get_selection()->select (*i);
                }
        }

        return true;
}

bool
MidiListEditor::key_press (GdkEventKey* ev)
{
        bool ret = false;
        TreeModel::Path path;
        TreeViewColumn* col;
        int colnum;

        switch (ev->keyval) {
        case GDK_Tab:
                if (edit_column > 0) {
                        colnum = edit_column;
                        path = edit_path;
                        if (editing_editable) {
                                editing_editable->editing_done ();
                        }
                        if (colnum >= 5) {
                                /* wrap to next line */
                                colnum = 0;
                                path.next();
                        } else {
                                colnum++;
                        }
                        col = view.get_column (colnum);
                        view.set_cursor (path, *col, true);
                        ret = true;
                }
                break;
                
        case GDK_Up:
        case GDK_uparrow:
                if (edit_column > 0) {
                        colnum = edit_column;
                        path = edit_path;
                        if (editing_editable) {
                                editing_editable->editing_done ();
                        }
                        path.prev ();
                        col = view.get_column (colnum);
                        view.set_cursor (path, *col, true);
                        ret = true;
                }
                break;

        case GDK_Down:
        case GDK_downarrow:
                if (edit_column > 0) {
                        colnum = edit_column;
                        path = edit_path;
                        if (editing_editable) {
                                editing_editable->editing_done ();
                        }
                        path.next ();
                        col = view.get_column (colnum);
                        view.set_cursor (path, *col, true);
                        ret = true;
                }
                break;

        case GDK_Escape:
                stop_editing (true);
                break;
                
        }

        return ret;
}

bool
MidiListEditor::key_release (GdkEventKey* ev)
{
        bool ret = false;
        TreeModel::Path path;
        TreeViewColumn* col;
        TreeModel::iterator iter;
        MidiModel::NoteDiffCommand* cmd;
        boost::shared_ptr<MidiModel> m (region->midi_source(0)->model());
        boost::shared_ptr<NoteType> note;
        boost::shared_ptr<NoteType> copy;

        switch (ev->keyval) {
        case GDK_Insert:
                /* add a new note to the model, based on the note at the cursor
                 * pos
                 */
                view.get_cursor (path, col);
                iter = model->get_iter (path);
                cmd = m->new_note_diff_command (_("insert new note"));
                note = (*iter)[columns._note];
                copy.reset (new NoteType (*note.get()));
                cmd->add (copy);
                m->apply_command (*_session, cmd);
                /* model has been redisplayed by now */
                path.next ();
                /* select, start editing column 2 (note) */
                col = view.get_column (2);
                view.set_cursor (path, *col, true);
                break;

        case GDK_Delete:
        case GDK_BackSpace:
                if (edit_column < 0) {
                        delete_selected_note ();
                }
                ret = true;
                break;

        case GDK_z:
                if (_session && Gtkmm2ext::Keyboard::modifier_state_contains (ev->state, Gtkmm2ext::Keyboard::PrimaryModifier)) {
                        _session->undo (1);
                        ret = true;
                }
                break;
                
        case GDK_r:
                if (_session && Gtkmm2ext::Keyboard::modifier_state_contains (ev->state, Gtkmm2ext::Keyboard::PrimaryModifier)) {
                        _session->redo (1);
                        ret = true;
                }
                break;

        default:
                break;
        }

        return ret;
}

void
MidiListEditor::delete_selected_note ()
{
        Glib::RefPtr<TreeSelection> selection = view.get_selection();
        TreeView::Selection::ListHandle_Path rows = selection->get_selected_rows ();

        if (rows.empty()) {
                return;
        }

        typedef vector<boost::shared_ptr<NoteType> > Notes;
        Notes to_delete;

        for (TreeView::Selection::ListHandle_Path::iterator i = rows.begin(); i != rows.end(); ++i) {
                TreeIter iter;

                if ((iter = model->get_iter (*i))) {
                        boost::shared_ptr<NoteType> note = (*iter)[columns._note];
                        to_delete.push_back (note);
                }
        }

        boost::shared_ptr<MidiModel> m (region->midi_source(0)->model());
        MidiModel::NoteDiffCommand* cmd = m->new_note_diff_command (_("delete notes (from list)"));

        for (Notes::iterator i = to_delete.begin(); i != to_delete.end(); ++i) {
                cmd->remove (*i);
        }

