src/gigedit/regionchooser.cpp

/*
 * Copyright (C) 2006-2011 Andreas Persson
 *
 * 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, 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 program; see the file COPYING. If not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */

#include "regionchooser.h"

#include <algorithm>

#include <cairomm/context.h>
#include <gdkmm/general.h>
#include <gdkmm/cursor.h>
#include <gtkmm/stock.h>
#include <gtkmm/spinbutton.h>
#include <gtkmm/dialog.h>

#include "global.h"

#define REGION_BLOCK_HEIGHT             20
#define KEYBOARD_HEIGHT                 40

void SortedRegions::update(gig::Instrument* instrument) {
    // Usually, the regions in a gig file are ordered after their key
    // range, but there are files where they are not. The
    // RegionChooser code needs a sorted list of regions.
    regions.clear();
    if (instrument) {
        for (gig::Region* r = instrument->GetFirstRegion() ;
             r ;
             r = instrument->GetNextRegion()) {
            regions.push_back(r);
        }
        sort(regions.begin(), regions.end(), *this);
    }
}

gig::Region* SortedRegions::first() {
    region_iterator = regions.begin();
    return region_iterator == regions.end() ? 0 : *region_iterator;
}

gig::Region* SortedRegions::next() {
    region_iterator++;
    return region_iterator == regions.end() ? 0 : *region_iterator;
}


RegionChooser::RegionChooser() :
    activeKeyColor("red"),
    red("#8070ff"),
    grey1("grey69"),
    white("white"),
    black("black"),
    m_VirtKeybModeChoice(_("Virtual Keyboard Mode")),
    currentActiveKey(-1)
{
    set_size_request(500, KEYBOARD_HEIGHT + REGION_BLOCK_HEIGHT);

    instrument = 0;
    region = 0;
    resize.active = false;
    move.active = false;
    cursor_is_resize = false;
    h1 = REGION_BLOCK_HEIGHT;

    // properties of the virtual keyboard
    {
        const char* choices[] = { _("normal"), _("chord"), 0 };
        static const virt_keyboard_mode_t values[] = {
            VIRT_KEYBOARD_MODE_NORMAL,
            VIRT_KEYBOARD_MODE_CHORD
        };
        m_VirtKeybModeChoice.set_choices(choices, values);
        m_VirtKeybModeChoice.set_value(VIRT_KEYBOARD_MODE_NORMAL);
    }
    m_VirtKeybVelocityLabelDescr.set_text(_("Note-On Velocity:"));
    m_VirtKeybVelocityLabel.set_text("-");
    m_VirtKeybOffVelocityLabelDescr.set_text(_("Note-Off Velocity:"));
    m_VirtKeybOffVelocityLabel.set_text("-");
    m_VirtKeybPropsBox.pack_start(m_VirtKeybModeChoice.label, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.pack_start(m_VirtKeybModeChoice.widget, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.pack_start(m_VirtKeybVelocityLabelDescr, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.pack_start(m_VirtKeybVelocityLabel, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.pack_start(m_VirtKeybOffVelocityLabelDescr, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.pack_start(m_VirtKeybOffVelocityLabel, Gtk::PACK_SHRINK);
    m_VirtKeybPropsBox.set_spacing(10);
    m_VirtKeybPropsBox.show();
    for (int i = 0 ; i < 128 ; i++) key_pressed[i] = false;

    actionGroup = Gtk::ActionGroup::create();
    actionGroup->add(Gtk::Action::create("Properties",
                                         Gtk::Stock::PROPERTIES),
                     sigc::mem_fun(*this,
                                   &RegionChooser::show_region_properties));
    actionGroup->add(Gtk::Action::create("Remove", Gtk::Stock::REMOVE),
                     sigc::mem_fun(*this, &RegionChooser::delete_region));
    actionGroup->add(Gtk::Action::create("Add", Gtk::Stock::ADD),
                     sigc::mem_fun(*this, &RegionChooser::add_region));
    actionGroup->add(Gtk::Action::create("Dimensions", _("Dimensions...")),
                     sigc::mem_fun(*this, &RegionChooser::manage_dimensions));

