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# A simple ActiveQt control (executable)

The ActiveX control in this example is a layouted 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.

It demonstrates the use of QAxBindable::requestPropertyChange() and QAxBindable::propertyChanged(), and the use of the default QAxFactory through the QAXFACTORY_DEFAULT macro.

The Qt implementation of the ActiveX for this example is

        class QSimpleAX : public QWidget, public QAxBindable
        {
            Q_OBJECT
            Q_PROPERTY( QString text READ text WRITE setText )
            Q_PROPERTY( int value READ value WRITE setValue )
        public:
            QSimpleAX( QWidget *parent = 0, const char *name = 0 )
            : QWidget( parent, name )
            {
                QVBoxLayout *vbox = new QVBoxLayout( this );

                slider = new QSlider( 0, 100, 1, 0, QSlider::Horizontal, this );
                LCD = new QLCDNumber( 3, this );
                edit = new QLineEdit( this );

                connect( slider, SIGNAL( valueChanged( int ) ), this, SLOT( setValue(int) ) );
                connect( edit, SIGNAL(textChanged(const QString&)), this, SLOT(setText(const QString&)) );

                vbox->addWidget( slider );
                vbox->addWidget( LCD );
                vbox->addWidget( edit );
            }

            QString text() const
            {
                return edit->text();
            }
            int value() const
            {
                return slider->value();
            }

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

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

                edit->blockSignals( TRUE );
                edit->setText( string );
                edit->blockSignals( FALSE );
                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 dispatching!" );
            }
            void setValue( int i )
            {
                if ( !requestPropertyChange( "value" ) )
                    return;
                slider->blockSignals( TRUE );
                slider->setValue( i );
                slider->blockSignals( FALSE );
                LCD->display( i );
                emit valueChanged( i );

                propertyChanged( "value" );
            }

        private:
            QSlider *slider;
            QLCDNumber *LCD;
            QLineEdit *edit;
        };

The control is exported using the default QAxFactory

        QAXFACTORY_DEFAULT(QSimpleAX,
                   "{DF16845C-92CD-4AAB-A982-EB9840E74669}",
                   "{616F620B-91C5-4410-A74E-6B81C76FFFE0}",
                   "{E1816BBA-BF5D-4A31-9855-D6BA432055FF}",
                   "{EC08F8FC-2754-47AB-8EFE-56A54057F34E}",
                   "{A095BA0C-224F-4933-A458-2DD7F6B85D8F}")

The implementation of `main` returns an error code when QAxFactory::isServer() returns FALSE, otherwise a QApplication object is created and the event loop entered.

        int main( int argc, char **argv )
        {
            if ( !QAxFactory::isServer() )
                return -1;

            QApplication app( argc, argv );
            return app.exec();

To build the example you must first build the QAxServer library. Then run qmake and your make tool in `examples/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://www.trolltech.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>

See also The QAxServer Examples.