OpenGL 范例 (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::setAttribute(Qt::AA_EnableHighDpiScaling);
    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();
}

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}")

类重实现 QAxBindable::createAggregate () 函数从 QAxBindable 以返回指针指向 QAxAggregated 对象。

public:
explicit GLBox(QWidget *parent, const char *name = nullptr);
virtual ~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 类包括 objsafe.h system header, in which the IObjectSafety COM interface is defined.

#include <objsafe.h>

类 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.

    explicit ObjectSafetyImpl() {}
    long queryInterface(const QUuid &iid, void **iface)
    {
        *iface = nullptr;
        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 对象。

QAxAggregated *GLBox::createAggregate()
{
    return new ObjectSafetyImpl();
}

要构建范例必须先构建 QAxServer 库。然后运行 qmake 和 make 工具在 examples/activeqt/wrapper .

demonstration 要求您的 WebBrowser 支持 ActiveX 控件，并启用脚本。

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>

文件：