////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave 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 3 of the License, or
// (at your option) any later version.
//
// Octave 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 Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QApplication>
#include <QBitmap>
#include <QCursor>
#include <QInputDialog>
#include <QList>
#include <QMouseEvent>
#include <QWheelEvent>
#include <QRectF>

#include "Canvas.h"
#include "ContextMenu.h"
#include "GLCanvas.h"
#include "QtHandlesUtils.h"
#include "qt-graphics-toolkit.h"

#include "annotation-dialog.h"
#include "octave-qobject.h"
#include "qt-interpreter-events.h"

#include "builtin-defun-decls.h"
#include "graphics.h"
#include "interpreter.h"
#include "oct-opengl.h"

OCTAVE_BEGIN_NAMESPACE(octave)

void
Canvas::redraw (bool sync)
{
  QWidget *w = qWidget ();

  if (w)
    {
      if (sync)
        w->repaint ();
      else
        w->update ();
    }
}

void
Canvas::blockRedraw (bool block)
{
  m_redrawBlocked = block;
}

QCursor
Canvas::make_cursor (const QString& name, int hot_x, int hot_y)
{
  octave::resource_manager& rmgr = m_octave_qobj.get_resource_manager ();

  QIcon icon = rmgr.icon (name);

  return QCursor (icon.pixmap (22, 22), hot_x, hot_y);
}

void
Canvas::setCursor (MouseMode mode, std::string fallback,
                   QImage cdata, Matrix hotspot)
{
  QWidget *w = qWidget ();
  QCursor cursor = Qt::ArrowCursor;
  if (w)
    {
      switch (mode)
        {
        case NoMode:
          {
            cursor = Qt::ArrowCursor;

            if (fallback == "arrow")
              cursor = Qt::ArrowCursor;
            else if (fallback == "botl")
              cursor = make_cursor ("bottom_left_corner", 5, 16);
            else if (fallback == "botr")
              cursor = make_cursor ("bottom_right_corner", 16, 16);
            else if (fallback == "bottom")
              cursor = make_cursor ("bottom_side", 11, 16);
            else if (fallback == "circle")
              cursor = make_cursor ("circle", 10, 10);
            else if (fallback == "cross" || fallback == "crosshair")
              cursor = make_cursor ("cross", 10, 10);
            else if (fallback == "custom")
              {
                if (hotspot(0) > cdata.width () || hotspot(0) < 1.0
                    || hotspot(1) > cdata.height () || hotspot(1) < 1.0)
                  hotspot = Matrix (1, 2, 1);

                cursor = QCursor (QPixmap::fromImage (cdata),
                                  static_cast<int> (hotspot(1) - 1),
                                  static_cast<int> (hotspot(0) - 1));
              }
            else if (fallback == "fleur")
              cursor = make_cursor ("fleur", 10, 4);
            else if (fallback == "hand")
              cursor = make_cursor ("hand2", 7, 3);
            else if (fallback == "ibeam")
              cursor = Qt::IBeamCursor;
            else if (fallback == "left")
              cursor = make_cursor ("left_side", 4, 10);
            else if (fallback == "right")
              cursor = make_cursor ("right_side", 17, 10);
            else if (fallback == "top")
              cursor = make_cursor ("top_side", 11, 4);
            else if (fallback == "topl")
              cursor = make_cursor ("top_left_corner", 4, 4);
            else if (fallback == "topr")
              cursor = make_cursor ("top_right_corner", 16, 4);
            else if (fallback == "watch")
              cursor = Qt::BusyCursor;
          }
          break;
        case SelectMode:
          cursor = Qt::ArrowCursor;
          break;

        case PanMode:
          cursor = make_cursor ("figure-pan");
          break;

        case RotateMode:
          cursor = make_cursor ("figure-rotate");
          break;

        case TextMode:
          cursor = Qt::IBeamCursor;
          break;

        case ZoomInMode:
          cursor = make_cursor ("figure-zoom-in", 9, 9);
          break;

        case ZoomOutMode:
          cursor = make_cursor ("figure-zoom-out", 9, 9);
          break;

        default:
          cursor = Qt::ArrowCursor;
          break;
        }
      w->setCursor (cursor);
    }
}

