/*

Copyright (C) 2011-2016 Michael Goffioul

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
<http://www.gnu.org/licenses/>.

*/

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

#include <QListWidget>

#include "Container.h"
#include "ListBoxControl.h"
#include "QtHandlesUtils.h"

namespace QtHandles
{

  static void
  updateSelection (QListWidget* list, const Matrix& value)
  {
    octave_idx_type n = value.numel ();
    int lc = list->count ();

    list->clearSelection ();

    for (octave_idx_type i = 0; i < n; i++)
      {
        int idx = octave::math::round (value(i));

        if (1 <= idx && idx <= lc)
          {
            list->item (idx-1)->setSelected (true);
            list->scrollToItem (list->item (idx-1));
            if (i == 0
                && list->selectionMode () == QAbstractItemView::SingleSelection)
              break;
          }
        else
          {
            // Invalid selection.
            list->clearSelection ();
            break;
          }
      }
  }

  ListBoxControl*
  ListBoxControl::create (const graphics_object& go)
  {
    Object* parent = Object::parentObject (go);

    if (parent)
      {
        Container* container = parent->innerContainer ();

        if (container)
          return new ListBoxControl (go, new QListWidget (container));
      }

    return 0;
  }

  ListBoxControl::ListBoxControl (const graphics_object& go, QListWidget* list)
    : BaseControl (go, list), m_blockCallback (false)
  {
    uicontrol::properties& up = properties<uicontrol> ();

    list->addItems (Utils::fromStringVector (up.get_string_vector ()));
    if ((up.get_max () - up.get_min ()) > 1)
      list->setSelectionMode (QAbstractItemView::ExtendedSelection);
    else
      list->setSelectionMode (QAbstractItemView::SingleSelection);
    Matrix value = up.get_value ().matrix_value ();
    if (value.numel () > 0)
      {
        octave_idx_type n = value.numel ();
        int lc = list->count ();

        for (octave_idx_type i = 0; i < n; i++)
          {
            int idx = octave::math::round (value(i));

            if (1 <= idx && idx <= lc)
              {
                list->item (idx-1)->setSelected (true);
                list->scrollToItem (list->item (idx-1));
                if (i == 0 && (list->selectionMode ()
                               == QAbstractItemView::SingleSelection))
                  break;
              }
          }
      }

    list->removeEventFilter (this);
    list->viewport ()->installEventFilter (this);

    connect (list, SIGNAL (itemSelectionChanged (void)),
             SLOT (itemSelectionChanged (void)));
  }

  ListBoxControl::~ListBoxControl (void)
  { }

  void
  ListBoxControl::update (int pId)
  {
    uicontrol::properties& up = properties<uicontrol> ();
    QListWidget* list = qWidget<QListWidget> ();

    switch (pId)
      {
      case uicontrol::properties::ID_STRING:
        m_blockCallback = true;
        list->clear ();
        list->addItems (Utils::fromStringVector (up.get_string_vector ()));
        updateSelection (list, up.get_value ().matrix_value ());
        m_blockCallback = false;
        break;

      case uicontrol::properties::ID_MIN:

      case uicontrol::properties::ID_MAX:
        if ((up.get_max () - up.get_min ()) > 1)
          list->setSelectionMode (QAbstractItemView::ExtendedSelection);
        else
          list->setSelectionMode (QAbstractItemView::SingleSelection);
        break;

      case uicontrol::properties::ID_VALUE:
        m_blockCallback = true;
        updateSelection (list, up.get_value ().matrix_value ());
        m_blockCallback = false;
        break;

      default:
        BaseControl::update (pId);
        break;
      }
  }

  void
  ListBoxControl::itemSelectionChanged (void)
  {
    if (! m_blockCallback)
      {
        QListWidget* list = qWidget<QListWidget> ();

        QModelIndexList l = list->selectionModel ()->selectedIndexes ();
        Matrix value (dim_vector (1, l.size ()));
        int i = 0;

        foreach (const QModelIndex& idx, l)
        value(i++) = (idx.row () + 1);

        gh_manager::post_set (m_handle, "value", octave_value (value), false);
        gh_manager::post_callback (m_handle, "callback");
      }
  }

}

