#include <QtCore>
#include <QtGui>
#include <QtScroller>
#include <QtScrollEvent>
#include <QtScrollPrepareEvent>
 
class KineticList : public QGraphicsWidget
{
    Q_OBJECT
 
public:
    enum Orientation { Horizontal, Vertical };
 
    KineticList(Orientation orientation, QSizeF size, QGraphicsWidget *parent = 0)
        : QGraphicsWidget(parent)
    {
        this->setMinimumSize(size);
        this->setFlag(QGraphicsItem::ItemHasNoContents, true);
        this->setFlag(QGraphicsItem::ItemClipsChildrenToShape, true);
        this->setFlag(QGraphicsItem::ItemClipsToShape, true);
 
        if (orientation == KineticList::Horizontal) {
            _layout = new QGraphicsLinearLayout(Qt::Horizontal);
            _layout->setMinimumHeight(size.height());
        } else {
            _layout = new QGraphicsLinearLayout(Qt::Vertical);
            _layout->setMinimumWidth(size.width());
        }
        _layout->setSpacing(3);
        _layout->setContentsMargins(2, 0, 2, 0);
 
        _list = new QGraphicsWidget(this);
        _list->setLayout(_layout);
    }
 
    void addItem(QGraphicsWidget *item)
    {
        _layout->insertItem(0, item);
    }
 
private:
    QGraphicsWidget *_list;
    QGraphicsLinearLayout *_layout;
};
 
class RectWidget : public QGraphicsWidget
{
    Q_OBJECT
 
public:
 
    RectWidget(const QString &text;, qreal width, qreal height, QBrush brush, QGraphicsItem *parent = 0)
        : QGraphicsWidget(parent)
        , m_text(text)
        , m_rect(0, 0, width, height)
        , m_pen(brush.color().lighter(), 3.0)
        , m_brush(brush)
    {
        setFlag(QGraphicsItem::ItemClipsToShape, true);
        setMinimumSize(width, height);
        setMaximumSize(width, height);
        setGeometry(0, 0, width, height);
    }
 
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
    {
        Q_UNUSED(option);
        Q_UNUSED(widget);
        painter->setPen(m_pen);
        painter->setBrush(m_brush);
        painter->drawRect(m_rect);
 
        painter->setPen(Qt::black);
        QFont f;
        f.setPixelSize(m_rect.height());
        painter->setFont(f);
        painter->drawText(m_rect, Qt::AlignCenter, m_text);
    }
 
    QString m_text;
    QRectF m_rect;
    QPen m_pen;
    QBrush m_brush;
};
 
#define NUM_ITEMS 100
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
 
    QGraphicsScene scene(0, 0, 800, 480);
    QGraphicsView view(&scene;);
 
    view.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    view.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    view.setFrameStyle(0);
    view.show();
 
    QPalette p = view.viewport()->palette();
    p.setColor(QPalette::Base, Qt::transparent);
    view.viewport()->setPalette(p);
 
    KineticList *list = new KineticList(KineticList::Vertical, QSizeF(200, 200));
    scene.addItem(list);
 
    for(int i = 0; i < NUM_ITEMS; ++i) {
        QColor color =  QColor(255*i/NUM_ITEMS, 255*(NUM_ITEMS-i)/NUM_ITEMS, 127*(i%2)+64*(i/2%2));
        QString text = QLatin1String("Item #") + QString::number(i);
        RectWidget *rect = new RectWidget(text, 200, 30, QBrush(color));
        list->addItem(rect);
    }
 
    QtScrollerProperties sp;
    QtScrollerProperties::setDefaultScrollerProperties(sp);
 
    QtScroller *scroller = QtScroller::scroller(list);
    scroller->setScrollerProperties(sp);
    scroller->grabGesture(list, QtScroller::LeftMouseButtonGesture);
 
    return app.exec();
}