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#include <QApplication>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsItem>
#include <QGraphicsRectItem>
#include <QDebug>

class MyCursor : public QGraphicsRectItem
{
public:
    MyCursor(QGraphicsItem *_parent = 0) : QGraphicsRectItem(0, 0, 40, 15, _parent) { }

    ~MyCursor() { }

    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0)
    {
        QList<QGraphicsItem *> colliding = collidingItems();

        QString str = QString("coll: ") + QString::number(colliding.size());

        painter->setPen(QPen(QColor(Qt::black), 2));
        painter->drawText(5, 12, str);

        painter->setPen(QPen(QColor(Qt::darkGreen), 2));
        painter->drawRect(rect());
        
    }



};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QGraphicsScene *my_scene = new QGraphicsScene(QRectF(-100, -100, 400, 300));
    QGraphicsView *my_view = new QGraphicsView(my_scene);

    QGraphicsRectItem *redFrame = new QGraphicsRectItem(QRectF(0, 0, 250, 120));
    redFrame->setPen(QPen(QColor(Qt::red), 2));
    redFrame->setPos(10, 10);
    //redFrame->setFlag(QGraphicsItem::ItemClipsChildrenToShape);
    my_scene->addItem(redFrame);

    QGraphicsRectItem *blueRect = new QGraphicsRectItem(QRectF(-40, -40, 80, 80), redFrame);
    blueRect->setPen(QPen(QColor(Qt::blue), 2));
    blueRect->setFlag(QGraphicsItem::ItemIsMovable);

    MyCursor *greenCursor = new MyCursor();
    greenCursor->setFlag(QGraphicsItem::ItemIsMovable);
    greenCursor->setPos(135, 160);
    my_scene->addItem(greenCursor);

    my_view->show();

    return a.exec();
}