/*
  Two updateCurrentPoint() routines are required:
  1) Used for QMouseEvents where cursor position data is in callback from Qt.
  2) Used for QKeyEvents where cursor position must be determined.
*/
void
Canvas::updateCurrentPoint (const graphics_object& fig,
                            const graphics_object& obj, QMouseEvent *event)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  octave::autolock guard (gh_mgr.graphics_lock ());

  emit gh_set_event (fig.get_handle (), "currentpoint",
                     Utils::figureCurrentPoint (fig, event), false);

  Matrix children = obj.get_properties ().get_children ();
  octave_idx_type num_children = children.numel ();

  for (int i = 0; i < num_children; i++)
    {
      graphics_object childObj (gh_mgr.get_object (children(i)));

      if (childObj.isa ("axes"))
        {
          axes::properties& ap = Utils::properties<axes> (childObj);
          Matrix x_zlim = ap.get_transform_zlim ();
          graphics_xform x_form = ap.get_transform ();

          ColumnVector p1 = x_form.untransform (event->x (), event->y (),
                                                x_zlim(0));
          ColumnVector p2 = x_form.untransform (event->x (), event->y (),
                                                x_zlim(1));

          Matrix cp (2, 3, 0.0);

          cp(0, 0) = p1(0); cp(0, 1) = p1(1); cp(0, 2) = p1(2);
          cp(1, 0) = p2(0); cp(1, 1) = p2(1); cp(1, 2) = p2(2);

          emit gh_set_event (childObj.get_handle (), "currentpoint", cp,
                             false);
        }
    }
}

void
Canvas::updateCurrentPoint (const graphics_object& fig,
                            const graphics_object& obj)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  octave::autolock guard (gh_mgr.graphics_lock ());

  emit gh_set_event (fig.get_handle (), "currentpoint",
                     Utils::figureCurrentPoint (fig), false);

  Matrix children = obj.get_properties ().get_children ();
  octave_idx_type num_children = children.numel ();

  for (int i = 0; i < num_children; i++)
    {
      graphics_object childObj (gh_mgr.get_object (children(i)));

      if (childObj.isa ("axes"))
        {
          // FIXME: QCursor::pos() may give inaccurate results with
          //        asynchronous window systems like X11 over ssh.
          QWidget *w = qWidget ();
          QPoint p = w->mapFromGlobal (QCursor::pos ());
          axes::properties& ap = Utils::properties<axes> (childObj);
          Matrix x_zlim = ap.get_transform_zlim ();
          graphics_xform x_form = ap.get_transform ();

          ColumnVector p1 = x_form.untransform (p.x (), p.y (), x_zlim(0));
          ColumnVector p2 = x_form.untransform (p.x (), p.y (), x_zlim(1));

          Matrix cp (2, 3, 0.0);

          cp(0, 0) = p1(0); cp(0, 1) = p1(1); cp(0, 2) = p1(2);
          cp(1, 0) = p2(0); cp(1, 1) = p2(1); cp(1, 2) = p2(2);

          emit gh_set_event (childObj.get_handle (), "currentpoint", cp,
                             false);
        }
    }
}

static void
autoscale_axes (gh_manager& gh_mgr, axes::properties& ap)
{
  octave::autolock guard (gh_mgr.graphics_lock ());

  // Reset zoom stack
  ap.clear_zoom_stack (false);

  ap.set_xlimmode ("auto");
  ap.set_ylimmode ("auto");
  ap.set_zlimmode ("auto");
}

void
Canvas::canvasPaintEvent (void)
{
  if (! m_redrawBlocked)
    {
      gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

      octave::autolock guard (gh_mgr.graphics_lock ());

      draw (m_handle);

      if ((m_mouseMode == ZoomInMode && m_mouseAxes.ok ()) || m_rectMode)
        drawZoomBox (m_mouseAnchor, m_mouseCurrent);
    }
}

static bool
pan_enabled (const graphics_object figObj)
{
  // Getting pan mode property:
  octave_value ov_pm
    = Utils::properties<figure> (figObj).get___pan_mode__ ();

  octave_scalar_map pm = ov_pm.scalar_map_value ();

  return pm.contents ("Enable").string_value () == "on";
}

static std::string
pan_mode (const graphics_object figObj)
{
  // Getting pan mode property:
  octave_value ov_pm
    = Utils::properties<figure> (figObj).get___pan_mode__ ();

  octave_scalar_map pm = ov_pm.scalar_map_value ();

  return pm.contents ("Motion").string_value ();
}

static bool
zoom_enabled (const graphics_object figObj)
{
  // Getting zoom mode property:
  octave_value ov_zm
    = Utils::properties<figure> (figObj).get___zoom_mode__ ();

