C++ QDesignerWidgetDataBaseItemInterface::extends方法代码示例

QDESIGNER_SHARED_EXPORT WidgetDataBaseItemList
        promotionCandidates(const QDesignerWidgetDataBaseInterface *db,
                            const QString &baseClassName)
{
    WidgetDataBaseItemList rc;
    // find existing promoted widgets deriving from base.
    const int count = db->count();
    for (int i = 0; i < count; ++i) {
        QDesignerWidgetDataBaseItemInterface *item = db->item(i);
        if (item->isPromoted() && item->extends() == baseClassName) {
            rc.push_back(item);
        }
    }
    return rc;
}

    QDesignerWidgetDataBaseItemInterface *QDesignerPromotionDialog::databaseItemAt(const QItemSelection &selected, unsigned &flags) const {
        flags = 0;
        const QModelIndexList indexes = selected.indexes();
        if (indexes.empty())
            return 0;

        bool referenced;
        QDesignerWidgetDataBaseItemInterface *dbItem = m_model->databaseItemAt(indexes.front(), &referenced);

        if (dbItem) {
            if (referenced)
                flags |= Referenced;
            // In choose mode, can we promote to the class?
            if (m_mode == ModeEditChooseClass &&  dbItem && dbItem->isPromoted() && dbItem->extends() ==  m_promotableWidgetClassName)
                flags |= CanPromote;

        }
        return dbItem;
    }

QDESIGNER_SHARED_EXPORT QDesignerWidgetDataBaseItemInterface *
        appendDerived(QDesignerWidgetDataBaseInterface *db,
                      const QString &className, const QString &group,
                      const QString &baseClassName,
                      const QString &includeFile,
                      bool promoted, bool custom)
{
    if (debugWidgetDataBase)
        qDebug() << "appendDerived " << className << " derived from " << baseClassName;
    // Check.
    if (className.isEmpty() || baseClassName.isEmpty()) {
        qWarning("** WARNING %s called with an empty class names: '%s' extends '%s'.",
                 Q_FUNC_INFO, className.toUtf8().constData(), baseClassName.toUtf8().constData());
        return 0;
    }
    // Check whether item already exists.
    QDesignerWidgetDataBaseItemInterface *derivedItem = 0;
    const int existingIndex = db->indexOfClassName(className);
    if ( existingIndex != -1)
        derivedItem =  db->item(existingIndex);
    if (derivedItem) {
        // Check the existing item for base class mismatch. This will likely
        // happen when loading a file written by an instance with missing plugins.
        // In that case, just warn and ignore the file properties.
        //
        // An empty base class indicates that it is not known (for example, for custom plugins).
        // In this case, the widget DB is later updated once the widget is created
        // by DOM (by querying the metaobject). Suppress the warning.
        const QString existingBaseClass = derivedItem->extends();
        if (existingBaseClass.isEmpty() || baseClassName ==  existingBaseClass)
            return derivedItem;

        // Warn about mismatches
        designerWarning(QCoreApplication::translate("WidgetDataBase",
          "The file contains a custom widget '%1' whose base class (%2)"
          " differs from the current entry in the widget database (%3)."
          " The widget database is left unchanged.").
                        arg(className, baseClassName, existingBaseClass));
        return derivedItem;
    }
    // Create this item, inheriting its base properties
    const int baseIndex = db->indexOfClassName(baseClassName);
    if (baseIndex == -1) {
        if (debugWidgetDataBase)
            qDebug() << "appendDerived failed due to missing base class";
        return 0;
    }
    const QDesignerWidgetDataBaseItemInterface *baseItem = db->item(baseIndex);
    derivedItem = WidgetDataBaseItem::clone(baseItem);
    // Sort of hack: If base class is QWidget, we most likely
    // do not want to inherit the container attribute.
    static const QString qWidgetName = QLatin1String("QWidget");
    if (baseItem->name() == qWidgetName)
        derivedItem->setContainer(false);
    // set new props
    derivedItem->setName(className);
    derivedItem->setGroup(group);
    derivedItem->setCustom(custom);
    derivedItem->setPromoted(promoted);
    derivedItem->setExtends(baseClassName);
    derivedItem->setIncludeFile(includeFile);
    db->append(derivedItem);
    return derivedItem;
}