qqmllistmodel.cpp

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// Copyright (C) 2016 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 "qqmllistmodel_p_p.h"
#include "qqmllistmodelworkeragent_p.h"
 
#include <private/qjsvalue_p.h>
 
#include <private/qqmlcustomparser_p.h>
#include <private/qqmlengine_p.h>
#include <private/qqmljsast_p.h>
#include <private/qqmljsengine_p.h>
#include <private/qqmllistwrapper_p.h>
#include <private/qqmlnotifier_p.h>
#include <private/qqmlopenmetaobject_p.h>
 
#include <private/qv4alloca_p.h>
#include <private/qv4dateobject_p.h>
#include <private/qv4lookup_p.h>
#include <private/qv4object_p.h>
#include <private/qv4objectiterator_p.h>
#include <private/qv4qmlcontext_p.h>
#include <private/qv4sequenceobject_p.h>
#include <private/qv4urlobject_p.h>
 
#include <qqmlcontext.h>
#include <qqmlinfo.h>
 
#include <QtCore/qdebug.h>
#include <QtCore/qstack.h>
#include <QXmlStreamReader>
#include <QtCore/qdatetime.h>
#include <QScopedValueRollback>
 
Q_DECLARE_METATYPE(const QV4::CompiledData::Binding*);
 
QT_BEGIN_NAMESPACE
 
// Set to 1024 as a debugging aid - easier to distinguish uids from indices of elements/models.
enum { MIN_LISTMODEL_UID = 1024 };
 
static QAtomicInt uidCounter(MIN_LISTMODEL_UID);
 
template <typename T>
static bool isMemoryUsed(const char *mem)
{
    for (size_t i=0 ; i < sizeof(T) ; ++i) {
        if (mem[i] != 0)
            return true;
    }
 
    return false;
}
 
static QString roleTypeName(ListLayout::Role::DataType t)
{
    static const QString roleTypeNames[] = {
        QStringLiteral("String"), QStringLiteral("Number"), QStringLiteral("Bool"),
        QStringLiteral("List"), QStringLiteral("QObject"), QStringLiteral("VariantMap"),
        QStringLiteral("DateTime"), QStringLiteral("Url"), QStringLiteral("Function")
    };
 
    if (t > ListLayout::Role::Invalid && t < ListLayout::Role::MaxDataType)
        return roleTypeNames[t];
 
    return QString();
}
 
const ListLayout::Role &ListLayout::getRoleOrCreate(const QString &key, Role::DataType type)
{
    QStringHash<Role *>::Node *node = roleHash.findNode(key);
    if (node) {
        const Role &r = *node->value;
        if (type != r.type)
            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
        return r;
    }
 
    return createRole(key, type);
}
 
const ListLayout::Role &ListLayout::getRoleOrCreate(QV4::String *key, Role::DataType type)
{
    QStringHash<Role *>::Node *node = roleHash.findNode(key);
    if (node) {
        const Role &r = *node->value;
        if (type != r.type)
            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
        return r;
    }
 
    QString qkey = key->toQString();
 
    return createRole(qkey, type);
}
 
const ListLayout::Role &ListLayout::createRole(const QString &key, ListLayout::Role::DataType type)
{
    const int dataSizes[] = {
        sizeof(StringOrTranslation),
        sizeof(double),
        sizeof(bool),
        sizeof(ListModel *),
        sizeof(QV4::PersistentValue),
        sizeof(QVariantMap),
        sizeof(QDateTime),
        sizeof(QUrl),
        sizeof(QJSValue)
    };
    const int dataAlignments[] = {
        alignof(StringOrTranslation),
        alignof(double),
        alignof(bool),
        alignof(ListModel *),
        alignof(QV4::PersistentValue),
        alignof(QVariantMap),
        alignof(QDateTime),
        alignof(QUrl),
        alignof(QJSValue)
    };
 
