#include <QApplication>
#include <QComboBox>
#include <QScopedPointer>
#include <QStyledItemDelegate>

// demonstrate the failure of polish/unpolish and setStyle(style)
int main(int argc, char* argv[])
{
	QApplication a(argc, argv);
	a.setStyleSheet("QComboBox QAbstractItemView {selection-background-color:blue; background-color:white;} \
	                 #fancy QAbstractItemView {selection-background-color:red; background-color:black;} ");
	QScopedPointer<QComboBox> box(new QComboBox());
	box->addItems({"...","Style(Normal)","Style(Fancy)","Polish/Unpolish","SetStyle(Style)","SetStyleSheet(StyleSheet)"});
	box->setToolTip("A tooltip");
	box->setObjectName("normal");
	box->connect(box.data(), &QComboBox::currentTextChanged, [&box](const QString& text){
		if(text == "Style(Normal)") {
			box->setObjectName("normal");
		} else if (text == "Style(Fancy)") {
			box->setObjectName("fancy");
		} else if (text == "Polish/Unpolish") {
			box->style()->unpolish(box.data());
			box->style()->polish(box.data());
		} else if (text == "SetStyle(Style)") {
			box->setStyle(box->style());
		} else if (text == "SetStyleSheet(StyleSheet)") {
			box->setStyleSheet(box->styleSheet());
		}
	});
	box->show();
	return a.exec();
}