  octave_scalar_map zm = ov_zm.scalar_map_value ();

  return zm.contents ("Enable").string_value () == "on";
}

static std::string
zoom_mode (const graphics_object figObj)
{
  // Getting zoom mode property:
  octave_value ov_zm
    = Utils::properties<figure> (figObj).get___zoom_mode__ ();

  octave_scalar_map zm = ov_zm.scalar_map_value ();

  return zm.contents ("Motion").string_value ();
}

void
Canvas::select_object (graphics_object obj, QMouseEvent *event,
                       graphics_object& currentObj, graphics_object& axesObj,
                       bool axes_only, std::vector<std::string> omit)
{
  QList<graphics_object> axesList;
  Matrix children = obj.get_properties ().get_all_children ();
  octave_idx_type num_children = children.numel ();

  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  for (int i = 0; i < num_children; i++)
    {
      graphics_object childObj (gh_mgr.get_object (children(i)));

      if (childObj.isa ("axes"))
        {
          auto p = omit.begin ();
          bool omitfound = false;
          while (p != omit.end () && ! omitfound)
            {
              omitfound = (childObj.get ("tag").string_value () == *p);
              p++;
            }
          if (! omitfound)
            axesList.append (childObj);
        }
      else if (childObj.isa ("uicontrol") || childObj.isa ("uipanel")
               || childObj.isa ("uibuttongroup") || childObj.isa ("uitable"))
        {
          Matrix bb = childObj.get_properties ().get_boundingbox (false);
          QRectF r (bb(0), bb(1), bb(2), bb(3));

          r.adjust (-5, -5, 5, 5);

          bool rect_contains_pos = r.contains (event->localPos ());
          if (rect_contains_pos)
            {
              currentObj = childObj;
              break;
            }
        }
    }

  if (axes_only)
    {
      QPoint pt = event->pos ();

      for (QList<graphics_object>::ConstIterator it = axesList.begin ();
           it != axesList.end (); ++it)
        {
          const axes::properties& ap =
            dynamic_cast<const axes::properties&> ((*it).get_properties ());

          ColumnVector p0 = ap.pixel2coord (pt.x (), pt.y ());
          Matrix xlim = ap.get_xlim ().matrix_value ();
          Matrix ylim = ap.get_ylim ().matrix_value ();

          if (xlim(0) < p0(0) && xlim(1) > p0(0)
              && ylim(0) < p0(1) && ylim(1) > p0(1))
            {
              axesObj = *it;
              return;
            }
        }
    }
  else if (! currentObj)
    {
      for (QList<graphics_object>::ConstIterator it = axesList.begin ();
           it != axesList.end (); ++it)
        {
          graphics_object go = selectFromAxes (*it, event->pos ());

          if (go)
            {
              currentObj = go;
              axesObj = *it;
            }
          // FIXME: is this really necessary? the axes object should
          //        have been selected through selectFromAxes anyway
          else if (it->get_properties ().is_hittest ())
            {
              Matrix bb = it->get_properties ().get_boundingbox (true);
              QRectF r (bb(0), bb(1), bb(2), bb(3));

              // Allow a rectangle (e.g., Zoom box) to be slightly outside
              // the axes and still select it.
              r.adjust (-20, -20, 20, 20);

              bool rect_contains_pos = r.contains (event->localPos ());
              if (rect_contains_pos)
                axesObj = *it;
            }

          if (axesObj && currentObj)
            break;
        }
    }
}

void
Canvas::canvasMouseMoveEvent (QMouseEvent *event)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  octave::autolock guard (gh_mgr.graphics_lock ());

  graphics_object ax = gh_mgr.get_object (m_mouseAxes);

  if (m_mouseMode != NoMode && (ax.valid_object () || m_mouseMode == TextMode))
    {
      switch (m_mouseMode)
        {
        case RotateMode:
          {
            axes::properties& ap = Utils::properties<axes> (ax);

            ap.rotate3d (m_mouseCurrent.x (), event->x (),
                         m_mouseCurrent.y (), event->y ());

            // Update current mouse position
            m_mouseCurrent = event->pos ();

            // Force immediate redraw
            redraw (true);
          }
          break;
        case TextMode:
        case ZoomInMode:
        case ZoomOutMode:
          m_mouseCurrent = event->pos ();
          redraw (true);
          break;

        case PanMode:
          {
            axes::properties& ap = Utils::properties<axes> (ax);

            graphics_object figObj (ax.get_ancestor ("figure"));

            std::string mode = pan_mode (figObj);

