coloritem.cpp Example File
graphicsview/dragdroprobot/coloritem.cpp
#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);
setAcceptedMouseButtons(Qt::LeftButton);
}
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 *)
{
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);
}