#include <QApplication>
#include <QMainWindow.h>
#include <QToolBar>
#include <QSplitter>
#include <QTextEdit>
#include <QTreeWidget>
#include <QStringListModel>

QString styleSheet = R"(
QTreeView::item:selected {
    background-color: #CDE8FF;     /* Blue highlight color */
    color: black;                  /* text color when selected */

   /* border-radius: 3px;           rounded corners */
   /* padding: 5px;                 Prevent clipping with border */
}
QTreeView::item:selected:active {
    background-color: #CDE8FF;
    color: black;                  /* text color when selected */
}
QTreeView::item:selected:!active {
    background-color: #D9D9D9;   /* gray for inactive focus */
    color: black;                /* text color when selected */
}
QTreeView::item:hover {
    background: #E5F3FF;
}
QTreeView::item:selected:hover {
    border: 1px solid #99D1FF;
    padding: -1px; /* keep the size consistent */
}
)";

QTreeView* createTreeView()
{
    auto tree = new QTreeWidget;
    tree->setColumnCount(3);

    for (int i = 0; i < 1000; ++i) {
        const auto cnt = i % 9;
        QString str;
        str.fill(QChar('A' + cnt), cnt + 1);
        auto item = new QTreeWidgetItem(QStringList() << str << str);
        item->setFlags(item->flags() | Qt::ItemIsEditable);
        item->setFlags(item->flags() | Qt::ItemIsUserCheckable);
        item->setCheckState(0, Qt::Unchecked);
        tree->addTopLevelItem(item);
    }
    return tree;
}

#include <QStyledItemDelegate>
class Bla : public QStyledItemDelegate
{
    virtual void paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override
    {
        QStyledItemDelegate::paint(painter, option, index);// Set a breakpoint here and step into QWindows11Style::drawPrimitive (src/plugins/styles/modernwindows/qwindows11style.cpp)
    }
};

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    //app.setStyleSheet("{ }");   // force painting through QStyleSheetStyle

    auto splitter = new QSplitter;
    auto text = new QTextEdit;
    auto tree = createTreeView();
    tree->setItemDelegate(new Bla);
    //tree->setSortingEnabled(true);
    tree->setSelectionBehavior(QTreeView::SelectRows);
    tree->setSelectionMode(QTreeView::ExtendedSelection);

    QObject::connect(text, &QTextEdit::textChanged, tree, [&] {
        tree->setStyleSheet(text->toPlainText());
    });

    text->setPlainText(styleSheet);
    QMainWindow mw;

    auto tool = mw.addToolBar("Actions");
    auto alternate = new QAction("Alternate");
    alternate->setCheckable(true);
    tool->addAction(alternate);
    QObject::connect(alternate, &QAction::toggled, tree, [&](bool on) {
        tree->setAlternatingRowColors(on);
    });
    splitter->addWidget(text);
    splitter->addWidget(tree);
    mw.setCentralWidget(splitter);
    mw.show();
    return app.exec();
}