|  | Home · All Classes · All Functions · Overviews

# coloritem.cpp Example File
graphicsview/dragdroprobot/coloritem.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** 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 qt-info@nokia.com.
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QtGui>

     #include "coloritem.h"

     ColorItem::ColorItem()
         : color(qrand() % 256, qrand() % 256, qrand() % 256)
     {
         setToolTip(QString("QColor(%1, %2, %3)\n%4")
                   .arg(color.red()).arg(color.green()).arg(color.blue())
                   .arg("Click and drag this color onto the robot!"));
         setCursor(Qt::OpenHandCursor);
     }

     QRectF ColorItem::boundingRect() const
     {
         return QRectF(-15.5, -15.5, 34, 34);
     }

     void ColorItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
     {
         Q_UNUSED(option);
         Q_UNUSED(widget);
         painter->setPen(Qt::NoPen);
         painter->setBrush(Qt::darkGray);
         painter->drawEllipse(-12, -12, 30, 30);
         painter->setPen(QPen(Qt::black, 1));
         painter->setBrush(QBrush(color));
         painter->drawEllipse(-15, -15, 30, 30);
     }

     void ColorItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
     {
         if (event->button() != Qt::LeftButton) {
             event->ignore();
             return;
         }

         setCursor(Qt::ClosedHandCursor);
     }

     void ColorItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
     {
         if (QLineF(event->screenPos(), event->buttonDownScreenPos(Qt::LeftButton))
             .length() < QApplication::startDragDistance()) {
             return;
         }

         QDrag *drag = new QDrag(event->widget());
         QMimeData *mime = new QMimeData;
         drag->setMimeData(mime);

         static int n = 0;
         if (n++ > 2 && (qrand() % 3) == 0) {
             QImage image(":/images/head.png");
             mime->setImageData(image);

             drag->setPixmap(QPixmap::fromImage(image).scaled(30, 40));
             drag->setHotSpot(QPoint(15, 30));
         } else {
             mime->setColorData(color);
             mime->setText(QString("#%1%2%3")
                           .arg(color.red(), 2, 16, QLatin1Char('0'))
                           .arg(color.green(), 2, 16, QLatin1Char('0'))
                           .arg(color.blue(), 2, 16, QLatin1Char('0')));

             QPixmap pixmap(34, 34);
             pixmap.fill(Qt::white);

             QPainter painter(&pixmap);
             painter.translate(15, 15);
             painter.setRenderHint(QPainter::Antialiasing);
             paint(&painter, 0, 0);
             painter.end();

             pixmap.setMask(pixmap.createHeuristicMask());

             drag->setPixmap(pixmap);
             drag->setHotSpot(QPoint(15, 20));
         }

         drag->exec();
         setCursor(Qt::OpenHandCursor);
     }

     void ColorItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *)
     {
         setCursor(Qt::OpenHandCursor);
     }