    Role *r = new Role;
    r->name = key;
    r->type = type;
 
    if (type == Role::List) {
        r->subLayout = new ListLayout;
    } else {
        r->subLayout = nullptr;
    }
 
    int dataSize = dataSizes[type];
    int dataAlignment = dataAlignments[type];
 
    int dataOffset = (currentBlockOffset + dataAlignment-1) & ~(dataAlignment-1);
    if (dataOffset + dataSize > ListElement::BLOCK_SIZE) {
        r->blockIndex = ++currentBlock;
        r->blockOffset = 0;
        currentBlockOffset = dataSize;
    } else {
        r->blockIndex = currentBlock;
        r->blockOffset = dataOffset;
        currentBlockOffset = dataOffset + dataSize;
    }
 
    int roleIndex = roles.size();
    r->index = roleIndex;
 
    roles.append(r);
    roleHash.insert(key, r);
 
    return *r;
}
 
ListLayout::ListLayout(const ListLayout *other) : currentBlock(0), currentBlockOffset(0)
{
    const int otherRolesCount = other->roles.size();
    roles.reserve(otherRolesCount);
    for (int i=0 ; i < otherRolesCount; ++i) {
        Role *role = new Role(other->roles[i]);
        roles.append(role);
        roleHash.insert(role->name, role);
    }
    currentBlockOffset = other->currentBlockOffset;
    currentBlock = other->currentBlock;
}
 
ListLayout::~ListLayout()
{
    qDeleteAll(roles);
}
 
void ListLayout::sync(ListLayout *src, ListLayout *target)
{
    int roleOffset = target->roles.size();
    int newRoleCount = src->roles.size() - roleOffset;
 
    for (int i=0 ; i < newRoleCount ; ++i) {
        Role *role = new Role(src->roles[roleOffset + i]);
        target->roles.append(role);
        target->roleHash.insert(role->name, role);
    }
 
    target->currentBlockOffset = src->currentBlockOffset;
    target->currentBlock = src->currentBlock;
}
 
ListLayout::Role::Role(const Role *other)
{
    name = other->name;
    type = other->type;
    blockIndex = other->blockIndex;
    blockOffset = other->blockOffset;
    index = other->index;
    if (other->subLayout)
        subLayout = new ListLayout(other->subLayout);
    else
        subLayout = nullptr;
}
 
ListLayout::Role::~Role()
{
    delete subLayout;
}
 
const ListLayout::Role *ListLayout::getRoleOrCreate(const QString &key, const QVariant &data)
{
    Role::DataType type;
 
    switch (data.userType()) {
        case QMetaType::Double:      type = Role::Number;      break;
        case QMetaType::Int:         type = Role::Number;      break;
        case QMetaType::Bool:        type = Role::Bool;        break;
        case QMetaType::QString:     type = Role::String;      break;
        case QMetaType::QVariantMap: type = Role::VariantMap;  break;
        case QMetaType::QDateTime:   type = Role::DateTime;    break;
        case QMetaType::QUrl:        type = Role::Url;         break;
        default:    {
            if (data.userType() == qMetaTypeId<QJSValue>() &&
                data.value<QJSValue>().isCallable()) {
                type = Role::Function;
                break;
            } else if (data.userType() == qMetaTypeId<const QV4::CompiledData::Binding*>()
                       && data.value<const QV4::CompiledData::Binding*>()->isTranslationBinding()) {
                type = Role::String;
                break;
            } else if (data.userType() >= QMetaType::User) {
                type = Role::List;
                break;
            } else {
                type = Role::Invalid;
                break;
            }
        }
    }
 
    if (type == Role::Invalid) {
        qmlWarning(nullptr) << "Can't create role for unsupported data type";
        return nullptr;
    }
 
    return &getRoleOrCreate(key, type);
}
 
const ListLayout::Role *ListLayout::getExistingRole(const QString &key) const
{
    Role *r = nullptr;
    QStringHash<Role *>::Node *node = roleHash.findNode(key);
    if (node)
        r = node->value;
    return r;
}
 
const ListLayout::Role *ListLayout::getExistingRole(QV4::String *key) const
{
    Role *r = nullptr;
    QStringHash<Role *>::Node *node = roleHash.findNode(key);
    if (node)
        r = node->value;
    return r;
}
 