    uiManager = Gtk::UIManager::create();
    uiManager->insert_action_group(actionGroup);
    Glib::ustring ui_info =
        "<ui>"
        "  <popup name='PopupMenuInsideRegion'>"
        "    <menuitem action='Properties'/>"
        "    <menuitem action='Dimensions'/>"
        "    <menuitem action='Remove'/>"
        "  </popup>"
        "  <popup name='PopupMenuOutsideRegion'>"
        "    <menuitem action='Add'/>"
        "  </popup>"
        "</ui>";
    uiManager->add_ui_from_string(ui_info);

    popup_menu_inside_region = dynamic_cast<Gtk::Menu*>(
        uiManager->get_widget("/PopupMenuInsideRegion"));
    popup_menu_outside_region = dynamic_cast<Gtk::Menu*>(
        uiManager->get_widget("/PopupMenuOutsideRegion"));

    add_events(Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK |
               Gdk::POINTER_MOTION_MASK | Gdk::POINTER_MOTION_HINT_MASK);

    dimensionManager.region_to_be_changed_signal.connect(
        region_to_be_changed_signal.make_slot()
    );
    dimensionManager.region_changed_signal.connect(
        region_changed_signal.make_slot()
    );
    dimensionManager.region_changed_signal.connect(
        sigc::hide(
            sigc::mem_fun(*this, &RegionChooser::on_dimension_manager_changed)
        )
    );
    keyboard_key_hit_signal.connect(
        sigc::mem_fun(*this, &RegionChooser::on_note_on_event)
    );
    keyboard_key_released_signal.connect(
        sigc::mem_fun(*this, &RegionChooser::on_note_off_event)
    );
}

RegionChooser::~RegionChooser()
{
}

void RegionChooser::invalidate_key(int key) {
    const int h = KEYBOARD_HEIGHT;
    const int w = get_width() - 1;
    int x1 = key_to_x(key - 0.5, w);
    int x2 = key_to_x(key + 1.5, w);

    Gdk::Rectangle rect(x1 + 1, h1 + 1, x2 - x1 - 1, h - 2);
    get_window()->invalidate_rect(rect, false);
}

void RegionChooser::on_note_on_event(int key, int velocity) {
    key_pressed[key] = true;
    invalidate_key(key);
    m_VirtKeybVelocityLabel.set_text(ToString(velocity));
}

void RegionChooser::on_note_off_event(int key, int velocity) {
    key_pressed[key] = false;
    invalidate_key(key);
    m_VirtKeybOffVelocityLabel.set_text(ToString(velocity));
}


#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
bool RegionChooser::on_expose_event(GdkEventExpose* e) {
    double clipx1 = e->area.x;
    double clipx2 = e->area.x + e->area.width;
    double clipy1 = e->area.y;
    double clipy2 = e->area.y + e->area.height;

    const Cairo::RefPtr<Cairo::Context>& cr =
        get_window()->create_cairo_context();
#if 0
}
#endif
#else
bool RegionChooser::on_draw(const Cairo::RefPtr<Cairo::Context>& cr) {
    double clipx1, clipx2, clipy1, clipy2;
    cr->get_clip_extents(clipx1, clipy1, clipx2, clipy2);
#endif

    cr->save();
    cr->set_line_width(1);

#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
    const Gdk::Color bg = get_style()->get_bg(Gtk::STATE_NORMAL);
#else
    const Gdk::RGBA bg = get_style_context()->get_background_color();
#endif
    Gdk::Cairo::set_source_rgba(cr, bg);
    cr->paint();

    const int w = get_width() - 1;

    if (clipy2 > h1) {
        draw_keyboard(cr, clipx1, clipx2);
    }

    if (clipy1 < h1 && instrument) {
        draw_regions(cr, clipx1, clipx2);
    }

    cr->restore();

    return true;
}

void RegionChooser::draw_keyboard(const Cairo::RefPtr<Cairo::Context>& cr,
                                  int clip_low, int clip_high) {
    const int h = KEYBOARD_HEIGHT;
    const int w = get_width() - 1;
    const int bh = int(h * 0.55);

