editor_drag.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.

*/

#ifdef WAF_BUILD
#include "gtk2ardour-config.h"
#endif

#include <stdint.h>
#include <algorithm>

#include "pbd/memento_command.h"
#include "pbd/basename.h"
#include "pbd/stateful_diff_command.h"

#include "gtkmm2ext/utils.h"

#include "ardour/audioengine.h"
#include "ardour/audioregion.h"
#include "ardour/audio_track.h"
#include "ardour/dB.h"
#include "ardour/midi_region.h"
#include "ardour/midi_track.h"
#include "ardour/operations.h"
#include "ardour/region_factory.h"
#include "ardour/session.h"

#include "canvas/canvas.h"
#include "canvas/scroll_group.h"

#include "editor.h"
#include "i18n.h"
#include "keyboard.h"
#include "audio_region_view.h"
#include "automation_region_view.h"
#include "midi_region_view.h"
#include "ardour_ui.h"
#include "gui_thread.h"
#include "control_point.h"
#include "region_gain_line.h"
#include "editor_drag.h"
#include "audio_time_axis.h"
#include "midi_time_axis.h"
#include "selection.h"
#include "midi_selection.h"
#include "automation_time_axis.h"
#include "debug.h"
#include "editor_cursors.h"
#include "mouse_cursors.h"
#include "note_base.h"
#include "patch_change.h"
#include "verbose_cursor.h"

using namespace std;
using namespace ARDOUR;
using namespace PBD;
using namespace Gtk;
using namespace Gtkmm2ext;
using namespace Editing;
using namespace ArdourCanvas;

using Gtkmm2ext::Keyboard;

double ControlPointDrag::_zero_gain_fraction = -1.0;

DragManager::DragManager (Editor* e)
        : _editor (e)
        , _ending (false)
        , _current_pointer_frame (0)
{
}

DragManager::~DragManager ()
{
        abort ();
}

void
DragManager::abort ()
{
        _ending = true;

        cerr << "Aborting drag\n";

        for (list<Drag*>::const_iterator i = _drags.begin(); i != _drags.end(); ++i) {
                (*i)->abort ();
                delete *i;
        }

        if (!_drags.empty ()) {
                _editor->set_follow_playhead (_old_follow_playhead, false);
        }

        _drags.clear ();
        _editor->abort_reversible_command();

        _ending = false;
}

void
DragManager::add (Drag* d)
{
        d->set_manager (this);
        _drags.push_back (d);
}

void
DragManager::set (Drag* d, GdkEvent* e, Gdk::Cursor* c)
{
        d->set_manager (this);
        _drags.push_back (d);
        start_grab (e, c);
}

void
DragManager::start_grab (GdkEvent* e, Gdk::Cursor* c)
{
        /* Prevent follow playhead during the drag to be nice to the user */
        _old_follow_playhead = _editor->follow_playhead ();
        _editor->set_follow_playhead (false);

        _current_pointer_frame = _editor->canvas_event_sample (e, &_current_pointer_x, &_current_pointer_y);

        for (list<Drag*>::const_iterator i = _drags.begin(); i != _drags.end(); ++i) {
                (*i)->start_grab (e, c);
        }
}

bool
DragManager::end_grab (GdkEvent* e)
{
        _ending = true;

        bool r = false;
        for (list<Drag*>::iterator i = _drags.begin(); i != _drags.end(); ++i) {
                bool const t = (*i)->end_grab (e);
                if (t) {
                        r = true;
                }
                delete *i;
        }

        _drags.clear ();

        _ending = false;

        _editor->set_follow_playhead (_old_follow_playhead, false);

        return r;
}

void
DragManager::mark_double_click ()
{
        for (list<Drag*>::const_iterator i = _drags.begin(); i != _drags.end(); ++i) {
                (*i)->set_double_click (true);
        }
}

bool
DragManager::motion_handler (GdkEvent* e, bool from_autoscroll)
{
        bool r = false;

        /* calling this implies that we expect the event to have canvas
         * coordinates
         *
         * Can we guarantee that this is true?
         */

        _current_pointer_frame = _editor->canvas_event_sample (e, &_current_pointer_x, &_current_pointer_y);

        for (list<Drag*>::iterator i = _drags.begin(); i != _drags.end(); ++i) {
                bool const t = (*i)->motion_handler (e, from_autoscroll);
                /* run all handlers; return true if at least one of them
                   returns true (indicating that the event has been handled).
                */
                if (t) {
                        r = true;
                }

        }

        return r;
}

bool
DragManager::have_item (ArdourCanvas::Item* i) const
{
        list<Drag*>::const_iterator j = _drags.begin ();
        while (j != _drags.end() && (*j)->item () != i) {
                ++j;
        }

        return j != _drags.end ();
}

Drag::Drag (Editor* e, ArdourCanvas::Item* i, bool trackview_only)
        : _editor (e)
        , _item (i)
        , _pointer_frame_offset (0)
        , _trackview_only (trackview_only)
        , _move_threshold_passed (false)
        , _starting_point_passed (false)
        , _initially_vertical (false)
        , _was_double_click (false)
        , _raw_grab_frame (0)
        , _grab_frame (0)
        , _last_pointer_frame (0)
{

}

void
Drag::swap_grab (ArdourCanvas::Item* new_item, Gdk::Cursor* cursor, uint32_t /*time*/)
{
        _item->ungrab ();
        _item = new_item;

        if (!_cursor_ctx) {
                _cursor_ctx = CursorContext::create (*_editor, cursor);
        } else {
                _cursor_ctx->change (cursor);
        }

        _item->grab ();
}

void
Drag::start_grab (GdkEvent* event, Gdk::Cursor *cursor)
{
        // if dragging with button2, the motion is x constrained, with Alt-button2 it is y constrained

        if (Keyboard::is_button2_event (&event->button)) {
                if (Keyboard::modifier_state_equals (event->button.state, Keyboard::SecondaryModifier)) {
                        _y_constrained = true;
                        _x_constrained = false;
                } else {
                        _y_constrained = false;
                        _x_constrained = true;
                }
        } else {
                _x_constrained = false;
                _y_constrained = false;
        }

        _raw_grab_frame = _editor->canvas_event_sample (event, &_grab_x, &_grab_y);
        setup_pointer_frame_offset ();
        _grab_frame = adjusted_frame (_raw_grab_frame, event);
        _last_pointer_frame = _grab_frame;
        _last_pointer_x = _grab_x;

        if (_trackview_only) {
                _grab_y = _grab_y - _editor->get_trackview_group()->canvas_origin().y;
        }

        _last_pointer_y = _grab_y;

        _item->grab ();

        if (!_editor->cursors()->is_invalid (cursor)) {
                /* CAIROCANVAS need a variant here that passes *cursor */
                _cursor_ctx = CursorContext::create (*_editor, cursor);
        }

        if (_editor->session() && _editor->session()->transport_rolling()) {
                _was_rolling = true;
        } else {
                _was_rolling = false;
        }

        switch (_editor->snap_type()) {
        case SnapToRegionStart:
        case SnapToRegionEnd:
        case SnapToRegionSync:
        case SnapToRegionBoundary:
                _editor->build_region_boundary_cache ();
                break;
        default:
                break;
        }
}

bool
Drag::end_grab (GdkEvent* event)
{
        _editor->stop_canvas_autoscroll ();

        _item->ungrab ();

        finished (event, _move_threshold_passed);

        _editor->verbose_cursor()->hide ();
        _cursor_ctx.reset();

        return _move_threshold_passed;
}

framepos_t
Drag::adjusted_frame (framepos_t f, GdkEvent const * event, bool snap) const
{
        framepos_t pos = 0;

        if (f > _pointer_frame_offset) {
                pos = f - _pointer_frame_offset;
        }

        if (snap) {
                _editor->snap_to_with_modifier (pos, event);
        }

        return pos;
}

framepos_t
Drag::adjusted_current_frame (GdkEvent const * event, bool snap) const
{
        return adjusted_frame (_drags->current_pointer_frame (), event, snap);
}

double
Drag::current_pointer_x() const
{
        return _drags->current_pointer_x ();
}

double
Drag::current_pointer_y () const
{
        if (!_trackview_only) {
                return _drags->current_pointer_y ();
        }

        return _drags->current_pointer_y () - _editor->get_trackview_group()->canvas_origin().y;
}

bool
Drag::motion_handler (GdkEvent* event, bool from_autoscroll)
{
        /* check to see if we have moved in any way that matters since the last motion event */
        if (_move_threshold_passed &&
            (!x_movement_matters() || _last_pointer_x == current_pointer_x ()) &&
            (!y_movement_matters() || _last_pointer_y == current_pointer_y ()) ) {
                return false;
        }

        pair<framecnt_t, int> const threshold = move_threshold ();

        bool const old_move_threshold_passed = _move_threshold_passed;

        if (!_move_threshold_passed) {

                bool const xp = (::llabs (_drags->current_pointer_frame () - _raw_grab_frame) >= threshold.first);
                bool const yp = (::fabs ((current_pointer_y () - _grab_y)) >= threshold.second);

                _move_threshold_passed = ((xp && x_movement_matters()) || (yp && y_movement_matters()));
        }

        if (active (_editor->mouse_mode) && _move_threshold_passed) {

                if (event->motion.state & Gdk::BUTTON1_MASK || event->motion.state & Gdk::BUTTON2_MASK) {

                        if (old_move_threshold_passed != _move_threshold_passed) {

                                /* just changed */

                                if (fabs (current_pointer_y() - _grab_y) > fabs (current_pointer_x() - _grab_x)) {
                                        _initially_vertical = true;
                                } else {
                                        _initially_vertical = false;
                                }
                        }

                        if (!from_autoscroll) {
                                _editor->maybe_autoscroll (true, allow_vertical_autoscroll (), false);
                        }

                        if (!_editor->autoscroll_active() || from_autoscroll) {


                                bool first_move = (_move_threshold_passed != old_move_threshold_passed) || from_autoscroll;

                                motion (event, first_move && !_starting_point_passed);

                                if (first_move && !_starting_point_passed) {
                                        _starting_point_passed = true;
                                }

                                _last_pointer_x = _drags->current_pointer_x ();
                                _last_pointer_y = current_pointer_y ();
                                _last_pointer_frame = adjusted_current_frame (event);
                        }

                        return true;
                }
        }

        return false;
}

void
Drag::abort ()
{
        if (_item) {
                _item->ungrab ();
        }

        aborted (_move_threshold_passed);

        _editor->stop_canvas_autoscroll ();
        _editor->verbose_cursor()->hide ();
}

void
Drag::show_verbose_cursor_time (framepos_t frame)
{
        _editor->verbose_cursor()->set_time (frame);
        _editor->verbose_cursor()->show ();
}

void
Drag::show_verbose_cursor_duration (framepos_t start, framepos_t end, double /*xoffset*/)
{
        _editor->verbose_cursor()->set_duration (start, end);
        _editor->verbose_cursor()->show ();
}

void
Drag::show_verbose_cursor_text (string const & text)
{
        _editor->verbose_cursor()->set (text);
        _editor->verbose_cursor()->show ();
}

boost::shared_ptr<Region>
Drag::add_midi_region (MidiTimeAxisView* view)
{
        if (_editor->session()) {
                const TempoMap& map (_editor->session()->tempo_map());
                framecnt_t pos = grab_frame();
                const Meter& m = map.meter_at (pos);
                /* not that the frame rate used here can be affected by pull up/down which
                   might be wrong.
                */
                framecnt_t len = m.frames_per_bar (map.tempo_at (pos), _editor->session()->frame_rate());
                return view->add_region (grab_frame(), len, true);
        }

        return boost::shared_ptr<Region>();
}

struct EditorOrderTimeAxisViewSorter {
        bool operator() (TimeAxisView* a, TimeAxisView* b) {
                RouteTimeAxisView* ra = dynamic_cast<RouteTimeAxisView*> (a);
                RouteTimeAxisView* rb = dynamic_cast<RouteTimeAxisView*> (b);
                assert (ra && rb);
                return ra->route()->order_key () < rb->route()->order_key ();
        }
};

RegionDrag::RegionDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)
        : Drag (e, i)
        , _primary (p)
        , _ntracks (0)
{
        _editor->visible_order_range (&_visible_y_low, &_visible_y_high);

        /* Make a list of tracks to refer to during the drag; we include hidden tracks,
           as some of the regions we are dragging may be on such tracks.
        */

        TrackViewList track_views = _editor->track_views;
        track_views.sort (EditorOrderTimeAxisViewSorter ());

        for (TrackViewList::iterator i = track_views.begin(); i != track_views.end(); ++i) {
                _time_axis_views.push_back (*i);

                TimeAxisView::Children children_list = (*i)->get_child_list ();
                for (TimeAxisView::Children::iterator j = children_list.begin(); j != children_list.end(); ++j) {
                        _time_axis_views.push_back (j->get());
                }
        }

        /* the list of views can be empty at this point if this is a region list-insert drag
         */

        for (list<RegionView*>::const_iterator i = v.begin(); i != v.end(); ++i) {
                _views.push_back (DraggingView (*i, this, &(*i)->get_time_axis_view()));
        }

        RegionView::RegionViewGoingAway.connect (death_connection, invalidator (*this), boost::bind (&RegionDrag::region_going_away, this, _1), gui_context());
}

void
RegionDrag::region_going_away (RegionView* v)
{
        list<DraggingView>::iterator i = _views.begin ();
        while (i != _views.end() && i->view != v) {
                ++i;
        }

        if (i != _views.end()) {
                _views.erase (i);
        }
}

int
RegionDrag::find_time_axis_view (TimeAxisView* t) const
{
        int i = 0;
        int const N = _time_axis_views.size ();
        while (i < N && _time_axis_views[i] != t) {
                ++i;
        }

        if (_time_axis_views[i] != t) {
                return -1;
        }

        return i;
}

RegionMotionDrag::RegionMotionDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v, bool b)
        : RegionDrag (e, i, p, v)
        , _brushing (b)
        , _total_x_delta (0)
        , _last_pointer_time_axis_view (0)
        , _last_pointer_layer (0)
        , _single_axis (false)
        , _ndropzone (0)
        , _pdropzone (0)
        , _ddropzone (0)
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionMotionDrag\n");
}

void
RegionMotionDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        if (Keyboard::modifier_state_contains (event->button.state, Keyboard::TertiaryModifier)) {
                _single_axis = true;
        }

        show_verbose_cursor_time (_last_frame_position);

        pair<TimeAxisView*, double> const tv = _editor->trackview_by_y_position (current_pointer_y ());
        if (tv.first) {
                _last_pointer_time_axis_view = find_time_axis_view (tv.first);
                assert(_last_pointer_time_axis_view >= 0);
                _last_pointer_layer = tv.first->layer_display() == Overlaid ? 0 : tv.second;
        }
}

double
RegionMotionDrag::compute_x_delta (GdkEvent const * event, framepos_t* pending_region_position)
{
        /* compute the amount of pointer motion in frames, and where
           the region would be if we moved it by that much.
        */
        *pending_region_position = adjusted_current_frame (event);

        framepos_t sync_frame;
        framecnt_t sync_offset;
        int32_t sync_dir;

        sync_offset = _primary->region()->sync_offset (sync_dir);

        /* we don't handle a sync point that lies before zero.
         */
        if (sync_dir >= 0 || (sync_dir < 0 && *pending_region_position >= sync_offset)) {

                sync_frame = *pending_region_position + (sync_dir*sync_offset);

                _editor->snap_to_with_modifier (sync_frame, event);

                *pending_region_position = _primary->region()->adjust_to_sync (sync_frame);

        } else {
                *pending_region_position = _last_frame_position;
        }

        if (*pending_region_position > max_framepos - _primary->region()->length()) {
                *pending_region_position = _last_frame_position;
        }

        double dx = 0;

        /* in locked edit mode, reverse the usual meaning of _x_constrained */
        bool const x_move_allowed = Config->get_edit_mode() == Lock ? _x_constrained : !_x_constrained;

        if ((*pending_region_position != _last_frame_position) && x_move_allowed) {

                /* x movement since last time (in pixels) */
                dx = (static_cast<double> (*pending_region_position) - _last_frame_position) / _editor->samples_per_pixel;

                /* total x movement */
                framecnt_t total_dx = *pending_region_position;
                if (regions_came_from_canvas()) {
                        total_dx = total_dx - grab_frame ();
                }

                /* check that no regions have gone off the start of the session */
                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                        if ((i->view->region()->position() + total_dx) < 0) {
                                dx = 0;
                                *pending_region_position = _last_frame_position;
                                break;
                        }
                }

        }

        return dx;
}

int
RegionDrag::apply_track_delta (const int start, const int delta, const int skip, const bool distance_only) const
{
        if (delta == 0) {
                return start;
        }

        const int tavsize  = _time_axis_views.size();
        const int dt = delta > 0 ? +1 : -1;
        int current  = start;
        int target   = start + delta - skip;

        assert (current < 0 || current >= tavsize || !_time_axis_views[current]->hidden());
        assert (skip == 0 || (skip < 0 && delta < 0) || (skip > 0 && delta > 0));

        while (current >= 0 && current != target) {
                current += dt;
                if (current < 0 && dt < 0) {
                        break;
                }
                if (current >= tavsize && dt > 0) {
                        break;
                }
                if (current < 0 || current >= tavsize) {
                        continue;
                }

                RouteTimeAxisView const * rtav = dynamic_cast<RouteTimeAxisView const *> (_time_axis_views[current]);
                if (_time_axis_views[current]->hidden() || !rtav || !rtav->is_track()) {
                        target += dt;
                }

                if (distance_only && current == start + delta) {
                        break;
                }
        }
        return target;
}

bool
RegionMotionDrag::y_movement_allowed (int delta_track, double delta_layer, int skip_invisible) const
{
        if (_y_constrained) {
                return false;
        }

        const int tavsize  = _time_axis_views.size();
        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                int n = apply_track_delta (i->time_axis_view, delta_track, skip_invisible);
                assert (n < 0 || n >= tavsize || !_time_axis_views[n]->hidden());

                if (i->time_axis_view < 0 || i->time_axis_view >= tavsize) {
                        /* already in the drop zone */
                        if (delta_track >= 0) {
                                /* downward motion - OK if others are still not in the dropzone */
                                continue;
                        }

                }

                if (n < 0) {
                        /* off the top */
                        return false;
                } else if (n >= tavsize) {
                        /* downward motion into drop zone. That's fine. */
                        continue;
                }

                RouteTimeAxisView const * to = dynamic_cast<RouteTimeAxisView const *> (_time_axis_views[n]);
                if (to == 0 || to->hidden() || !to->is_track() || to->track()->data_type() != i->view->region()->data_type()) {
                        /* not a track, or the wrong type */
                        return false;
                }

                double const l = i->layer + delta_layer;

                /* Note that we allow layer to be up to 0.5 below zero, as this is used by `Expanded'
                   mode to allow the user to place a region below another on layer 0.
                */
                if (delta_track == 0 && (l < -0.5 || l >= int (to->view()->layers()))) {
                        /* Off the top or bottom layer; note that we only refuse if the track hasn't changed.
                           If it has, the layers will be munged later anyway, so it's ok.
                        */
                        return false;
                }
        }

        /* all regions being dragged are ok with this change */
        return true;
}

struct DraggingViewSorter {
        bool operator() (const DraggingView& a, const DraggingView& b) {
                return a.time_axis_view < b.time_axis_view;
        }
};

void
RegionMotionDrag::motion (GdkEvent* event, bool first_move)
{
        double delta_layer = 0;
        int delta_time_axis_view = 0;
        int current_pointer_time_axis_view = -1;

        assert (!_views.empty ());

        if (first_move) {
                if (_single_axis) {
                        if (initially_vertical()) {
                                _y_constrained = false;
                                _x_constrained = true;
                        } else {
                                _y_constrained = true;
                                _x_constrained = false;
                        }
                }
        }

        /* Note: time axis views in this method are often expressed as an index into the _time_axis_views vector */

        /* Find the TimeAxisView that the pointer is now over */
        const double cur_y = current_pointer_y ();
        pair<TimeAxisView*, double> const r = _editor->trackview_by_y_position (cur_y);
        TimeAxisView* tv = r.first;

        if (!tv && cur_y < 0) {
                /* above trackview area, autoscroll hasn't moved us since last time, nothing to do */
                return;
        }

        /* find drop-zone y-position */
        Coord last_track_bottom_edge;
        last_track_bottom_edge = 0;
        for (std::vector<TimeAxisView*>::reverse_iterator t = _time_axis_views.rbegin(); t != _time_axis_views.rend(); ++t) {
                if (!(*t)->hidden()) {
                        last_track_bottom_edge = (*t)->canvas_display()->canvas_origin ().y + (*t)->effective_height();
                        break;
                }
        }

        if (tv && tv->view()) {
                /* the mouse is over a track */
                double layer = r.second;

                if (first_move && tv->view()->layer_display() == Stacked) {
                        tv->view()->set_layer_display (Expanded);
                }

                /* Here's the current pointer position in terms of time axis view and layer */
                current_pointer_time_axis_view = find_time_axis_view (tv);
                assert(current_pointer_time_axis_view >= 0);

                double const current_pointer_layer = tv->layer_display() == Overlaid ? 0 : layer;

