Qt 4.8: Simple Example (ActiveQt)

Qt Reference Documentation

- Qt 4.8
- ALL VERSIONS

- A
- A
- A
- Print

# Simple Example (ActiveQt)

Files:

- activeqt/simple/main.cpp
- activeqt/simple/simple.pro

The Simple example demonstrates the use of QAxBindable::requestPropertyChange() and QAxBindable::propertyChanged(), and the use of the default QAxFactory through the `QAXFACTORY_DEFAULT()` macro.

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_PROPERTY( QString text READ text WRITE setText )
         Q_PROPERTY( int value READ value WRITE setValue )
     public:
         QSimpleAX(QWidget *parent = 0)
         : QWidget(parent)
         {
             QVBoxLayout *vbox = new QVBoxLayout( this );

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

             connect( slider, SIGNAL(valueChanged(int)), this, SLOT(setValue(int)) );
             connect( edit, SIGNAL(textChanged(QString)), this, SLOT(setText(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 automation!" );
         }
         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}")

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>