QWizardPage::nextId called way to often

HoMa

Hi there!

I just learned from this code, that QWizardPage::nextId() is not called for the final page. This seams OK, because there is no "next" on the final page but only "finish".
However: What I don't understand:
nextId is called twice (!) before each page is displayed. Is this a bug? Or can you explain why?

Header:

enum  {
    FIRST = 0,
    SECOND = 1
};

class firstP : public QWizardPage
{
    Q_OBJECT;
public:
    firstP(QWidget* p) : QWizardPage(p){}
    void initializePage() override;
    bool validatePage() override;
    int nextId() const override;

};
class secP : public QWizardPage
{
    Q_OBJECT;
public:
    secP(QWidget* p) : QWizardPage(p){}
    void initializePage() override;
    bool validatePage() override;
    int nextId() const override;

};
class wiz : public QWizard
{
    Q_OBJECT;
public:
    wiz(QWidget* p);
};

cpp:

void secP::initializePage()
{
    qInfo() << "init of second Page";
}
bool secP::validatePage()
{
    qInfo() << "validate second Page";
    return false;
}
int secP::nextId() const
{
    qInfo() << "nextId from second Page";
    return -1;
}
wiz::wiz(QWidget* p) : QWizard(p)
{
    setPage(FIRST, new firstP(p));
    setPage(SECOND, new secP(p));
}

output:

init of first Page
nextId from first Page
nextId from first Page
validate first Page
nextId from first Page
init of second Page
nextId from second Page
nextId from second Page
validate second Page

JonB

@HoMa
My thought would be: to decide about enablement of Next/Finish buttons? If you read through https://doc.qt.io/qt-5/qwizardpage.html#details, it says e.g.

By default, isFinalPage() is true only when nextId() returns -1.

?

SGaist

Hi,

Which version of Qt ?
Which OS ?

JonB

@HoMa
My thought would be: to decide about enablement of Next/Finish buttons? If you read through https://doc.qt.io/qt-5/qwizardpage.html#details, it says e.g.

By default, isFinalPage() is true only when nextId() returns -1.

?

HoMa

@SGaist latest version of Qt, I work on Windows with mingGw

HoMa

@JonB that's a good thought ... Thanks. This would explain at least one of the calls :)