C++ QObject::qt_metacast方法代码示例

void QAudioPluginLoader::load()
{
    if (!m_plugins.isEmpty())
        return;

    QStringList plugins = pluginList();
    for (int i=0; i < plugins.count(); i++) {
        QPluginLoader* loader = new QPluginLoader(plugins.at(i));
        QObject *o = loader->instance();
        if (o != 0 && o->qt_metacast(m_iid) != 0)
            m_plugins.append(loader);
        else {
            qWarning() << "QAudioPluginLoader: Failed to load plugin: "
                << plugins.at(i) << loader->errorString();
        }
    }
}

//.........这里部分代码省略.........
                QObject *obj = stack.pop();
                QDeclarativePropertyValueInterceptor *vi = reinterpret_cast<QDeclarativePropertyValueInterceptor *>(reinterpret_cast<char *>(obj) + instr.assignValueInterceptor.castValue);
                QObject *target = stack.at(stack.count() - 1 - instr.assignValueInterceptor.owner);
                QDeclarativeProperty prop = 
                    QDeclarativePropertyPrivate::restore(datas.at(instr.assignValueInterceptor.property), target, ctxt);
                obj->setParent(target);
                vi->setTarget(prop);
                QDeclarativeVMEMetaObject *mo = static_cast<QDeclarativeVMEMetaObject *>((QMetaObject*)target->metaObject());
                mo->registerInterceptor(prop.index(), QDeclarativePropertyPrivate::valueTypeCoreIndex(prop), vi);
            }
            break;

        case QDeclarativeInstruction::StoreObjectQList:
            {
                QObject *assign = stack.pop();

                const ListInstance &list = qliststack.top();
                list.qListProperty.append((QDeclarativeListProperty<void>*)&list.qListProperty, assign);
            }
            break;

        case QDeclarativeInstruction::AssignObjectList:
            {
                // This is only used for assigning interfaces
                QObject *assign = stack.pop();
                const ListInstance &list = qliststack.top();

                int type = list.type;

                void *ptr = 0;

                const char *iid = QDeclarativeMetaType::interfaceIId(type);
                if (iid) 
                    ptr = assign->qt_metacast(iid);
                if (!ptr) 
                    VME_EXCEPTION(QCoreApplication::translate("QDeclarativeVME","Cannot assign object to list"));


                list.qListProperty.append((QDeclarativeListProperty<void>*)&list.qListProperty, ptr);
            }
            break;

        case QDeclarativeInstruction::StoreVariantObject:
            {
                QObject *assign = stack.pop();
                QObject *target = stack.top();
                CLEAN_PROPERTY(target, instr.storeObject.propertyIndex);

                QVariant v = QVariant::fromValue(assign);
                void *a[] = { &v, 0, &status, &flags };
                QMetaObject::metacall(target, QMetaObject::WriteProperty, 
                                      instr.storeObject.propertyIndex, a);
            }
            break;

        case QDeclarativeInstruction::StoreInterface:
            {
                QObject *assign = stack.pop();
                QObject *target = stack.top();
                CLEAN_PROPERTY(target, instr.storeObject.propertyIndex);

                int coreIdx = instr.storeObject.propertyIndex;
                QMetaProperty prop = target->metaObject()->property(coreIdx);
                int t = prop.userType();
                const char *iid = QDeclarativeMetaType::interfaceIId(t);
                bool ok = false;

//.........这里部分代码省略.........
#if __REQUIRED_RPCNDR_H_VERSION__ < Q_REQUIRED_RPCNDR_H_VERSION
    out << "\t** Required version of MIDL could not be verified. QRect, QSize and QPoint" << endl;
    out << "\t** support needs an updated Platform SDK to be installed." << endl;
    out << "\t*************************************************************************" << endl;
#else
    out << "\t************************************************************************/" << endl;
#endif

    out << endl;
    out << "\t[uuid(" << idQRect << ")]" << endl;
    out << "\tstruct QRect {" << endl;
    out << "\t\tint left;" << endl;
    out << "\t\tint top;" << endl;
    out << "\t\tint right;" << endl;
    out << "\t\tint bottom;" << endl;
    out << "\t};" << endl << endl;

    out << "\t[uuid(" << idQSize << ")]" << endl;
    out << "\tstruct QSize {" << endl;
    out << "\t\tint width;" << endl;
    out << "\t\tint height;" << endl;
    out << "\t};" << endl << endl;

    out << "\t[uuid(" << idQPoint << ")]" << endl;
    out << "\tstruct QPoint {" << endl;
    out << "\t\tint x;" << endl;
    out << "\t\tint y;" << endl;
    out << "\t};" << endl;
#if __REQUIRED_RPCNDR_H_VERSION__ < Q_REQUIRED_RPCNDR_H_VERSION
    out << "\t*/" << endl;
#endif
    out << endl;

    out << "\t/* Forward declaration of classes that might be used as parameters */" << endl << endl;

    int res = S_OK;
    for (const QString &className : keys) {
        const QMetaObject *mo = qAxFactory()->metaObject(className);
        // We have meta object information for this type. Forward declare it.
        if (mo) {
            QByteArray cleanType = qax_clean_type(className, mo).toLatin1();
            out << "\tcoclass " << cleanType << ';' << endl;
            subtypes.append(cleanType);
            if (!QMetaType::type(cleanType))
                qRegisterMetaType<void *>(cleanType);
            cleanType += '*';
            subtypes.append(cleanType);
            if (!QMetaType::type(cleanType))
                qRegisterMetaType<void *>(cleanType);
        }
    }
    out << endl;

    for (const QString &className : keys) {
        const QMetaObject *mo = qAxFactory()->metaObject(className);
        // We have meta object information for this type. Define it.
        if (mo) {
            QObject *o = qAxFactory()->createObject(className);
            // It's not a control class, so it is actually a subtype. Define it.
            if (!o)
                res = classIDL(0, mo, className, false, out);
            delete o;
        }
    }

    out << endl;
    if (res != S_OK)
        goto ErrorInClass;

    for (const QString &className : keys) {
        QObject *o = qAxFactory()->createObject(className);
        if (!o)
            continue;
        const QMetaObject *mo = o->metaObject();
        QAxBindable *bind = static_cast<QAxBindable *>(o->qt_metacast("QAxBindable"));
        bool isBindable =  bind != 0;

        const QByteArray cleanType = qax_clean_type(className, mo).toLatin1();
        subtypes.append(cleanType);
        subtypes.append(cleanType + '*');
        res = classIDL(o, mo, className, isBindable, out);
        delete o;
        if (res != S_OK)
            break;
    }

    out << "};" << endl;
    out.flush();

ErrorInClass:
    if (delete_qApp)
        delete qApp;

    if (res != S_OK) {
        file.close();
        file.remove();
    }

    return res;
}