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

coloritem.cpp Example File
^{graphicsview/dragdroprobot/coloritem.cpp}

 /****************************************************************************
 **
 ** Copyright (C) 2006-2007 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 version 2.0 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 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 gives you certain
 ** additional rights. These rights are described in the Trolltech GPL
 ** Exception version 1.0, which can be found at
 ** http://www.trolltech.com/products/qt/gplexception/ and in the file
 ** GPL_EXCEPTION.txt in this package.
 **
 ** 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.
 **
 ** Trolltech reserves all rights not expressly granted herein.
 **
 ** Trolltech ASA (c) 2007
 **
 ** 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 "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);
 }