    Gdk::Cairo::set_source_rgba(cr, black);
    cr->rectangle(0.5, h1 + 0.5, w, h - 1);
    cr->stroke();

    int x1 = key_to_x(20.5, w);
    Gdk::Cairo::set_source_rgba(cr, grey1);
    cr->rectangle(1, h1 + 1, x1 - 1, h - 2);
    cr->fill();

    int x2 = key_to_x(109.5, w);
    Gdk::Cairo::set_source_rgba(cr, white);
    cr->rectangle(x1 + 1, h1 + 1, x2 - x1 - 1, h - 2);
    cr->fill();

    Gdk::Cairo::set_source_rgba(cr, grey1);
    cr->rectangle(x2 + 1, h1 + 1, w - x2 - 1, h - 2);
    cr->fill();

    Gdk::Cairo::set_source_rgba(cr, black);

    int clipkey1 = std::max(0, x_to_key_right(clip_low - 1, w));
    int clipkey2 = std::min(x_to_key_right(clip_high - 1, w) + 1, 128);

    for (int i = clipkey1 ; i < clipkey2 ; i++) {
        int note = (i + 3) % 12;
        int x = key_to_x(i, w);

        if (note == 1 || note == 4 || note == 6 ||
            note == 9 || note == 11) {
            // black key: short line in the middle, with a rectangle
            // on top
            int x2 = key_to_x(i + 0.5, w);
            cr->move_to(x2 + 0.5, h1 + bh + 0.5);
            cr->line_to(x2 + 0.5, h1 + h - 1);
            cr->stroke();

            int x3 = key_to_x(i + 1, w);
            cr->rectangle(x, h1 + 1, x3 - x + 1, bh);
            cr->fill();
        } else if (note == 3 || note == 8) {
            // C or F: long line to the left
            cr->move_to(x + 0.5, h1 + 1);
            cr->line_to(x + 0.5, h1 + h - 1);
            cr->stroke();
        }

        if (key_pressed[i]) draw_key(cr, i);

        if (note == 3) draw_digit(cr, i);
    }
}


void RegionChooser::draw_regions(const Cairo::RefPtr<Cairo::Context>& cr,
                                 int clip_low, int clip_high) {
    const int w = get_width() - 1;

    Gdk::Cairo::set_source_rgba(cr, black);
    gig::Region* next_region;
    int x3 = -1;
    for (gig::Region* r = regions.first() ; r ; r = next_region) {
        next_region = regions.next();

        if (x3 < 0) {
            x3 = key_to_x(r->KeyRange.low, w);
            if (x3 >= clip_high) break;
        }
        if (!next_region ||
            r->KeyRange.high + 1 != next_region->KeyRange.low ||
            r == region || next_region == region) {

            int x2 = key_to_x(r->KeyRange.high + 1, w);
            if (x2 >= clip_low) {
                cr->move_to(x3, 0.5);
                cr->line_to(x2 + 0.5, 0.5);
                cr->line_to(x2 + 0.5, h1 - 0.5);
                cr->line_to(x3, h1 - 0.5);
                cr->stroke();

                Gdk::Cairo::set_source_rgba(cr, region == r ? red : white);
                cr->rectangle(x3 + 1, 1, x2 - x3 - 1, h1 - 2);
                cr->fill();
                Gdk::Cairo::set_source_rgba(cr, black);
            }
            x3 = -1;
        }
    }

    for (gig::Region* r = regions.first() ; r ; r = regions.next()) {
        int x = key_to_x(r->KeyRange.low, w);

        if (x < clip_low) continue;
        if (x >= clip_high) break;

        cr->move_to(x + 0.5, 1);
        cr->line_to(x + 0.5, h1 - 1);
        cr->stroke();
    }
}

bool RegionChooser::is_black_key(int key) {
    const int note = (key + 3) % 12;
    return note == 1 || note == 4 || note == 6 || note == 9 || note == 11;
}