                /* Work out the change in y */

                RouteTimeAxisView* rtv = dynamic_cast<RouteTimeAxisView*> (tv);
                if (!rtv || !rtv->is_track()) {
                        /* ignore busses early on. we can't move any regions on them */
                } else if (_last_pointer_time_axis_view < 0) {
                        /* Was in the drop-zone, now over a track.
                         * Hence it must be an upward move (from the bottom)
                         *
                         * track_index is still -1, so delta must be set to
                         * move up the correct number of tracks from the bottom.
                         *
                         * This is necessary because steps may be skipped if
                         * the bottom-most track is not a valid target and/or
                         * if there are hidden tracks at the bottom.
                         * Hence the initial offset (_ddropzone) as well as the
                         * last valid pointer position (_pdropzone) need to be
                         * taken into account.
                         */
                        delta_time_axis_view = current_pointer_time_axis_view - _time_axis_views.size () + _ddropzone - _pdropzone;
                } else {
                        delta_time_axis_view = current_pointer_time_axis_view - _last_pointer_time_axis_view;
                }

                /* TODO needs adjustment per DraggingView,
                 *
                 * e.g. select one region on the top-layer of a track
                 * and one region which is at the bottom-layer of another track
                 * drag both.
                 *
                 * Indicated drop-zones and layering is wrong.
                 * and may infer additional layers on the target-track
                 * (depending how many layers the original track had).
                 *
                 * Or select two regions (different layers) on a same track,
                 * move across a non-layer track.. -> layering info is lost.
                 * on drop either of the regions may be on top.
                 *
                 * Proposed solution: screw it :) well,
                 *   don't use delta_layer, use an absolute value
                 *   1) remember DraggingView's layer  as float 0..1  [current layer / all layers of source]
                 *   2) calculate current mouse pos, y-pos inside track divided by height of mouse-over track.
                 *   3) iterate over all DraggingView, find the one that is over the track with most layers
                 *   4) proportionally scale layer to layers available on target
                 */
                delta_layer = current_pointer_layer - _last_pointer_layer;

        }
        /* for automation lanes, there is a TimeAxisView but no ->view()
         * if (!tv) -> dropzone 
         */
        else if (!tv && cur_y >= 0 && _last_pointer_time_axis_view >= 0) {
                /* Moving into the drop-zone.. */
                delta_time_axis_view = _time_axis_views.size () - _last_pointer_time_axis_view;
                /* delta_time_axis_view may not be sufficient to move into the DZ
                 * the mouse may enter it, but it may not be a valid move due to
                 * constraints.
                 *
                 * -> remember the delta needed to move into the dropzone
                 */
                _ddropzone = delta_time_axis_view;
                /* ..but subtract hidden tracks (or routes) at the bottom.
                 * we silently move mover them
                 */
                _ddropzone -= apply_track_delta(_last_pointer_time_axis_view, delta_time_axis_view, 0, true)
                              - _time_axis_views.size();
        }
        else if (!tv && cur_y >= 0 && _last_pointer_time_axis_view < 0) {
                /* move around inside the zone.
                 * This allows to move further down until all regions are in the zone.
                 */
                const double ptr_y = cur_y + _editor->get_trackview_group()->canvas_origin().y;
                assert(ptr_y >= last_track_bottom_edge);
                assert(_ddropzone > 0);

                /* calculate mouse position in 'tracks' below last track. */
                const double dzi_h = TimeAxisView::preset_height (HeightNormal);
                uint32_t dzpos = _ddropzone + floor((1 + ptr_y - last_track_bottom_edge) / dzi_h);

                if (dzpos > _pdropzone && _ndropzone < _ntracks) {
                        // move further down
                        delta_time_axis_view =  dzpos - _pdropzone;
                } else if (dzpos < _pdropzone && _ndropzone > 0) {
                        // move up inside the DZ
                        delta_time_axis_view =  dzpos - _pdropzone;
                }
        }

        /* Work out the change in x */
        framepos_t pending_region_position;
        double const x_delta = compute_x_delta (event, &pending_region_position);
        _last_frame_position = pending_region_position;

        /* calculate hidden tracks in current y-axis delta */
        int delta_skip = 0;
        if (_last_pointer_time_axis_view < 0 && _pdropzone > 0) {
                /* The mouse is more than one track below the dropzone.
                 * distance calculation is not needed (and would not work, either
                 * because the dropzone is "packed").
                 *
                 * Except when [partially] moving regions out of dropzone in a large step.
                 * (the mouse may or may not remain in the DZ)
                 * Hidden tracks at the bottom of the TAV need to be skipped.
                 *
                 * This also handles the case if the mouse entered the DZ
                 * in a large step (exessive delta), either due to fast-movement,
                 * autoscroll, laggy UI. _ddropzone copensates for that (see "move into dz" above)
                 */
                if (delta_time_axis_view < 0 && (int)_ddropzone - delta_time_axis_view >= (int)_pdropzone) {
                        const int dt = delta_time_axis_view + (int)_pdropzone - (int)_ddropzone;
                        assert(dt <= 0);
                        delta_skip = apply_track_delta(_time_axis_views.size(), dt, 0, true)
                                -_time_axis_views.size() - dt;
                }
        }
        else if (_last_pointer_time_axis_view < 0) {
                /* Moving out of the zone. Check for hidden tracks at the bottom. */
                delta_skip = apply_track_delta(_time_axis_views.size(), delta_time_axis_view, 0, true)
                             -_time_axis_views.size() - delta_time_axis_view;
        } else {
                /* calculate hidden tracks that are skipped by the pointer movement */
                delta_skip = apply_track_delta(_last_pointer_time_axis_view, delta_time_axis_view, 0, true)
                             - _last_pointer_time_axis_view
                             - delta_time_axis_view;
        }

        /* Verify change in y */
        if (!y_movement_allowed (delta_time_axis_view, delta_layer, delta_skip)) {
                /* this y movement is not allowed, so do no y movement this time */
                delta_time_axis_view = 0;
                delta_layer = 0;
                delta_skip = 0;
        }

        if (x_delta == 0 && (tv && tv->view() && delta_time_axis_view == 0) && delta_layer == 0 && !first_move) {
                /* haven't reached next snap point, and we're not switching
                   trackviews nor layers. nothing to do.
                */
                return;
        }

        typedef map<boost::shared_ptr<Playlist>, double> PlaylistDropzoneMap;
        PlaylistDropzoneMap playlist_dropzone_map;
        _ndropzone = 0; // number of elements currently in the dropzone

        if (first_move) {
                /* sort views by time_axis.
                 * This retains track order in the dropzone, regardless
                 * of actual selection order
                 */
                _views.sort (DraggingViewSorter());

                /* count number of distinct tracks of all regions
                 * being dragged, used for dropzone.
                 */
                int prev_track = -1;
                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                        if (i->time_axis_view != prev_track) {
                                prev_track = i->time_axis_view;
                                ++_ntracks;
                        }
                }
#ifndef NDEBUG
                int spread =
                        _views.back().time_axis_view -
                        _views.front().time_axis_view;

                spread -= apply_track_delta (_views.front().time_axis_view, spread, 0, true)
                          -  _views.back().time_axis_view;

                printf("Dragging region(s) from %d different track(s), max dist: %d\n", _ntracks, spread);
#endif
        }

        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {

                RegionView* rv = i->view;
                double y_delta;

                y_delta = 0;

                if (rv->region()->locked() || rv->region()->video_locked()) {
                        continue;
                }

                if (first_move) {
                        rv->drag_start ();

                        /* reparent the regionview into a group above all
                         * others
                         */

                        ArdourCanvas::Item* rvg = rv->get_canvas_group();
                        Duple rv_canvas_offset = rvg->parent()->canvas_origin ();
                        Duple dmg_canvas_offset = _editor->_drag_motion_group->canvas_origin ();
                        rv->get_canvas_group()->reparent (_editor->_drag_motion_group);
                        /* move the item so that it continues to appear at the
                           same location now that its parent has changed.
                           */
                        rvg->move (rv_canvas_offset - dmg_canvas_offset);
                }

                /* If we have moved tracks, we'll fudge the layer delta so that the
                   region gets moved back onto layer 0 on its new track; this avoids
                   confusion when dragging regions from non-zero layers onto different
                   tracks.
                */
                double this_delta_layer = delta_layer;
                if (delta_time_axis_view != 0) {
                        this_delta_layer = - i->layer;
                }

                int this_delta_time_axis_view = apply_track_delta(i->time_axis_view, delta_time_axis_view, delta_skip) - i->time_axis_view;

                int track_index = i->time_axis_view + this_delta_time_axis_view;
                assert(track_index >= 0);

                if (track_index < 0 || track_index >= (int) _time_axis_views.size()) {
                        /* Track is in the Dropzone */

                        i->time_axis_view = track_index;
                        assert(i->time_axis_view >= (int) _time_axis_views.size());
                        if (cur_y >= 0) {

                                double yposition = 0;
                                PlaylistDropzoneMap::iterator pdz = playlist_dropzone_map.find (i->view->region()->playlist());
                                rv->set_height (TimeAxisView::preset_height (HeightNormal));
                                ++_ndropzone;

                                /* store index of each new playlist as a negative count, starting at -1 */

                                if (pdz == playlist_dropzone_map.end()) {
                                        /* compute where this new track (which doesn't exist yet) will live
                                           on the y-axis.
                                        */
                                        yposition = last_track_bottom_edge; /* where to place the top edge of the regionview */

                                        /* How high is this region view ? */

                                        boost::optional<ArdourCanvas::Rect> obbox = rv->get_canvas_group()->bounding_box ();
                                        ArdourCanvas::Rect bbox;

                                        if (obbox) {
                                                bbox = obbox.get ();
                                        }

                                        last_track_bottom_edge += bbox.height();

                                        playlist_dropzone_map.insert (make_pair (i->view->region()->playlist(), yposition));

                                } else {
                                        yposition = pdz->second;
                                }

                                /* values are zero or negative, hence the use of min() */
                                y_delta = yposition - rv->get_canvas_group()->canvas_origin().y;
                        }

                } else {

                        /* The TimeAxisView that this region is now over */
                        TimeAxisView* current_tv = _time_axis_views[track_index];

                        /* Ensure it is moved from stacked -> expanded if appropriate */
                        if (current_tv->view()->layer_display() == Stacked) {
                                current_tv->view()->set_layer_display (Expanded);
                        }

                        /* We're only allowed to go -ve in layer on Expanded views */
                        if (current_tv->view()->layer_display() != Expanded && (i->layer + this_delta_layer) < 0) {
                                this_delta_layer = - i->layer;
                        }

                        /* Set height */
                        rv->set_height (current_tv->view()->child_height ());

                        /* Update show/hidden status as the region view may have come from a hidden track,
                           or have moved to one.
                        */
                        if (current_tv->hidden ()) {
                                rv->get_canvas_group()->hide ();
                        } else {
                                rv->get_canvas_group()->show ();
                        }

                        /* Update the DraggingView */
                        i->time_axis_view = track_index;
                        i->layer += this_delta_layer;

                        if (_brushing) {
                                _editor->mouse_brush_insert_region (rv, pending_region_position);
                        } else {
                                Duple track_origin;

                                /* Get the y coordinate of the top of the track that this region is now over */
                                track_origin = current_tv->canvas_display()->item_to_canvas (track_origin);

                                /* And adjust for the layer that it should be on */
                                StreamView* cv = current_tv->view ();
                                switch (cv->layer_display ()) {
                                case Overlaid:
                                        break;
                                case Stacked:
                                        track_origin.y += (cv->layers() - i->layer - 1) * cv->child_height ();
                                        break;
                                case Expanded:
                                        track_origin.y += (cv->layers() - i->layer - 0.5) * 2 * cv->child_height ();
                                        break;
                                }

                                /* need to get the parent of the regionview
                                 * canvas group and get its position in
                                 * equivalent coordinate space as the trackview
                                 * we are now dragging over.
                                 */

                                y_delta = track_origin.y - rv->get_canvas_group()->canvas_origin().y;

                        }
                }

                /* Now move the region view */
                rv->move (x_delta, y_delta);

        } /* foreach region */

        _total_x_delta += x_delta;

        if (x_delta != 0 && !_brushing) {
                show_verbose_cursor_time (_last_frame_position);
        }

        /* keep track of pointer movement */
        if (tv) {
                /* the pointer is currently over a time axis view */

                if (_last_pointer_time_axis_view < 0) {
                        /* last motion event was not over a time axis view
                         * or last y-movement out of the dropzone was not valid
                         */
                        int dtz = 0;
                        if (delta_time_axis_view < 0) {
                                /* in the drop zone, moving up */

                                /* _pdropzone is the last known pointer y-axis position inside the DZ.
                                 * We do not use negative _last_pointer_time_axis_view because
                                 * the dropzone is "packed" (the actual track offset is ignored)
                                 *
                                 * As opposed to the actual number 
                                 * of elements in the dropzone (_ndropzone)
                                 * _pdropzone is not constrained. This is necessary
                                 * to allow moving multiple regions with y-distance
                                 * into the DZ.
                                 *
                                 * There can be 0 elements in the dropzone,
                                 * even though the drag-pointer is inside the DZ.
                                 *
                                 * example:
                                 * [ Audio-track, Midi-track, Audio-track, DZ ]
                                 * move regions from both audio tracks at the same time into the
                                 * DZ by grabbing the region in the bottom track.
                                 */
                                assert(current_pointer_time_axis_view >= 0);
                                dtz = std::min((int)_pdropzone, (int)_ddropzone - delta_time_axis_view);
                                _pdropzone -= dtz;
                        }

                        /* only move out of the zone if the movement is OK */
                        if (_pdropzone == 0 && delta_time_axis_view != 0) {
                                assert(delta_time_axis_view < 0);
                                _last_pointer_time_axis_view = current_pointer_time_axis_view;
                                /* if all logic and maths are correct, there is no need to assign the 'current' pointer.
                                 * the current position can be calculated as follows:
                                 */
                                // a well placed oofus attack can still throw this off.
                                // likley auto-scroll related, printf() debugging may tell, commented out for now.
                                //assert (current_pointer_time_axis_view == _time_axis_views.size() - dtz + _ddropzone + delta_time_axis_view);
                        }
                } else {
                        /* last motion event was also over a time axis view */
                        _last_pointer_time_axis_view += delta_time_axis_view;
                        assert(_last_pointer_time_axis_view >= 0);
                }

        } else {

                /* the pointer is not over a time axis view */
                assert ((delta_time_axis_view > 0) || (((int)_pdropzone) >= (delta_skip - delta_time_axis_view)));
                _pdropzone += delta_time_axis_view - delta_skip;
                _last_pointer_time_axis_view = -1; // <0 : we're in the zone, value does not matter.
        }

        _last_pointer_layer += delta_layer;
}

void
RegionMoveDrag::motion (GdkEvent* event, bool first_move)
{
        if (_copy && first_move) {

                if (_x_constrained) {
                        _editor->begin_reversible_command (Operations::fixed_time_region_copy);
                } else {
                        _editor->begin_reversible_command (Operations::region_copy);
                }

                /* duplicate the regionview(s) and region(s) */

                list<DraggingView> new_regionviews;

                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {

                        RegionView* rv = i->view;
                        AudioRegionView* arv = dynamic_cast<AudioRegionView*>(rv);
                        MidiRegionView* mrv = dynamic_cast<MidiRegionView*>(rv);

                        const boost::shared_ptr<const Region> original = rv->region();
                        boost::shared_ptr<Region> region_copy = RegionFactory::create (original, true);
                        region_copy->set_position (original->position());
                        /* need to set this so that the drop zone code can work. This doesn't
                           actually put the region into the playlist, but just sets a weak pointer
                           to it.
                        */
                        region_copy->set_playlist (original->playlist());

                        RegionView* nrv;
                        if (arv) {
                                boost::shared_ptr<AudioRegion> audioregion_copy
                                = boost::dynamic_pointer_cast<AudioRegion>(region_copy);

                                nrv = new AudioRegionView (*arv, audioregion_copy);
                        } else if (mrv) {
                                boost::shared_ptr<MidiRegion> midiregion_copy
                                        = boost::dynamic_pointer_cast<MidiRegion>(region_copy);
                                nrv = new MidiRegionView (*mrv, midiregion_copy);
                        } else {
                                continue;
                        }

                        nrv->get_canvas_group()->show ();
                        new_regionviews.push_back (DraggingView (nrv, this, i->initial_time_axis_view));

                        /* swap _primary to the copy */

                        if (rv == _primary) {
                                _primary = nrv;
                        }

                        /* ..and deselect the one we copied */

                        rv->set_selected (false);
                }

                if (!new_regionviews.empty()) {

                        /* reflect the fact that we are dragging the copies */

                        _views = new_regionviews;

                        swap_grab (new_regionviews.front().view->get_canvas_group (), 0, event ? event->motion.time : 0);
                }

        } else if (!_copy && first_move) {

                if (_x_constrained) {
                        _editor->begin_reversible_command (_("fixed time region drag"));
                } else {
                        _editor->begin_reversible_command (Operations::region_drag);
                }
        }

        RegionMotionDrag::motion (event, first_move);
}

void
RegionMotionDrag::finished (GdkEvent *, bool)
{
        for (vector<TimeAxisView*>::iterator i = _time_axis_views.begin(); i != _time_axis_views.end(); ++i) {
                if (!(*i)->view()) {
                        continue;
                }

                if ((*i)->view()->layer_display() == Expanded) {
                        (*i)->view()->set_layer_display (Stacked);
                }
        }
}

void
RegionMoveDrag::finished (GdkEvent* ev, bool movement_occurred)
{
        RegionMotionDrag::finished (ev, movement_occurred);

        if (!movement_occurred) {

                /* just a click */

                if (was_double_click() && !_views.empty()) {
                        DraggingView dv = _views.front();
                        dv.view->show_region_editor ();

                }

                return;
        }

        /* reverse this here so that we have the correct logic to finalize
           the drag.
        */

        if (Config->get_edit_mode() == Lock) {
                _x_constrained = !_x_constrained;
        }

        assert (!_views.empty ());

        /* We might have hidden region views so that they weren't visible during the drag
           (when they have been reparented).  Now everything can be shown again, as region
           views are back in their track parent groups.
        */
        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                i->view->get_canvas_group()->show ();
        }

        bool const changed_position = (_last_frame_position != _primary->region()->position());
        bool const changed_tracks = (_time_axis_views[_views.front().time_axis_view] != &_views.front().view->get_time_axis_view());
        framecnt_t const drag_delta = _primary->region()->position() - _last_frame_position;

        if (_copy) {

                finished_copy (
                        changed_position,
                        changed_tracks,
                        drag_delta
                        );

        } else {

                finished_no_copy (
                        changed_position,
                        changed_tracks,
                        drag_delta
                        );

        }

        _editor->maybe_locate_with_edit_preroll (_editor->get_selection().regions.start());
}

RouteTimeAxisView*
RegionMoveDrag::create_destination_time_axis (boost::shared_ptr<Region> region, TimeAxisView* original)
{
        /* Add a new track of the correct type, and return the RouteTimeAxisView that is created to display the
           new track.
         */

        try {
                if (boost::dynamic_pointer_cast<AudioRegion> (region)) {
                        list<boost::shared_ptr<AudioTrack> > audio_tracks;
                        uint32_t output_chan = region->n_channels();
                        if ((Config->get_output_auto_connect() & AutoConnectMaster) && _editor->session()->master_out()) {
                                output_chan =  _editor->session()->master_out()->n_inputs().n_audio();
                        }
                        audio_tracks = _editor->session()->new_audio_track (region->n_channels(), output_chan, ARDOUR::Normal, 0, 1, region->name());
                        RouteTimeAxisView* rtav = _editor->axis_view_from_route (audio_tracks.front());
                        if (rtav) {
                                rtav->set_height (original->current_height());
                        }
                        return rtav;
                } else {
                        ChanCount one_midi_port (DataType::MIDI, 1);
                        list<boost::shared_ptr<MidiTrack> > midi_tracks;
                        midi_tracks = _editor->session()->new_midi_track (one_midi_port, one_midi_port, boost::shared_ptr<ARDOUR::PluginInfo>(), ARDOUR::Normal, 0, 1, region->name());
                        RouteTimeAxisView* rtav = _editor->axis_view_from_route (midi_tracks.front());
                        if (rtav) {
                                rtav->set_height (original->current_height());
                        }
                        return rtav;
                }
        } catch (...) {
                error << _("Could not create new track after region placed in the drop zone") << endmsg;
                return 0;
        }
}

void
RegionMoveDrag::finished_copy (bool const changed_position, bool const /*changed_tracks*/, framecnt_t const drag_delta)
{
        RegionSelection new_views;
        PlaylistSet modified_playlists;
        RouteTimeAxisView* new_time_axis_view = 0;

        if (_brushing) {
                /* all changes were made during motion event handlers */

                for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                        delete i->view;
                }

                _editor->commit_reversible_command ();
                return;
        }

        typedef map<boost::shared_ptr<Playlist>, RouteTimeAxisView*> PlaylistMapping;
        PlaylistMapping playlist_mapping;

        /* insert the regions into their new playlists */
        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end();) {

                RouteTimeAxisView* dest_rtv = 0;

                if (i->view->region()->locked() || i->view->region()->video_locked()) {
                        continue;
                }

                framepos_t where;

                if (changed_position && !_x_constrained) {
                        where = i->view->region()->position() - drag_delta;
                } else {
                        where = i->view->region()->position();
                }

                if (i->time_axis_view < 0 || i->time_axis_view >= (int)_time_axis_views.size()) {
                        /* dragged to drop zone */