        m->apply_command (*_session, cmd);
}

void
MidiListEditor::stop_editing (bool cancelled)
{
        if (!cancelled) {
                if (editing_editable) {
                        editing_editable->editing_done ();
                }
        } else {
                if (editing_renderer) {
                        editing_renderer->stop_editing (cancelled);
                }
        }
}

void
MidiListEditor::editing_started (CellEditable* ed, const string& path, int colno)
{
        edit_path = TreePath (path);
        edit_column = colno;
        editing_renderer = dynamic_cast<CellRendererText*>(view.get_column_cell_renderer (colno));
        editing_editable = ed;

        if (ed) {
                Gtk::Entry *e = dynamic_cast<Gtk::Entry*> (ed);
                if (e) {
                        e->signal_key_press_event().connect (sigc::mem_fun (*this, &MidiListEditor::key_press), false);
                        e->signal_key_release_event().connect (sigc::mem_fun (*this, &MidiListEditor::key_release), false);
                }
        }
}

void
MidiListEditor::editing_canceled ()
{
        edit_path.clear ();
        edit_column = -1;
        editing_renderer = 0;
        editing_editable = 0;
}

void
MidiListEditor::edited (const std::string& path, const std::string& text)
{
        TreeModel::iterator iter = model->get_iter (path);

        if (!iter || text.empty()) {
                return;
        }

        boost::shared_ptr<NoteType> note = (*iter)[columns._note];
        MidiModel::NoteDiffCommand::Property prop (MidiModel::NoteDiffCommand::NoteNumber);

        double fval;
        int    ival;
        bool   apply = false;
        int    idelta = 0;
        double fdelta = 0;
        char const * opname;
        switch (edit_column) {
        case 0: // start
                break;
        case 1: // channel
                // correct ival for zero-based counting after scan
                if (sscanf (text.c_str(), "%d", &ival) == 1 && --ival != note->channel()) {
                        idelta = ival - note->channel();
                        prop = MidiModel::NoteDiffCommand::Channel;
                        opname = _("change note channel");
                        apply = true;
                }
                break;
        case 2: // note
                if (sscanf (text.c_str(), "%d", &ival) == 1 && ival != note->note()) {
                        idelta = ival - note->note();
                        prop = MidiModel::NoteDiffCommand::NoteNumber;
                        opname = _("change note number");
                        apply = true;
                }
                break;
        case 3: // name
                break;
        case 4: // velocity
                if (sscanf (text.c_str(), "%d", &ival) == 1 && ival != note->velocity()) {
                        idelta = ival - note->velocity();
                        prop = MidiModel::NoteDiffCommand::Velocity;
                        opname = _("change note velocity");
                        apply = true;
                }
                break;
        case 5: // length

                if (sscanf (text.c_str(), "%lf", &fval) == 1) {

                        /* numeric value entered */
                        
                        if (text.find ('.') == string::npos && text.find (',') == string::npos) {
                                /* integral => units are ticks */
                                fval = fval / BBT_Time::ticks_per_beat;
                        } else {
                                /* non-integral => beats, so use as-is */
                        }

                } else {

                        /* assume its text from the combo. look for the map
                         * entry for the actual note ticks
                         */

                        uint64_t len_ticks = note->length().to_ticks();
                        std::map<int,string>::iterator x = note_length_map.find (len_ticks);

                        if (x == note_length_map.end()) {

                                /* tick length not in map - was
                                 * displaying numeric value ... use new value
                                 * from note length map, and convert to beats.
                                 */
                                
                                for (x = note_length_map.begin(); x != note_length_map.end(); ++x) {
                                        if (x->second == text) {
                                                break;
                                        }
                                }
                                
                                if (x != note_length_map.end()) {
                                        fval = x->first / BBT_Time::ticks_per_beat;
                                }

                        } else {

                                fval = -1.0;

                                if (text != x->second) {
                                        
                                        /* get ticks for the newly selected
                                         * note length
                                         */

                                        for (x = note_length_map.begin(); x != note_length_map.end(); ++x) {
                                                if (x->second == text) {
                                                        break;
                                                }
                                        }
                                        