void RegionChooser::draw_digit(const Cairo::RefPtr<Cairo::Context>& cr,
                               int key) {
    const int h = KEYBOARD_HEIGHT;
    const int w = get_width() - 1;
    Glib::RefPtr<Pango::Layout> layout =
        Pango::Layout::create(get_pango_context());
    char buf[30];
    sprintf(buf, "<span size=\"8000\">%d</span>", key / 12 - 1);
    layout->set_markup(buf);
    Pango::Rectangle rectangle = layout->get_logical_extents();
    double text_w = double(rectangle.get_width()) / Pango::SCALE;
    double text_h = double(rectangle.get_height()) / Pango::SCALE;
    double x = w * (key + 0.75) / 128.0;
    Gdk::Cairo::set_source_rgba(cr, black);
    cr->move_to(int(x - text_w / 2 + 1), int(h1 + h - text_h + 0.5));
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 16) || GTKMM_MAJOR_VERSION < 2
    pango_cairo_show_layout(cr->cobj(), layout->gobj());
#else
    layout->show_in_cairo_context(cr);
#endif
}

void RegionChooser::draw_key(const Cairo::RefPtr<Cairo::Context>& cr,
                             int key) {
    const int h = KEYBOARD_HEIGHT;
    const int w = get_width() - 1;
    const int bh = int(h * 0.55);

    Gdk::Cairo::set_source_rgba(cr, activeKeyColor);

    int note = (key + 3) % 12;
    int x = key_to_x(key, w) + 1;
    int x2 = key_to_x(key + 1.5, w);
    int x3 = key_to_x(key + 1, w);
    int x4 = key_to_x(key - 0.5, w);
    int w1 = x3 - x;
    switch (note) {
    case 0: case 5: case 10:
        cr->rectangle(x, h1 + 1, w1, bh);
        cr->fill();
        cr->rectangle(x4 + 1, h1 + bh + 1, x2 - x4 - 1, h - bh - 2);
        cr->fill();
        break;
    case 2: case 7:
        cr->rectangle(x, h1 + 1, w1, bh);
        cr->fill();
        cr->rectangle(x4 + 1, h1 + bh + 1, x3 - x4 - 1, h - bh - 2);
        cr->fill();
        break;
    case 3: case 8:
        cr->rectangle(x, h1 + 1, w1, bh);
        cr->fill();
        cr->rectangle(x, h1 + bh + 1, x2 - x, h - bh - 2);
        cr->fill();
        break;
    default:
        cr->rectangle(x, h1 + 1, w1, bh - 1);
        cr->fill();
        break;
    }
    Gdk::Cairo::set_source_rgba(cr, black);
}

void RegionChooser::set_instrument(gig::Instrument* instrument)
{
    this->instrument = instrument;
    regions.update(instrument);
    region = regions.first();
    queue_draw();
    region_selected();
    dimensionManager.set_region(region);
}

bool RegionChooser::on_button_release_event(GdkEventButton* event)
{
    const int k = x_to_key(event->x, get_width() - 1);

    // handle-note off on virtual keyboard
    if (event->type == GDK_BUTTON_RELEASE) {
        int velocity = (event->y >= REGION_BLOCK_HEIGHT + KEYBOARD_HEIGHT - 1) ? 127 :
                       int(float(event->y - REGION_BLOCK_HEIGHT) / float(KEYBOARD_HEIGHT) * 128.0f) + 1;
        if (velocity <= 0) velocity = 1;
        switch (m_VirtKeybModeChoice.get_value()) {
            case VIRT_KEYBOARD_MODE_CHORD:
                if (event->y >= REGION_BLOCK_HEIGHT)
                    keyboard_key_released_signal.emit(k, velocity);
                break;
            case VIRT_KEYBOARD_MODE_NORMAL:
            default:
                if (currentActiveKey >= 0 && currentActiveKey <= 127) {
                    keyboard_key_released_signal.emit(currentActiveKey, velocity);
                    currentActiveKey = -1;
                }
                break;
        }
    }

    if (resize.active) {
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
        get_window()->pointer_ungrab(event->time);
#else
        Glib::wrap(event->device, true)->ungrab(event->time);
#endif
        resize.active = false;

