Home · All Classes · All Functions · Overviews

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

 /****************************************************************************
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** 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.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3.0 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
 ** If you have questions regarding the use of this file, please contact
 ** Nokia at [email protected].
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #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));
 }