#include <QApplication> 
#include <QComboBox> 
#include <QPainter> 
#include <QStyleOptionComboBox> 
#include <QWidget> 
#include <QVBoxLayout> 
#include <QTimer> 
#include <QScroller> 
#include <QAbstractItemView>

class CustomComboBox : public QComboBox 
{     
    Q_OBJECT
public:     
    CustomComboBox(QWidget *parent = nullptr) : QComboBox(parent)     
    {         
        setCurrentIndex(-1);     
    } 
protected:     
    void paintEvent(QPaintEvent *event) override 
    {         
        QComboBox::paintEvent(event);        
        if (currentIndex() == -1)         
        {
            QStyleOptionComboBox opt;             
            initStyleOption(&opt);            
            QPainter painter(this);             
            QFont italicFont = painter.font();
            italicFont.setItalic(true);             
            painter.setFont(italicFont);            
            painter.setPen(Qt::gray);
            painter.drawText(rect().adjusted(4, 0, -4, 0), Qt::AlignVCenter | 
            Qt::AlignLeft, placeholderText);         
         }     
     }

public:     
void setPlaceholderText(const QString &text) 
{         
    placeholderText = text;         
    update();     
}

private:     
QString placeholderText; 
};

int main(int argc, char *argv[]) 
{     
    QApplication app(argc, argv);    
    QWidget window;    
    CustomComboBox *comboBox = new CustomComboBox;    
    comboBox->addItems( {"Dungeon Worlds","DnD","Cyberpunk","Call of Cuthulu","ODnD","Dungeon Worlds2","DnD2","Cyberpunk2","Call of Cuthulu2","ODnD2"} );

comboBox->setItemIcon(0,QIcon(":/RES/dungeonworldlogomini.png"));     
comboBox->setItemIcon(1,QIcon(":/RES/dndlogomini.png"));     
comboBox->setItemIcon(2,QIcon(":/RES/cyberpunklogomini.png"));     
comboBox->setItemIcon(3,QIcon(":/RES/callofcuthululogomini.png"));     
comboBox->setItemIcon(4,QIcon(":/RES/odndlogomini.png"));     
comboBox->setItemIcon(5,QIcon(":/RES/dungeonworldlogomini.png"));     
comboBox->setItemIcon(6,QIcon(":/RES/dndlogomini.png"));     
comboBox->setItemIcon(7,QIcon(":/RES/cyberpunklogomini.png"));     
comboBox->setItemIcon(8,QIcon(":/RES/callofcuthululogomini.png"));     
comboBox->setItemIcon(9,QIcon(":/RES/odndlogomini.png"));    

comboBox->setMaxVisibleItems(5);     
comboBox->setPlaceholderText("Choose one item...");     
comboBox->setStyleSheet("combobox-popup:0;");     
QScroller::grabGesture(comboBox->view()>viewport(),QScroller::LeftMouseButtonGesture);     comboBox>view()>setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);     comboBox>view()>setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);     comboBox>view()>setAutoScroll(false);     
comboBox>setCurrentIndex(-1);     

comboBox>setIconSize(QSize(30,30));    

QVBoxLayout *layout = new QVBoxLayout(&window);     
layout->addStretch();     
layout->addWidget(comboBox);     
layout->addStretch();    

window.show();    
return app.exec(); 
}

#include "main.moc"