        if (!is_in_resize_zone(event->x, event->y) && cursor_is_resize) {
            get_window()->set_cursor();
            cursor_is_resize = false;
        }
    } else if (move.active) {
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
        get_window()->pointer_ungrab(event->time);
#else
        Glib::wrap(event->device, true)->ungrab(event->time);
#endif
        move.active = false;

        if (is_in_resize_zone(event->x, event->y)) {
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
            get_window()->set_cursor(Gdk::Cursor(Gdk::SB_H_DOUBLE_ARROW));
#else
            get_window()->set_cursor(Gdk::Cursor::create(Gdk::SB_H_DOUBLE_ARROW));
#endif
            cursor_is_resize = true;
        }
    }
    return true;
}

void RegionChooser::update_after_resize()
{
    if (resize.mode == resize.moving_high_limit) {
        if (resize.region->KeyRange.high != resize.pos - 1) {
            instrument_struct_to_be_changed_signal.emit(instrument);
            resize.region->SetKeyRange(resize.region->KeyRange.low,
                                       resize.pos - 1);
            regions.update(instrument);
            instrument_changed.emit();
            instrument_struct_changed_signal.emit(instrument);
        }
    } else if (resize.mode == resize.moving_low_limit) {
        if (resize.region->KeyRange.low != resize.pos) {
            instrument_struct_to_be_changed_signal.emit(instrument);
            resize.region->SetKeyRange(resize.pos,
                                       resize.region->KeyRange.high);
            regions.update(instrument);
            instrument_changed.emit();
            instrument_struct_changed_signal.emit(instrument);
        }
    }
}

void RegionChooser::update_after_move(int pos)
{
    instrument_struct_to_be_changed_signal.emit(instrument);
    region->SetKeyRange(pos, pos + region->KeyRange.high -
                        region->KeyRange.low);
    regions.update(instrument);
    instrument_changed.emit();
    instrument_struct_changed_signal.emit(instrument);
}

bool RegionChooser::on_button_press_event(GdkEventButton* event)
{
    if (!instrument) return true;

    const int w = get_width() - 1;
    const int k = x_to_key(event->x, w);

    if (event->type == GDK_BUTTON_PRESS) {
        if (event->y >= REGION_BLOCK_HEIGHT) {
            int velocity = (event->y >= REGION_BLOCK_HEIGHT + KEYBOARD_HEIGHT - 1) ? 127 :
                           int(float(event->y - REGION_BLOCK_HEIGHT) / float(KEYBOARD_HEIGHT) * 128.0f) + 1;
            currentActiveKey = k;
            keyboard_key_hit_signal.emit(k, velocity);
        }
    }

    if (event->y >= REGION_BLOCK_HEIGHT) return true;
    if (event->type == GDK_BUTTON_PRESS && event->button == 3) {
        gig::Region* r = get_region(k);
        if (r) {
            region = r;
            queue_draw();
            region_selected();
            dimensionManager.set_region(region);
            popup_menu_inside_region->popup(event->button, event->time);
        } else {
            new_region_pos = k;
            popup_menu_outside_region->popup(event->button, event->time);
        }
    } else {
        if (is_in_resize_zone(event->x, event->y)) {
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
            get_window()->pointer_grab(false,
                                       Gdk::BUTTON_RELEASE_MASK |
                                       Gdk::POINTER_MOTION_MASK |
                                       Gdk::POINTER_MOTION_HINT_MASK,
                                       Gdk::Cursor(Gdk::SB_H_DOUBLE_ARROW),
                                       event->time);
#else
            Glib::wrap(event->device, true)->grab(get_window(),
                                                  Gdk::OWNERSHIP_NONE,
                                                  false,
                                                  Gdk::BUTTON_RELEASE_MASK |
                                                  Gdk::POINTER_MOTION_MASK |
                                                  Gdk::POINTER_MOTION_HINT_MASK,
                                                  Gdk::Cursor::create(Gdk::SB_H_DOUBLE_ARROW),
                                                  event->time);
#endif
            resize.active = true;
        } else {
            gig::Region* r = get_region(k);
            if (r) {
                region = r;
                queue_draw();
                region_selected();
                dimensionManager.set_region(region);

