Qt 4.6: pieceslist.cpp Example File (draganddrop/puzzle/pieceslist.cpp)

|  | Home · All Classes · Overviews |

# pieceslist.cpp Example File
draganddrop/puzzle/pieceslist.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** No Commercial Usage
     ** This file contains pre-release code and may not be distributed.
     ** You may use this file in accordance with the terms and conditions
     ** contained in the Technology Preview License Agreement accompanying
     ** this package.
     **
     ** GNU Lesser General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU Lesser
     ** General Public License version 2.1 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.LGPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU Lesser General Public License version 2.1 requirements
     ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
     **
     ** In addition, as a special exception, Nokia gives you certain
     ** additional rights.  These rights are described in the Nokia Qt LGPL
     ** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
     ** package.
     **
     ** If you have questions regarding the use of this file, please contact
     ** Nokia at qt-info@nokia.com.
     **
     **
     **
     **
     **
     **
     **
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QtGui>

     #include "pieceslist.h"

     PiecesList::PiecesList(QWidget *parent)
         : QListWidget(parent)
     {
         setDragEnabled(true);
         setViewMode(QListView::IconMode);
         setIconSize(QSize(60, 60));
         setSpacing(10);
         setAcceptDrops(true);
         setDropIndicatorShown(true);
     }

     void PiecesList::dragEnterEvent(QDragEnterEvent *event)
     {
         if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
             event->accept();
         else
             event->ignore();
     }

     void PiecesList::dragMoveEvent(QDragMoveEvent *event)
     {
         if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
             event->setDropAction(Qt::MoveAction);
             event->accept();
         } else
             event->ignore();
     }

     void PiecesList::dropEvent(QDropEvent *event)
     {
         if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
             QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
             QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
             QPixmap pixmap;
             QPoint location;
             dataStream >> pixmap >> location;

             addPiece(pixmap, location);

             event->setDropAction(Qt::MoveAction);
             event->accept();
         } else
             event->ignore();
     }

     void PiecesList::addPiece(QPixmap pixmap, QPoint location)
     {
         QListWidgetItem *pieceItem = new QListWidgetItem(this);
         pieceItem->setIcon(QIcon(pixmap));
         pieceItem->setData(Qt::UserRole, QVariant(pixmap));
         pieceItem->setData(Qt::UserRole+1, location);
         pieceItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable
                             | Qt::ItemIsDragEnabled);
     }

     void PiecesList::startDrag(Qt::DropActions /*supportedActions*/)
     {
         QListWidgetItem *item = currentItem();

         QByteArray itemData;
         QDataStream dataStream(&itemData, QIODevice::WriteOnly);
         QPixmap pixmap = qVariantValue<QPixmap>(item->data(Qt::UserRole));
         QPoint location = item->data(Qt::UserRole+1).toPoint();

         dataStream << pixmap << location;

         QMimeData *mimeData = new QMimeData;
         mimeData->setData("image/x-puzzle-piece", itemData);

         QDrag *drag = new QDrag(this);
         drag->setMimeData(mimeData);
         drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2));
         drag->setPixmap(pixmap);

         if (drag->exec(Qt::MoveAction) == Qt::MoveAction)
             delete takeItem(row(item));
     }