                        PlaylistMapping::iterator pm;

                        if ((pm = playlist_mapping.find (i->view->region()->playlist())) == playlist_mapping.end()) {
                                /* first region from this original playlist: create a new track */
                                new_time_axis_view = create_destination_time_axis (i->view->region(), i->initial_time_axis_view);
                                playlist_mapping.insert (make_pair (i->view->region()->playlist(), new_time_axis_view));
                                dest_rtv = new_time_axis_view;
                        } else {
                                /* we already created a new track for regions from this playlist, use it */
                                dest_rtv = pm->second;
                        }
                } else {
                        /* destination time axis view is the one we dragged to */
                        dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[i->time_axis_view]);
                }

                if (dest_rtv != 0) {
                        RegionView* new_view = insert_region_into_playlist (i->view->region(), dest_rtv, i->layer, where, modified_playlists);
                        if (new_view != 0) {
                                new_views.push_back (new_view);
                        }
                }

                /* Delete the copy of the view that was used for dragging. Need to play safe with the iterator
                   since deletion will automagically remove it from _views, thus invalidating i as an iterator.
                 */

                list<DraggingView>::const_iterator next = i;
                ++next;
                delete i->view;
                i = next;
        }

        /* If we've created new regions either by copying or moving
           to a new track, we want to replace the old selection with the new ones
        */

        if (new_views.size() > 0) {
                _editor->selection->set (new_views);
        }

        /* write commands for the accumulated diffs for all our modified playlists */
        add_stateful_diff_commands_for_playlists (modified_playlists);

        _editor->commit_reversible_command ();
}

void
RegionMoveDrag::finished_no_copy (
        bool const changed_position,
        bool const changed_tracks,
        framecnt_t const drag_delta
        )
{
        RegionSelection new_views;
        PlaylistSet modified_playlists;
        PlaylistSet frozen_playlists;
        set<RouteTimeAxisView*> views_to_update;
        RouteTimeAxisView* new_time_axis_view = 0;

        if (_brushing) {
                /* all changes were made during motion event handlers */
                _editor->commit_reversible_command ();
                return;
        }

        typedef map<boost::shared_ptr<Playlist>, RouteTimeAxisView*> PlaylistMapping;
        PlaylistMapping playlist_mapping;

        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ) {

                RegionView* rv = i->view;
                RouteTimeAxisView* dest_rtv = 0;

                if (rv->region()->locked() || rv->region()->video_locked()) {
                        ++i;
                        continue;
                }

                if (i->time_axis_view < 0 || i->time_axis_view >= (int)_time_axis_views.size()) {
                        /* dragged to drop zone */

                        PlaylistMapping::iterator pm;

                        if ((pm = playlist_mapping.find (i->view->region()->playlist())) == playlist_mapping.end()) {
                                /* first region from this original playlist: create a new track */
                                new_time_axis_view = create_destination_time_axis (i->view->region(), i->initial_time_axis_view);
                                playlist_mapping.insert (make_pair (i->view->region()->playlist(), new_time_axis_view));
                                dest_rtv = new_time_axis_view;
                        } else {
                                /* we already created a new track for regions from this playlist, use it */
                                dest_rtv = pm->second;
                        }

                } else {
                        /* destination time axis view is the one we dragged to */
                        dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[i->time_axis_view]);
                }

                assert (dest_rtv);

                double const dest_layer = i->layer;

                views_to_update.insert (dest_rtv);

                framepos_t where;

                if (changed_position && !_x_constrained) {
                        where = rv->region()->position() - drag_delta;
                } else {
                        where = rv->region()->position();
                }

                if (changed_tracks) {

                        /* insert into new playlist */

                        RegionView* new_view = insert_region_into_playlist (
                                RegionFactory::create (rv->region (), true), dest_rtv, dest_layer, where, modified_playlists
                                );

                        if (new_view == 0) {
                                ++i;
                                continue;
                        }

                        new_views.push_back (new_view);

                        /* remove from old playlist */

                        /* the region that used to be in the old playlist is not
                           moved to the new one - we use a copy of it. as a result,
                           any existing editor for the region should no longer be
                           visible.
                        */
                        rv->hide_region_editor();


                        remove_region_from_playlist (rv->region(), i->initial_playlist, modified_playlists);

                } else {

                        boost::shared_ptr<Playlist> playlist = dest_rtv->playlist();

                        /* this movement may result in a crossfade being modified, or a layering change,
                           so we need to get undo data from the playlist as well as the region.
                        */

                        pair<PlaylistSet::iterator, bool> r = modified_playlists.insert (playlist);
                        if (r.second) {
                                playlist->clear_changes ();
                        }

                        rv->region()->clear_changes ();

                        /*
                           motion on the same track. plonk the previously reparented region
                           back to its original canvas group (its streamview).
                           No need to do anything for copies as they are fake regions which will be deleted.
                        */

                        rv->get_canvas_group()->reparent (dest_rtv->view()->canvas_item());
                        rv->get_canvas_group()->set_y_position (i->initial_y);
                        rv->drag_end ();

                        /* just change the model */
                        if (dest_rtv->view()->layer_display() == Stacked || dest_rtv->view()->layer_display() == Expanded) {
                                playlist->set_layer (rv->region(), dest_layer);
                        }

                        /* freeze playlist to avoid lots of relayering in the case of a multi-region drag */

                        r = frozen_playlists.insert (playlist);

                        if (r.second) {
                                playlist->freeze ();
                        }

                        rv->region()->set_position (where);

                        _editor->session()->add_command (new StatefulDiffCommand (rv->region()));
                }

                if (changed_tracks) {

                        /* OK, this is where it gets tricky. If the playlist was being used by >1 tracks, and the region
                           was selected in all of them, then removing it from a playlist will have removed all
                           trace of it from _views (i.e. there were N regions selected, we removed 1,
                           but since its the same playlist for N tracks, all N tracks updated themselves, removed the
                           corresponding regionview, and _views is now empty).

                           This could have invalidated any and all iterators into _views.

                           The heuristic we use here is: if the region selection is empty, break out of the loop
                           here. if the region selection is not empty, then restart the loop because we know that
                           we must have removed at least the region(view) we've just been working on as well as any
                           that we processed on previous iterations.

                           EXCEPT .... if we are doing a copy drag, then _views hasn't been modified and
                           we can just iterate.
                        */


                        if (_views.empty()) {
                                break;
                        } else {
                                i = _views.begin();
                        }

                } else {
                        ++i;
                }
        }

        /* If we've created new regions either by copying or moving
           to a new track, we want to replace the old selection with the new ones
        */

        if (new_views.size() > 0) {
                _editor->selection->set (new_views);
        }

        for (set<boost::shared_ptr<Playlist> >::iterator p = frozen_playlists.begin(); p != frozen_playlists.end(); ++p) {
                (*p)->thaw();
        }

        /* write commands for the accumulated diffs for all our modified playlists */
        add_stateful_diff_commands_for_playlists (modified_playlists);

        _editor->commit_reversible_command ();

        /* We have futzed with the layering of canvas items on our streamviews.
           If any region changed layer, this will have resulted in the stream
           views being asked to set up their region views, and all will be well.
           If not, we might now have badly-ordered region views.  Ask the StreamViews
           involved to sort themselves out, just in case.
        */

        for (set<RouteTimeAxisView*>::iterator i = views_to_update.begin(); i != views_to_update.end(); ++i) {
                (*i)->view()->playlist_layered ((*i)->track ());
        }
}

void
RegionMoveDrag::remove_region_from_playlist (
        boost::shared_ptr<Region> region,
        boost::shared_ptr<Playlist> playlist,
        PlaylistSet& modified_playlists
        )
{
        pair<set<boost::shared_ptr<Playlist> >::iterator, bool> r = modified_playlists.insert (playlist);

        if (r.second) {
                playlist->clear_changes ();
        }

        playlist->remove_region (region); // should be no need to ripple; we better already have rippled the playlist in RegionRippleDrag
}


RegionView *
RegionMoveDrag::insert_region_into_playlist (
        boost::shared_ptr<Region> region,
        RouteTimeAxisView* dest_rtv,
        layer_t dest_layer,
        framecnt_t where,
        PlaylistSet& modified_playlists
        )
{
        boost::shared_ptr<Playlist> dest_playlist = dest_rtv->playlist ();
        if (!dest_playlist) {
                return 0;
        }

        /* arrange to collect the new region view that will be created as a result of our playlist insertion */
        _new_region_view = 0;
        sigc::connection c = dest_rtv->view()->RegionViewAdded.connect (sigc::mem_fun (*this, &RegionMoveDrag::collect_new_region_view));

        /* clear history for the playlist we are about to insert to, provided we haven't already done so */
        pair<PlaylistSet::iterator, bool> r = modified_playlists.insert (dest_playlist);
        if (r.second) {
                dest_playlist->clear_changes ();
        }

        dest_playlist->add_region (region, where);

        if (dest_rtv->view()->layer_display() == Stacked || dest_rtv->view()->layer_display() == Expanded) {
                dest_playlist->set_layer (region, dest_layer);
        }

        c.disconnect ();

        assert (_new_region_view);

        return _new_region_view;
}

void
RegionMoveDrag::collect_new_region_view (RegionView* rv)
{
        _new_region_view = rv;
}

void
RegionMoveDrag::add_stateful_diff_commands_for_playlists (PlaylistSet const & playlists)
{
        for (PlaylistSet::const_iterator i = playlists.begin(); i != playlists.end(); ++i) {
                StatefulDiffCommand* c = new StatefulDiffCommand (*i);
                if (!c->empty()) {
                        _editor->session()->add_command (c);
                } else {
                        delete c;
                }
        }
}


void
RegionMoveDrag::aborted (bool movement_occurred)
{
        if (_copy) {

                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end();) {
                        list<DraggingView>::const_iterator next = i;
                        ++next;
                        delete i->view;
                        i = next;
                }

                _views.clear ();

        } else {
                RegionMotionDrag::aborted (movement_occurred);
        }
}

void
RegionMotionDrag::aborted (bool)
{
        for (vector<TimeAxisView*>::iterator i = _time_axis_views.begin(); i != _time_axis_views.end(); ++i) {

                StreamView* sview = (*i)->view();

                if (sview) {
                        if (sview->layer_display() == Expanded) {
                                sview->set_layer_display (Stacked);
                        }
                }
        }

        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                RegionView* rv = i->view;
                TimeAxisView* tv = &(rv->get_time_axis_view ());
                RouteTimeAxisView* rtv = dynamic_cast<RouteTimeAxisView*> (tv);
                assert (rtv);
                rv->get_canvas_group()->reparent (rtv->view()->canvas_item());
                rv->get_canvas_group()->set_y_position (0);
                rv->drag_end ();
                rv->move (-_total_x_delta, 0);
                rv->set_height (rtv->view()->child_height ());
        }
}

RegionMoveDrag::RegionMoveDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v, bool b, bool c)
        : RegionMotionDrag (e, i, p, v, b)
        , _copy (c)
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionMoveDrag\n");

        double speed = 1;
        RouteTimeAxisView* rtv = dynamic_cast<RouteTimeAxisView*> (&_primary->get_time_axis_view ());
        if (rtv && rtv->is_track()) {
                speed = rtv->track()->speed ();
        }

        _last_frame_position = static_cast<framepos_t> (_primary->region()->position() / speed);
}

void
RegionMoveDrag::setup_pointer_frame_offset ()
{
        _pointer_frame_offset = raw_grab_frame() - _last_frame_position;
}

RegionInsertDrag::RegionInsertDrag (Editor* e, boost::shared_ptr<Region> r, RouteTimeAxisView* v, framepos_t pos)
        : RegionMotionDrag (e, 0, 0, list<RegionView*> (), false)
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionInsertDrag\n");

        assert ((boost::dynamic_pointer_cast<AudioRegion> (r) && dynamic_cast<AudioTimeAxisView*> (v)) ||
                (boost::dynamic_pointer_cast<MidiRegion> (r) && dynamic_cast<MidiTimeAxisView*> (v)));

        _primary = v->view()->create_region_view (r, false, false);

        _primary->get_canvas_group()->show ();
        _primary->set_position (pos, 0);
        _views.push_back (DraggingView (_primary, this, v));

        _last_frame_position = pos;

        _item = _primary->get_canvas_group ();
}

void
RegionInsertDrag::finished (GdkEvent *, bool)
{
        int pos = _views.front().time_axis_view;
        assert(pos >= 0 && pos < (int)_time_axis_views.size());

        RouteTimeAxisView* dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[pos]);

        _primary->get_canvas_group()->reparent (dest_rtv->view()->canvas_item());
        _primary->get_canvas_group()->set_y_position (0);

        boost::shared_ptr<Playlist> playlist = dest_rtv->playlist();

        _editor->begin_reversible_command (Operations::insert_region);
        playlist->clear_changes ();
        playlist->add_region (_primary->region (), _last_frame_position);

        // Mixbus doesn't seem to ripple when inserting regions from the list: should we? yes, probably
        if (Config->get_edit_mode() == Ripple) {
                playlist->ripple (_last_frame_position, _primary->region()->length(), _primary->region());
        }

        _editor->session()->add_command (new StatefulDiffCommand (playlist));
        _editor->commit_reversible_command ();

        delete _primary;
        _primary = 0;
        _views.clear ();
}

void
RegionInsertDrag::aborted (bool)
{
        delete _primary;
        _primary = 0;
        _views.clear ();
}

RegionSpliceDrag::RegionSpliceDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)
        : RegionMoveDrag (e, i, p, v, false, false)
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionSpliceDrag\n");
}

struct RegionSelectionByPosition {
        bool operator() (RegionView*a, RegionView* b) {
                return a->region()->position () < b->region()->position();
        }
};

void
RegionSpliceDrag::motion (GdkEvent* event, bool)
{
        /* Which trackview is this ? */

        pair<TimeAxisView*, double> const tvp = _editor->trackview_by_y_position (current_pointer_y ());
        RouteTimeAxisView* tv = dynamic_cast<RouteTimeAxisView*> (tvp.first);

        /* The region motion is only processed if the pointer is over
           an audio track.
        */

        if (!tv || !tv->is_track()) {
                /* To make sure we hide the verbose canvas cursor when the mouse is
                   not held over an audio track.
                */
                _editor->verbose_cursor()->hide ();
                return;
        } else {
                _editor->verbose_cursor()->show ();
        }

        int dir;

        if ((_drags->current_pointer_x() - last_pointer_x()) > 0) {
                dir = 1;
        } else {
                dir = -1;
        }

        RegionSelection copy;
        _editor->selection->regions.by_position(copy);

        framepos_t const pf = adjusted_current_frame (event);

        for (RegionSelection::iterator i = copy.begin(); i != copy.end(); ++i) {

                RouteTimeAxisView* atv = dynamic_cast<RouteTimeAxisView*> (&(*i)->get_time_axis_view());

                if (!atv) {
                        continue;
                }

                boost::shared_ptr<Playlist> playlist;

                if ((playlist = atv->playlist()) == 0) {
                        continue;
                }

                if (!playlist->region_is_shuffle_constrained ((*i)->region())) {
                        continue;
                }

                if (dir > 0) {
                        if (pf < (*i)->region()->last_frame() + 1) {
                                continue;
                        }
                } else {
                        if (pf > (*i)->region()->first_frame()) {
                                continue;
                        }
                }


                playlist->shuffle ((*i)->region(), dir);
        }
}

void
RegionSpliceDrag::finished (GdkEvent* event, bool movement_occurred)
{
        RegionMoveDrag::finished (event, movement_occurred);
}

void
RegionSpliceDrag::aborted (bool)
{
        /* XXX: TODO */
}

/***
 * ripple mode...
 */

void
RegionRippleDrag::add_all_after_to_views(TimeAxisView *tav, framepos_t where, const RegionSelection &exclude, bool drag_in_progress)
{

        boost::shared_ptr<RegionList> rl = tav->playlist()->regions_with_start_within (Evoral::Range<framepos_t>(where, max_framepos));

        RouteTimeAxisView* rtv = dynamic_cast<RouteTimeAxisView*>(tav);
        RegionSelection to_ripple;
        for (RegionList::iterator i = rl->begin(); i != rl->end(); ++i) {
                if ((*i)->position() >= where) {
                        to_ripple.push_back (rtv->view()->find_view(*i));
                }
        }

        for (RegionSelection::iterator i = to_ripple.begin(); i != to_ripple.end(); ++i) {
                if (!exclude.contains (*i)) {
                        // the selection has already been added to _views

                        if (drag_in_progress) {
                                // do the same things that RegionMotionDrag::motion does when
                                // first_move is true, for the region views that we're adding
                                // to _views this time

                                (*i)->drag_start();
                                ArdourCanvas::Item* rvg = (*i)->get_canvas_group();
                                Duple rv_canvas_offset = rvg->item_to_canvas (Duple (0,0));
                                Duple dmg_canvas_offset = _editor->_drag_motion_group->canvas_origin ();
                                rvg->reparent (_editor->_drag_motion_group);

                                // we only need to move in the y direction
                                Duple fudge = rv_canvas_offset - dmg_canvas_offset;
                                fudge.x = 0;
                                rvg->move (fudge);

                        }
                        _views.push_back (DraggingView (*i, this, tav));
                }
        }
}

void
RegionRippleDrag::remove_unselected_from_views(framecnt_t amount, bool move_regions)
{

        for (std::list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ) {
                // we added all the regions after the selection

                std::list<DraggingView>::iterator to_erase = i++;
                if (!_editor->selection->regions.contains (to_erase->view)) {
                        // restore the non-selected regions to their original playlist & positions,
                        // and then ripple them back by the length of the regions that were dragged away
                        // do the same things as RegionMotionDrag::aborted

                        RegionView *rv = to_erase->view;
                        TimeAxisView* tv = &(rv->get_time_axis_view ());
                        RouteTimeAxisView* rtv = dynamic_cast<RouteTimeAxisView*> (tv);
                        assert (rtv);

                        // plonk them back onto their own track
                        rv->get_canvas_group()->reparent(rtv->view()->canvas_item());
                        rv->get_canvas_group()->set_y_position (0);
                        rv->drag_end ();

                        if (move_regions) {
                                // move the underlying region to match the view
                                rv->region()->set_position (rv->region()->position() + amount);
                        } else {
                                // restore the view to match the underlying region's original position
                                rv->move(-amount, 0);   // second parameter is y delta - seems 0 is OK
                        }

                        rv->set_height (rtv->view()->child_height ());
                        _views.erase (to_erase);
                }
        }
}

bool
RegionRippleDrag::y_movement_allowed (int delta_track, double delta_layer, int skip_invisible) const
{
        if (RegionMotionDrag::y_movement_allowed (delta_track, delta_layer, skip_invisible)) {
                if (delta_track) {
                        return allow_moves_across_tracks;
                } else {
                        return true;
                }
        }
        return false;
}

RegionRippleDrag::RegionRippleDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)
        : RegionMoveDrag (e, i, p, v, false, false)
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionRippleDrag\n");
        // compute length of selection
        RegionSelection selected_regions = _editor->selection->regions;
        selection_length = selected_regions.end_frame() - selected_regions.start();

        // we'll only allow dragging to another track in ripple mode if all the regions
        // being dragged start off on the same track
        allow_moves_across_tracks = (selected_regions.playlists().size() == 1);
        prev_tav = NULL;
        prev_amount = 0;
        exclude = new RegionList;
        for (RegionSelection::iterator i =selected_regions.begin(); i != selected_regions.end(); ++i) {
                exclude->push_back((*i)->region());
        }

        // also add regions before start of selection to exclude, to be consistent with how Mixbus does ripple
        RegionSelection copy;
        selected_regions.by_position(copy); // get selected regions sorted by position into copy

        std::set<boost::shared_ptr<ARDOUR::Playlist> > playlists = copy.playlists();
        std::set<boost::shared_ptr<ARDOUR::Playlist> >::const_iterator pi;

        for (pi = playlists.begin(); pi != playlists.end(); ++pi) {
                // find ripple start point on each applicable playlist
                RegionView *first_selected_on_this_track = NULL;
                for (RegionSelection::iterator i = copy.begin(); i != copy.end(); ++i) {
                        if ((*i)->region()->playlist() == (*pi)) {
                                // region is on this playlist - it's the first, because they're sorted
                                first_selected_on_this_track = *i;
                                break;
                        }
                }
                assert (first_selected_on_this_track); // we should always find the region in one of the playlists...
                add_all_after_to_views (
                                &first_selected_on_this_track->get_time_axis_view(),
                                first_selected_on_this_track->region()->position(),
                                selected_regions, false);
        }

        if (allow_moves_across_tracks) {
                orig_tav = &(*selected_regions.begin())->get_time_axis_view();
        } else {
                orig_tav = NULL;
        }

}

void
RegionRippleDrag::motion (GdkEvent* event, bool first_move)
{
        /* Which trackview is this ? */

        pair<TimeAxisView*, double> const tvp = _editor->trackview_by_y_position (current_pointer_y ());
        RouteTimeAxisView* tv = dynamic_cast<RouteTimeAxisView*> (tvp.first);