#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
                get_window()->pointer_grab(false,
                                           Gdk::BUTTON_RELEASE_MASK |
                                           Gdk::POINTER_MOTION_MASK |
                                           Gdk::POINTER_MOTION_HINT_MASK,
                                           Gdk::Cursor(Gdk::FLEUR),
                                           event->time);
#else
                Glib::wrap(event->device, true)->grab(get_window(),
                                                      Gdk::OWNERSHIP_NONE,
                                                      false,
                                                      Gdk::BUTTON_RELEASE_MASK |
                                                      Gdk::POINTER_MOTION_MASK |
                                                      Gdk::POINTER_MOTION_HINT_MASK,
                                                      Gdk::Cursor::create(Gdk::FLEUR),
                                                      event->time);
#endif
                move.active = true;
                move.offset = event->x - key_to_x(region->KeyRange.low, w);
            }
        }
    }
    return true;
}

gig::Region* RegionChooser::get_region(int key)
{
    for (gig::Region* r = regions.first() ; r ; r = regions.next()) {
        if (key < r->KeyRange.low) return 0;
        if (key <= r->KeyRange.high) return r;
    }
    return 0;
}

void RegionChooser::motion_resize_region(int x, int y)
{
    const int w = get_width() - 1;

    int k = int(double(x) / w * 128.0 + 0.5);

    if (k < resize.min) k = resize.min;
    else if (k > resize.max) k = resize.max;

    if (k != resize.pos) {
        if (resize.mode == resize.undecided) {
            if (k < resize.pos) {
                // edit high limit of prev_region
                resize.max = resize.region->KeyRange.low;
                resize.region = resize.prev_region;
                resize.mode = resize.moving_high_limit;
            } else {
                // edit low limit of region
                resize.min = resize.prev_region->KeyRange.high + 1;
                resize.mode = resize.moving_low_limit;
            }
        }
        resize.pos = k;

        int x1, x2;
        if (resize.mode == resize.moving_high_limit) {
            if (resize.region->KeyRange.high < resize.pos - 1) {
                x1 = resize.region->KeyRange.high;
                x2 = resize.pos - 1;
            } else {
                x1 = resize.pos - 1;
                x2 = resize.region->KeyRange.high;
            }
        } else {
            if (resize.region->KeyRange.low < resize.pos) {
                x1 = resize.region->KeyRange.low;
                x2 = resize.pos;
            } else {
                x1 = resize.pos;
                x2 = resize.region->KeyRange.low;
            }
        }
        x1 = key_to_x(x1, w);
        x2 = key_to_x(x2 + 1, w) + 1;
        Gdk::Rectangle rect(x1, 0, x2 - x1, h1);

        update_after_resize();

        get_window()->invalidate_rect(rect, false);
    }
}

void RegionChooser::motion_move_region(int x, int y)
{
    const int w = get_width() - 1;

    int l = int(double(x - move.offset) / w * 128.0 + 0.5);

    if (l == region->KeyRange.low) return;
    int new_l;
    int regionsize = region->KeyRange.high - region->KeyRange.low;
    int a = 0;
    if (l > region->KeyRange.low) {
        for (gig::Region* r = regions.first() ; ; r = regions.next()) {
            if (r != region) {
                int b = r ? r->KeyRange.low : 128;

                // gap: from a to b (not inclusive b)

                if (region->KeyRange.high >= b) {
                    // not found the current gap yet, just continue
                } else {

                    if (a > l) {
                        // this gap is too far to the right, break
                        break;
                    }

                    int newhigh = std::min(l + regionsize, b - 1);
                    int newlo = newhigh - regionsize;

                    if (newlo >= a) {
                        // yes it fits - it's a candidate
                        new_l = newlo;
                    }
                }
                if (!r) break;
                a = r->KeyRange.high + 1;
            }
        }
    } else {
        for (gig::Region* r = regions.first() ; ; r = regions.next()) {
            if (r != region) {
                int b = r ? r->KeyRange.low : 128;

