Revision control
++ // 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
++
++ #include "qobjectregistrysingleton_p.h"
++
++ #include <private/qabstractobjectregistryref_p.h>
++ #include <private/qqmldata_p.h>
++
++ #include <QtQml/qqmlengine.h>
++
++ QT_BEGIN_NAMESPACE
++
++ QObjectRegistrySingleton::QObjectRegistrySingleton(QObject *parent)
++ : QObject(parent)
++ {
++ }
++
++ QObjectRegistrySingleton::~QObjectRegistrySingleton()
++ {
++ for (const auto &guards : std::as_const(m_objects))
++ qDeleteAll(guards);
++ }
++
++ void QObjectRegistrySingleton::add(const QString &key, QObject *obj)
++ {
++ if (key.isEmpty() || !obj)
++ return;
++
++ if (QQmlData::wasDeleted(obj))
++ return;
++
++ auto &guards = m_objects[key];
++ if (guards.contains(obj))
++ return;
++
++ guards.insert(obj, new ObjectGuard(this, key, obj));
++
++ notifyRefs(key, obj, Notification::ObjectAdded);
++ }
++
++ void QObjectRegistrySingleton::remove(const QString &key, QObject *obj)
++ {
++ if (key.isEmpty() || !obj)
++ return;
++
++ const auto keyIt = m_objects.find(key);
++ if (keyIt == m_objects.end())
++ return;
++
++ const std::unique_ptr<ObjectGuard> guard(keyIt->take(obj));
++ if (!guard)
++ return;
++
++ if (keyIt->isEmpty())
++ m_objects.erase(keyIt);
++
++ notifyRefs(key, obj, Notification::ObjectRemoved);
++ }
++
++ void QObjectRegistrySingleton::notifyRefs(const QString &key, QObject *obj,
++ Notification notification)
++ {
++ // Guard against add/remove handlers changing/removing existing references by iterating over
++ // a copy of references and checking each reference is still registered before each notification
++ const auto refs = m_refs.value(key);
++ for (const auto &ref : refs) {
++ const auto keyIt = m_refs.constFind(key);
++ if (keyIt == m_refs.cend() || !keyIt->contains(ref))
++ continue;
++
++ if (notification == Notification::ObjectAdded)
++ ref->handleObjectAdded(obj);
++ else
++ ref->handleObjectRemoved(obj);
++ }
++ }
++
++ QSet<QObject*> QObjectRegistrySingleton::objects(const QString &key) const
++ {
++ const auto keyIt = m_objects.constFind(key);
++ if (keyIt == m_objects.cend())
++ return {};
++
++ return QSet<QObject *>(keyIt->keyBegin(), keyIt->keyEnd());
++ }
++
++ void QObjectRegistrySingleton::registerRef(QAbstractObjectRegistryRefPrivate *ref)
++ {
++ if (!ref)
++ return;
++
++ m_refs[ref->key()].insert(ref);
++ }
++
++ void QObjectRegistrySingleton::deregisterRef(QAbstractObjectRegistryRefPrivate *ref)
++ {
++ if (!ref)
++ return;
++
++ if (m_refs.contains(ref->key())) {
++ m_refs[ref->key()].remove(ref);
++ if (m_refs[ref->key()].isEmpty())
++ m_refs.remove(ref->key());
++ }
++ }
++
++ QObjectRegistrySingleton *QObjectRegistrySingleton::registryForObject(QObject *obj)
++ {
++ return registryForEngine(qmlEngine(obj));
++ }
++
++ QObjectRegistrySingleton *QObjectRegistrySingleton::registryForEngine(QQmlEngine *engine)
++ {
++ if (engine) {
++ static int typeId = qmlTypeId("QtQml.DesignSupport",
++ QT_VERSION_MAJOR,
++ QT_VERSION_MINOR,
++ "InternalObjectRegistry");
++
++ return engine->singletonInstance<QObjectRegistrySingleton *>(typeId);
++ }
++ return nullptr;
++ }
++
++ QT_END_NAMESPACE