            ColumnVector p0 = ap.pixel2coord (m_mouseCurrent.x (),
                                              m_mouseCurrent.y ());
            ColumnVector p1 = ap.pixel2coord (event->x (),
                                              event->y ());

            ap.translate_view (mode, p0(0), p1(0), p0(1), p1(1));

            // Update current mouse position
            m_mouseCurrent = event->pos ();

            // Force immediate redraw
            redraw (true);
          }

        default:
          break;
        }
    }
  else if (m_mouseMode == NoMode)
    {
      graphics_object obj = gh_mgr.get_object (m_handle);

      if (obj.valid_object ())
        {
          graphics_object figObj (obj.get_ancestor ("figure"));

          if (figObj.valid_object ()
              && ! figObj.get ("windowbuttonmotionfcn").isempty ())
            {
              updateCurrentPoint (figObj, obj, event);
              emit gh_callback_event (figObj.get_handle (),
                                      "windowbuttonmotionfcn");
            }
        }
    }

  // Update mouse coordinates in the figure window status bar
  graphics_object obj = gh_mgr.get_object (m_handle);
  graphics_object figObj = obj.get_ancestor ("figure");

  if (figObj.valid_object () && obj.valid_object ())
    {
      graphics_object currentObj, axesObj;
      std::vector<std::string> omit = {"legend", "colorbar", "scribeoverlay"};
      select_object (obj, event, currentObj, axesObj, true, omit);

      if (axesObj.valid_object ())
        {
          // FIXME: should we use signal/slot mechanism instead of
          //        directly calling parent fig methods
          Figure *fig =
            dynamic_cast<Figure *> (qt_graphics_toolkit::toolkitObject (figObj));
          axes::properties& ap = Utils::properties<axes> (axesObj);

          if (fig)
            fig->updateStatusBar (ap.pixel2coord (event->x (), event->y ()));
        }
    }
}

void
Canvas::canvasMouseDoubleClickEvent (QMouseEvent *event)
{
  // same processing as normal click, but event type is MouseButtonDblClick
  canvasMousePressEvent (event);
}

static double
button_number (QMouseEvent *event)
{
  double retval = 0;

  switch (event->button ())
    {
    case Qt::LeftButton:
      retval = 1;
      break;

    case Qt::MiddleButton:
      retval = 2;
      break;

    case Qt::RightButton:
      retval = 3;
      break;

    default:
      break;
    }

  return retval;
}

void
Canvas::canvasMousePressEvent (QMouseEvent *event)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  octave::autolock guard (gh_mgr.graphics_lock ());

  graphics_object obj = gh_mgr.get_object (m_handle);

  bool isdblclick = (event->type () == QEvent::MouseButtonDblClick);

  if (obj.valid_object ())
    {
      graphics_object figObj (obj.get_ancestor ("figure"));

      // Any click in a figure canvas makes it current
      if (figObj)
        {
          graphics_object root = gh_mgr.get_object (0);
          Utils::properties<root_figure> (root)
            .set_currentfigure (figObj.get_handle ().as_octave_value ());
        }

      graphics_object currentObj, axesObj;

      // Retrieve selected object.
      select_object (obj, event, currentObj, axesObj);

      // currentObj may be invalid if, e.g., all objects under the mouse
      // click had "hittest" -> "off" or "pickableparts" -> "none".  In that
      // case, replace with underlying figObj which always accepts mouse
      // clicks.
      if (! currentObj.valid_object ())
        currentObj = figObj;
      else if (! currentObj.get_properties ().is_hittest ())
        {
          // Objects with "hittest"->"off" pass the mouse event to their
          // parent and so on.
          graphics_object tmpgo;
          tmpgo = gh_mgr.get_object (currentObj.get_parent ());
          while (tmpgo && ! tmpgo.get_properties ().is_hittest ())
            tmpgo = gh_mgr.get_object (tmpgo.get_parent ());

          if (tmpgo && tmpgo.get_handle () != 0.0)
            currentObj = tmpgo;
          else
            currentObj = graphics_object ();
        }

