why QCombobox receive mousePressEvent when user click on other window?

[Xiao Yang]

when user click outside QCombobox, the QComboBoxPrivateContainer::mousePressEvent will be trigger, then the hidepopup() function will be call. how can i implement this behavior like qt qcombobox.cpp.
i write a own QWidget subclass,but i dont know how to close the popup-listview when user click other space in the window.

void QComboBoxPrivateContainer::mousePressEvent(QMouseEvent *e){

    QStyleOptionComboBox opt = comboStyleOption();
    opt.subControls = QStyle::SC_All;
    opt.activeSubControls = QStyle::SC_ComboBoxArrow;
    QStyle::SubControl sc = combo->style()->hitTestComplexControl(QStyle::CC_ComboBox, &opt,
                                                           combo->mapFromGlobal(e->globalPos()),
                                                           combo);
    if ((combo->isEditable() && sc == QStyle::SC_ComboBoxArrow)
        || (!combo->isEditable() && sc != QStyle::SC_None))
        setAttribute(Qt::WA_NoMouseReplay);
    combo->hidePopup();
}

[Bonnie]

As doc says in void QWidget::mousePressEvent(QMouseEvent *event) ：

The default implementation implements the closing of popup widgets when you click outside the window. For other widget types it does nothing.

That means a popup window (Qt::Popup) will receive mousePressEvent when clicking outside it (to close it).

[Xiao Yang]

@Bonnie thankyou. I need to learn about window with Qt::popup.