                // gap from a to b (not inclusive b)

                if (l + regionsize >= b) {
                    // not found the current gap yet, just continue
                } else {

                    if (a > region->KeyRange.low) {
                        // this gap is too far to the right, break
                        break;
                    }

                    int newlo = std::max(l, a);
                    int newhigh = newlo + regionsize;

                    if (newhigh < b) {
                        // yes it fits - break as the first one is the best
                        new_l = newlo;
                        break;
                    }
                }
                if (!r) break;
                a = r->KeyRange.high + 1;
            }
        }
    }
    if (new_l == region->KeyRange.low) return;

    int x1 = key_to_x(std::min(int(region->KeyRange.low), new_l), w);
    int x2 = key_to_x(std::max(int(region->KeyRange.high),
                               new_l + regionsize) + 1, w) + 1;

    Gdk::Rectangle rect(x1, 0, x2 - x1, h1);
    update_after_move(new_l);

    get_window()->invalidate_rect(rect, false);
}


bool RegionChooser::on_motion_notify_event(GdkEventMotion* event)
{
    Glib::RefPtr<Gdk::Window> window = get_window();
    int x, y;
    Gdk::ModifierType state = Gdk::ModifierType(0);
    window->get_pointer(x, y, state);

    // handle virtual MIDI keyboard
    if (m_VirtKeybModeChoice.get_value() != VIRT_KEYBOARD_MODE_CHORD &&
        currentActiveKey > 0 &&
        event->y >= REGION_BLOCK_HEIGHT &&
        event->y < REGION_BLOCK_HEIGHT + KEYBOARD_HEIGHT)
    {
        const int k = x_to_key(event->x, get_width() - 1);
        if (k != currentActiveKey) {
            int velocity =
                (event->y >= REGION_BLOCK_HEIGHT + KEYBOARD_HEIGHT - 1) ? 127 :
                int(float(event->y - REGION_BLOCK_HEIGHT) /
                    float(KEYBOARD_HEIGHT) * 128.0f) + 1;
            if (velocity <= 0) velocity = 1;
            keyboard_key_released_signal.emit(currentActiveKey, velocity);
            currentActiveKey = k;
            keyboard_key_hit_signal.emit(k, velocity);
        }
    }

    if (resize.active) {
        motion_resize_region(x, y);
    } else if (move.active) {
        motion_move_region(x, y);
    } else {
        if (is_in_resize_zone(x, y)) {
            if (!cursor_is_resize) {
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
                window->set_cursor(Gdk::Cursor(Gdk::SB_H_DOUBLE_ARROW));
#else
                window->set_cursor(Gdk::Cursor::create(Gdk::SB_H_DOUBLE_ARROW));
#endif
                cursor_is_resize = true;
            }
        } else if (cursor_is_resize) {
            window->set_cursor();
            cursor_is_resize = false;
        }
    }

    return true;
}

bool RegionChooser::is_in_resize_zone(double x, double y) {
    const int w = get_width() - 1;

    if (instrument && y >= 0 && y <= h1) {
        gig::Region* prev_region = 0;
        gig::Region* next_region;
        for (gig::Region* r = regions.first(); r ; r = next_region) {
            next_region = regions.next();

            int lo = key_to_x(r->KeyRange.low, w);
            if (x <= lo - 2) break;
            if (x < lo + 2) {
                resize.region = r;
                resize.pos = r->KeyRange.low;
                resize.max = r->KeyRange.high;

                if (prev_region && prev_region->KeyRange.high + 1 == r->KeyRange.low) {
                    // we don't know yet if it's the high limit of
                    // prev_region or the low limit of r that's going
                    // to be edited
                    resize.mode = resize.undecided;
                    resize.min = prev_region->KeyRange.low + 1;
                    resize.prev_region = prev_region;
                    return resize.min != resize.max;
                }

