[Qt-interest] QTableView Drag and Drop

[Alexander O. Anisimov]

Hi all,

I try to make DnD in QTableView. I made a sub-class of QAbstractTableModel.

[code]

#include "dragdroptableview.h"

DragDropTableView::DragDropTableView(QObject *parent) :
   QAbstractTableModel(parent)
{
}

DragDropTableView::DragDropTableView(QList< QPair<QString, QString> > pairs,
QObject *parent):
       QAbstractTableModel(parent)
{
   listOfPairs = pairs;
}

int DragDropTableView::rowCount(const QModelIndex &parent) const
 {
    Q_UNUSED(parent);
     return listOfPairs.size();
}

int DragDropTableView::columnCount(const QModelIndex &parent) const
 {
    Q_UNUSED(parent);
     return 2;
}

QVariant DragDropTableView::data(const QModelIndex &index, int role) const
  {
     if (!index.isValid())
          return QVariant();

      if (index.row() >= listOfPairs.size() || index.row() < 0)
         return QVariant();

     if (role == Qt::DisplayRole) {
          QPair<QString, QString> pair = listOfPairs.at(index.row());

          if (index.column() == 0)
             return pair.first;
          else if (index.column() == 1)
             return pair.second;
      }
     return QVariant();
  }

QVariant DragDropTableView::headerData(int section, Qt::Orientation
orientation, int role) const
  {
     if (role != Qt::DisplayRole)
          return QVariant();

      if (orientation == Qt::Horizontal) {
         switch (section) {
              case 0:
                 return tr("Name");

             case 1:
                  return tr("Address");

              default:
                 return QVariant();
          }
     }
      return QVariant();
 }

bool DragDropTableView::insertRows(int position, int rows, const QModelIndex
&index)
 {
    Q_UNUSED(index);
     beginInsertRows(QModelIndex(), position, position+rows-1);

     for (int row=0; row < rows; row++) {
        QPair<QString, QString> pair(" ", " ");
         listOfPairs.insert(position, pair);
    }

    endInsertRows();
     return true;
}

bool DragDropTableView::removeRows(int position, int rows, const QModelIndex
&index)
 {
    Q_UNUSED(index);
     beginRemoveRows(QModelIndex(), position, position+rows-1);

     for (int row=0; row < rows; ++row) {
        listOfPairs.removeAt(position);
     }

    endRemoveRows();
     return true;
}

Qt::ItemFlags DragDropTableView::flags(const QModelIndex &index) const
 {
    if (!index.isValid())
         return Qt::ItemIsEnabled;

     return QAbstractTableModel::flags(index) | Qt::ItemIsDragEnabled |
Qt::ItemIsDropEnabled;
}

QStringList DragDropTableView::mimeTypes() const
 {
   QStringList types;
    types << "application/vnd.text.list";
   return types;
 }

QMimeData* DragDropTableView::mimeData(const QModelIndexList &indexes) const
 {
   QMimeData *mimeData = new QMimeData();
    QByteArray encodedData;
   QDataStream stream(&encodedData, QIODevice::WriteOnly);
    QModelIndex index;
   foreach (index, indexes)
    {
       if (index.isValid())
        {
           QString text;
            text = data(index, Qt::DisplayRole).toString();
           stream << text;
        }
   }
    mimeData->setData("application/vnd.text.list", encodedData);
   return mimeData;
}

Qt::DropAction DragDropTableView::supportedDropActions()
{
   return Qt::MoveAction;
}

bool DragDropTableView::dropMimeData(const QMimeData *data,
                                     Qt::DropAction action,
                                    int row, int column,
                                     const QModelIndex &parent)
{
    Q_UNUSED(column)
   if (!data->hasFormat("application/vnd.text.list"))
    {
       return false;
    }
   if (action == Qt::IgnoreAction)
    {
       return true;
    }
   int endRow = 0;
    if (!parent.isValid() && row < 0)
   {
        endRow = listOfPairs.count();
   }
    else if (!parent.isValid())
   {
        endRow = qMin(row, listOfPairs.count());
   }
    else
   {
        endRow = parent.row();
   }

   QByteArray encodedData = data->data("application/vnd.text.list");
    QDataStream stream(&encodedData, QIODevice::ReadOnly);

    while (!stream.atEnd())
   {
        QString first, second;
       stream >> first >> second;
        QPair <QString, QString> pair(first, second);
       beginInsertRows(QModelIndex(), endRow, endRow);
        listOfPairs.insert(endRow, pair);
       endInsertRows();
        endRow ++;
   }
    return true;
}

[/code]

When I DnD some item from first table to second the item is copied into
second table, but not removed from first table. Can you help me?

Thanks in advance

.''`.  With best regards,
: :' : Alexander Anisimov
`. `'  JID alenyashka at gmail.com
  `-   Debian - when you have better things to do than fixing systems
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