      // Make selected axes current
      bool valid_axes = axesObj.valid_object ()
        && axesObj.get_properties ().handlevisibility_is ("on")
        && axesObj.get_properties ().get_tag () != "legend"
        && axesObj.get_properties ().get_tag () != "colorbar";

      if (valid_axes)
        Utils::properties<figure> (figObj)
          .set_currentaxes (axesObj.get_handle ().as_octave_value ());

      Figure *fig = dynamic_cast<Figure *> (qt_graphics_toolkit::toolkitObject (figObj));

      MouseMode newMouseMode = NoMode;

      if (fig)
        newMouseMode = fig->mouseMode ();

      switch (newMouseMode)
        {
        case NoMode:
          {
            // Update the figure "currentobject"
            auto& fprop = Utils::properties<figure> (figObj);

            if (currentObj
                && currentObj.get_properties ().handlevisibility_is ("on"))
              fprop.set_currentobject (currentObj.get_handle ()
                                       .as_octave_value ());
            else
              fprop.set_currentobject (Matrix ());

            // Update figure "selectiontype" and "currentpoint"
            emit gh_set_event (figObj.get_handle (), "selectiontype",
                               Utils::figureSelectionType (event, isdblclick),
                               false);

            updateCurrentPoint (figObj, obj, event);

            emit gh_callback_event (figObj.get_handle (),
                                    "windowbuttondownfcn",
                                    button_number (event));

            // Execute the "buttondownfcn" of the selected object.  If the
            // latter is empty then execute the figure "buttondownfcn"
            if (currentObj && ! currentObj.get ("buttondownfcn").isempty ())
              emit gh_callback_event (currentObj.get_handle (),
                                      "buttondownfcn", button_number (event));
            else if (figObj && ! figObj.get ("buttondownfcn").isempty ())
              emit gh_callback_event (figObj.get_handle (),
                                      "buttondownfcn", button_number (event));

            // Show context menu of the selected object
            if (currentObj && event->button () == Qt::RightButton)
              ContextMenu::executeAt (m_interpreter,
                                      currentObj.get_properties (),
                                      event->globalPos ());
          }
          break;

        case TextMode:
          {
            if (event->modifiers () == Qt::NoModifier)
              {
                switch (event->buttons ())
                  {
                  case Qt::LeftButton:
                    m_mouseAnchor = m_mouseCurrent = event->pos ();
                    m_mouseMode = newMouseMode;
                    m_rectMode = true;
                  }
              }
            redraw (false);
          }
          break;

        case PanMode:
        case RotateMode:
        case ZoomInMode:
        case ZoomOutMode:
          if (valid_axes)
            {
              bool redraw_figure = true;

              if (isdblclick)
                {
                  if (event->button () == Qt::LeftButton)
                    {
                      axes::properties& ap = Utils::properties<axes> (axesObj);

                      autoscale_axes (gh_mgr, ap);
                    }
                  else
                    {
                      redraw_figure = false;
                    }
                }
              else if (event->modifiers () == Qt::NoModifier)
                {
                  switch (event->buttons ())
                    {
                    case Qt::LeftButton:
                      m_mouseAnchor = m_mouseCurrent = event->pos ();
                      m_mouseAxes = axesObj.get_handle ();
                      m_mouseMode = newMouseMode;
                      m_clickMode = newMouseMode == ZoomInMode;
                      break;

                    case Qt::RightButton:
                      if (newMouseMode == ZoomInMode)
                        {
                          m_mouseAnchor = m_mouseCurrent = event->pos ();
                          m_mouseAxes = axesObj.get_handle ();
                          m_mouseMode = newMouseMode;
                          m_clickMode = false;
                        }

                      break;

                    case Qt::MiddleButton:
                      {
                        axes::properties& ap =
                          Utils::properties<axes> (axesObj);

                        autoscale_axes (gh_mgr, ap);
                      }
                      break;

                    default:
                      redraw_figure = false;
                      break;
                    }
                }
              else if (event->modifiers () == Qt::ShiftModifier)
                {
                  switch (event->buttons ())
                    {
                    case Qt::LeftButton:
                      if (newMouseMode == ZoomInMode)
                        {
                          m_mouseAnchor = m_mouseCurrent = event->pos ();
                          m_mouseAxes = axesObj.get_handle ();
                          m_mouseMode = newMouseMode;
                          m_clickMode = false;
                        }
                      break;

                    default:
                      redraw_figure = false;
                      break;
                    }
                }

              if (redraw_figure)
                redraw (false);
            }
          break;

