Delegate辅助绘制

void ShareeSignatureDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const 
{
        // 沿用父类的绘制效果
    QStyledItemDelegate::paint(painter, option, index);

    painter->save();

        // 从mode的data接口里根据role获取姓名和签名内容(NameRole,SignatureRole为data接口里自定义的角色名)
    QString sharerName = index.data(NameRole).toString();
    QString signature = index.data(SignatureRole).toString();

    QStyleOptionViewItemV4 optV4 = option;
    initStyleOption(&optV4, index);
    const QWidget *widget = optV4.widget;
    QStyle *style = widget ? widget->style() : QApplication::style();

    QRect rect = style->subElementRect(QStyle::SE_ItemViewItemText, &optV4, widget);

        // 定义起始位置
    rect = rect.adjusted(5, 0, 0, - optV4.rect.height() / 2);

        // 设置文字的长度，以及文字过长时的省略模式
    QFontMetrics fontMetrics = painter->fontMetrics();
    QString elidedNameLine = fontMetrics.elidedText(sharerName, Qt::ElideMiddle, rect.width());
    QString elidedSignatureLine = fontMetrics.elidedText(signature, Qt::ElideMiddle, rect.width());

        // 执行文字绘制
    style->drawItemText(painter, rect, Qt::AlignBottom, QApplication::palette(), true, elidedNameLine);
        // 设置签名内容的位置，使得该内容在姓名的下方
    rect.moveTop(rect.bottom());
    painter->setPen(QColor("#949fa5"));
    if(!signature.isEmpty())
        style->drawItemText(painter, rect, Qt::AlignVCenter, QApplication::palette(), true, elidedSignatureLine);
    else
        style->drawItemText(painter, rect, Qt::AlignVCenter, QApplication::palette(), true, "无T签?名?信?息￠");

    painter->restore();
}