        /* The region motion is only processed if the pointer is over
           an audio track.
         */

        if (!tv || !tv->is_track()) {
                /* To make sure we hide the verbose canvas cursor when the mouse is
                   not held over an audiotrack.
                 */
                _editor->verbose_cursor()->hide ();
                return;
        }

        framepos_t where = adjusted_current_frame (event);
        assert (where >= 0);
        framepos_t after;
        double delta = compute_x_delta (event, &after);

        framecnt_t amount = _editor->pixel_to_sample (delta);

        if (allow_moves_across_tracks) {
                // all the originally selected regions were on the same track

                framecnt_t adjust = 0;
                if (prev_tav && tv != prev_tav) {
                        // dragged onto a different track
                        // remove the unselected regions from _views, restore them to their original positions
                        // and add the regions after the drop point on the new playlist to _views instead.
                        // undo the effect of rippling the previous playlist, and include the effect of removing
                        // the dragged region(s) from this track

                        remove_unselected_from_views (prev_amount, false);
                        // ripple previous playlist according to the regions that have been removed onto the new playlist
                        prev_tav->playlist()->ripple(prev_position, -selection_length, exclude);
                        prev_amount = 0;

                        // move just the selected regions
                        RegionMoveDrag::motion(event, first_move);

                        // ensure that the ripple operation on the new playlist inserts selection_length time
                        adjust = selection_length;
                        // ripple the new current playlist
                        tv->playlist()->ripple (where, amount+adjust, exclude);

                        // add regions after point where drag entered this track to subsequent ripples
                        add_all_after_to_views (tv, where, _editor->selection->regions, true);

                } else {
                        // motion on same track
                        RegionMoveDrag::motion(event, first_move);
                }
                prev_tav = tv;

                // remember what we've done to this playlist so we can undo it if the selection is dragged to another track
                prev_position = where;
        } else {
                // selection encompasses multiple tracks - just drag
                // cross-track drags are forbidden
                RegionMoveDrag::motion(event, first_move);
        }

        if (!_x_constrained) {
                prev_amount += amount;
        }

        _last_frame_position = after;
}

void
RegionRippleDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {

                /* just a click */

                if (was_double_click() && !_views.empty()) {
                        DraggingView dv = _views.front();
                        dv.view->show_region_editor ();

                }

                return;
        }

        _editor->begin_reversible_command(_("Ripple drag"));

        // remove the regions being rippled from the dragging view, updating them to
        // their new positions
        remove_unselected_from_views (prev_amount, true);

        if (allow_moves_across_tracks) {
                if (orig_tav) {
                        // if regions were dragged across tracks, we've rippled any later
                        // regions on the track the regions were dragged off, so we need
                        // to add the original track to the undo record
                        orig_tav->playlist()->clear_changes();
                        vector<Command*> cmds;
                        orig_tav->playlist()->rdiff (cmds);
                        _editor->session()->add_commands (cmds);
                }
                if (prev_tav && prev_tav != orig_tav) {
                        prev_tav->playlist()->clear_changes();
                        vector<Command*> cmds;
                        prev_tav->playlist()->rdiff (cmds);
                        _editor->session()->add_commands (cmds);
                }
        } else {
                // selection spanned multiple tracks - all will need adding to undo record

                std::set<boost::shared_ptr<ARDOUR::Playlist> > playlists = _editor->selection->regions.playlists();
                std::set<boost::shared_ptr<ARDOUR::Playlist> >::const_iterator pi;

                for (pi = playlists.begin(); pi != playlists.end(); ++pi) {
                        (*pi)->clear_changes();
                        vector<Command*> cmds;
                        (*pi)->rdiff (cmds);
                        _editor->session()->add_commands (cmds);
                }
        }

        // other modified playlists are added to undo by RegionMoveDrag::finished()
        RegionMoveDrag::finished (event, movement_occurred);
        _editor->commit_reversible_command();
}

void
RegionRippleDrag::aborted (bool movement_occurred)
{
        RegionMoveDrag::aborted (movement_occurred);
        _views.clear ();
}


RegionCreateDrag::RegionCreateDrag (Editor* e, ArdourCanvas::Item* i, TimeAxisView* v)
        : Drag (e, i),
          _view (dynamic_cast<MidiTimeAxisView*> (v))
{
        DEBUG_TRACE (DEBUG::Drags, "New RegionCreateDrag\n");

        assert (_view);
}

void
RegionCreateDrag::motion (GdkEvent* event, bool first_move)
{
        if (first_move) {
                _region = add_midi_region (_view);
                _view->playlist()->freeze ();
        } else {
                if (_region) {
                        framepos_t const f = adjusted_current_frame (event);
                        if (f < grab_frame()) {
                                _region->set_position (f);
                        }

                        /* Don't use a zero-length region, and subtract 1 frame from the snapped length
                           so that if this region is duplicated, its duplicate starts on
                           a snap point rather than 1 frame after a snap point.  Otherwise things get
                           a bit confusing as if a region starts 1 frame after a snap point, one cannot
                           place snapped notes at the start of the region.
                        */

                        framecnt_t const len = (framecnt_t) fabs ((double)(f - grab_frame () - 1));
                        _region->set_length (len < 1 ? 1 : len);
                }
        }
}

void
RegionCreateDrag::finished (GdkEvent*, bool movement_occurred)
{
        if (!movement_occurred) {
                add_midi_region (_view);
        } else {
                _view->playlist()->thaw ();
        }
}

void
RegionCreateDrag::aborted (bool)
{
        if (_region) {
                _view->playlist()->thaw ();
        }

        /* XXX */
}

NoteResizeDrag::NoteResizeDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
        , region (0)
{
        DEBUG_TRACE (DEBUG::Drags, "New NoteResizeDrag\n");
}

void
NoteResizeDrag::start_grab (GdkEvent* event, Gdk::Cursor* /*ignored*/)
{
        Gdk::Cursor* cursor;
        NoteBase* cnote = reinterpret_cast<NoteBase*> (_item->get_data ("notebase"));
        assert (cnote);
        float x_fraction = cnote->mouse_x_fraction ();

        if (x_fraction > 0.0 && x_fraction < 0.25) {
                cursor = _editor->cursors()->left_side_trim;
                at_front = true;
        } else  {
                cursor = _editor->cursors()->right_side_trim;
                at_front = false;
        }

        Drag::start_grab (event, cursor);

        region = &cnote->region_view();

        _item->grab ();

        if (event->motion.state & Keyboard::PrimaryModifier) {
                relative = false;
        } else {
                relative = true;
        }

        MidiRegionSelection& ms (_editor->get_selection().midi_regions);

        if (ms.size() > 1) {
                /* has to be relative, may make no sense otherwise */
                relative = true;
        }

        /* select this note; if it is already selected, preserve the existing selection,
           otherwise make this note the only one selected.
        */
        region->note_selected (cnote, cnote->selected ());

        _editor->begin_reversible_command (_("resize notes"));

        for (MidiRegionSelection::iterator r = ms.begin(); r != ms.end(); ) {
                MidiRegionSelection::iterator next;
                next = r;
                ++next;
                MidiRegionView* mrv = dynamic_cast<MidiRegionView*>(*r);
                if (mrv) {
                        mrv->begin_resizing (at_front);
                }
                r = next;
        }
}

void
NoteResizeDrag::motion (GdkEvent* /*event*/, bool /*first_move*/)
{
        MidiRegionSelection& ms (_editor->get_selection().midi_regions);
        for (MidiRegionSelection::iterator r = ms.begin(); r != ms.end(); ++r) {
                NoteBase* nb = reinterpret_cast<NoteBase*> (_item->get_data ("notebase"));
                assert (nb);
                MidiRegionView* mrv = dynamic_cast<MidiRegionView*>(*r);
                if (mrv) {
                        mrv->update_resizing (nb, at_front, _drags->current_pointer_x() - grab_x(), relative);
                }
        }
}

void
NoteResizeDrag::finished (GdkEvent*, bool /*movement_occurred*/)
{
        MidiRegionSelection& ms (_editor->get_selection().midi_regions);
        for (MidiRegionSelection::iterator r = ms.begin(); r != ms.end(); ++r) {
                NoteBase* nb = reinterpret_cast<NoteBase*> (_item->get_data ("notebase"));
                assert (nb);
                MidiRegionView* mrv = dynamic_cast<MidiRegionView*>(*r);
                if (mrv) {
                        mrv->commit_resizing (nb, at_front, _drags->current_pointer_x() - grab_x(), relative);
                }
        }

        _editor->commit_reversible_command ();
}

void
NoteResizeDrag::aborted (bool)
{
        MidiRegionSelection& ms (_editor->get_selection().midi_regions);
        for (MidiRegionSelection::iterator r = ms.begin(); r != ms.end(); ++r) {
                MidiRegionView* mrv = dynamic_cast<MidiRegionView*>(*r);
                if (mrv) {
                        mrv->abort_resizing ();
                }
        }
}

AVDraggingView::AVDraggingView (RegionView* v)
        : view (v)
{
        initial_position = v->region()->position ();
}

VideoTimeLineDrag::VideoTimeLineDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
{
        DEBUG_TRACE (DEBUG::Drags, "New VideoTimeLineDrag\n");

        RegionSelection rs;
        TrackViewList empty;
        empty.clear();
        _editor->get_regions_after(rs, (framepos_t) 0, empty);
        std::list<RegionView*> views = rs.by_layer();

        for (list<RegionView*>::iterator i = views.begin(); i != views.end(); ++i) {
                RegionView* rv = (*i);
                if (!rv->region()->video_locked()) {
                        continue;
                }
                _views.push_back (AVDraggingView (rv));
        }
}

void
VideoTimeLineDrag::start_grab (GdkEvent* event, Gdk::Cursor*)
{
        Drag::start_grab (event);
        if (_editor->session() == 0) {
                return;
        }

        _startdrag_video_offset=ARDOUR_UI::instance()->video_timeline->get_offset();
        _max_backwards_drag = (
                          ARDOUR_UI::instance()->video_timeline->get_duration()
                        + ARDOUR_UI::instance()->video_timeline->get_offset()
                        - ceil(ARDOUR_UI::instance()->video_timeline->get_apv())
                        );

        for (list<AVDraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                if (i->initial_position < _max_backwards_drag || _max_backwards_drag < 0) {
                        _max_backwards_drag = ARDOUR_UI::instance()->video_timeline->quantify_frames_to_apv (i->initial_position);
                }
        }
        DEBUG_TRACE (DEBUG::Drags, string_compose("VideoTimeLineDrag: max backwards-drag: %1\n", _max_backwards_drag));

        char buf[128];
        Timecode::Time timecode;
        _editor->session()->sample_to_timecode(abs(_startdrag_video_offset), timecode, true /* use_offset */, false /* use_subframes */ );
        snprintf (buf, sizeof (buf), "Video Start:\n%c%02" PRId32 ":%02" PRId32 ":%02" PRId32 ":%02" PRId32, (_startdrag_video_offset<0?'-':' '), timecode.hours, timecode.minutes, timecode.seconds, timecode.frames);
        show_verbose_cursor_text (buf);
}

void
VideoTimeLineDrag::motion (GdkEvent* event, bool first_move)
{
        if (_editor->session() == 0) {
                return;
        }
        if (ARDOUR_UI::instance()->video_timeline->is_offset_locked()) {
                return;
        }

        framecnt_t dt = adjusted_current_frame (event) - raw_grab_frame() + _pointer_frame_offset;
        dt = ARDOUR_UI::instance()->video_timeline->quantify_frames_to_apv(_startdrag_video_offset+dt) - _startdrag_video_offset;

        if (_max_backwards_drag >= 0 && dt <= - _max_backwards_drag) {
                dt = - _max_backwards_drag;
        }

        ARDOUR_UI::instance()->video_timeline->set_offset(_startdrag_video_offset+dt);
        ARDOUR_UI::instance()->flush_videotimeline_cache(true);

        for (list<AVDraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                RegionView* rv = i->view;
                DEBUG_TRACE (DEBUG::Drags, string_compose("SHIFT REGION at %1 by %2\n", i->initial_position, dt));
                if (first_move) {
                        rv->drag_start ();
                        rv->region()->clear_changes ();
                        rv->region()->suspend_property_changes();
                }
                rv->region()->set_position(i->initial_position + dt);
                rv->region_changed(ARDOUR::Properties::position);
        }

        const framepos_t offset = ARDOUR_UI::instance()->video_timeline->get_offset();
        Timecode::Time timecode;
        Timecode::Time timediff;
        char buf[128];
        _editor->session()->sample_to_timecode(abs(offset), timecode, true /* use_offset */, false /* use_subframes */ );
        _editor->session()->sample_to_timecode(abs(dt), timediff, false /* use_offset */, false /* use_subframes */ );
        snprintf (buf, sizeof (buf),
                        "%s\n%c%02" PRId32 ":%02" PRId32 ":%02" PRId32 ":%02" PRId32
                        "\n%s\n%c%02" PRId32 ":%02" PRId32 ":%02" PRId32 ":%02" PRId32
                        , _("Video Start:"),
                                (offset<0?'-':' '), timecode.hours, timecode.minutes, timecode.seconds, timecode.frames
                        , _("Diff:"),
                                (dt<0?'-':' '), timediff.hours, timediff.minutes, timediff.seconds, timediff.frames
                                );
        show_verbose_cursor_text (buf);
}

void
VideoTimeLineDrag::finished (GdkEvent * /*event*/, bool movement_occurred)
{
        if (ARDOUR_UI::instance()->video_timeline->is_offset_locked()) {
                return;
        }

        if (!movement_occurred || ! _editor->session()) {
                return;
        }

        ARDOUR_UI::instance()->flush_videotimeline_cache(true);

        _editor->begin_reversible_command (_("Move Video"));

        XMLNode &before = ARDOUR_UI::instance()->video_timeline->get_state();
        ARDOUR_UI::instance()->video_timeline->save_undo();
        XMLNode &after = ARDOUR_UI::instance()->video_timeline->get_state();
        _editor->session()->add_command(new MementoCommand<VideoTimeLine>(*(ARDOUR_UI::instance()->video_timeline), &before, &after));

        for (list<AVDraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                i->view->drag_end();
                i->view->region()->resume_property_changes ();

                _editor->session()->add_command (new StatefulDiffCommand (i->view->region()));
        }

        _editor->session()->maybe_update_session_range(
                        std::max(ARDOUR_UI::instance()->video_timeline->get_offset(), (ARDOUR::frameoffset_t) 0),
                        std::max(ARDOUR_UI::instance()->video_timeline->get_offset() + ARDOUR_UI::instance()->video_timeline->get_duration(), (ARDOUR::frameoffset_t) 0)
                        );


        _editor->commit_reversible_command ();
}

void
VideoTimeLineDrag::aborted (bool)
{
        if (ARDOUR_UI::instance()->video_timeline->is_offset_locked()) {
                return;
        }
        ARDOUR_UI::instance()->video_timeline->set_offset(_startdrag_video_offset);
        ARDOUR_UI::instance()->flush_videotimeline_cache(true);

        for (list<AVDraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                i->view->region()->resume_property_changes ();
                i->view->region()->set_position(i->initial_position);
        }
}

TrimDrag::TrimDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v, bool preserve_fade_anchor)
        : RegionDrag (e, i, p, v)
        , _preserve_fade_anchor (preserve_fade_anchor)
        , _jump_position_when_done (false)
{
        DEBUG_TRACE (DEBUG::Drags, "New TrimDrag\n");
}

void
TrimDrag::start_grab (GdkEvent* event, Gdk::Cursor*)
{
        double speed = 1.0;
        TimeAxisView* tvp = &_primary->get_time_axis_view ();
        RouteTimeAxisView* tv = dynamic_cast<RouteTimeAxisView*>(tvp);

        if (tv && tv->is_track()) {
                speed = tv->track()->speed();
        }

        framepos_t const region_start = (framepos_t) (_primary->region()->position() / speed);
        framepos_t const region_end = (framepos_t) (_primary->region()->last_frame() / speed);
        framecnt_t const region_length = (framecnt_t) (_primary->region()->length() / speed);

        framepos_t const pf = adjusted_current_frame (event);

        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::PrimaryModifier)) {
                /* Move the contents of the region around without changing the region bounds */
                _operation = ContentsTrim;
                Drag::start_grab (event, _editor->cursors()->trimmer);
        } else {
                /* These will get overridden for a point trim.*/
                if (pf < (region_start + region_length/2)) {
                        /* closer to front */
                        _operation = StartTrim;

                        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                                Drag::start_grab (event, _editor->cursors()->anchored_left_side_trim);
                        } else {
                                Drag::start_grab (event, _editor->cursors()->left_side_trim);
                        }
                } else {
                        /* closer to end */
                        _operation = EndTrim;
                        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                                Drag::start_grab (event, _editor->cursors()->anchored_right_side_trim);
                        } else {
                                Drag::start_grab (event, _editor->cursors()->right_side_trim);
                        }
                }
        }

        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                _jump_position_when_done = true;
        }

        switch (_operation) {
        case StartTrim:
                show_verbose_cursor_time (region_start);
                for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                        i->view->trim_front_starting ();
                }
                break;
        case EndTrim:
                show_verbose_cursor_time (region_end);
                break;
        case ContentsTrim:
                show_verbose_cursor_time (pf);
                break;
        }

        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                i->view->region()->suspend_property_changes ();
        }
}

void
TrimDrag::motion (GdkEvent* event, bool first_move)
{
        RegionView* rv = _primary;

        double speed = 1.0;
        TimeAxisView* tvp = &_primary->get_time_axis_view ();
        RouteTimeAxisView* tv = dynamic_cast<RouteTimeAxisView*>(tvp);
        pair<set<boost::shared_ptr<Playlist> >::iterator,bool> insert_result;
        frameoffset_t frame_delta = 0;

        if (tv && tv->is_track()) {
                speed = tv->track()->speed();
        }

        framecnt_t dt = adjusted_current_frame (event) - raw_grab_frame () + _pointer_frame_offset;

        if (first_move) {

                string trim_type;

                switch (_operation) {
                case StartTrim:
                        trim_type = "Region start trim";
                        break;
                case EndTrim:
                        trim_type = "Region end trim";
                        break;
                case ContentsTrim:
                        trim_type = "Region content trim";
                        break;
                default:
                        assert(0);
                        break;
                }

                _editor->begin_reversible_command (trim_type);

                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                        RegionView* rv = i->view;
                        rv->enable_display (false);
                        rv->region()->playlist()->clear_owned_changes ();

                        AudioRegionView* const arv = dynamic_cast<AudioRegionView*> (rv);

                        if (arv) {
                                arv->temporarily_hide_envelope ();
                                arv->drag_start ();
                        }

                        boost::shared_ptr<Playlist> pl = rv->region()->playlist();
                        insert_result = _editor->motion_frozen_playlists.insert (pl);

                        if (insert_result.second) {
                                pl->freeze();
                        }
                }
        }

        bool non_overlap_trim = false;

        if (event && Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                non_overlap_trim = true;
        }

        /* contstrain trim to fade length */
        if (_preserve_fade_anchor) {
                switch (_operation) {
                        case StartTrim:
                                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                        if (!arv) continue;
                                        boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                        if (ar->locked()) continue;
                                        framecnt_t len = ar->fade_in()->back()->when;
                                        if (len < dt) dt = min(dt, len);
                                }
                                break;
                        case EndTrim:
                                for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                        if (!arv) continue;
                                        boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                        if (ar->locked()) continue;
                                        framecnt_t len = ar->fade_out()->back()->when;
                                        if (len < -dt) dt = max(dt, -len);
                                }
                                break;
                        case ContentsTrim:
                                break;
                }
        }


        switch (_operation) {
        case StartTrim:
                for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                        bool changed = i->view->trim_front (i->initial_position + dt, non_overlap_trim);
                        if (changed && _preserve_fade_anchor) {
                                AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                if (arv) {
                                        boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                        framecnt_t len = ar->fade_in()->back()->when;
                                        framecnt_t diff = ar->first_frame() - i->initial_position;
                                        framepos_t new_length = len - diff;
                                        i->anchored_fade_length = min (ar->length(), new_length);
                                        //i->anchored_fade_length = ar->verify_xfade_bounds (new_length, true  /*START*/ );
                                        arv->reset_fade_in_shape_width (ar, i->anchored_fade_length, true);
                                }
                        }
                }
                break;

        case EndTrim:
                for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                        bool changed = i->view->trim_end (i->initial_end + dt, non_overlap_trim);
                        if (changed && _preserve_fade_anchor) {
                                AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                if (arv) {
                                        boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                        framecnt_t len = ar->fade_out()->back()->when;
                                        framecnt_t diff = 1 + ar->last_frame() - i->initial_end;
                                        framepos_t new_length = len + diff;
                                        i->anchored_fade_length = min (ar->length(), new_length);
                                        //i->anchored_fade_length = ar->verify_xfade_bounds (new_length, false  /*END*/ );
                                        arv->reset_fade_out_shape_width (ar, i->anchored_fade_length, true);
                                }
                        }
                }
                break;

        case ContentsTrim:
                {
                        frame_delta = (last_pointer_frame() - adjusted_current_frame(event));