                                        if (x != note_length_map.end()) {
                                                /* convert to beats */
                                                fval = (double) x->first / BBT_Time::ticks_per_beat;
                                        }
                                }
                        }
                }

                if (fval > 0.0) {
                        fdelta = fval - note->length().to_double();
                        prop = MidiModel::NoteDiffCommand::Length;
                        opname = _("change note length");
                        apply = true;
                }
                break;

        default:
                break;
        }

        if (apply) {

                boost::shared_ptr<MidiModel> m (region->midi_source(0)->model());
                MidiModel::NoteDiffCommand* cmd = m->new_note_diff_command (opname);

                TreeView::Selection::ListHandle_Path rows = view.get_selection()->get_selected_rows ();
                
                for (TreeView::Selection::ListHandle_Path::iterator i = rows.begin(); i != rows.end(); ++i) {
                        if ((iter = model->get_iter (*i))) {

                                note = (*iter)[columns._note];          
                                
                                switch (prop) {
                                case MidiModel::NoteDiffCommand::Velocity:
                                        cmd->change (note, prop, (uint8_t) (note->velocity() + idelta));
                                        break;
                                case MidiModel::NoteDiffCommand::Length:
                                        cmd->change (note, prop, note->length() + fdelta);
                                        break;
                                case MidiModel::NoteDiffCommand::Channel:
                                        cmd->change (note, prop, (uint8_t) (note->channel() + idelta));
                                        break;
                                case MidiModel::NoteDiffCommand::NoteNumber:
                                        cmd->change (note, prop, (uint8_t) (note->note() + idelta));
                                        break;
                                default:
                                        continue;
                                }
                        }
                }

                m->apply_command (*_session, cmd);

                /* model has been redisplayed by now */
                /* keep selected row(s), move cursor there, don't continue editing */
                
                TreeViewColumn* col = view.get_column (edit_column);
                view.set_cursor (edit_path, *col, 0);

                /* reset edit info, since we're done */

                edit_path.clear ();
                edit_column = -1;
                editing_renderer = 0;
                editing_editable = 0;
        }
}

void
MidiListEditor::redisplay_model ()
{
        view.set_model (Glib::RefPtr<Gtk::ListStore>(0));
        model->clear ();

        if (_session) {

                BeatsFramesConverter conv (_session->tempo_map(), region->position());
                MidiModel::Notes notes = region->midi_source(0)->model()->notes();
                TreeModel::Row row;
                stringstream ss;

                for (MidiModel::Notes::iterator i = notes.begin(); i != notes.end(); ++i) {
                        row = *(model->append());
                        row[columns.channel] = (*i)->channel() + 1;
                        row[columns.note_name] = Evoral::midi_note_name ((*i)->note());
                        row[columns.note] = (*i)->note();
                        row[columns.velocity] = (*i)->velocity();

                        Timecode::BBT_Time bbt;

                        _session->tempo_map().bbt_time (conv.to ((*i)->time()), bbt);

                        ss.str ("");
                        ss << bbt;
                        row[columns.start] = ss.str();

                        bbt.bars = 0;
                        const Evoral::Beats dur = (*i)->end_time() - (*i)->time();
                        bbt.beats = dur.get_beats ();
                        bbt.ticks = dur.get_ticks ();
                        
                        int len_ticks = (*i)->length().to_ticks();
                        std::map<int,string>::iterator x = note_length_map.find (len_ticks);

                        if (x != note_length_map.end()) {
                                row[columns.length] = x->second;
                        } else {
                                ss.str ("");
                                ss << len_ticks;
                                row[columns.length] = ss.str();
                        }

                        row[columns._note] = (*i);
                }
        }

        view.set_model (model);
}

void
MidiListEditor::selection_changed ()
{
        if (!ARDOUR_UI::config()->get_sound_midi_notes()) {
                return;
        }

        TreeModel::Path path;
        TreeModel::iterator iter;
        boost::shared_ptr<NoteType> note;
        TreeView::Selection::ListHandle_Path rows = view.get_selection()->get_selected_rows ();

        NotePlayer* player = new NotePlayer (track);

        for (TreeView::Selection::ListHandle_Path::iterator i = rows.begin(); i != rows.end(); ++i) {
                if ((iter = model->get_iter (*i))) {
                        note = (*iter)[columns._note];          
                        player->add (note);
                }
        }

        player->play ();
}