License Wizard Example

The License Wizard example shows how to implement complex wizards in Qt.

Most wizards have a linear structure, with page 1 followed by page 2 and so on until the last page. The Class Wizard example shows how to create such wizards.

Some wizards are more complex in that they allow different traversal paths based on the information provided by the user. The License Wizard example illustrates this. It provides five wizard pages; depending on which options are selected, the user can reach different pages.

The example consists of the following classes:

• LicenseWizard inherits QWizard and implements a non-linear five-page wizard that leads the user through the process of choosing a license agreement.

• IntroPage, EvaluatePage, RegisterPage, DetailsPage, and ConclusionPage are QWizardPage subclasses that implement the wizard pages.

The LicenseWizard Class

The LicenseWizard class derives from QWizard and provides a five-page wizard that guides the user through the process of registering their copy of a fictitious software product. Here’s the class definition:

class LicenseWizard(QWizard):


    Q_OBJECT
# public

    enum { Page_Intro, Page_Evaluate, Page_Register, Page_Details,
           Page_Conclusion }

    LicenseWizard(QWidget parent = None)
slots: = private()
    def showHelp():

The class’s public API is limited to a constructor and an enum. The enum defines the IDs associated with the various pages:

Class name	Enum value	Page ID
IntroPage	Page_Intro	0
EvaluatePage	Page_Evaluate	1
RegisterPage	Page_Register	2
DetailsPage	Page_Details	3
ConclusionPage	Page_Conclusion	4

For this example, the IDs are arbitrary. The only constraints are that they must be unique and different from -1. IDs allow us to refer to pages.

def __init__(self, parent):
    QWizard.__init__(self, parent)


    setPage(Page_Intro, IntroPage)
    setPage(Page_Evaluate, EvaluatePage)
    setPage(Page_Register, RegisterPage)
    setPage(Page_Details, DetailsPage)
    setPage(Page_Conclusion, ConclusionPage)

    setStartId(Page_Intro)

In the constructor, we create the five pages, insert them into the wizard using setPage() , and set Page_Intro to be the first page.

#ifndef Q_OS_MAC            setWizardStyle(ModernStyle)
#endif

We set the style to ModernStyle on all platforms except macOS,

setOption(HaveHelpButton, True)        setPixmap(QWizard.LogoPixmap, QPixmap(":/images/logo.png"))

connect(self, QWizard.helpRequested, self, LicenseWizard.showHelp)

setWindowTitle(tr("License Wizard"))

We configure the QWizard to show a Help button, which is connected to our showHelp() slot. We also set the LogoPixmap for all pages that have a header (i.e., EvaluatePage, RegisterPage, and DetailsPage).

def showHelp(self):        lastHelpMessage = QString()
message = QString()
switch (currentId()) {
Page_Intro: = case()
    message = tr("The decision you make here will affect which page you "
                 "get to see next.")
    break            ...
default:
    message = tr("This help is likely not to be of any help.")


if (lastHelpMessage == message)
    message = tr("Sorry, I already gave what help I could. "
                 "Maybe you should try asking a human?")

QMessageBox.information(self, tr("License Wizard Help"), message)

lastHelpMessage = message

In showHelp(), we display help texts that are appropriate for the current page. If the user clicks Help twice for the same page, we say, “Sorry, I already gave what help I could. Maybe you should try asking a human?”

The IntroPage Class

The pages are defined in licensewizard.h and implemented in licensewizard.cpp, together with LicenseWizard.

Here’s the definition and implementation of IntroPage:

class IntroPage(QWizardPage):

    Q_OBJECT
# public
    IntroPage(QWidget parent = None)
    nextId = int()
# private
    topLabel = QLabel()
    registerRadioButton = QRadioButton()
    evaluateRadioButton = QRadioButton()
def __init__(self, parent):
    QWizardPage.__init__(self, parent)

    setTitle(tr("Introduction"))
    setPixmap(QWizard.WatermarkPixmap, QPixmap(":/images/watermark.png"))
    topLabel = QLabel(tr("This wizard will help you register your copy of "
                             "<i>Super Product One</i>trade; or start "
                             "evaluating the product."))
    topLabel.setWordWrap(True)
    registerRadioButton = QRadioButton(tr("Register your copy"))
    evaluateRadioButton = QRadioButton(tr("Evaluate the product for 30 "
                                              "days"))
    registerRadioButton.setChecked(True)
    layout = QVBoxLayout()
    layout.addWidget(topLabel)
    layout.addWidget(registerRadioButton)
    layout.addWidget(evaluateRadioButton)
    setLayout(layout)

A page inherits from QWizardPage . We set a title and a watermark pixmap . By not setting any subTitle , we ensure that no header is displayed for this page. (On Windows, it is customary for wizards to display a watermark pixmap on the first and last pages, and to have a header on the other pages.)

def nextId(self):        if (evaluateRadioButton.isChecked()) {
    return LicenseWizard::Page_Evaluate
else:
    return LicenseWizard::Page_Register

The nextId() function returns the ID for EvaluatePage if the Evaluate the product for 30 days option is checked; otherwise it returns the ID for RegisterPage.

