#include <QtWidgets>

static void changeDarkMode()
{
    static int toggleDarkLight = 0;
    QGuiApplication::styleHints()->setColorScheme(static_cast<Qt::ColorScheme>(++toggleDarkLight % 2 + 1));
}

int main(int argc, char** argv) {
    QApplication app(argc, argv);
    int row = 0;
    int col = 0;
    QWidget w;
    auto lay = new QGridLayout(&w);

    QCheckBox cb("DarkMode");
    lay->addWidget(&cb, row++, col);
    QObject::connect(&cb, &QCheckBox::checkStateChanged, &app, []() { changeDarkMode(); });

    QLineEdit le;
    le.setText("0");
    le.setFrame(true);
    lay->addWidget(&le, row, col++);
    QLineEdit le2;
    le2.setText("0");
    le2.setFrame(false);
    lay->addWidget(&le2, row++, col);

    col = 0;
    QSpinBox sb;
    sb.setFrame(true);
    lay->addWidget(&sb, row, col++);
    QSpinBox sb2;
    sb2.setFrame(false);
    lay->addWidget(&sb2, row++, col);

    col = 0;
    QComboBox cbx1;
    cbx1.addItem("0");
    cbx1.setEditable(true);
    cbx1.setFrame(true);
    lay->addWidget(&cbx1, row, col++);
    QComboBox cbx2;
    cbx2.addItem("0");
    cbx2.setEditable(true);
    cbx2.setFrame(false);
    lay->addWidget(&cbx2, row++, col);

    col = 0;
    QComboBox cbx3;
    cbx3.addItem("0");
    cbx3.setEditable(false);
    cbx3.setFrame(true);
    lay->addWidget(&cbx3, row, col++);
    QComboBox cbx4;
    cbx4.addItem("0");
    cbx4.setEditable(false);
    cbx4.setFrame(false);
    lay->addWidget(&cbx4, row++, col);

    w.show();

    return app.exec();
}