        default:
          break;
        }
    }

}

void
Canvas::canvasMouseReleaseEvent (QMouseEvent *event)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  if ((m_mouseMode == ZoomInMode || m_mouseMode == ZoomOutMode)
      && m_mouseAxes.ok ())
    {
      octave::autolock guard (gh_mgr.graphics_lock ());

      graphics_object ax = gh_mgr.get_object (m_mouseAxes);

      if (ax.valid_object ())
        {
          axes::properties& ap = Utils::properties<axes> (ax);

          graphics_object obj = gh_mgr.get_object (m_handle);

          graphics_object figObj (obj.get_ancestor ("figure"));

          std::string zm = zoom_mode (figObj);

          if (m_mouseAnchor == event->pos ())
            {
              double factor = (m_clickMode ? 2.0 : 0.5);

              ColumnVector p1 = ap.pixel2coord (event->x (), event->y ());

              ap.zoom_about_point (zm, p1(0), p1(1), factor);
            }
          else if (m_mouseMode == ZoomInMode)
            {
              ColumnVector p0 = ap.pixel2coord (m_mouseAnchor.x (),
                                                m_mouseAnchor.y ());
              ColumnVector p1 = ap.pixel2coord (event->x (),
                                                event->y ());

              Matrix xl (1, 2, 0.0);
              Matrix yl (1, 2, 0.0);

              xl(0) = std::min (p0(0), p1(0));
              xl(1) = std::max (p0(0), p1(0));
              yl(0) = std::min (p0(1), p1(1));
              yl(1) = std::max (p0(1), p1(1));

              ap.zoom (zm, xl, yl);
            }

          redraw (false);
        }
    }
  else if (m_mouseMode == NoMode)
    {
      octave::autolock guard (gh_mgr.graphics_lock ());

      graphics_object obj = gh_mgr.get_object (m_handle);

      if (obj.valid_object ())
        {
          graphics_object figObj (obj.get_ancestor ("figure"));

          updateCurrentPoint (figObj, obj, event);
          emit gh_callback_event (figObj.get_handle (), "windowbuttonupfcn");
        }
    }
  else if (m_mouseMode == TextMode)
    {
      octave::autolock guard (gh_mgr.graphics_lock ());

      graphics_object figObj
        = gh_mgr.get_object (m_handle).get_ancestor ("figure");

      if (figObj.valid_object ())
        {
          QWidget *w = qWidget ();
          if (w)
            {
              Matrix bb = figObj.get ("position").matrix_value ();
              bb(0) = m_mouseAnchor.x () / bb(2);
              bb(1) = 1.0 - (m_mouseAnchor.y () / bb(3));
              bb(2) = (event->x () - m_mouseAnchor.x ()) / bb(2);
              bb(3) = (m_mouseAnchor.y () - event->y ()) / bb(3);

              octave_value_list props = ovl ("textbox", bb);

              annotation_dialog anno_dlg (m_octave_qobj, w, props);

              if (anno_dlg.exec () == QDialog::Accepted)
                {
                  props = anno_dlg.get_properties ();
                  props.prepend (figObj.get_handle ().as_octave_value ());

                  emit interpreter_event
                    ([=] (octave::interpreter& interp)
                    {
                      // INTERPRETER THREAD

                      interp.feval ("annotation", props);

                      redraw ();
                    });
                }
            }
        }
    }
  m_rectMode = false;
  m_mouseAxes = graphics_handle ();
  m_mouseMode = NoMode;
}

void
Canvas::canvasWheelEvent (QWheelEvent *event)
{
  gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

  octave::autolock guard (gh_mgr.graphics_lock ());

  graphics_object obj = gh_mgr.get_object (m_handle);

  if (obj.valid_object ())
    {
      std::string mode;

      graphics_object figObj (obj.get_ancestor ("figure"));

      graphics_object axesObj;

      Matrix children = obj.get_properties ().get_children ();
      octave_idx_type num_children = children.numel ();

      for (int i = 0; i < num_children; i++)
        {
          graphics_object childObj (gh_mgr.get_object (children(i)));

          if (childObj.isa ("axes"))
            {
#if defined (HAVE_QWHEELEVENT_POSITION)
              QPoint pos = event->position().toPoint ();
#else
              QPoint pos = event->pos ();
#endif
              graphics_object go = selectFromAxes (childObj, pos);

              if (go)
                {
                  axesObj = childObj;
                  break;
                }
            }
        }

      if (axesObj)
        {
          MouseMode newMouseMode = NoMode;

