Subclassing QGraphicsItem to work as a layer

[kefir]

Hello everyone! I have a little problem: after subclassing QGraphicsItem in this way:

#ifndef LAYER_H
#define LAYER_H
#include <QGraphicsItem>
#include <QPointF>
#include <QRectF>
#include <QPolygonF>
#include <QPainter>
#include <QPainterPath>
#include <QWidget>
class Layer : public QGraphicsItem
{
public:
    Layer(int layerId = -1, QString layerName = "", QGraphicsItem *parent = 0);
    QRectF boundingRect() const
    {
        return QRectF(QPoint(0,0), QSizeF(10000.0, 10000.0)); //size can change
    }
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
               QWidget *widget)
    {
       painter->setRenderHint(QPainter::HighQualityAntialiasing);
    }
    int getId();
    bool setId(int layerId);
    QString getName();
    bool setName(QString layerName);
signals:
public slots:
private:
    int layerId;
    QString layerName;
protected:
//    void mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent);
};
#endif // LAYER_H

#ifndef LAYER_H
#define LAYER_H
#include <QGraphicsItem>
#include <QPointF>
#include <QRectF>
#include <QPolygonF>
#include <QPainter>
#include <QPainterPath>
#include <QWidget>
class Layer : public QGraphicsItem
{
public:
    Layer(int layerId = -1, QString layerName = "", QGraphicsItem *parent = 0);
    QRectF boundingRect() const
    {
        return QRectF(QPoint(0,0), QSizeF(10000.0, 10000.0)); //size can change
    }
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
               QWidget *widget)
    {
       painter->setRenderHint(QPainter::HighQualityAntialiasing);
    }
    int getId();
    bool setId(int layerId);
    QString getName();
    bool setName(QString layerName);
signals:
public slots:
private:
    int layerId;
    QString layerName;
protected:
//    void mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent);
};
#endif // LAYER_H

To copy to clipboard, switch view to plain text mode 

The Layer class should work as a container for map tiles 256x256 px each. I got tiles displayed properly in a QGraphicsScene but when I add a Layer into it and then add same map tiles I get a blank screen. Debugging however shows that my parent Label contains correct number of tiles in it.

Thanx in advance!