StringOrTranslation::~StringOrTranslation()
{
    clear();
}
 
void StringOrTranslation::setString(const QString &s)
{
    clear();
    if (s.isEmpty())
        return;
    QString mutableString(s);
    QString::DataPointer dataPointer = mutableString.data_ptr();
    arrayData = dataPointer->d_ptr();
    stringData = dataPointer->data();
    stringSize = mutableString.size();
    if (arrayData)
        arrayData->ref();
}
 
void StringOrTranslation::setTranslation(const QV4::CompiledData::Binding *binding)
{
    clear();
    this->binding = binding;
}
 
QString StringOrTranslation::toString(const QQmlListModel *owner) const
{
    if (stringSize) {
        if (arrayData)
            arrayData->ref();
        return QString(QStringPrivate(arrayData, stringData, stringSize));
    }
    if (!owner)
        return QString();
    return owner->m_compilationUnit->bindingValueAsString(binding);
}
 
QString StringOrTranslation::asString() const
{
    if (!arrayData)
        return QString();
    arrayData->ref();
    return QString(QStringPrivate(arrayData, stringData, stringSize));
}
 
void StringOrTranslation::clear()
{
    if (arrayData && !arrayData->deref())
        QTypedArrayData<ushort>::deallocate(arrayData);
    arrayData = nullptr;
    stringData = nullptr;
    stringSize = 0;
    binding = nullptr;
}
 
QObject *ListModel::getOrCreateModelObject(QQmlListModel *model, int elementIndex)
{
    ListElement *e = elements[elementIndex];
    if (e->m_objectCache == nullptr) {
        void *memory = operator new(sizeof(QObject) + sizeof(QQmlData));
        void *ddataMemory = ((char *)memory) + sizeof(QObject);
        e->m_objectCache = new (memory) QObject;
 
        const QAbstractDeclarativeData *old = std::exchange(
            QObjectPrivate::get(e->m_objectCache)->declarativeData,
            new (ddataMemory) QQmlData(QQmlData::DoesNotOwnMemory));
        Q_ASSERT(!old); // QObject should really not manipulate QQmlData
 
        (void)new ModelNodeMetaObject(e->m_objectCache, model, elementIndex);
    }
    return e->m_objectCache;
}
 
bool ListModel::sync(ListModel *src, ListModel *target)
{
    // Sanity check
 
    bool hasChanges = false;
 
    // Build hash of elements <-> uid for each of the lists
    QHash<int, ElementSync> elementHash;
    for (int i = 0; i < target->elements.count(); ++i) {
        ListElement *e = target->elements.at(i);
        int uid = e->getUid();
        ElementSync sync;
        sync.target = e;
        sync.targetIndex = i;
        elementHash.insert(uid, sync);
    }
    for (int i = 0; i < src->elements.count(); ++i) {
        ListElement *e = src->elements.at(i);
        int uid = e->getUid();
 
        QHash<int, ElementSync>::iterator it = elementHash.find(uid);
        if (it == elementHash.end()) {
            ElementSync sync;
            sync.src = e;
            sync.srcIndex = i;
            elementHash.insert(uid, sync);
        } else {
            ElementSync &sync = it.value();
            sync.src = e;
            sync.srcIndex = i;
        }
    }
 
    QQmlListModel *targetModel = target->m_modelCache;
 
    // Get list of elements that are in the target but no longer in the source. These get deleted first.
    int rowsRemoved = 0;
    for (int i = 0 ; i < target->elements.count() ; ++i) {
        ListElement *element = target->elements.at(i);
        ElementSync &s = elementHash.find(element->getUid()).value();
        Q_ASSERT(s.targetIndex >= 0);
        // need to update the targetIndex, to keep it correct after removals
        s.targetIndex -= rowsRemoved;
        if (s.src == nullptr) {
            Q_ASSERT(s.targetIndex == i);
            hasChanges = true;
            if (targetModel)
                targetModel->beginRemoveRows(QModelIndex(), i, i);
            s.target->destroy(target->m_layout);
            target->elements.removeOne(s.target);
            delete s.target;
            if (targetModel)
                targetModel->endRemoveRows();
            ++rowsRemoved;
            --i;
            continue;
        }
    }
 
    // Sync the layouts
    ListLayout::sync(src->m_layout, target->m_layout);
 