          Figure *fig = dynamic_cast<Figure *> (qt_graphics_toolkit::toolkitObject (figObj));

          if (fig)
            newMouseMode = fig->mouseMode ();

          if (axesObj.get_properties ().handlevisibility_is ("on"))
            {
              Utils::properties<figure> (figObj)
                .set_currentaxes (axesObj.get_handle ().as_octave_value ());

              if (zoom_enabled (figObj))
                {
#if defined (HAVE_QWHEELEVENT_ANGLEDELTA)
                  if (event->angleDelta().y () > 0)
#else
                    if (event->delta () > 0)
#endif
                      newMouseMode = ZoomInMode;
                    else
                      newMouseMode = ZoomOutMode;

                  mode = zoom_mode (figObj);
                }
              else if (pan_enabled (figObj))
                {
                  newMouseMode = PanMode;

                  mode = pan_mode (figObj);
                }
            }

          bool redrawFigure = true;

          switch (newMouseMode)
            {
            case ZoomInMode:
            case ZoomOutMode:
              {
                axes::properties& ap = Utils::properties<axes> (axesObj);

                // Control how fast to zoom when using scroll wheel.
                double wheel_zoom_speed = ap.get_mousewheelzoom ();

                // Determine if we're zooming in or out.
                double factor = (newMouseMode == ZoomInMode
                                 ? 1 / (1.0 - wheel_zoom_speed)
                                 : 1.0 - wheel_zoom_speed);

                // FIXME: should we zoom about point for 2D plots?

                ap.zoom (mode, factor);
              }
              break;

            case PanMode:
              {
                axes::properties& ap = Utils::properties<axes> (axesObj);

#if defined (HAVE_QWHEELEVENT_ANGLEDELTA)
                double factor = (event->angleDelta().y () > 0 ? 0.1 : -0.1);
#else
                double factor = (event->delta () > 0 ? 0.1 : -0.1);
#endif

                if (event->modifiers () == Qt::NoModifier
                    && mode != "horizontal")
                  ap.pan ("vertical", factor);
                else if (event->modifiers () == Qt::ShiftModifier
                         && mode != "vertical")
                  ap.pan ("horizontal", factor);
              }
              break;

            default:
              redrawFigure = false;
              break;
            }

          if (redrawFigure)
            redraw (false);
        }

      if (! figObj.get ("windowscrollwheelfcn").isempty ())
        {
          octave_scalar_map eventData = Utils::makeScrollEventStruct (event);
          emit gh_callback_event (m_handle, "windowscrollwheelfcn",
                                  eventData);
        }
    }
}

bool
Canvas::canvasKeyPressEvent (QKeyEvent *event)
{
  if (m_eventMask & KeyPress)
    {
      gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

      octave::autolock guard (gh_mgr.graphics_lock ());

      graphics_object obj = gh_mgr.get_object (m_handle);

      if (obj.valid_object ())
        {
          graphics_object figObj (obj.get_ancestor ("figure"));

          updateCurrentPoint (figObj, obj);

          octave_scalar_map eventData = Utils::makeKeyEventStruct (event);

          emit gh_set_event (figObj.get_handle (), "currentcharacter",
                             eventData.getfield ("Character"), false);
          emit gh_callback_event (figObj.get_handle (), "keypressfcn",
                                  eventData);
        }

      return true;
    }

  return false;
}

bool
Canvas::canvasKeyReleaseEvent (QKeyEvent *event)
{
  if (! event->isAutoRepeat () && (m_eventMask & KeyRelease))
    {
      gh_manager& gh_mgr = m_interpreter.get_gh_manager ();

      octave::autolock guard (gh_mgr.graphics_lock ());

      graphics_object obj = gh_mgr.get_object (m_handle);

      if (obj.valid_object ())
        {
          graphics_object figObj (obj.get_ancestor ("figure"));
          emit gh_callback_event (figObj.get_handle (), "keyreleasefcn",
                                  Utils::makeKeyEventStruct (event));
        }

      return true;
    }

  return false;
}

Canvas *
Canvas::create (octave::base_qobject& oct_qobj, octave::interpreter& interp,
                const graphics_handle& handle, QWidget *parent,
                const std::string& /* name */)
{
  // Only OpenGL
  return new GLCanvas (oct_qobj, interp, handle, parent);
}

OCTAVE_END_NAMESPACE(octave)