OpenGL Example (ActiveQt)
The ActiveX control in this example uses the QGlWidget class in Qt to render an OpenGL scene in an ActiveX. The control exposes a few methods to change the scene.
The application uses QAxFactory through the QAXFACTORY_BEGIN()
, QAXCLASS()
and QAXFACTORY_END()
macros to expose the GLBox
widget as an ActiveX control.
#include <QAxFactory> QAXFACTORY_BEGIN( "{2c3c183a-eeda-41a4-896e-3d9c12c3577d}", // type library ID "{83e16271-6480-45d5-aaf1-3f40b7661ae4}") // application ID QAXCLASS(GLBox) QAXFACTORY_END()
The implementation of main
initializes the QApplication object, and uses QAxFactory::isServer()
to determine whether or not it is appropriate to create and show the application interface.
/* The main program is here. */ int main( int argc, char **argv ) { QApplication::setColorSpec( QApplication::CustomColor ); QApplication a(argc,argv); if (QOpenGLContext::openGLModuleType() != QOpenGLContext::LibGL) { qWarning( "This system does not support OpenGL. Exiting." ); return -1; } if ( !QAxFactory::isServer() ) { GLObjectWindow w; w.resize( 400, 350 ); w.show(); return a.exec(); } return a.exec(); }
The GLBox
class inherits from both the QGLWidget class to be able to render OpenGL, and from QAxBindable.
#include <QAxBindable> class GLBox : public QGLWidget, public QOpenGLFunctions_1_1, public QAxBindable { Q_OBJECT Q_CLASSINFO("ClassID", "{5fd9c22e-ed45-43fa-ba13-1530bb6b03e0}") Q_CLASSINFO("InterfaceID", "{33b051af-bb25-47cf-a390-5cfd2987d26a}") Q_CLASSINFO("EventsID", "{8c996c29-eafa-46ac-a6f9-901951e765b5}")
The class reimplements the QAxBindable::createAggregate() function from QAxBindable to return the pointer to a QAxAggregated object.
public: GLBox( QWidget* parent, const char* name = 0 ); ~GLBox(); QAxAggregated *createAggregate(); public slots: void setXRotation( int degrees );
The rest of the class declaration and the implementation of the OpenGL rendering is identical to the original "box" example.
The implementation file of the GLBox
class includes the objsafe.h
system header, in which the IObjectSafety
COM interface is defined.
#include <objsafe.h>
A class ObjectSafetyImpl
is declared using multiple inheritance to subclass the QAxAggregated class, and to implement the IObjectSafety interface.
class ObjectSafetyImpl : public QAxAggregated, public IObjectSafety { public:
The class declares a default constructor, and implements the queryInterface function to support the IObjectSafety interface.
ObjectSafetyImpl() {} long queryInterface( const QUuid &iid, void **iface ) { *iface = 0; if ( iid == IID_IObjectSafety ) *iface = (IObjectSafety*)this; else return E_NOINTERFACE; AddRef(); return S_OK; }
Since every COM interface inherits IUnknown
the QAXAGG_IUNKNOWN
macro is used to provide the default implementation of the IUnknown
interface. The macro is defined to delegate all calls to QueryInterface
, AddRef
and Release
to the interface returned by the controllingUnknown() function.
QAXAGG_IUNKNOWN;
The implementation of the IObjectSafety
interface provides the caller with information about supported and enabled safety options, and returns S_OK
for all calls to indicate that the ActiveX control is safe.
HRESULT WINAPI GetInterfaceSafetyOptions( REFIID riid, DWORD *pdwSupportedOptions, DWORD *pdwEnabledOptions ) { *pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER; *pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA | INTERFACESAFE_FOR_UNTRUSTED_CALLER; return S_OK; } HRESULT WINAPI SetInterfaceSafetyOptions( REFIID riid, DWORD pdwSupportedOptions, DWORD pdwEnabledOptions ) { return S_OK; } };
The implementation of the createAggregate()
function just returns a new ObjectSafetyImpl
object.
QAxAggregated *GLBox::createAggregate() { return new ObjectSafetyImpl(); }
To build the example you must first build the QAxServer library. Then run qmake
and your make tool in examples/activeqt/wrapper
.
The demonstration requires your WebBrowser to support ActiveX controls, and scripting to be enabled.
In contrast to the other QAxServer examples Internet Explorer will not open a dialog box to ask the user whether or not the scripting of the GLBox control should be allowed (the exact browser behaviour depends on the security settings in the Internet Options dialog).
<SCRIPT LANGUAGE="JavaScript"> function setRot( form ) { GLBox.setXRotation( form.XEdit.value ); GLBox.setYRotation( form.YEdit.value ); GLBox.setZRotation( form.ZEdit.value ); } </SCRIPT> <p /> An OpenGL scene:<br /> <object ID="GLBox" CLASSID="CLSID:5fd9c22e-ed45-43fa-ba13-1530bb6b03e0" CODEBASE="http://qt.nokia.com/demos/openglax.cab"> [Object not available! Did you forget to build and register the server?] </object><br /> <form> Rotate the scene:<br /> X:<input type="edit" ID="XEdit" value="0" /><br /> Y:<input type="edit" name="YEdit" value="0" /><br /> Z:<input type="edit" name="ZEdit" value="0" /><br /> <input type="button" value="Set" onClick="setRot(this.form)" /> </form>
Files:
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