                // edit low limit
                resize.mode = resize.moving_low_limit;
                resize.min = prev_region ? prev_region->KeyRange.high + 1 : 0;
                return resize.min != resize.max;
            }
            if (!next_region || r->KeyRange.high + 1 != next_region->KeyRange.low) {
                int hi = key_to_x(r->KeyRange.high + 1, w);
                if (x <= hi - 2) break;
                if (x < hi + 2) {
                    // edit high limit
                    resize.region = r;
                    resize.pos = r->KeyRange.high + 1;
                    resize.mode = resize.moving_high_limit;
                    resize.min = r->KeyRange.low + 1;
                    resize.max = next_region ? next_region->KeyRange.low : 128;
                    return resize.min != resize.max;
                }
            }
            prev_region = r;
        }
    }
    return false;
}

sigc::signal<void>& RegionChooser::signal_region_selected()
{
    return region_selected;
}

sigc::signal<void>& RegionChooser::signal_instrument_changed()
{
    return instrument_changed;
}

void RegionChooser::show_region_properties()
{
    if (!region) return;
    Gtk::Dialog dialog(_("Region Properties"), true /*modal*/);
    // add "Keygroup" checkbox
    Gtk::CheckButton checkBoxKeygroup(_("Member of a Keygroup (Exclusive Group)"));
    checkBoxKeygroup.set_active(region->KeyGroup);
    dialog.get_vbox()->pack_start(checkBoxKeygroup);
    checkBoxKeygroup.show();
    // add "Keygroup" spinbox
#if (GTKMM_MAJOR_VERSION == 2 && GTKMM_MINOR_VERSION < 90) || GTKMM_MAJOR_VERSION < 2
    Gtk::Adjustment adjustment(1, 1, 999);
    Gtk::SpinButton spinBox(adjustment);
#else
    Gtk::SpinButton spinBox(Gtk::Adjustment::create(1, 1, 999));
#endif
    if (region->KeyGroup) spinBox.set_value(region->KeyGroup);
    dialog.get_vbox()->pack_start(spinBox);
    spinBox.show();
    // add OK and CANCEL buttons to the dialog
    dialog.add_button(Gtk::Stock::OK, 0);
    dialog.add_button(Gtk::Stock::CANCEL, 1);
    dialog.show_all_children();
    if (!dialog.run()) { // OK selected ...
        region->KeyGroup =
            (checkBoxKeygroup.get_active()) ? spinBox.get_value_as_int() : 0;
    }
}

void RegionChooser::add_region()
{
    instrument_struct_to_be_changed_signal.emit(instrument);

    region = instrument->AddRegion();
    region->SetKeyRange(new_region_pos, new_region_pos);

    instrument_struct_changed_signal.emit(instrument);
    regions.update(instrument);

    queue_draw();
    region_selected();
    dimensionManager.set_region(region);
    instrument_changed();
}

void RegionChooser::delete_region()
{
    instrument_struct_to_be_changed_signal.emit(instrument);
    instrument->DeleteRegion(region);
    instrument_struct_changed_signal.emit(instrument);
    regions.update(instrument);

    region = 0;
    queue_draw();
    region_selected();
    dimensionManager.set_region(region);
    instrument_changed();
}

void RegionChooser::manage_dimensions()
{
    gig::Region* region = get_region();
    if (!region) return;
    dimensionManager.show(region);
}

void RegionChooser::on_dimension_manager_changed() {
    region_selected();
    instrument_changed();
}

sigc::signal<void, gig::Instrument*>& RegionChooser::signal_instrument_struct_to_be_changed() {
    return instrument_struct_to_be_changed_signal;
}

sigc::signal<void, gig::Instrument*>& RegionChooser::signal_instrument_struct_changed() {
    return instrument_struct_changed_signal;
}

sigc::signal<void, gig::Region*>& RegionChooser::signal_region_to_be_changed() {
    return region_to_be_changed_signal;
}

sigc::signal<void, gig::Region*>& RegionChooser::signal_region_changed_signal() {
    return region_changed_signal;
}

sigc::signal<void, int/*key*/, int/*velocity*/>& RegionChooser::signal_keyboard_key_hit() {
    return keyboard_key_hit_signal;
}

sigc::signal<void, int/*key*/, int/*velocity*/>& RegionChooser::signal_keyboard_key_released() {
    return keyboard_key_released_signal;
}