    // Clear the target list, and append in correct order from the source
    target->elements.clear();
    for (int i = 0; i < src->elements.count(); ++i) {
        ListElement *srcElement = src->elements.at(i);
        ElementSync &s = elementHash.find(srcElement->getUid()).value();
        Q_ASSERT(s.srcIndex >= 0);
        ListElement *targetElement = s.target;
        if (targetElement == nullptr) {
            targetElement = new ListElement(srcElement->getUid());
        }
        s.changedRoles = ListElement::sync(srcElement, src->m_layout, targetElement, target->m_layout);
        target->elements.append(targetElement);
    }
 
    target->updateCacheIndices();
 
    // Update values stored in target meta objects
    for (int i=0 ; i < target->elements.count() ; ++i) {
        ListElement *e = target->elements[i];
        if (ModelNodeMetaObject *mo = e->objectCache())
            mo->updateValues();
    }
 
    // now emit the change notifications required. This can be safely done, as we're only emitting changes, moves and inserts,
    // so the model indices can't be out of bounds
    //
    // to ensure things are kept in the correct order, emit inserts and moves first. This shouls ensure all persistent
    // model indices are updated correctly
    int rowsInserted = 0;
    const int targetElementCount = target->elements.count();
    for (int i = 0 ; i < targetElementCount ; ++i) {
        ListElement *element = target->elements.at(i);
        ElementSync &s = elementHash.find(element->getUid()).value();
        Q_ASSERT(s.srcIndex >= 0);
        s.srcIndex += rowsInserted;
        if (s.srcIndex != s.targetIndex) {
            if (targetModel) {
                if (s.targetIndex == -1) {
                    targetModel->beginInsertRows(QModelIndex(), i, i);
                    targetModel->endInsertRows();
                    ++rowsInserted;
                } else {
                    bool validMove = targetModel->beginMoveRows(QModelIndex(), s.targetIndex, s.targetIndex, QModelIndex(), i);
                    Q_ASSERT(validMove);
                    targetModel->endMoveRows();
                    // fixup target indices of elements that still need to move
                    for (int j=i+1; j < targetElementCount; ++j) {
                        ListElement *eToFix = target->elements.at(j);
                        ElementSync &sToFix = elementHash.find(eToFix->getUid()).value();
                        if (i < s.targetIndex) {
                            // element was moved down
                            if (sToFix.targetIndex > s.targetIndex || sToFix.targetIndex < i)
                                continue; // unaffected by reordering
                            else
                                sToFix.targetIndex += 1;
                        } else {
                            // element was moved up
                            if (sToFix.targetIndex < s.targetIndex || sToFix.targetIndex > i)
                                continue; // unaffected by reordering
                            else
                                sToFix.targetIndex -= 1;
                        }
                    }
                }
            }
            hasChanges = true;
        }
        if (s.targetIndex != -1 && !s.changedRoles.isEmpty()) {
            QModelIndex idx = targetModel->createIndex(i, 0);
            if (targetModel)
                targetModel->dataChanged(idx, idx, s.changedRoles);
            hasChanges = true;
        }
    }
    return hasChanges;
}
 
ListModel::ListModel(ListLayout *layout, QQmlListModel *modelCache) : m_layout(layout), m_modelCache(modelCache)
{
}
 
void ListModel::destroy()
{
    for (const auto &destroyer : remove(0, elements.count()))
        destroyer();
 
    m_layout = nullptr;
    if (m_modelCache && m_modelCache->m_primary == false)
        delete m_modelCache;
    m_modelCache = nullptr;
}
 
int ListModel::appendElement()
{
    int elementIndex = elements.count();
    newElement(elementIndex);
    return elementIndex;
}
 
void ListModel::insertElement(int index)
{
    newElement(index);
    updateCacheIndices(index);
}
 
void ListModel::move(int from, int to, int n)
{
    if (from > to) {
        // Only move forwards - flip if backwards moving
        int tfrom = from;
        int tto = to;
        from = tto;
        to = tto+n;
        n = tfrom-tto;
    }
 
