问模仿基于颜色样式行为的QApplication::palette()

EN

#include <QtWidgets>

enum FakeRoles {
    FakeEnableRole = Qt::UserRole + 1000
};

class ForegroundDelegate: public QStyledItemDelegate
{
public:
    using QStyledItemDelegate::QStyledItemDelegate;
protected:
    void initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const override{
        QStyledItemDelegate::initStyleOption(option, index);
        QVariant val = index.data(FakeRoles::FakeEnableRole);
        if(val.canConvert<bool>()){
            bool enabled = val.value<bool>();
            option->palette.setBrush(QPalette::Text,
                                     QApplication::palette().color(enabled ? QPalette::Active:
                                                                             QPalette::Disabled, QPalette::Text));
        }
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QTableWidget w(4, 4);
    ForegroundDelegate *delegate = new ForegroundDelegate(&w);
    w.setItemDelegate(delegate);
    for(int i=0; i< w.rowCount(); ++i)
        for (int j=0; j< w.columnCount(); ++j) {
            QTableWidgetItem *it = new QTableWidgetItem(QString("%1-%2").arg(i).arg(j));
            w.setItem(i, j, it);
            bool enabled =  QRandomGenerator::global()->bounded(0, 2) == 0;
            it->setData(FakeRoles::FakeEnableRole, enabled);
        }
    w.show();
    QTimer::singleShot(1000, [](){
        QPalette pal = QApplication::palette();
        pal.setColor(QPalette::Active, QPalette::Text, QColor("salmon"));
        pal.setColor(QPalette::Disabled, QPalette::Text, QColor("cyan"));
        QApplication::setPalette(pal);
    });
    return a.exec();
}