The EvaluatePage Class

The EvaluatePage is slightly more involved:

class EvaluatePage(QWizardPage):

    Q_OBJECT
# public
    EvaluatePage(QWidget parent = None)
    nextId = int()
# private
    nameLabel = QLabel()
    emailLabel = QLabel()
    nameLineEdit = QLineEdit()
    emailLineEdit = QLineEdit()
def __init__(self, parent):
    QWizardPage.__init__(self, parent)

    setTitle(tr("Evaluate <i>Super Product One</i>trade;"))
    setSubTitle(tr("Please fill both fields. Make sure to provide a valid "
                   "email address (e.g., john.smith@example.com)."))
    nameLabel = QLabel(tr("Name:"))
    nameLineEdit = QLineEdit            ...
registerField("evaluate.name*", nameLineEdit)
registerField("evaluate.email*", emailLineEdit)            ...

First, we set the page’s title and subTitle .

Then we create the child widgets, create wizard fields associated with them, and put them into layouts. The fields are created with an asterisk (*) next to their name. This makes them mandatory fields , that is, fields that must be filled before the user can press the Next button (Continue on macOS). The fields’ values can be accessed from any other page using field() .

Resetting the page amounts to clearing the two text fields.

def nextId(self):

    return LicenseWizard::Page_Conclusion

The next page is always the ConclusionPage.

The ConclusionPage Class

The RegisterPage and DetailsPage are very similar to EvaluatePage. Let’s go directly to the ConclusionPage:

class ConclusionPage(QWizardPage):

    Q_OBJECT
# public
    ConclusionPage(QWidget parent = None)
    def initializePage():
    nextId = int()
    def setVisible(visible):
slots: = private()
    def printButtonClicked():
# private
    bottomLabel = QLabel()
    agreeCheckBox = QCheckBox()

This time, we reimplement initializePage() and setVisible() , in addition to nextId() . We also declare a private slot: printButtonClicked().

def nextId(self):


    if (evaluateRadioButton.isChecked()) {
        return LicenseWizard::Page_Evaluate
    else:
        return LicenseWizard::Page_Register

The default implementation of nextId() returns the page with the next ID, or -1 if the current page has the highest ID. This behavior would work here, because Page_Conclusion equals 5 and there is no page with a higher ID, but to avoid relying on such subtle behavior, we reimplement nextId() to return -1.

def initializePage(self):

    licenseText = QString()
    if (wizard().hasVisitedPage(LicenseWizard.Page_Evaluate)) {
        licenseText = tr("<u>Evaluation License Agreement:</u> "
                         "You can use self software for 30 days and make one "
                         "backup, but you are not allowed to distribute it.")
    } else if (wizard().hasVisitedPage(LicenseWizard.Page_Details)) {
        licenseText = tr("<u>First-Time License Agreement:</u> "
                         "You can use self software subject to the license "
                         "you will receive by email.")
    else:
        licenseText = tr("<u>Upgrade License Agreement:</u> "
                         "This software is licensed under the terms of your "
                         "current license.")

    bottomLabel.setText(licenseText)

We use hasVisitedPage() to determine the type of license agreement the user has chosen. If the user filled the EvaluatePage, the license text refers to an Evaluation License Agreement. If the user filled the DetailsPage, the license text is a First-Time License Agreement. If the user provided an upgrade key and skipped the DetailsPage, the license text is an Update License Agreement.

def setVisible(self, visible):

    QWizardPage.setVisible(visible)
    if (visible) {

        wizard().setButtonText(QWizard.CustomButton1, tr("Print"))
        wizard().setOption(QWizard.HaveCustomButton1, True)
        connect(wizard(), QWizard.customButtonClicked,
                self, ConclusionPage::printButtonClicked)

    else:
        wizard().setOption(QWizard.HaveCustomButton1, False)
        disconnect(wizard(), QWizard.customButtonClicked,
                   self, ConclusionPage::printButtonClicked)

We want to display a Print button in the wizard when the ConclusionPage is up. One way to accomplish this is to reimplement setVisible() :

• If the page is shown, we set the CustomButton1 button’s text to Print, we enable the HaveCustomButton1 option, and we connect the QWizard ‘s customButtonClicked() signal to our printButtonClicked() slot.

• If the page is hidden, we disable the HaveCustomButton1 option and disconnect the printButtonClicked() slot.

See also

QWizard Class Wizard Example Trivial Wizard Example

Example project @ code.qt.io