    QPODVector<ListElement *, 4> store;
    for (int i=0 ; i < (to-from) ; ++i)
        store.append(elements[from+n+i]);
    for (int i=0 ; i < n ; ++i)
        store.append(elements[from+i]);
    for (int i=0 ; i < store.count() ; ++i)
        elements[from+i] = store[i];
 
    updateCacheIndices(from, to + n);
}
 
void ListModel::newElement(int index)
{
    ListElement *e = new ListElement;
    elements.insert(index, e);
}
 
void ListModel::updateCacheIndices(int start, int end)
{
    int count = elements.count();
 
    if (end < 0 || end > count)
        end = count;
 
    for (int i = start; i < end; ++i) {
        ListElement *e = elements.at(i);
        if (ModelNodeMetaObject *mo = e->objectCache())
            mo->m_elementIndex = i;
    }
}
 
QVariant ListModel::getProperty(int elementIndex, int roleIndex, const QQmlListModel *owner, QV4::ExecutionEngine *eng)
{
    if (roleIndex >= m_layout->roleCount())
        return QVariant();
    ListElement *e = elements[elementIndex];
    const ListLayout::Role &r = m_layout->getExistingRole(roleIndex);
    return e->getProperty(r, owner, eng);
}
 
ListModel *ListModel::getListProperty(int elementIndex, const ListLayout::Role &role)
{
    ListElement *e = elements[elementIndex];
    return e->getListProperty(role);
}
 
void ListModel::updateTranslations()
{
    for (int index = 0; index != elements.count(); ++index) {
        ListElement *e = elements[index];
        if (ModelNodeMetaObject *cache = e->objectCache()) {
            // TODO: more fine grained tracking?
            cache->updateValues();
        }
    }
}
 
void ListModel::set(int elementIndex, QV4::Object *object, QVector<int> *roles)
{
    ListElement *e = elements[elementIndex];
 
    QV4::ExecutionEngine *v4 = object->engine();
    QV4::Scope scope(v4);
    QV4::ScopedObject o(scope);
 
    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::EnumerableOnly);
    QV4::ScopedString propertyName(scope);
    QV4::ScopedValue propertyValue(scope);
    while (1) {
        propertyName = it.nextPropertyNameAsString(propertyValue);
        if (!propertyName)
            break;
 
        // Check if this key exists yet
        int roleIndex = -1;
 
        // Add the value now
        if (const QV4::String *s = propertyValue->as<QV4::String>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::String);
            roleIndex = e->setStringProperty(r, s->toQString());
        } else if (propertyValue->isNumber()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Number);
            roleIndex = e->setDoubleProperty(r, propertyValue->asDouble());
        } else if (QV4::ArrayObject *a = propertyValue->as<QV4::ArrayObject>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::List);
            ListModel *subModel = new ListModel(r.subLayout, nullptr);
 
            int arrayLength = a->getLength();
            for (int j=0 ; j < arrayLength ; ++j) {
                o = a->get(j);
                subModel->append(o);
            }
 
            roleIndex = e->setListProperty(r, subModel);
        } else if (propertyValue->isBoolean()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Bool);
            roleIndex = e->setBoolProperty(r, propertyValue->booleanValue());
        } else if (QV4::DateObject *dd = propertyValue->as<QV4::DateObject>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::DateTime);
            QDateTime dt = dd->toQDateTime();
            roleIndex = e->setDateTimeProperty(r, dt);
        } else if (QV4::UrlObject *url = propertyValue->as<QV4::UrlObject>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Url);
            QUrl qurl = QUrl(url->href());
            roleIndex = e->setUrlProperty(r, qurl);
        } else if (QV4::FunctionObject *f = propertyValue->as<QV4::FunctionObject>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Function);
            QV4::ScopedFunctionObject func(scope, f);
            QJSValue jsv;
            QJSValuePrivate::setValue(&jsv, func);
            roleIndex = e->setFunctionProperty(r, jsv);
        } else if (QV4::Object *o = propertyValue->as<QV4::Object>()) {
            if (QV4::QObjectWrapper *wrapper = o->as<QV4::QObjectWrapper>()) {
                const ListLayout::Role &role = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::QObject);
                if (role.type == ListLayout::Role::QObject)
                    roleIndex = e->setQObjectProperty(role, wrapper);
            } else if (QVariant maybeUrl = QV4::ExecutionEngine::toVariant(
                           o->asReturnedValue(), QMetaType::fromType<QUrl>(), true);
                       maybeUrl.metaType() == QMetaType::fromType<QUrl>()) {
                const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Url);
                QUrl qurl = maybeUrl.toUrl();
                roleIndex = e->setUrlProperty(r, qurl);
            } else {
                const ListLayout::Role &role = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::VariantMap);
                if (role.type == ListLayout::Role::VariantMap) {
                    QV4::ScopedObject obj(scope, o);
                    roleIndex = e->setVariantMapProperty(role, obj);
                }
            }
        } else if (propertyValue->isNullOrUndefined()) {
            const ListLayout::Role *r = m_layout->getExistingRole(propertyName);
            if (r)
                e->clearProperty(*r);
        }
 
