- Qt 6.7
- Active Qt
- ActiveQt Examples and Tutorials
- Simple Example (ActiveQt)
- Qt 6.7.0 Reference Documentation

# Simple Example (ActiveQt)

The Simple example demonstrates the use of QAxBindable and QAxFactory.

The Simple example demonstrates the use of QAxBindable::requestPropertyChange() and QAxBindable::propertyChanged(), and the use of QAxFactory through the `QAXFACTORY_BEGIN()`, `QAXCLASS()` and `QAXFACTORY_END()` macros.

The ActiveX control in this example is a laid out QWidget with a QSlider, a QLCDNumber and a QLineEdit. It provides a signal/slot/property interface to change the values of the slider and the line edit, and to get notified of any property changes.

The Qt implementation of the ActiveX for this example is

     class QSimpleAX : public QWidget, public QAxBindable
     {
         Q_OBJECT
         Q_CLASSINFO("ClassID",     "{DF16845C-92CD-4AAB-A982-EB9840E74669}")
         Q_CLASSINFO("InterfaceID", "{616F620B-91C5-4410-A74E-6B81C76FFFE0}")
         Q_CLASSINFO("EventsID",    "{E1816BBA-BF5D-4A31-9855-D6BA432055FF}")
         Q_PROPERTY(QString text READ text WRITE setText)
         Q_PROPERTY(int value READ value WRITE setValue)
     public:
         explicit QSimpleAX(QWidget *parent = nullptr)
         : QWidget(parent)
         {
             QVBoxLayout *vbox = new QVBoxLayout(this);

             m_slider = new QSlider(Qt::Horizontal, this);
             m_LCD = new QLCDNumber(3, this);
             m_edit = new QLineEdit(this);

             connect(m_slider, &QAbstractSlider::valueChanged, this, &QSimpleAX::setValue);
             connect(m_edit, &QLineEdit::textChanged, this, &QSimpleAX::setText);

             vbox->addWidget(m_slider);
             vbox->addWidget(m_LCD);
             vbox->addWidget(m_edit);
         }

         QString text() const
         {
             return m_edit->text();
         }

         int value() const
         {
             return m_slider->value();
         }

     signals:
         void someSignal();
         void valueChanged(int);
         void textChanged(const QString&);

     public slots:
         void setText(const QString &string)
         {
             if (!requestPropertyChange("text"))
                 return;

             QSignalBlocker blocker(m_edit);
             m_edit->setText(string);
             emit someSignal();
             emit textChanged(string);

             propertyChanged("text");
         }

         void about()
         {
             QMessageBox::information( this, "About QSimpleAX", "This is a Qt widget, and this slot has been\n"
                                                               "called through ActiveX/OLE automation!" );
         }

         void setValue(int i)
         {
             if (!requestPropertyChange("value"))
                 return;

             QSignalBlocker blocker(m_slider);
             m_slider->setValue(i);
             m_LCD->display(i);
             emit valueChanged(i);

             propertyChanged("value");
         }

     private:
         QSlider *m_slider;
         QLCDNumber *m_LCD;
         QLineEdit *m_edit;
     };

The control is exported using the default QAxFactory

     QAXFACTORY_BEGIN(
         "{EC08F8FC-2754-47AB-8EFE-56A54057F34E}", // type library ID
         "{A095BA0C-224F-4933-A458-2DD7F6B85D8F}") // application ID
         QAXCLASS(QSimpleAX)
     QAXFACTORY_END()

To build the example you must first build the QAxServer library. Then run qmake and your make tool in `examples/activeqt/simple`.

The demonstration requires your WebBrowser to support ActiveX controls, and scripting to be enabled.

The simple ActiveX control is embedded using the `<object>` tag.

     <object ID="QSimpleAX" CLASSID="CLSID:DF16845C-92CD-4AAB-A982-EB9840E74669"
     CODEBASE="http://qt.nokia.com/demos/simpleax.cab">
         <PARAM NAME="text" VALUE="A simple control" />
         <PARAM NAME="value" VALUE="1" />
     [Object not available! Did you forget to build and register the server?]
     </object>

A simple HTML button is connected to the ActiveQt's about() slot.

     <FORM>
         <INPUT TYPE="BUTTON" VALUE="About..." onClick="QSimpleAX.about()" />
     </FORM>

A second ActiveX control - the standard Calendar Control - is instantiated

     <object ID="Calendar" CLASSID="CLSID:8E27C92B-1264-101C-8A2F-040224009C02">
     [Standard Calendar control not available!]
         <PARAM NAME="day" VALUE="1" />
     </object>

Events from the ActiveX controls are handled using both Visual Basic Script and JavaScript.

     <SCRIPT LANGUAGE="VBScript">
     Sub Calendar_Click()
         MsgBox( "Calendar Clicked!" )
     End Sub

     Sub QSimpleAX_TextChanged( str )
         document.title = str
     End Sub
     </SCRIPT>

     <SCRIPT LANGUAGE="JavaScript">
     function QSimpleAX::ValueChanged( Newvalue )
     {
         Calendar.Day = Newvalue;
     }
     </SCRIPT>

Example project @ code.qt.io