                        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                i->view->move_contents (frame_delta);
                        }
                }
                break;
        }

        switch (_operation) {
        case StartTrim:
                show_verbose_cursor_time ((framepos_t) (rv->region()->position() / speed));
                break;
        case EndTrim:
                show_verbose_cursor_time ((framepos_t) (rv->region()->last_frame() / speed));
                break;
        case ContentsTrim:
                // show_verbose_cursor_time (frame_delta);
                break;
        }
}


void
TrimDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (movement_occurred) {
                motion (event, false);

                if (_operation == StartTrim) {
                        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                {
                                        /* This must happen before the region's StatefulDiffCommand is created, as it may
                                           `correct' (ahem) the region's _start from being negative to being zero.  It
                                           needs to be zero in the undo record.
                                        */
                                        i->view->trim_front_ending ();
                                }
                                if (_preserve_fade_anchor) {
                                        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                        if (arv) {
                                                boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                                arv->reset_fade_in_shape_width (ar, i->anchored_fade_length);
                                                ar->set_fade_in_length(i->anchored_fade_length);
                                                ar->set_fade_in_active(true);
                                        }
                                }
                                if (_jump_position_when_done) {
                                        i->view->region()->set_position (i->initial_position);
                                }
                        }
                } else if (_operation == EndTrim) {
                        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                if (_preserve_fade_anchor) {
                                        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
                                        if (arv) {
                                                boost::shared_ptr<AudioRegion> ar (arv->audio_region());
                                                arv->reset_fade_out_shape_width (ar, i->anchored_fade_length);
                                                ar->set_fade_out_length(i->anchored_fade_length);
                                                ar->set_fade_out_active(true);
                                        }
                                }
                                if (_jump_position_when_done) {
                                        i->view->region()->set_position (i->initial_end - i->view->region()->length());
                                }
                        }
                }

                if (!_views.empty()) {
                        if (_operation == StartTrim) {
                                _editor->maybe_locate_with_edit_preroll(
                                        _views.begin()->view->region()->position());
                        }
                        if (_operation == EndTrim) {
                                _editor->maybe_locate_with_edit_preroll(
                                        _views.begin()->view->region()->position() +
                                        _views.begin()->view->region()->length());
                        }
                }

                if (!_editor->selection->selected (_primary)) {
                        _primary->thaw_after_trim ();
                } else {

                        set<boost::shared_ptr<Playlist> > diffed_playlists;

                        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                                i->view->thaw_after_trim ();
                                i->view->enable_display (true);

                                /* Trimming one region may affect others on the playlist, so we need
                                   to get undo Commands from the whole playlist rather than just the
                                   region.  Use diffed_playlists to make sure we don't diff a given
                                   playlist more than once.
                                */
                                boost::shared_ptr<Playlist> p = i->view->region()->playlist ();
                                if (diffed_playlists.find (p) == diffed_playlists.end()) {
                                        vector<Command*> cmds;
                                        p->rdiff (cmds);
                                        _editor->session()->add_commands (cmds);
                                        diffed_playlists.insert (p);
                                }
                        }
                }

                for (set<boost::shared_ptr<Playlist> >::iterator p = _editor->motion_frozen_playlists.begin(); p != _editor->motion_frozen_playlists.end(); ++p) {
                        (*p)->thaw ();
                }

                _editor->motion_frozen_playlists.clear ();
                _editor->commit_reversible_command();

        } else {
                /* no mouse movement */
                _editor->point_trim (event, adjusted_current_frame (event));
        }

        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                if (_operation == StartTrim) {
                        i->view->trim_front_ending ();
                }

                i->view->region()->resume_property_changes ();
        }
}

void
TrimDrag::aborted (bool movement_occurred)
{
        /* Our motion method is changing model state, so use the Undo system
           to cancel.  Perhaps not ideal, as this will leave an Undo point
           behind which may be slightly odd from the user's point of view.
        */

        finished (0, true);

        if (movement_occurred) {
                _editor->undo ();
        }

        for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ++i) {
                i->view->region()->resume_property_changes ();
        }
}

void
TrimDrag::setup_pointer_frame_offset ()
{
        list<DraggingView>::iterator i = _views.begin ();
        while (i != _views.end() && i->view != _primary) {
                ++i;
        }

        if (i == _views.end()) {
                return;
        }

        switch (_operation) {
        case StartTrim:
                _pointer_frame_offset = raw_grab_frame() - i->initial_position;
                break;
        case EndTrim:
                _pointer_frame_offset = raw_grab_frame() - i->initial_end;
                break;
        case ContentsTrim:
                break;
        }
}

MeterMarkerDrag::MeterMarkerDrag (Editor* e, ArdourCanvas::Item* i, bool c)
        : Drag (e, i),
          _copy (c)
{
        DEBUG_TRACE (DEBUG::Drags, "New MeterMarkerDrag\n");
        _marker = reinterpret_cast<MeterMarker*> (_item->get_data ("marker"));
        assert (_marker);
}

void
MeterMarkerDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);
        show_verbose_cursor_time (adjusted_current_frame(event));
}

void
MeterMarkerDrag::setup_pointer_frame_offset ()
{
        _pointer_frame_offset = raw_grab_frame() - _marker->meter().frame();
}

void
MeterMarkerDrag::motion (GdkEvent* event, bool first_move)
{
        if (!_marker->meter().movable()) {
                return;
        }

        if (first_move) {

                // create a dummy marker for visual representation of moving the
                // section, because whether its a copy or not, we're going to
                // leave or lose the original marker (leave if its a copy; lose if its
                // not, because we'll remove it from the map).

                MeterSection section (_marker->meter());

                if (!section.movable()) {
                        return;
                }

                char name[64];
                snprintf (name, sizeof(name), "%g/%g", _marker->meter().divisions_per_bar(), _marker->meter().note_divisor ());

                _marker = new MeterMarker (
                        *_editor,
                        *_editor->meter_group,
                        ARDOUR_UI::config()->color ("meter marker"),
                        name,
                        *new MeterSection (_marker->meter())
                );

                /* use the new marker for the grab */
                swap_grab (&_marker->the_item(), 0, GDK_CURRENT_TIME);

                if (!_copy) {
                        TempoMap& map (_editor->session()->tempo_map());
                        /* get current state */
                        before_state = &map.get_state();
                        /* remove the section while we drag it */
                        map.remove_meter (section, true);
                }
        }

        framepos_t const pf = adjusted_current_frame (event);

        _marker->set_position (pf);
        show_verbose_cursor_time (pf);
}

void
MeterMarkerDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {
                if (was_double_click()) {
                        _editor->edit_meter_marker (*_marker);
                }
                return;
        }

        if (!_marker->meter().movable()) {
                return;
        }

        motion (event, false);

        Timecode::BBT_Time when;

        TempoMap& map (_editor->session()->tempo_map());
        map.bbt_time (last_pointer_frame(), when);

        if (_copy == true) {
                _editor->begin_reversible_command (_("copy meter mark"));
                XMLNode &before = map.get_state();
                map.add_meter (_marker->meter(), when);
                XMLNode &after = map.get_state();
                _editor->session()->add_command(new MementoCommand<TempoMap>(map, &before, &after));
                _editor->commit_reversible_command ();

        } else {
                _editor->begin_reversible_command (_("move meter mark"));

                /* we removed it before, so add it back now */

                map.add_meter (_marker->meter(), when);
                XMLNode &after = map.get_state();
                _editor->session()->add_command(new MementoCommand<TempoMap>(map, before_state, &after));
                _editor->commit_reversible_command ();
        }

        // delete the dummy marker we used for visual representation while moving.
        // a new visual marker will show up automatically.
        delete _marker;
}

void
MeterMarkerDrag::aborted (bool moved)
{
        _marker->set_position (_marker->meter().frame ());

        if (moved) {
                TempoMap& map (_editor->session()->tempo_map());
                /* we removed it before, so add it back now */
                map.add_meter (_marker->meter(), _marker->meter().frame());
                // delete the dummy marker we used for visual representation while moving.
                // a new visual marker will show up automatically.
                delete _marker;
        }
}

TempoMarkerDrag::TempoMarkerDrag (Editor* e, ArdourCanvas::Item* i, bool c)
        : Drag (e, i),
          _copy (c)
{
        DEBUG_TRACE (DEBUG::Drags, "New TempoMarkerDrag\n");

        _marker = reinterpret_cast<TempoMarker*> (_item->get_data ("marker"));
        assert (_marker);
}

void
TempoMarkerDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);
        show_verbose_cursor_time (adjusted_current_frame (event));
}

void
TempoMarkerDrag::setup_pointer_frame_offset ()
{
        _pointer_frame_offset = raw_grab_frame() - _marker->tempo().frame();
}

void
TempoMarkerDrag::motion (GdkEvent* event, bool first_move)
{
        if (!_marker->tempo().movable()) {
                return;
        }

        if (first_move) {

                // create a dummy marker for visual representation of moving the
                // section, because whether its a copy or not, we're going to
                // leave or lose the original marker (leave if its a copy; lose if its
                // not, because we'll remove it from the map).

                // create a dummy marker for visual representation of moving the copy.
                // The actual copying is not done before we reach the finish callback.

                char name[64];
                snprintf (name, sizeof (name), "%.2f", _marker->tempo().beats_per_minute());

                TempoSection section (_marker->tempo());

                _marker = new TempoMarker (
                        *_editor,
                        *_editor->tempo_group,
                        ARDOUR_UI::config()->color ("tempo marker"),
                        name,
                        *new TempoSection (_marker->tempo())
                        );

                /* use the new marker for the grab */
                swap_grab (&_marker->the_item(), 0, GDK_CURRENT_TIME);

                if (!_copy) {
                        TempoMap& map (_editor->session()->tempo_map());
                        /* get current state */
                        before_state = &map.get_state();
                        /* remove the section while we drag it */
                        map.remove_tempo (section, true);
                }
        }

        framepos_t const pf = adjusted_current_frame (event);
        _marker->set_position (pf);
        show_verbose_cursor_time (pf);
}

void
TempoMarkerDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {
                if (was_double_click()) {
                        _editor->edit_tempo_marker (*_marker);
                }
                return;
        }

        if (!_marker->tempo().movable()) {
                return;
        }

        motion (event, false);

        TempoMap& map (_editor->session()->tempo_map());
        framepos_t beat_time = map.round_to_beat (last_pointer_frame(), RoundNearest);
        Timecode::BBT_Time when;

        map.bbt_time (beat_time, when);

        if (_copy == true) {
                _editor->begin_reversible_command (_("copy tempo mark"));
                XMLNode &before = map.get_state();
                map.add_tempo (_marker->tempo(), when);
                XMLNode &after = map.get_state();
                _editor->session()->add_command (new MementoCommand<TempoMap>(map, &before, &after));
                _editor->commit_reversible_command ();

        } else {
                _editor->begin_reversible_command (_("move tempo mark"));
                /* we removed it before, so add it back now */
                map.add_tempo (_marker->tempo(), when);
                XMLNode &after = map.get_state();
                _editor->session()->add_command (new MementoCommand<TempoMap>(map, before_state, &after));
                _editor->commit_reversible_command ();
        }

        // delete the dummy marker we used for visual representation while moving.
        // a new visual marker will show up automatically.
        delete _marker;
}

void
TempoMarkerDrag::aborted (bool moved)
{
        _marker->set_position (_marker->tempo().frame());
        if (moved) {
                TempoMap& map (_editor->session()->tempo_map());
                /* we removed it before, so add it back now */
                map.add_tempo (_marker->tempo(), _marker->tempo().start());
                // delete the dummy marker we used for visual representation while moving.
                // a new visual marker will show up automatically.
                delete _marker;
        }
}

CursorDrag::CursorDrag (Editor* e, EditorCursor& c, bool s)
        : Drag (e, &c.track_canvas_item(), false)
        , _cursor (c)
        , _stop (s)
{
        DEBUG_TRACE (DEBUG::Drags, "New CursorDrag\n");
}

void
CursorDrag::fake_locate (framepos_t t)
{
        _editor->playhead_cursor->set_position (t);

        Session* s = _editor->session ();
        if (s->timecode_transmission_suspended ()) {
                framepos_t const f = _editor->playhead_cursor->current_frame ();
                /* This is asynchronous so it will be sent "now"
                 */
                s->send_mmc_locate (f);
                /* These are synchronous and will be sent during the next
                   process cycle
                */
                s->queue_full_time_code ();
                s->queue_song_position_pointer ();
        }

        show_verbose_cursor_time (t);
        _editor->UpdateAllTransportClocks (t);
}

void
CursorDrag::start_grab (GdkEvent* event, Gdk::Cursor* c)
{
        Drag::start_grab (event, c);

        _grab_zoom = _editor->samples_per_pixel;

        framepos_t where = _editor->canvas_event_sample (event);

        _editor->snap_to_with_modifier (where, event);

        _editor->_dragging_playhead = true;

        Session* s = _editor->session ();

        /* grab the track canvas item as well */

        _cursor.track_canvas_item().grab();

        if (s) {
                if (_was_rolling && _stop) {
                        s->request_stop ();
                }

                if (s->is_auditioning()) {
                        s->cancel_audition ();
                }


                if (AudioEngine::instance()->connected()) {

                        /* do this only if we're the engine is connected
                         * because otherwise this request will never be
                         * serviced and we'll busy wait forever. likewise,
                         * notice if we are disconnected while waiting for the
                         * request to be serviced.
                         */

                        s->request_suspend_timecode_transmission ();
                        while (AudioEngine::instance()->connected() && !s->timecode_transmission_suspended ()) {
                                /* twiddle our thumbs */
                        }
                }
        }

        fake_locate (where);
}

void
CursorDrag::motion (GdkEvent* event, bool)
{
        framepos_t const adjusted_frame = adjusted_current_frame (event);
        if (adjusted_frame != last_pointer_frame()) {
                fake_locate (adjusted_frame);
        }
}

void
CursorDrag::finished (GdkEvent* event, bool movement_occurred)
{
        _editor->_dragging_playhead = false;

        _cursor.track_canvas_item().ungrab();

        if (!movement_occurred && _stop) {
                return;
        }

        motion (event, false);

        Session* s = _editor->session ();
        if (s) {
                s->request_locate (_editor->playhead_cursor->current_frame (), _was_rolling);
                _editor->_pending_locate_request = true;
                s->request_resume_timecode_transmission ();
        }
}

void
CursorDrag::aborted (bool)
{
        _cursor.track_canvas_item().ungrab();

        if (_editor->_dragging_playhead) {
                _editor->session()->request_resume_timecode_transmission ();
                _editor->_dragging_playhead = false;
        }

        _editor->playhead_cursor->set_position (adjusted_frame (grab_frame (), 0, false));
}

FadeInDrag::FadeInDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)
        : RegionDrag (e, i, p, v)
{
        DEBUG_TRACE (DEBUG::Drags, "New FadeInDrag\n");
}

void
FadeInDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (_primary);
        boost::shared_ptr<AudioRegion> const r = arv->audio_region ();

        show_verbose_cursor_duration (r->position(), r->position() + r->fade_in()->back()->when, 32);
}

void
FadeInDrag::setup_pointer_frame_offset ()
{
        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (_primary);
        boost::shared_ptr<AudioRegion> const r = arv->audio_region ();
        _pointer_frame_offset = raw_grab_frame() - ((framecnt_t) r->fade_in()->back()->when + r->position());
}

void
FadeInDrag::motion (GdkEvent* event, bool)
{
        framecnt_t fade_length;
        framepos_t const pos = adjusted_current_frame (event);
        boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion> (_primary->region ());

        if (pos < (region->position() + 64)) {
                fade_length = 64; // this should be a minimum defined somewhere
        } else if (pos > region->position() + region->length() - region->fade_out()->back()->when) {
                fade_length = region->length() - region->fade_out()->back()->when - 1;
        } else {
                fade_length = pos - region->position();
        }

        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {

                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                tmp->reset_fade_in_shape_width (tmp->audio_region(), fade_length);
        }

        show_verbose_cursor_duration (region->position(), region->position() + fade_length, 32);
}

void
FadeInDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {
                return;
        }

        framecnt_t fade_length;

        framepos_t const pos = adjusted_current_frame (event);

        boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion> (_primary->region ());

        if (pos < (region->position() + 64)) {
                fade_length = 64; // this should be a minimum defined somewhere
        } else if (pos >= region->position() + region->length() - region->fade_out()->back()->when) {
                fade_length = region->length() - region->fade_out()->back()->when - 1;
        } else {
                fade_length = pos - region->position();
        }

        _editor->begin_reversible_command (_("change fade in length"));

        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {

                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                boost::shared_ptr<AutomationList> alist = tmp->audio_region()->fade_in();
                XMLNode &before = alist->get_state();

                tmp->audio_region()->set_fade_in_length (fade_length);
                tmp->audio_region()->set_fade_in_active (true);

                XMLNode &after = alist->get_state();
                _editor->session()->add_command(new MementoCommand<AutomationList>(*alist.get(), &before, &after));
        }

        _editor->commit_reversible_command ();
}

void
FadeInDrag::aborted (bool)
{
        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                tmp->reset_fade_in_shape_width (tmp->audio_region(), tmp->audio_region()->fade_in()->back()->when);
        }
}

FadeOutDrag::FadeOutDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)
        : RegionDrag (e, i, p, v)
{
        DEBUG_TRACE (DEBUG::Drags, "New FadeOutDrag\n");
}

void
FadeOutDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (_primary);
        boost::shared_ptr<AudioRegion> r = arv->audio_region ();

        show_verbose_cursor_duration (r->last_frame() - r->fade_out()->back()->when, r->last_frame());
}

void
FadeOutDrag::setup_pointer_frame_offset ()
{
        AudioRegionView* arv = dynamic_cast<AudioRegionView*> (_primary);
        boost::shared_ptr<AudioRegion> r = arv->audio_region ();
        _pointer_frame_offset = raw_grab_frame() - (r->length() - (framecnt_t) r->fade_out()->back()->when + r->position());
}

void
FadeOutDrag::motion (GdkEvent* event, bool)
{
        framecnt_t fade_length;

        framepos_t const pos = adjusted_current_frame (event);

        boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion> (_primary->region ());

        if (pos > (region->last_frame() - 64)) {
                fade_length = 64; // this should really be a minimum fade defined somewhere
        } else if (pos <= region->position() + region->fade_in()->back()->when) {
                fade_length = region->length() - region->fade_in()->back()->when - 1;
        } else {
                fade_length = region->last_frame() - pos;
        }

        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {

                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                tmp->reset_fade_out_shape_width (tmp->audio_region(), fade_length);
        }

        show_verbose_cursor_duration (region->last_frame() - fade_length, region->last_frame());
}

void
FadeOutDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {
                return;
        }

        framecnt_t fade_length;

        framepos_t const pos = adjusted_current_frame (event);

        boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion> (_primary->region ());

        if (pos > (region->last_frame() - 64)) {
                fade_length = 64; // this should really be a minimum fade defined somewhere
        } else if (pos <= region->position() + region->fade_in()->back()->when) {
                fade_length = region->length() - region->fade_in()->back()->when - 1;
        } else {
                fade_length = region->last_frame() - pos;
        }

        _editor->begin_reversible_command (_("change fade out length"));

        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {

                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                boost::shared_ptr<AutomationList> alist = tmp->audio_region()->fade_out();
                XMLNode &before = alist->get_state();

                tmp->audio_region()->set_fade_out_length (fade_length);
                tmp->audio_region()->set_fade_out_active (true);

                XMLNode &after = alist->get_state();
                _editor->session()->add_command(new MementoCommand<AutomationList>(*alist.get(), &before, &after));
        }

        _editor->commit_reversible_command ();
}

void
FadeOutDrag::aborted (bool)
{
        for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
                AudioRegionView* tmp = dynamic_cast<AudioRegionView*> (i->view);

                if (!tmp) {
                        continue;
                }

                tmp->reset_fade_out_shape_width (tmp->audio_region(), tmp->audio_region()->fade_out()->back()->when);
        }
}

MarkerDrag::MarkerDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
{
        DEBUG_TRACE (DEBUG::Drags, "New MarkerDrag\n");

        _marker = reinterpret_cast<Marker*> (_item->get_data ("marker"));
        assert (_marker);

        _points.push_back (ArdourCanvas::Duple (0, 0));
        _points.push_back (ArdourCanvas::Duple (0, physical_screen_height (_editor->get_window())));
}

MarkerDrag::~MarkerDrag ()
{
        for (CopiedLocationInfo::iterator i = _copied_locations.begin(); i != _copied_locations.end(); ++i) {
                delete i->location;
        }
}

MarkerDrag::CopiedLocationMarkerInfo::CopiedLocationMarkerInfo (Location* l, Marker* m)
{
        location = new Location (*l);
        markers.push_back (m);
        move_both = false;
}

void
MarkerDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        bool is_start;

        Location *location = _editor->find_location_from_marker (_marker, is_start);
        _editor->_dragging_edit_point = true;

        update_item (location);

        // _drag_line->show();
        // _line->raise_to_top();

        if (is_start) {
                show_verbose_cursor_time (location->start());
        } else {
                show_verbose_cursor_time (location->end());
        }

        Selection::Operation op = ArdourKeyboard::selection_type (event->button.state);

        switch (op) {
        case Selection::Toggle:
                /* we toggle on the button release */
                break;
        case Selection::Set:
                if (!_editor->selection->selected (_marker)) {
                        _editor->selection->set (_marker);
                }
                break;
        case Selection::Extend:
        {
                Locations::LocationList ll;
                list<Marker*> to_add;
                framepos_t s, e;
                _editor->selection->markers.range (s, e);
                s = min (_marker->position(), s);
                e = max (_marker->position(), e);
                s = min (s, e);
                e = max (s, e);
                if (e < max_framepos) {
                        ++e;
                }
                _editor->session()->locations()->find_all_between (s, e, ll, Location::Flags (0));
                for (Locations::LocationList::iterator i = ll.begin(); i != ll.end(); ++i) {
                        Editor::LocationMarkers* lm = _editor->find_location_markers (*i);
                        if (lm) {
                                if (lm->start) {
                                        to_add.push_back (lm->start);
                                }
                                if (lm->end) {
                                        to_add.push_back (lm->end);
                                }
                        }
                }
                if (!to_add.empty()) {
                        _editor->selection->add (to_add);
                }
                break;
        }
        case Selection::Add:
                _editor->selection->add (_marker);
                break;
        }

