qobjectregistry_p.h

Go to the documentation of this file.

// Copyright (C) 2026 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#ifndef QOBJECTREGISTRY_P_H
#define QOBJECTREGISTRY_P_H
 
#include <QtQmlDesignSupport/qtqmldesignsupportexports.h>
 
#include <QtCore/qpointer.h>
 
#include <QtQml/qqml.h>
#include <QtQml/qqmlparserstatus.h>
#include <QtQml/private/qqmlguard_p.h>
 
QT_BEGIN_NAMESPACE
 
class QAbstractObjectRegistryRefPrivate;
class QObjectRegistrySingleton;
 
class Q_QMLDESIGNSUPPORT_EXPORT QObjectRegistryAttachedType
    : public QObject, public QQmlParserStatus
{
    Q_OBJECT
    Q_INTERFACES(QQmlParserStatus)
 
    Q_PROPERTY(QString key READ key WRITE setKey NOTIFY keyChanged FINAL)
 
    QML_ANONYMOUS
 
public:
    QObjectRegistryAttachedType(QObject *parent = nullptr);
    ~QObjectRegistryAttachedType();
 
    QString key() const;
    void setKey(const QString &key);
 
    void classBegin() override;
    void componentComplete() override;
 
Q_SIGNALS:
    void keyChanged();
 
private:
    QString m_key;
    bool m_qmlSetupInProgress = false;
    QPointer<QObjectRegistrySingleton> m_registry;
};
 
class Q_QMLDESIGNSUPPORT_EXPORT QObjectRegistry : public QObject
{
    Q_OBJECT
 
    Q_PROPERTY(QString key READ key WRITE setKey NOTIFY keyChanged REQUIRED FINAL)
    Q_PROPERTY(QObject *target READ target WRITE setTarget NOTIFY targetChanged REQUIRED FINAL)
 
    QML_ATTACHED(QObjectRegistryAttachedType)
 
    QML_NAMED_ELEMENT(ObjectRegistry)
 
public:
    QObjectRegistry(QObject *parent = nullptr);
    ~QObjectRegistry();
 
    static QObjectRegistryAttachedType *qmlAttachedProperties(QObject *object);
 
    QString key() const;
    void setKey(const QString &key);
 
    QObject *target() const;
    void setTarget(QObject *target);
 
Q_SIGNALS:
    void keyChanged();
    void targetChanged();
 
private:
    class TargetGuard : public QQmlGuard<QObject>
    {
    public:
        explicit TargetGuard(QObjectRegistry *owner)
            : QQmlGuard<QObject>(&TargetGuard::objectDestroyedImpl, nullptr)
            , m_owner(owner)
        {
        }
 
    private:
        static void objectDestroyedImpl(QQmlGuardImpl *guard)
        {
            TargetGuard *self = static_cast<TargetGuard *>(guard);
            emit self->m_owner->targetChanged();
        }
 
        QObjectRegistry *m_owner = nullptr;
    };
 
    QString m_key;
    TargetGuard m_target { this };
    QPointer<QObjectRegistrySingleton> m_registry;
};
 
QT_END_NAMESPACE
 
#endif // QOBJECTREGISTRY_P_H