QWidget 函数的意义

QWidget *QWidget::window() const // 找到自己所属的窗体

{

    QWidget *w = (QWidget *)this;

    QWidget *p = w->parentWidget();

    while (!w->isWindow() && p) {

        w = p;

        p = p->parentWidget();

    }

    return w;

}
inline bool QWidget::isWindow() const // 返回是否是窗体
{ return (windowType() & Qt::Window); }

QPoint QWidget::mapTo(QWidget * parent, const QPoint & pos) const  //坐标映射
{
    QPoint p = pos;
    if (parent) {
        const QWidget * w = this;
        while (w != parent) {
            Q_ASSERT_X(w, "QWidget::mapTo(QWidget *parent, const QPoint &pos)",
                       "parent must be in parent hierarchy");
            p = w->mapToParent(p);
            w = w->parentWidget();
        }
    }
    return p;
}