        /* Set up copies for us to manipulate during the drag
         */

        for (MarkerSelection::iterator i = _editor->selection->markers.begin(); i != _editor->selection->markers.end(); ++i) {

                Location* l = _editor->find_location_from_marker (*i, is_start);

                if (!l) {
                        continue;
                }

                if (l->is_mark()) {
                        _copied_locations.push_back (CopiedLocationMarkerInfo (l, *i));
                } else {
                        /* range: check that the other end of the range isn't
                           already there.
                        */
                        CopiedLocationInfo::iterator x;
                        for (x = _copied_locations.begin(); x != _copied_locations.end(); ++x) {
                                if (*(*x).location == *l) {
                                        break;
                                }
                        }
                        if (x == _copied_locations.end()) {
                                _copied_locations.push_back (CopiedLocationMarkerInfo (l, *i));
                        } else {
                                (*x).markers.push_back (*i);
                                (*x).move_both = true;
                        }
                }

        }
}

void
MarkerDrag::setup_pointer_frame_offset ()
{
        bool is_start;
        Location *location = _editor->find_location_from_marker (_marker, is_start);
        _pointer_frame_offset = raw_grab_frame() - (is_start ? location->start() : location->end());
}

void
MarkerDrag::motion (GdkEvent* event, bool)
{
        framecnt_t f_delta = 0;
        bool is_start;
        bool move_both = false;
        Location *real_location;
        Location *copy_location = 0;

        framepos_t const newframe = adjusted_current_frame (event);
        framepos_t next = newframe;

        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::PrimaryModifier)) {
                move_both = true;
        }

        CopiedLocationInfo::iterator x;

        /* find the marker we're dragging, and compute the delta */

        for (x = _copied_locations.begin(); x != _copied_locations.end(); ++x) {

                copy_location = (*x).location;

                if (find (x->markers.begin(), x->markers.end(), _marker) != x->markers.end()) {

                        /* this marker is represented by this
                         * CopiedLocationMarkerInfo
                         */

                        if ((real_location = _editor->find_location_from_marker (_marker, is_start)) == 0) {
                                /* que pasa ?? */
                                return;
                        }

                        if (real_location->is_mark()) {
                                f_delta = newframe - copy_location->start();
                        } else {


                                switch (_marker->type()) {
                                case Marker::SessionStart:
                                case Marker::RangeStart:
                                case Marker::LoopStart:
                                case Marker::PunchIn:
                                        f_delta = newframe - copy_location->start();
                                        break;

                                case Marker::SessionEnd:
                                case Marker::RangeEnd:
                                case Marker::LoopEnd:
                                case Marker::PunchOut:
                                        f_delta = newframe - copy_location->end();
                                        break;
                                default:
                                        /* what kind of marker is this ? */
                                        return;
                                }
                        }

                        break;
                }
        }

        if (x == _copied_locations.end()) {
                /* hmm, impossible - we didn't find the dragged marker */
                return;
        }

        /* now move them all */

        for (x = _copied_locations.begin(); x != _copied_locations.end(); ++x) {

                copy_location = x->location;

                if ((real_location = _editor->find_location_from_marker (x->markers.front(), is_start)) == 0) {
                        continue;
                }

                if (real_location->locked()) {
                        continue;
                }

                if (copy_location->is_mark()) {

                        /* now move it */

                        copy_location->set_start (copy_location->start() + f_delta);

                } else {

                        framepos_t new_start = copy_location->start() + f_delta;
                        framepos_t new_end = copy_location->end() + f_delta;

                        if (is_start) { // start-of-range marker

                                if (move_both || (*x).move_both) {
                                        copy_location->set_start (new_start);
                                        copy_location->set_end (new_end);
                                } else  if (new_start < copy_location->end()) {
                                        copy_location->set_start (new_start);
                                } else if (newframe > 0) {
                                        _editor->snap_to (next, RoundUpAlways, true);
                                        copy_location->set_end (next);
                                        copy_location->set_start (newframe);
                                }

                        } else { // end marker

                                if (move_both || (*x).move_both) {
                                        copy_location->set_end (new_end);
                                        copy_location->set_start (new_start);
                                } else if (new_end > copy_location->start()) {
                                        copy_location->set_end (new_end);
                                } else if (newframe > 0) {
                                        _editor->snap_to (next, RoundDownAlways, true);
                                        copy_location->set_start (next);
                                        copy_location->set_end (newframe);
                                }
                        }
                }

                update_item (copy_location);

                /* now lookup the actual GUI items used to display this
                 * location and move them to wherever the copy of the location
                 * is now. This means that the logic in ARDOUR::Location is
                 * still enforced, even though we are not (yet) modifying
                 * the real Location itself.
                 */

                Editor::LocationMarkers* lm = _editor->find_location_markers (real_location);

                if (lm) {
                        lm->set_position (copy_location->start(), copy_location->end());
                }

        }

        assert (!_copied_locations.empty());

        show_verbose_cursor_time (newframe);
}

void
MarkerDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {

                if (was_double_click()) {
                        _editor->rename_marker (_marker);
                        return;
                }

                /* just a click, do nothing but finish
                   off the selection process
                */

                Selection::Operation op = ArdourKeyboard::selection_type (event->button.state);

                switch (op) {
                case Selection::Set:
                        if (_editor->selection->selected (_marker) && _editor->selection->markers.size() > 1) {
                                _editor->selection->set (_marker);
                        }
                        break;

                case Selection::Toggle:
                        /* we toggle on the button release, click only */
                        _editor->selection->toggle (_marker);
                        break;

                case Selection::Extend:
                case Selection::Add:
                        break;
                }

                return;
        }

        _editor->_dragging_edit_point = false;

        _editor->begin_reversible_command ( _("move marker") );
        XMLNode &before = _editor->session()->locations()->get_state();

        MarkerSelection::iterator i;
        CopiedLocationInfo::iterator x;
        bool is_start;

        for (i = _editor->selection->markers.begin(), x = _copied_locations.begin();
             x != _copied_locations.end() && i != _editor->selection->markers.end();
             ++i, ++x) {

                Location * location = _editor->find_location_from_marker (*i, is_start);

                if (location) {

                        if (location->locked()) {
                                return;
                        }

                        if (location->is_mark()) {
                                location->set_start (((*x).location)->start());
                        } else {
                                location->set (((*x).location)->start(), ((*x).location)->end());
                        }
                }
        }

        XMLNode &after = _editor->session()->locations()->get_state();
        _editor->session()->add_command(new MementoCommand<Locations>(*(_editor->session()->locations()), &before, &after));
        _editor->commit_reversible_command ();
}

void
MarkerDrag::aborted (bool movement_occured)
{
        if (!movement_occured) {
                return;
        }

        for (CopiedLocationInfo::iterator x = _copied_locations.begin(); x != _copied_locations.end(); ++x) {

                /* move all markers to their original location */


                for (vector<Marker*>::iterator m = x->markers.begin(); m != x->markers.end(); ++m) {

                        bool is_start;
                        Location * location = _editor->find_location_from_marker (*m, is_start);

                        if (location) {
                                (*m)->set_position (is_start ? location->start() : location->end());
                        }
                }
        }
}

void
MarkerDrag::update_item (Location*)
{
        /* noop */
}

ControlPointDrag::ControlPointDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i),
          _cumulative_x_drag (0),
          _cumulative_y_drag (0)
{
        if (_zero_gain_fraction < 0.0) {
                _zero_gain_fraction = gain_to_slider_position_with_max (dB_to_coefficient (0.0), Config->get_max_gain());
        }

        DEBUG_TRACE (DEBUG::Drags, "New ControlPointDrag\n");

        _point = reinterpret_cast<ControlPoint*> (_item->get_data ("control_point"));
        assert (_point);
}


void
ControlPointDrag::start_grab (GdkEvent* event, Gdk::Cursor* /*cursor*/)
{
        Drag::start_grab (event, _editor->cursors()->fader);

        // start the grab at the center of the control point so
        // the point doesn't 'jump' to the mouse after the first drag
        _fixed_grab_x = _point->get_x();
        _fixed_grab_y = _point->get_y();

        float const fraction = 1 - (_point->get_y() / _point->line().height());

        _point->line().start_drag_single (_point, _fixed_grab_x, fraction);

        show_verbose_cursor_text (_point->line().get_verbose_cursor_string (fraction));

        _pushing = Keyboard::modifier_state_contains (event->button.state, Keyboard::PrimaryModifier);

        if (!_point->can_slide ()) {
                _x_constrained = true;
        }
}

void
ControlPointDrag::motion (GdkEvent* event, bool)
{
        double dx = _drags->current_pointer_x() - last_pointer_x();
        double dy = current_pointer_y() - last_pointer_y();

        if (event->button.state & Keyboard::SecondaryModifier) {
                dx *= 0.1;
                dy *= 0.1;
        }

        /* coordinate in pixels relative to the start of the region (for region-based automation)
           or track (for track-based automation) */
        double cx = _fixed_grab_x + _cumulative_x_drag + dx;
        double cy = _fixed_grab_y + _cumulative_y_drag + dy;

        // calculate zero crossing point. back off by .01 to stay on the
        // positive side of zero
        double const zero_gain_y = (1.0 - _zero_gain_fraction) * _point->line().height() - .01;

        // make sure we hit zero when passing through
        if ((cy < zero_gain_y && (cy - dy) > zero_gain_y) || (cy > zero_gain_y && (cy - dy) < zero_gain_y)) {
                cy = zero_gain_y;
        }

        if (_x_constrained) {
                cx = _fixed_grab_x;
        }
        if (_y_constrained) {
                cy = _fixed_grab_y;
        }

        _cumulative_x_drag = cx - _fixed_grab_x;
        _cumulative_y_drag = cy - _fixed_grab_y;

        cx = max (0.0, cx);
        cy = max (0.0, cy);
        cy = min ((double) _point->line().height(), cy);

        framepos_t cx_frames = _editor->pixel_to_sample (cx);

        if (!_x_constrained) {
                _editor->snap_to_with_modifier (cx_frames, event);
        }

        cx_frames = min (cx_frames, _point->line().maximum_time());

        float const fraction = 1.0 - (cy / _point->line().height());

        _point->line().drag_motion (_editor->sample_to_pixel_unrounded (cx_frames), fraction, false, _pushing, _final_index);

        show_verbose_cursor_text (_point->line().get_verbose_cursor_string (fraction));
}

void
ControlPointDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (!movement_occurred) {

                /* just a click */

                if (Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                        _editor->reset_point_selection ();
                }

        } else {
                motion (event, false);
        }

        _point->line().end_drag (_pushing, _final_index);
        _editor->commit_reversible_command ();
}

void
ControlPointDrag::aborted (bool)
{
        _point->line().reset ();
}

bool
ControlPointDrag::active (Editing::MouseMode m)
{
        if (m == Editing::MouseDraw) {
                /* always active in mouse draw */
                return true;
        }

        /* otherwise active if the point is on an automation line (ie not if its on a region gain line) */
        return dynamic_cast<AutomationLine*> (&(_point->line())) != 0;
}

LineDrag::LineDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i),
          _line (0),
          _cumulative_y_drag (0)
{
        DEBUG_TRACE (DEBUG::Drags, "New LineDrag\n");
}

void
LineDrag::start_grab (GdkEvent* event, Gdk::Cursor* /*cursor*/)
{
        _line = reinterpret_cast<AutomationLine*> (_item->get_data ("line"));
        assert (_line);

        _item = &_line->grab_item ();

        /* need to get x coordinate in terms of parent (TimeAxisItemView)
           origin, and ditto for y.
        */

        double cx = event->button.x;
        double cy = event->button.y;

        _line->parent_group().canvas_to_item (cx, cy);

        framecnt_t const frame_within_region = (framecnt_t) floor (cx * _editor->samples_per_pixel);

        uint32_t before;
        uint32_t after;

        if (!_line->control_points_adjacent (frame_within_region, before, after)) {
                /* no adjacent points */
                return;
        }

        Drag::start_grab (event, _editor->cursors()->fader);

        /* store grab start in parent frame */

        _fixed_grab_x = cx;
        _fixed_grab_y = cy;

        double fraction = 1.0 - (cy / _line->height());

        _line->start_drag_line (before, after, fraction);

        show_verbose_cursor_text (_line->get_verbose_cursor_string (fraction));
}

void
LineDrag::motion (GdkEvent* event, bool)
{
        double dy = current_pointer_y() - last_pointer_y();

        if (event->button.state & Keyboard::SecondaryModifier) {
                dy *= 0.1;
        }

        double cy = _fixed_grab_y + _cumulative_y_drag + dy;

        _cumulative_y_drag = cy - _fixed_grab_y;

        cy = max (0.0, cy);
        cy = min ((double) _line->height(), cy);

        double const fraction = 1.0 - (cy / _line->height());
        uint32_t ignored;

        /* we are ignoring x position for this drag, so we can just pass in anything */
        _line->drag_motion (0, fraction, true, false, ignored);

        show_verbose_cursor_text (_line->get_verbose_cursor_string (fraction));
}

void
LineDrag::finished (GdkEvent* event, bool movement_occured)
{
        if (movement_occured) {
                motion (event, false);
                _line->end_drag (false, 0);
        } else {
                /* add a new control point on the line */

                AutomationTimeAxisView* atv;

                _line->end_drag (false, 0);

                if ((atv = dynamic_cast<AutomationTimeAxisView*>(_editor->clicked_axisview)) != 0) {
                        framepos_t where = _editor->window_event_sample (event, 0, 0);
                        atv->add_automation_event (event, where, event->button.y, false);
                }
        }

        _editor->commit_reversible_command ();
}

void
LineDrag::aborted (bool)
{
        _line->reset ();
}

FeatureLineDrag::FeatureLineDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i),
          _line (0),
          _cumulative_x_drag (0)
{
        DEBUG_TRACE (DEBUG::Drags, "New FeatureLineDrag\n");
}

void
FeatureLineDrag::start_grab (GdkEvent* event, Gdk::Cursor* /*cursor*/)
{
        Drag::start_grab (event);

        _line = reinterpret_cast<Line*> (_item);
        assert (_line);

        /* need to get x coordinate in terms of parent (AudioRegionView) origin. */

        double cx = event->button.x;
        double cy = event->button.y;

        _item->parent()->canvas_to_item (cx, cy);

        /* store grab start in parent frame */
        _region_view_grab_x = cx;

        _before = *(float*) _item->get_data ("position");

        _arv = reinterpret_cast<AudioRegionView*> (_item->get_data ("regionview"));

        _max_x = _editor->sample_to_pixel(_arv->get_duration());
}

void
FeatureLineDrag::motion (GdkEvent*, bool)
{
        double dx = _drags->current_pointer_x() - last_pointer_x();

        double cx = _region_view_grab_x + _cumulative_x_drag + dx;

        _cumulative_x_drag += dx;

        /* Clamp the min and max extent of the drag to keep it within the region view bounds */

        if (cx > _max_x){
                cx = _max_x;
        }
        else if(cx < 0){
                cx = 0;
        }

        boost::optional<ArdourCanvas::Rect> bbox = _line->bounding_box ();
        assert (bbox);
        _line->set (ArdourCanvas::Duple (cx, 2.0), ArdourCanvas::Duple (cx, bbox.get().height ()));

        float *pos = new float;
        *pos = cx;

        _line->set_data ("position", pos);

        _before = cx;
}

void
FeatureLineDrag::finished (GdkEvent*, bool)
{
        _arv = reinterpret_cast<AudioRegionView*> (_item->get_data ("regionview"));
        _arv->update_transient(_before, _before);
}

void
FeatureLineDrag::aborted (bool)
{
        //_line->reset ();
}

RubberbandSelectDrag::RubberbandSelectDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
        , _vertical_only (false)
{
        DEBUG_TRACE (DEBUG::Drags, "New RubberbandSelectDrag\n");
}

void
RubberbandSelectDrag::start_grab (GdkEvent* event, Gdk::Cursor *)
{
        Drag::start_grab (event);
        show_verbose_cursor_time (adjusted_current_frame (event, ARDOUR_UI::config()->get_rubberbanding_snaps_to_grid()));
}

void
RubberbandSelectDrag::motion (GdkEvent* event, bool)
{
        framepos_t start;
        framepos_t end;
        double y1;
        double y2;

        framepos_t const pf = adjusted_current_frame (event, ARDOUR_UI::config()->get_rubberbanding_snaps_to_grid());

        framepos_t grab = grab_frame ();
        if (ARDOUR_UI::config()->get_rubberbanding_snaps_to_grid ()) {
                _editor->snap_to_with_modifier (grab, event);
        } else {
                grab = raw_grab_frame ();
        }

        /* base start and end on initial click position */

        if (pf < grab) {
                start = pf;
                end = grab;
        } else {
                end = pf;
                start = grab;
        }

        if (current_pointer_y() < grab_y()) {
                y1 = current_pointer_y();
                y2 = grab_y();
        } else {
                y2 = current_pointer_y();
                y1 = grab_y();
        }

        if (start != end || y1 != y2) {

                double x1 = _editor->sample_to_pixel (start);
                double x2 = _editor->sample_to_pixel (end);
                const double min_dimension = 2.0;

                if (_vertical_only) {
                        /* fixed 10 pixel width */
                        x2 = x1 + 10;
                } else {
                        if (x2 < x1) {
                                x2 = min (x1 - min_dimension, x2);
                        } else {
                                x2 = max (x1 + min_dimension, x2);
                        }
                }

                if (y2 < y1) {
                        y2 = min (y1 - min_dimension, y2);
                } else {
                        y2 = max (y1 + min_dimension, y2);
                }

                /* translate rect into item space and set */

                ArdourCanvas::Rect r (x1, y1, x2, y2);

                /* this drag is a _trackview_only == true drag, so the y1 and
                 * y2 (computed using current_pointer_y() and grab_y()) will be
                 * relative to the top of the trackview group). The
                 * rubberband rect has the same parent/scroll offset as the
                 * the trackview group, so we can use the "r" rect directly
                 * to set the shape of the rubberband.
                 */

                _editor->rubberband_rect->set (r);
                _editor->rubberband_rect->show();
                _editor->rubberband_rect->raise_to_top();

                show_verbose_cursor_time (pf);

                do_select_things (event, true);
        }
}

void
RubberbandSelectDrag::do_select_things (GdkEvent* event, bool drag_in_progress)
{
        framepos_t x1;
        framepos_t x2;
        framepos_t grab = grab_frame ();
        framepos_t lpf = last_pointer_frame ();

        if (!ARDOUR_UI::config()->get_rubberbanding_snaps_to_grid ()) {
                grab = raw_grab_frame ();
                lpf = _editor->pixel_to_sample_from_event (last_pointer_x());
        }

        if (grab < lpf) {
                x1 = grab;
                x2 = lpf;
        } else {
                x2 = grab;
                x1 = lpf;
        }

        double y1;
        double y2;

        if (current_pointer_y() < grab_y()) {
                y1 = current_pointer_y();
                y2 = grab_y();
        } else {
                y2 = current_pointer_y();
                y1 = grab_y();
        }

        select_things (event->button.state, x1, x2, y1, y2, drag_in_progress);
}

void
RubberbandSelectDrag::finished (GdkEvent* event, bool movement_occurred)
{
        if (movement_occurred) {

                motion (event, false);
                do_select_things (event, false);

        } else {

                /* just a click */

                bool do_deselect = true;
                MidiTimeAxisView* mtv;

                if ((mtv = dynamic_cast<MidiTimeAxisView*>(_editor->clicked_axisview)) != 0) {
                        /* MIDI track */
                        if (_editor->selection->empty() && _editor->mouse_mode == MouseDraw) {
                                /* nothing selected */
                                add_midi_region (mtv);
                                do_deselect = false;
                        }
                }

                /* do not deselect if Primary or Tertiary (toggle-select or
                 * extend-select are pressed.
                 */

                if (!Keyboard::modifier_state_contains (event->button.state, Keyboard::PrimaryModifier) &&
                    !Keyboard::modifier_state_contains (event->button.state, Keyboard::TertiaryModifier) &&
                    do_deselect) {
                        deselect_things ();
                }

        }

        _editor->rubberband_rect->hide();
}

void
RubberbandSelectDrag::aborted (bool)
{
        _editor->rubberband_rect->hide ();
}

TimeFXDrag::TimeFXDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, std::list<RegionView*> const & v)
        : RegionDrag (e, i, p, v)
{
        DEBUG_TRACE (DEBUG::Drags, "New TimeFXDrag\n");
}

void
TimeFXDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        show_verbose_cursor_time (adjusted_current_frame (event));
}

void
TimeFXDrag::motion (GdkEvent* event, bool)
{
        RegionView* rv = _primary;
        StreamView* cv = rv->get_time_axis_view().view ();

        pair<TimeAxisView*, double> const tv = _editor->trackview_by_y_position (grab_y());
        int layer = tv.first->layer_display() == Overlaid ? 0 : tv.second;
        int layers = tv.first->layer_display() == Overlaid ? 1 : cv->layers();

        framepos_t const pf = adjusted_current_frame (event);

        if (pf > rv->region()->position()) {
                rv->get_time_axis_view().show_timestretch (rv->region()->position(), pf, layers, layer);
        }

        show_verbose_cursor_time (pf);
}

void
TimeFXDrag::finished (GdkEvent* /*event*/, bool movement_occurred)
{
        _primary->get_time_axis_view().hide_timestretch ();

        if (!movement_occurred) {
                return;
        }

        if (last_pointer_frame() < _primary->region()->position()) {
                /* backwards drag of the left edge - not usable */
                return;
        }

        framecnt_t newlen = last_pointer_frame() - _primary->region()->position();

        float percentage = (double) newlen / (double) _primary->region()->length();

