OpenGL 范例 (ActiveQt)

The OpenGL example demonstrates the use of the default factory and QAxFactory::isServer (), and the implementation of an additional COM interface using QAxBindable and QAxAggregated . The server executable can run both as an ActiveX server and as a stand-alone application.

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 the default factory as provided by the QAXFACTORY_DEFAULT macro to expose the GLBox 小部件作为 ActiveX 控制。

#include <QAxFactory>
QAXFACTORY_DEFAULT( GLBox,
                    "{5fd9c22e-ed45-43fa-ba13-1530bb6b03e0}",
                    "{33b051af-bb25-47cf-a390-5cfd2987d26a}",
                    "{8c996c29-eafa-46ac-a6f9-901951e765b5}",
                    "{2c3c183a-eeda-41a4-896e-3d9c12c3577d}",
                    "{83e16271-6480-45d5-aaf1-3f40b7661ae4}"
                  )

实现为 main 初始化 QApplication 对象，和使用 QAxFactory::isServer() 以确定创建和展示应用程序界面是否合适。

/*
  The main program is here.
*/
int main( int argc, char **argv )
{
    QApplication::setColorSpec( QApplication::CustomColor );
    QApplication a(argc,argv);
    if ( !QGLFormat::hasOpenGL() ) {
        qWarning( "This system has no OpenGL support. Exiting." );
        return -1;
    }
    if ( !QAxFactory::isServer() ) {
        GLObjectWindow w;
        w.resize( 400, 350 );
        w.show();
        return a.exec();
    }
    return a.exec();
}

The GLBox 类继承自两者 QGLWidget class to be able to render OpenGL , and from QAxBindable .

#include <QAxBindable>
class GLBox : public QGLWidget,
              public QAxBindable
{
    Q_OBJECT

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

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.

实现文件为 GLBox 类包括 objsafe.h 系统头，在那里 IObjectSafety COM 接口有定义。

#include <objsafe.h>

类 ObjectSafetyImpl 的声明是使用多继承以子类化 QAxAggregated 类，并实现 IObjectSafety 接口。

class ObjectSafetyImpl : public QAxAggregated,
                         public IObjectSafety
{
public:

类声明默认构造函数，并实现 queryInterface 函数以支持 IObjectSafety 接口。

    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;
    }

由于各 COM 接口继承 IUnknown the QAXAGG_IUNKNOWN 宏用于提供默认实现为 IUnknown 接口。宏定义将所有调用委托给 QueryInterface , AddRef and Release 到由 controllingUnknown() 函数返回的接口。

    QAXAGG_IUNKNOWN;

实现为 IObjectSafety 接口为调用者提供支持和启用安全选项的有关信息，并返回 S_OK 为所有调用以指示 ActiveX 控件是安全的。

    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;
    }
};

实现为 createAggregate() 函数仅仅返回新 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 .

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

相比其它 QAxServer 范例，Internet Explorer 不会打开对话框询问用户是否应该允许运行 GLBox 控件脚本 (浏览器的准确行为从属 "Internet 选项" 对话框中的安全设置)。

<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：