Qt 4.3: draglabel.cpp Example File (draganddrop/fridgemagnets/draglabel.cpp)

|  | Home · All Classes · Main Classes · Grouped Classes · Modules · Functions |

# draglabel.cpp Example File
draganddrop/fridgemagnets/draglabel.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2005-2008 Trolltech ASA. All rights reserved.
     **
     ** This file is part of the example classes of the Qt Toolkit.
     **
     ** This file may be used under the terms of the GNU General Public
     ** License versions 2.0 or 3.0 as published by the Free Software
     ** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
     ** included in the packaging of this file.  Alternatively you may (at
     ** your option) use any later version of the GNU General Public
     ** License if such license has been publicly approved by Trolltech ASA
     ** (or its successors, if any) and the KDE Free Qt Foundation. In
     ** addition, as a special exception, Trolltech gives you certain
     ** additional rights. These rights are described in the Trolltech GPL
     ** Exception version 1.1, which can be found at
     ** http://www.trolltech.com/products/qt/gplexception/ and in the file
     ** GPL_EXCEPTION.txt in this package.
     **
     ** Please review the following information to ensure GNU General
     ** Public Licensing requirements will be met:
     ** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
     ** you are unsure which license is appropriate for your use, please
     ** review the following information:
     ** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
     ** or contact the sales department at sales@trolltech.com.
     **
     ** In addition, as a special exception, Trolltech, as the sole
     ** copyright holder for Qt Designer, grants users of the Qt/Eclipse
     ** Integration plug-in the right for the Qt/Eclipse Integration to
     ** link to functionality provided by Qt Designer and its related
     ** libraries.
     **
     ** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
     ** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
     ** granted herein.
     **
     ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
     ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     **
     ****************************************************************************/

     #include <QtGui>

     #include "draglabel.h"

     DragLabel::DragLabel(const QString &text, QWidget *parent)
         : QLabel(parent)
     {
         QFontMetrics metric(font());
         QSize size = metric.size(Qt::TextSingleLine, text);

         QImage image(size.width() + 12, size.height() + 12,
                      QImage::Format_ARGB32_Premultiplied);
         image.fill(qRgba(0, 0, 0, 0));

         QFont font;
         font.setStyleStrategy(QFont::ForceOutline);

         QPainter painter;
         painter.begin(&image);
         painter.setRenderHint(QPainter::Antialiasing);
         painter.setBrush(Qt::white);
         painter.drawRoundRect(QRectF(0.5, 0.5, image.width()-1, image.height()-1),
                               25, 25);

         painter.setFont(font);
         painter.setBrush(Qt::black);
         painter.drawText(QRect(QPoint(6, 6), size), Qt::AlignCenter, text);
         painter.end();

         setPixmap(QPixmap::fromImage(image));
         labelText = text;
     }

     void DragLabel::mousePressEvent(QMouseEvent *event)
     {
         QByteArray itemData;
         QDataStream dataStream(&itemData, QIODevice::WriteOnly);
         dataStream << labelText << QPoint(event->pos() - rect().topLeft());

         QMimeData *mimeData = new QMimeData;
         mimeData->setData("application/x-fridgemagnet", itemData);
         mimeData->setText(labelText);

         QDrag *drag = new QDrag(this);
         drag->setMimeData(mimeData);
         drag->setHotSpot(event->pos() - rect().topLeft());
         drag->setPixmap(*pixmap());

         hide();

         if (drag->exec(Qt::MoveAction | Qt::CopyAction, Qt::CopyAction) == Qt::MoveAction)
             close();
         else
             show();
     }