#ifndef USE_RUBBERBAND
        // Soundtouch uses percentage / 100 instead of normal (/ 1)
        if (_primary->region()->data_type() == DataType::AUDIO) {
                percentage = (float) ((double) newlen - (double) _primary->region()->length()) / ((double) newlen) * 100.0f;
        }
#endif

        if (!_editor->get_selection().regions.empty()) {
                /* primary will already be included in the selection, and edit
                   group shared editing will propagate selection across
                   equivalent regions, so just use the current region
                   selection.
                */

                if (_editor->time_stretch (_editor->get_selection().regions, percentage) == -1) {
                        error << _("An error occurred while executing time stretch operation") << endmsg;
                }
        }
}

void
TimeFXDrag::aborted (bool)
{
        _primary->get_time_axis_view().hide_timestretch ();
}

ScrubDrag::ScrubDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
{
        DEBUG_TRACE (DEBUG::Drags, "New ScrubDrag\n");
}

void
ScrubDrag::start_grab (GdkEvent* event, Gdk::Cursor *)
{
        Drag::start_grab (event);
}

void
ScrubDrag::motion (GdkEvent* /*event*/, bool)
{
        _editor->scrub (adjusted_current_frame (0, false), _drags->current_pointer_x ());
}

void
ScrubDrag::finished (GdkEvent* /*event*/, bool movement_occurred)
{
        if (movement_occurred && _editor->session()) {
                /* make sure we stop */
                _editor->session()->request_transport_speed (0.0);
        }
}

void
ScrubDrag::aborted (bool)
{
        /* XXX: TODO */
}

SelectionDrag::SelectionDrag (Editor* e, ArdourCanvas::Item* i, Operation o)
        : Drag (e, i)
        , _operation (o)
        , _add (false)
        , _time_selection_at_start (!_editor->get_selection().time.empty())
{
        DEBUG_TRACE (DEBUG::Drags, "New SelectionDrag\n");

        if (_time_selection_at_start) {
                start_at_start = _editor->get_selection().time.start();
                end_at_start = _editor->get_selection().time.end_frame();
        }
}

void
SelectionDrag::start_grab (GdkEvent* event, Gdk::Cursor*)
{
        if (_editor->session() == 0) {
                return;
        }

        Gdk::Cursor* cursor = MouseCursors::invalid_cursor();

        switch (_operation) {
        case CreateSelection:
                if (Keyboard::modifier_state_equals (event->button.state, Keyboard::CopyModifier)) {
                        _add = true;
                } else {
                        _add = false;
                }
                cursor = _editor->cursors()->selector;
                Drag::start_grab (event, cursor);
                break;

        case SelectionStartTrim:
                if (_editor->clicked_axisview) {
                        _editor->clicked_axisview->order_selection_trims (_item, true);
                }
                Drag::start_grab (event, _editor->cursors()->left_side_trim);
                break;

        case SelectionEndTrim:
                if (_editor->clicked_axisview) {
                        _editor->clicked_axisview->order_selection_trims (_item, false);
                }
                Drag::start_grab (event, _editor->cursors()->right_side_trim);
                break;

        case SelectionMove:
                Drag::start_grab (event, cursor);
                break;

        case SelectionExtend:
                Drag::start_grab (event, cursor);
                break;
        }

        if (_operation == SelectionMove) {
                show_verbose_cursor_time (_editor->selection->time[_editor->clicked_selection].start);
        } else {
                show_verbose_cursor_time (adjusted_current_frame (event));
        }
}

void
SelectionDrag::setup_pointer_frame_offset ()
{
        switch (_operation) {
        case CreateSelection:
                _pointer_frame_offset = 0;
                break;

        case SelectionStartTrim:
        case SelectionMove:
                _pointer_frame_offset = raw_grab_frame() - _editor->selection->time[_editor->clicked_selection].start;
                break;

        case SelectionEndTrim:
                _pointer_frame_offset = raw_grab_frame() - _editor->selection->time[_editor->clicked_selection].end;
                break;

        case SelectionExtend:
                break;
        }
}

void
SelectionDrag::motion (GdkEvent* event, bool first_move)
{
        framepos_t start = 0;
        framepos_t end = 0;
        framecnt_t length = 0;
        framecnt_t distance = 0;

        framepos_t const pending_position = adjusted_current_frame (event);

        if (_operation != CreateSelection && pending_position == last_pointer_frame()) {
                return;
        }

        switch (_operation) {
        case CreateSelection:
        {
                framepos_t grab = grab_frame ();

                if (first_move) {
                        grab = adjusted_current_frame (event, false);
                        if (grab < pending_position) {
                                _editor->snap_to (grab, RoundDownMaybe);
                        }  else {
                                _editor->snap_to (grab, RoundUpMaybe);
                        }
                }

                if (pending_position < grab) {
                        start = pending_position;
                        end = grab;
                } else {
                        end = pending_position;
                        start = grab;
                }

                /* first drag: Either add to the selection
                   or create a new selection
                */

                if (first_move) {

                        if (_add) {

                                /* adding to the selection */
                                _editor->set_selected_track_as_side_effect (Selection::Add);
                                _editor->clicked_selection = _editor->selection->add (start, end);
                                _add = false;

                        } else {

                                /* new selection */

                                if (_editor->clicked_axisview && !_editor->selection->selected (_editor->clicked_axisview)) {
                                        _editor->set_selected_track_as_side_effect (Selection::Set);
                                }

                                _editor->clicked_selection = _editor->selection->set (start, end);
                        }
                }

                //if user is selecting a range on an automation track, bail out here before we get to the grouped stuff,
                // because the grouped stuff will start working on tracks (routeTAVs), and end up removing this
                AutomationTimeAxisView *atest = dynamic_cast<AutomationTimeAxisView *>(_editor->clicked_axisview);
                if (atest) {
                        _editor->selection->add (atest);
                        break;
                }

                /* select all tracks within the rectangle that we've marked out so far */
                TrackViewList new_selection;
                TrackViewList& all_tracks (_editor->track_views);

                ArdourCanvas::Coord const top = grab_y();
                ArdourCanvas::Coord const bottom = current_pointer_y();

                if (top >= 0 && bottom >= 0) {

                        //first, find the tracks that are covered in the y range selection
                        for (TrackViewList::const_iterator i = all_tracks.begin(); i != all_tracks.end(); ++i) {
                                if ((*i)->covered_by_y_range (top, bottom)) {
                                        new_selection.push_back (*i);
                                }
                        }

                        //now find any tracks that are GROUPED with the tracks we selected
                        TrackViewList grouped_add = new_selection;
                        for (TrackViewList::const_iterator i = new_selection.begin(); i != new_selection.end(); ++i) {
                                RouteTimeAxisView *n = dynamic_cast<RouteTimeAxisView *>(*i);
                                if ( n && n->route()->route_group() && n->route()->route_group()->is_active() && n->route()->route_group()->enabled_property (ARDOUR::Properties::select.property_id) ) {
                                        for (TrackViewList::const_iterator j = all_tracks.begin(); j != all_tracks.end(); ++j) {
                                                RouteTimeAxisView *check = dynamic_cast<RouteTimeAxisView *>(*j);
                                                if ( check && (n != check) && (check->route()->route_group() == n->route()->route_group()) )
                                                        grouped_add.push_back (*j);
                                        }
                                }
                        }

                        //now compare our list with the current selection, and add or remove as necessary
                        //( NOTE: most mouse moves don't change the selection so we can't just SET it for every mouse move; it gets clunky )
                        TrackViewList tracks_to_add;
                        TrackViewList tracks_to_remove;
                        for (TrackViewList::const_iterator i = grouped_add.begin(); i != grouped_add.end(); ++i)
                                if ( !_editor->selection->tracks.contains ( *i ) )
                                        tracks_to_add.push_back ( *i );
                        for (TrackViewList::const_iterator i = _editor->selection->tracks.begin(); i != _editor->selection->tracks.end(); ++i)
                                if ( !grouped_add.contains ( *i ) )
                                        tracks_to_remove.push_back ( *i );
                        _editor->selection->add(tracks_to_add);
                        _editor->selection->remove(tracks_to_remove);

                }
        }
        break;

        case SelectionStartTrim:

                start = _editor->selection->time[_editor->clicked_selection].start;
                end = _editor->selection->time[_editor->clicked_selection].end;

                if (pending_position > end) {
                        start = end;
                } else {
                        start = pending_position;
                }
                break;

        case SelectionEndTrim:

                start = _editor->selection->time[_editor->clicked_selection].start;
                end = _editor->selection->time[_editor->clicked_selection].end;

                if (pending_position < start) {
                        end = start;
                } else {
                        end = pending_position;
                }

                break;

        case SelectionMove:

                start = _editor->selection->time[_editor->clicked_selection].start;
                end = _editor->selection->time[_editor->clicked_selection].end;

                length = end - start;
                distance = pending_position - start;
                start = pending_position;
                _editor->snap_to (start);

                end = start + length;

                break;

        case SelectionExtend:
                break;
        }

        if (start != end) {
                switch (_operation) {
                case SelectionMove:
                        if (_time_selection_at_start) {
                                _editor->selection->move_time (distance);
                        }
                        break;
                default:
                        _editor->selection->replace (_editor->clicked_selection, start, end);
                }
        }

        if (_operation == SelectionMove) {
                show_verbose_cursor_time(start);
        } else {
                show_verbose_cursor_time(pending_position);
        }
}

void
SelectionDrag::finished (GdkEvent* event, bool movement_occurred)
{
        Session* s = _editor->session();

        _editor->begin_reversible_selection_op (X_("Change Time Selection"));
        if (movement_occurred) {
                motion (event, false);
                /* XXX this is not object-oriented programming at all. ick */
                if (_editor->selection->time.consolidate()) {
                        _editor->selection->TimeChanged ();
                }

                /* XXX what if its a music time selection? */
                if (s) {
                        if ( s->get_play_range() && s->transport_rolling() ) {
                                s->request_play_range (&_editor->selection->time, true);
                        } else {
                                if (ARDOUR_UI::config()->get_follow_edits() && !s->transport_rolling()) {
                                        if (_operation == SelectionEndTrim)
                                                _editor->maybe_locate_with_edit_preroll( _editor->get_selection().time.end_frame());
                                        else
                                                s->request_locate (_editor->get_selection().time.start());
                                }
                        }
                }

        } else {
                /* just a click, no pointer movement.
                 */

                if (_operation == SelectionExtend) {
                        if (_time_selection_at_start) {
                                framepos_t pos = adjusted_current_frame (event, false);
                                framepos_t start = min (pos, start_at_start);
                                framepos_t end = max (pos, end_at_start);
                                _editor->selection->set (start, end);
                        }
                } else {
                        if (Keyboard::modifier_state_equals (event->button.state, Keyboard::CopyModifier)) {
                                if (_editor->clicked_selection) {
                                        _editor->selection->remove (_editor->clicked_selection);
                                }
                        } else {
                                if (!_editor->clicked_selection) {
                                        _editor->selection->clear_time();
                                }
                        }
                }

                if (_editor->clicked_axisview && !_editor->selection->selected (_editor->clicked_axisview)) {
                        _editor->selection->set (_editor->clicked_axisview);
                }

                if (s && s->get_play_range () && s->transport_rolling()) {
                        s->request_stop (false, false);
                }

        }

        _editor->stop_canvas_autoscroll ();
        _editor->clicked_selection = 0;
        _editor->commit_reversible_selection_op ();
}

void
SelectionDrag::aborted (bool)
{
        /* XXX: TODO */
}

RangeMarkerBarDrag::RangeMarkerBarDrag (Editor* e, ArdourCanvas::Item* i, Operation o)
        : Drag (e, i, false),
          _operation (o),
          _copy (false)
{
        DEBUG_TRACE (DEBUG::Drags, "New RangeMarkerBarDrag\n");

        _drag_rect = new ArdourCanvas::Rectangle (_editor->time_line_group,
                                                  ArdourCanvas::Rect (0.0, 0.0, 0.0,
                                                                      physical_screen_height (_editor->get_window())));
        _drag_rect->hide ();

        _drag_rect->set_fill_color (ARDOUR_UI::config()->color ("range drag rect"));
        _drag_rect->set_outline_color (ARDOUR_UI::config()->color ("range drag rect"));
}

RangeMarkerBarDrag::~RangeMarkerBarDrag()
{
        /* normal canvas items will be cleaned up when their parent group is deleted. But
           this item is created as the child of a long-lived parent group, and so we
           need to explicitly delete it.
        */
        delete _drag_rect;
}

void
RangeMarkerBarDrag::start_grab (GdkEvent* event, Gdk::Cursor *)
{
        if (_editor->session() == 0) {
                return;
        }

        Gdk::Cursor* cursor = MouseCursors::invalid_cursor();

        if (!_editor->temp_location) {
                _editor->temp_location = new Location (*_editor->session());
        }

        switch (_operation) {
        case CreateSkipMarker:
        case CreateRangeMarker:
        case CreateTransportMarker:
        case CreateCDMarker:

                if (Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier)) {
                        _copy = true;
                } else {
                        _copy = false;
                }
                cursor = _editor->cursors()->selector;
                break;
        }

        Drag::start_grab (event, cursor);

        show_verbose_cursor_time (adjusted_current_frame (event));
}

void
RangeMarkerBarDrag::motion (GdkEvent* event, bool first_move)
{
        framepos_t start = 0;
        framepos_t end = 0;
        ArdourCanvas::Rectangle *crect;

        switch (_operation) {
        case CreateSkipMarker:
                crect = _editor->range_bar_drag_rect;
                break;
        case CreateRangeMarker:
                crect = _editor->range_bar_drag_rect;
                break;
        case CreateTransportMarker:
                crect = _editor->transport_bar_drag_rect;
                break;
        case CreateCDMarker:
                crect = _editor->cd_marker_bar_drag_rect;
                break;
        default:
                error << string_compose (_("programming_error: %1"), "Error: unknown range marker op passed to Editor::drag_range_markerbar_op ()") << endmsg;
                return;
                break;
        }

        framepos_t const pf = adjusted_current_frame (event);

        if (_operation == CreateSkipMarker || _operation == CreateRangeMarker || _operation == CreateTransportMarker || _operation == CreateCDMarker) {
                framepos_t grab = grab_frame ();
                _editor->snap_to (grab);

                if (pf < grab_frame()) {
                        start = pf;
                        end = grab;
                } else {
                        end = pf;
                        start = grab;
                }

                /* first drag: Either add to the selection
                   or create a new selection.
                */

                if (first_move) {

                        _editor->temp_location->set (start, end);

                        crect->show ();

                        update_item (_editor->temp_location);
                        _drag_rect->show();
                        //_drag_rect->raise_to_top();

                }
        }

        if (start != end) {
                _editor->temp_location->set (start, end);

                double x1 = _editor->sample_to_pixel (start);
                double x2 = _editor->sample_to_pixel (end);
                crect->set_x0 (x1);
                crect->set_x1 (x2);

                update_item (_editor->temp_location);
        }

        show_verbose_cursor_time (pf);

}

void
RangeMarkerBarDrag::finished (GdkEvent* event, bool movement_occurred)
{
        Location * newloc = 0;
        string rangename;
        int flags;

        if (movement_occurred) {
                motion (event, false);
                _drag_rect->hide();

                switch (_operation) {
                case CreateSkipMarker:
                case CreateRangeMarker:
                case CreateCDMarker:
                    {
                        XMLNode &before = _editor->session()->locations()->get_state();
                        if (_operation == CreateSkipMarker) {
                                _editor->begin_reversible_command (_("new skip marker"));
                                _editor->session()->locations()->next_available_name(rangename,_("skip"));
                                flags = Location::IsRangeMarker | Location::IsSkip;
                                _editor->range_bar_drag_rect->hide();
                        } else if (_operation == CreateCDMarker) {
                                _editor->session()->locations()->next_available_name(rangename, _("CD"));
                                _editor->begin_reversible_command (_("new CD marker"));
                                flags = Location::IsRangeMarker | Location::IsCDMarker;
                                _editor->cd_marker_bar_drag_rect->hide();
                        } else {
                                _editor->begin_reversible_command (_("new skip marker"));
                                _editor->session()->locations()->next_available_name(rangename, _("unnamed"));
                                flags = Location::IsRangeMarker;
                                _editor->range_bar_drag_rect->hide();
                        }
                        newloc = new Location (
                                *_editor->session(), _editor->temp_location->start(), _editor->temp_location->end(), rangename, (Location::Flags) flags
                                );

                        _editor->session()->locations()->add (newloc, true);
                        XMLNode &after = _editor->session()->locations()->get_state();
                        _editor->session()->add_command(new MementoCommand<Locations>(*(_editor->session()->locations()), &before, &after));
                        _editor->commit_reversible_command ();
                        break;
                    }

                case CreateTransportMarker:
                        // popup menu to pick loop or punch
                        _editor->new_transport_marker_context_menu (&event->button, _item);
                        break;
                }

        } else {

                /* just a click, no pointer movement. remember that context menu stuff was handled elsewhere */

                if (_operation == CreateTransportMarker) {

                        /* didn't drag, so just locate */

                        _editor->session()->request_locate (grab_frame(), _editor->session()->transport_rolling());

                } else if (_operation == CreateCDMarker) {

                        /* didn't drag, but mark is already created so do
                         * nothing */

                } else { /* operation == CreateRangeMarker || CreateSkipMarker */

                        framepos_t start;
                        framepos_t end;

                        _editor->session()->locations()->marks_either_side (grab_frame(), start, end);

                        if (end == max_framepos) {
                                end = _editor->session()->current_end_frame ();
                        }

                        if (start == max_framepos) {
                                start = _editor->session()->current_start_frame ();
                        }

                        switch (_editor->mouse_mode) {
                        case MouseObject:
                                /* find the two markers on either side and then make the selection from it */
                                _editor->select_all_within (start, end, 0.0f, FLT_MAX, _editor->track_views, Selection::Set, false);
                                break;

                        case MouseRange:
                                /* find the two markers on either side of the click and make the range out of it */
                                _editor->selection->set (start, end);
                                break;

                        default:
                                break;
                        }
                }
        }

        _editor->stop_canvas_autoscroll ();
}

void
RangeMarkerBarDrag::aborted (bool movement_occured)
{
        if (movement_occured) {
                _drag_rect->hide ();
        }
}

void
RangeMarkerBarDrag::update_item (Location* location)
{
        double const x1 = _editor->sample_to_pixel (location->start());
        double const x2 = _editor->sample_to_pixel (location->end());

        _drag_rect->set_x0 (x1);
        _drag_rect->set_x1 (x2);
}

NoteDrag::NoteDrag (Editor* e, ArdourCanvas::Item* i)
        : Drag (e, i)
        , _cumulative_dx (0)
        , _cumulative_dy (0)
{
        DEBUG_TRACE (DEBUG::Drags, "New NoteDrag\n");

        _primary = reinterpret_cast<NoteBase*> (_item->get_data ("notebase"));
        assert (_primary);
        _region = &_primary->region_view ();
        _note_height = _region->midi_stream_view()->note_height ();
}

void
NoteDrag::start_grab (GdkEvent* event, Gdk::Cursor *)
{
        Drag::start_grab (event);

        if (!(_was_selected = _primary->selected())) {

                /* tertiary-click means extend selection - we'll do that on button release,
                   so don't add it here, because otherwise we make it hard to figure
                   out the "extend-to" range.
                */

                bool extend = Keyboard::modifier_state_equals (event->button.state, Keyboard::TertiaryModifier);

                if (!extend) {
                        bool add = Keyboard::modifier_state_equals (event->button.state, Keyboard::PrimaryModifier);

                        if (add) {
                                _region->note_selected (_primary, true);
                        } else {
                                _region->unique_select (_primary);
                        }

                        _editor->begin_reversible_selection_op(X_("Select Note Press"));
                        _editor->commit_reversible_selection_op();
                }
        }
}

frameoffset_t
NoteDrag::total_dx () const
{
        /* dx in frames */
        frameoffset_t const dx = _editor->pixel_to_sample (_drags->current_pointer_x() - grab_x());

        /* primary note time */
        frameoffset_t const n = _region->source_beats_to_absolute_frames (_primary->note()->time ());

        /* new time of the primary note in session frames */
        frameoffset_t st = n + dx;

        framepos_t const rp = _region->region()->position ();

        /* prevent the note being dragged earlier than the region's position */
        st = max (st, rp);

        /* snap and return corresponding delta */
        return _region->snap_frame_to_frame (st - rp) + rp - n;
}

int8_t
NoteDrag::total_dy () const
{
        MidiStreamView* msv = _region->midi_stream_view ();
        double const y = _region->midi_view()->y_position ();
        /* new current note */
        uint8_t n = msv->y_to_note (current_pointer_y () - y);
        /* clamp */
        n = max (msv->lowest_note(), n);
        n = min (msv->highest_note(), n);
        /* and work out delta */
        return n - msv->y_to_note (grab_y() - y);
}

void
NoteDrag::motion (GdkEvent *, bool)
{
        /* Total change in x and y since the start of the drag */
        frameoffset_t const dx = total_dx ();
        int8_t const dy = total_dy ();

        /* Now work out what we have to do to the note canvas items to set this new drag delta */
        double const tdx = _editor->sample_to_pixel (dx) - _cumulative_dx;
        double const tdy = -dy * _note_height - _cumulative_dy;

        if (tdx || tdy) {
                _cumulative_dx += tdx;
                _cumulative_dy += tdy;

                int8_t note_delta = total_dy();

                _region->move_selection (tdx, tdy, note_delta);

                /* the new note value may be the same as the old one, but we
                 * don't know what that means because the selection may have
                 * involved more than one note and we might be doing something
                 * odd with them. so show the note value anyway, always.
                 */

                char buf[12];
                uint8_t new_note = min (max (_primary->note()->note() + note_delta, 0), 127);

                snprintf (buf, sizeof (buf), "%s (%d)", Evoral::midi_note_name (new_note).c_str(),
                          (int) floor ((double)new_note));

                show_verbose_cursor_text (buf);
        }
}

void
NoteDrag::finished (GdkEvent* ev, bool moved)
{
        if (!moved) {
                /* no motion - select note */

                if (_editor->current_mouse_mode() == Editing::MouseObject ||
                    _editor->current_mouse_mode() == Editing::MouseDraw) {

                        bool changed = false;

                        if (_was_selected) {
                                bool add = Keyboard::modifier_state_equals (ev->button.state, Keyboard::PrimaryModifier);
                                if (add) {
                                        _region->note_deselected (_primary);
                                        changed = true;
                                }
                        } else {
                                bool extend = Keyboard::modifier_state_equals (ev->button.state, Keyboard::TertiaryModifier);
                                bool add = Keyboard::modifier_state_equals (ev->button.state, Keyboard::PrimaryModifier);

                                if (!extend && !add && _region->selection_size() > 1) {
                                        _region->unique_select (_primary);
                                        changed = true;
                                } else if (extend) {
                                        _region->note_selected (_primary, true, true);
                                        changed = true;
                                } else {
                                        /* it was added during button press */
                                }
                        }

                        if (changed) {
                                _editor->begin_reversible_selection_op(X_("Select Note Release"));
                                _editor->commit_reversible_selection_op();
                        }
                }
        } else {
                _region->note_dropped (_primary, total_dx(), total_dy());
        }
}

void
NoteDrag::aborted (bool)
{
        /* XXX: TODO */
}

AutomationRangeDrag::AutomationRangeDrag (Editor* editor, AutomationTimeAxisView* atv, list<AudioRange> const & r)
        : Drag (editor, atv->base_item ())
        , _ranges (r)
        , _y_origin (atv->y_position())
        , _nothing_to_drag (false)
{
        DEBUG_TRACE (DEBUG::Drags, "New AutomationRangeDrag\n");
        setup (atv->lines ());
}

AutomationRangeDrag::AutomationRangeDrag (Editor* editor, RegionView* rv, list<AudioRange> const & r)
        : Drag (editor, rv->get_canvas_group ())
        , _ranges (r)
        , _y_origin (rv->get_time_axis_view().y_position())
        , _nothing_to_drag (false)
        , _integral (false)
{
        DEBUG_TRACE (DEBUG::Drags, "New AutomationRangeDrag\n");

        list<boost::shared_ptr<AutomationLine> > lines;

        AudioRegionView*      audio_view;
        AutomationRegionView* automation_view;
        if ((audio_view = dynamic_cast<AudioRegionView*>(rv))) {
                lines.push_back (audio_view->get_gain_line ());
        } else if ((automation_view = dynamic_cast<AutomationRegionView*>(rv))) {
                lines.push_back (automation_view->line ());
                _integral = true;
        } else {
                error << _("Automation range drag created for invalid region type") << endmsg;
        }

        setup (lines);
}

void
AutomationRangeDrag::setup (list<boost::shared_ptr<AutomationLine> > const & lines)
{
        /* find the lines that overlap the ranges being dragged */
        list<boost::shared_ptr<AutomationLine> >::const_iterator i = lines.begin ();
        while (i != lines.end ()) {
                list<boost::shared_ptr<AutomationLine> >::const_iterator j = i;
                ++j;

                pair<framepos_t, framepos_t> r = (*i)->get_point_x_range ();

                /* check this range against all the AudioRanges that we are using */
                list<AudioRange>::const_iterator k = _ranges.begin ();
                while (k != _ranges.end()) {
                        if (k->coverage (r.first, r.second) != Evoral::OverlapNone) {
                                break;
                        }
                        ++k;
                }

                /* add it to our list if it overlaps at all */
                if (k != _ranges.end()) {
                        Line n;
                        n.line = *i;
                        n.state = 0;
                        n.range = r;
                        _lines.push_back (n);
                }

                i = j;
        }

        /* Now ::lines contains the AutomationLines that somehow overlap our drag */
}

double
AutomationRangeDrag::y_fraction (boost::shared_ptr<AutomationLine> line, double global_y) const
{
        return 1.0 - ((global_y - _y_origin) / line->height());
}

double
AutomationRangeDrag::value (boost::shared_ptr<AutomationList> list, double x) const
{
        const double v = list->eval(x);
        return _integral ? rint(v) : v;
}

void
AutomationRangeDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        /* Get line states before we start changing things */
        for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {
                i->state = &i->line->get_state ();
                i->original_fraction = y_fraction (i->line, current_pointer_y());
        }

        if (_ranges.empty()) {

                /* No selected time ranges: drag all points */
                for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {
                        uint32_t const N = i->line->npoints ();
                        for (uint32_t j = 0; j < N; ++j) {
                                i->points.push_back (i->line->nth (j));
                        }
                }

        } else {

                for (list<AudioRange>::const_iterator i = _ranges.begin(); i != _ranges.end(); ++i) {

                        framecnt_t const half = (i->start + i->end) / 2;

                        /* find the line that this audio range starts in */
                        list<Line>::iterator j = _lines.begin();
                        while (j != _lines.end() && (j->range.first > i->start || j->range.second < i->start)) {
                                ++j;
                        }

                        if (j != _lines.end()) {
                                boost::shared_ptr<AutomationList> the_list = j->line->the_list ();

                                /* j is the line that this audio range starts in; fade into it;
                                   64 samples length plucked out of thin air.
                                */

                                framepos_t a = i->start + 64;
                                if (a > half) {
                                        a = half;
                                }

                                double const p = j->line->time_converter().from (i->start - j->line->time_converter().origin_b ());
                                double const q = j->line->time_converter().from (a - j->line->time_converter().origin_b ());

                                the_list->editor_add (p, value (the_list, p));
                                the_list->editor_add (q, value (the_list, q));
                        }

                        /* same thing for the end */

                        j = _lines.begin();
                        while (j != _lines.end() && (j->range.first > i->end || j->range.second < i->end)) {
                                ++j;
                        }

                        if (j != _lines.end()) {
                                boost::shared_ptr<AutomationList> the_list = j->line->the_list ();

                                /* j is the line that this audio range starts in; fade out of it;
                                   64 samples length plucked out of thin air.
                                */

                                framepos_t b = i->end - 64;
                                if (b < half) {
                                        b = half;
                                }

                                double const p = j->line->time_converter().from (b - j->line->time_converter().origin_b ());
                                double const q = j->line->time_converter().from (i->end - j->line->time_converter().origin_b ());

                                the_list->editor_add (p, value (the_list, p));
                                the_list->editor_add (q, value (the_list, q));
                        }
                }

                _nothing_to_drag = true;

                /* Find all the points that should be dragged and put them in the relevant
                   points lists in the Line structs.
                */

                for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {

                        uint32_t const N = i->line->npoints ();
                        for (uint32_t j = 0; j < N; ++j) {

                                /* here's a control point on this line */
                                ControlPoint* p = i->line->nth (j);
                                double const w = i->line->time_converter().to ((*p->model())->when) + i->line->time_converter().origin_b ();

                                /* see if it's inside a range */
                                list<AudioRange>::const_iterator k = _ranges.begin ();
                                while (k != _ranges.end() && (k->start >= w || k->end <= w)) {
                                        ++k;
                                }

                                if (k != _ranges.end()) {
                                        /* dragging this point */
                                        _nothing_to_drag = false;
                                        i->points.push_back (p);
                                }
                        }
                }
        }

        if (_nothing_to_drag) {
                return;
        }

        for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {
                i->line->start_drag_multiple (i->points, y_fraction (i->line, current_pointer_y()), i->state);
        }
}

void
AutomationRangeDrag::motion (GdkEvent*, bool /*first_move*/)
{
        if (_nothing_to_drag) {
                return;
        }

        for (list<Line>::iterator l = _lines.begin(); l != _lines.end(); ++l) {
                float const f = y_fraction (l->line, current_pointer_y());
                /* we are ignoring x position for this drag, so we can just pass in anything */
                uint32_t ignored;
                l->line->drag_motion (0, f, true, false, ignored);
                show_verbose_cursor_text (l->line->get_verbose_cursor_relative_string (l->original_fraction, f));
        }
}

void
AutomationRangeDrag::finished (GdkEvent* event, bool)
{
        if (_nothing_to_drag) {
                return;
        }

        motion (event, false);
        for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {
                i->line->end_drag (false, 0);
        }

        _editor->commit_reversible_command ();
}

void
AutomationRangeDrag::aborted (bool)
{
        for (list<Line>::iterator i = _lines.begin(); i != _lines.end(); ++i) {
                i->line->reset ();
        }
}

DraggingView::DraggingView (RegionView* v, RegionDrag* parent, TimeAxisView* itav)
        : view (v)
        , initial_time_axis_view (itav)
{
        /* note that time_axis_view may be null if the regionview was created
         * as part of a copy operation.
         */
        time_axis_view = parent->find_time_axis_view (&v->get_time_axis_view ());
        layer = v->region()->layer ();
        initial_y = v->get_canvas_group()->position().y;
        initial_playlist = v->region()->playlist ();
        initial_position = v->region()->position ();
        initial_end = v->region()->position () + v->region()->length ();
}

PatchChangeDrag::PatchChangeDrag (Editor* e, PatchChange* i, MidiRegionView* r)
        : Drag (e, i->canvas_item ())
        , _region_view (r)
        , _patch_change (i)
        , _cumulative_dx (0)
{
        DEBUG_TRACE (DEBUG::Drags, string_compose ("New PatchChangeDrag, patch @ %1, grab @ %2\n",
                                                   _region_view->source_beats_to_absolute_frames (_patch_change->patch()->time()),
                                                   grab_frame()));
}

void
PatchChangeDrag::motion (GdkEvent* ev, bool)
{
        framepos_t f = adjusted_current_frame (ev);
        boost::shared_ptr<Region> r = _region_view->region ();
        f = max (f, r->position ());
        f = min (f, r->last_frame ());

        framecnt_t const dxf = f - grab_frame(); // permitted dx in frames
        double const dxu = _editor->sample_to_pixel (dxf); // permitted fx in units
        _patch_change->move (ArdourCanvas::Duple (dxu - _cumulative_dx, 0));
        _cumulative_dx = dxu;
}

void
PatchChangeDrag::finished (GdkEvent* ev, bool movement_occurred)
{
        if (!movement_occurred) {
                return;
        }

        boost::shared_ptr<Region> r (_region_view->region ());
        framepos_t f = adjusted_current_frame (ev);
        f = max (f, r->position ());
        f = min (f, r->last_frame ());

        _region_view->move_patch_change (
                *_patch_change,
                _region_view->region_frames_to_region_beats (f - (r->position() - r->start()))
                );
}

void
PatchChangeDrag::aborted (bool)
{
        _patch_change->move (ArdourCanvas::Duple (-_cumulative_dx, 0));
}

void
PatchChangeDrag::setup_pointer_frame_offset ()
{
        boost::shared_ptr<Region> region = _region_view->region ();
        _pointer_frame_offset = raw_grab_frame() - _region_view->source_beats_to_absolute_frames (_patch_change->patch()->time());
}

MidiRubberbandSelectDrag::MidiRubberbandSelectDrag (Editor* e, MidiRegionView* rv)
        : RubberbandSelectDrag (e, rv->get_canvas_group ())
        , _region_view (rv)
{

}

void
MidiRubberbandSelectDrag::select_things (int button_state, framepos_t x1, framepos_t x2, double y1, double y2, bool /*drag_in_progress*/)
{
        _region_view->update_drag_selection (
                x1, x2, y1, y2,
                Keyboard::modifier_state_contains (button_state, Keyboard::TertiaryModifier));
}

void
MidiRubberbandSelectDrag::deselect_things ()
{
        /* XXX */
}

MidiVerticalSelectDrag::MidiVerticalSelectDrag (Editor* e, MidiRegionView* rv)
        : RubberbandSelectDrag (e, rv->get_canvas_group ())
        , _region_view (rv)
{
        _vertical_only = true;
}

void
MidiVerticalSelectDrag::select_things (int button_state, framepos_t /*x1*/, framepos_t /*x2*/, double y1, double y2, bool /*drag_in_progress*/)
{
        double const y = _region_view->midi_view()->y_position ();

        y1 = max (0.0, y1 - y);
        y2 = max (0.0, y2 - y);

        _region_view->update_vertical_drag_selection (
                y1,
                y2,
                Keyboard::modifier_state_contains (button_state, Keyboard::TertiaryModifier)
                );
}

void
MidiVerticalSelectDrag::deselect_things ()
{
        /* XXX */
}

EditorRubberbandSelectDrag::EditorRubberbandSelectDrag (Editor* e, ArdourCanvas::Item* i)
        : RubberbandSelectDrag (e, i)
{

}

void
EditorRubberbandSelectDrag::select_things (int button_state, framepos_t x1, framepos_t x2, double y1, double y2, bool drag_in_progress)
{
        if (drag_in_progress) {
                /* We just want to select things at the end of the drag, not during it */
                return;
        }

        Selection::Operation op = ArdourKeyboard::selection_type (button_state);

        _editor->begin_reversible_selection_op (X_("rubberband selection"));

        _editor->select_all_within (x1, x2 - 1, y1, y2, _editor->track_views, op, false);

        _editor->commit_reversible_selection_op ();
}

void
EditorRubberbandSelectDrag::deselect_things ()
{
        _editor->begin_reversible_selection_op (X_("Clear Selection (rubberband)"));

        _editor->selection->clear_tracks();
        _editor->selection->clear_regions();
        _editor->selection->clear_points ();
        _editor->selection->clear_lines ();
        _editor->selection->clear_midi_notes ();

        _editor->commit_reversible_selection_op();
}

NoteCreateDrag::NoteCreateDrag (Editor* e, ArdourCanvas::Item* i, MidiRegionView* rv)
        : Drag (e, i)
        , _region_view (rv)
        , _drag_rect (0)
{
        _note[0] = _note[1] = 0;
}

NoteCreateDrag::~NoteCreateDrag ()
{
        delete _drag_rect;
}

framecnt_t
NoteCreateDrag::grid_frames (framepos_t t) const
{
        bool success;
        Evoral::Beats grid_beats = _editor->get_grid_type_as_beats (success, t);
        if (!success) {
                grid_beats = Evoral::Beats(1);
        }

        return _region_view->region_beats_to_region_frames (grid_beats);
}

void
NoteCreateDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
{
        Drag::start_grab (event, cursor);

        _drag_rect = new ArdourCanvas::Rectangle (_region_view->get_canvas_group ());

        framepos_t pf = _drags->current_pointer_frame ();
        framecnt_t const g = grid_frames (pf);

        /* Hack so that we always snap to the note that we are over, instead of snapping
           to the next one if we're more than halfway through the one we're over.
        */
        if (_editor->snap_mode() == SnapNormal && pf > g / 2) {
                pf -= g / 2;
        }

        _note[0] = adjusted_frame (pf, event) - _region_view->region()->position ();
        _note[1] = _note[0];

        MidiStreamView* sv = _region_view->midi_stream_view ();
        double const x = _editor->sample_to_pixel (_note[0]);
        double const y = sv->note_to_y (sv->y_to_note (y_to_region (event->button.y)));

        _drag_rect->set (ArdourCanvas::Rect (x, y, x, y + floor (_region_view->midi_stream_view()->note_height ())));
        _drag_rect->set_outline_all ();
        _drag_rect->set_outline_color (0xffffff99);
        _drag_rect->set_fill_color (0xffffff66);
}

void
NoteCreateDrag::motion (GdkEvent* event, bool)
{
        _note[1] = max ((framepos_t)0, adjusted_current_frame (event) - _region_view->region()->position ());
        double const x0 = _editor->sample_to_pixel (_note[0]);
        double const x1 = _editor->sample_to_pixel (_note[1]);
        _drag_rect->set_x0 (std::min(x0, x1));
        _drag_rect->set_x1 (std::max(x0, x1));
}

void
NoteCreateDrag::finished (GdkEvent*, bool had_movement)
{
        if (!had_movement) {
                return;
        }

        framepos_t const start = min (_note[0], _note[1]);
        framecnt_t length = (framecnt_t) fabs ((double)(_note[0] - _note[1]));

        framecnt_t const g = grid_frames (start);
        Evoral::Beats const one_tick = Evoral::Beats::ticks(1);

        if (_editor->snap_mode() == SnapNormal && length < g) {
                length = g;
        }

        Evoral::Beats length_beats = max (
                one_tick, _region_view->region_frames_to_region_beats (length) - one_tick);

        _region_view->create_note_at (start, _drag_rect->y0(), length_beats, false);
}

double
NoteCreateDrag::y_to_region (double y) const
{
        double x = 0;
        _region_view->get_canvas_group()->canvas_to_item (x, y);
        return y;
}

void
NoteCreateDrag::aborted (bool)
{

}

CrossfadeEdgeDrag::CrossfadeEdgeDrag (Editor* e, AudioRegionView* rv, ArdourCanvas::Item* i, bool start_yn)
        : Drag (e, i)
        , arv (rv)
        , start (start_yn)
{
        std::cout << ("CrossfadeEdgeDrag is DEPRECATED.  See TrimDrag::preserve_fade_anchor") << endl;
}

void
CrossfadeEdgeDrag::start_grab (GdkEvent* event, Gdk::Cursor *cursor)
{
        Drag::start_grab (event, cursor);
}

void
CrossfadeEdgeDrag::motion (GdkEvent*, bool)
{
        double distance;
        double new_length;
        framecnt_t len;

        boost::shared_ptr<AudioRegion> ar (arv->audio_region());

        if (start) {
                distance = _drags->current_pointer_x() - grab_x();
                len = ar->fade_in()->back()->when;
        } else {
                distance = grab_x() - _drags->current_pointer_x();
                len = ar->fade_out()->back()->when;
        }

        /* how long should it be ? */

        new_length = len + _editor->pixel_to_sample (distance);

        /* now check with the region that this is legal */

        new_length = ar->verify_xfade_bounds (new_length, start);

        if (start) {
                arv->reset_fade_in_shape_width (ar, new_length);
        } else {
                arv->reset_fade_out_shape_width (ar, new_length);
        }
}

void
CrossfadeEdgeDrag::finished (GdkEvent*, bool)
{
        double distance;
        double new_length;
        framecnt_t len;

        boost::shared_ptr<AudioRegion> ar (arv->audio_region());

        if (start) {
                distance = _drags->current_pointer_x() - grab_x();
                len = ar->fade_in()->back()->when;
        } else {
                distance = grab_x() - _drags->current_pointer_x();
                len = ar->fade_out()->back()->when;
        }

        new_length = ar->verify_xfade_bounds (len + _editor->pixel_to_sample (distance), start);

        _editor->begin_reversible_command ("xfade trim");
        ar->playlist()->clear_owned_changes ();

        if (start) {
                ar->set_fade_in_length (new_length);
        } else {
                ar->set_fade_out_length (new_length);
        }

        /* Adjusting the xfade may affect other regions in the playlist, so we need
           to get undo Commands from the whole playlist rather than just the
           region.
        */

        vector<Command*> cmds;
        ar->playlist()->rdiff (cmds);
        _editor->session()->add_commands (cmds);
        _editor->commit_reversible_command ();

}

void
CrossfadeEdgeDrag::aborted (bool)
{
        if (start) {
                // arv->redraw_start_xfade ();
        } else {
                // arv->redraw_end_xfade ();
        }
}

RegionCutDrag::RegionCutDrag (Editor* e, ArdourCanvas::Item* item, framepos_t pos)
        : Drag (e, item, true)
        , line (new EditorCursor (*e))
{
        line->set_position (pos);
        line->show ();
}

RegionCutDrag::~RegionCutDrag ()
{
        delete line;
}

void
RegionCutDrag::motion (GdkEvent*, bool)
{
        framepos_t where = _drags->current_pointer_frame();
        _editor->snap_to (where);

        line->set_position (where);
}

void
RegionCutDrag::finished (GdkEvent*, bool)
{
        _editor->get_track_canvas()->canvas()->re_enter();

        framepos_t pos = _drags->current_pointer_frame();

        line->hide ();

        RegionSelection rs = _editor->get_regions_from_selection_and_mouse (pos);

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

        _editor->split_regions_at (pos, rs);
}

void
RegionCutDrag::aborted (bool)
{
}