        if (roleIndex != -1)
            roles->append(roleIndex);
    }
 
    if (ModelNodeMetaObject *mo = e->objectCache())
        mo->updateValues(*roles);
}
 
void ListModel::set(int elementIndex, QV4::Object *object, ListModel::SetElement reason)
{
    if (!object)
        return;
 
    ListElement *e = elements[elementIndex];
 
    QV4::ExecutionEngine *v4 = object->engine();
    QV4::Scope scope(v4);
 
    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::EnumerableOnly);
    QV4::ScopedString propertyName(scope);
    QV4::ScopedValue propertyValue(scope);
    QV4::ScopedObject o(scope);
    while (1) {
        propertyName = it.nextPropertyNameAsString(propertyValue);
        if (!propertyName)
            break;
 
        // Add the value now
        if (QV4::String *s = propertyValue->stringValue()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::String);
            if (r.type == ListLayout::Role::String)
                e->setStringPropertyFast(r, s->toQString());
        } else if (propertyValue->isNumber()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Number);
            if (r.type == ListLayout::Role::Number) {
                e->setDoublePropertyFast(r, propertyValue->asDouble());
            }
        } else if (QV4::ArrayObject *a = propertyValue->as<QV4::ArrayObject>()) {
            setArrayLike(&o, propertyName, e, a);
        } else if (QV4::Sequence *s = propertyValue->as<QV4::Sequence>()) {
            setArrayLike(&o, propertyName, e, s);
        } else if (QV4::QmlListWrapper *l = propertyValue->as<QV4::QmlListWrapper>()) {
            setArrayLike(&o, propertyName, e, l);
        } else if (propertyValue->isBoolean()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Bool);
            if (r.type == ListLayout::Role::Bool) {
                e->setBoolPropertyFast(r, propertyValue->booleanValue());
            }
        } else if (QV4::DateObject *date = propertyValue->as<QV4::DateObject>()) {
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::DateTime);
            if (r.type == ListLayout::Role::DateTime) {
                QDateTime dt = date->toQDateTime();
                e->setDateTimePropertyFast(r, dt);
            }
        } else if (QV4::UrlObject *url = propertyValue->as<QV4::UrlObject>()){
            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Url);
            if (r.type == ListLayout::Role::Url) {
                QUrl qurl = QUrl(url->href()); // does what the private UrlObject->toQUrl would do
                e->setUrlPropertyFast(r, qurl);
            }
        } else if (QV4::Object *o = propertyValue->as<QV4::Object>()) {
            if (QV4::QObjectWrapper *wrapper = o->as<QV4::QObjectWrapper>()) {
                const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::QObject);
                if (r.type == ListLayout::Role::QObject)
                    e->setQObjectPropertyFast(r, wrapper);
            } else {
                QVariant maybeUrl = QV4::ExecutionEngine::toVariant(
                            o->asReturnedValue(), QMetaType::fromType<QUrl>(), true);
                if (maybeUrl.metaType() == QMetaType::fromType<QUrl>()) {
                    const QUrl qurl = maybeUrl.toUrl();
                    const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Url);
                    if (r.type == ListLayout::Role::Url)
                        e->setUrlPropertyFast(r, qurl);
                } else {
                    const ListLayout::Role &role = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::VariantMap);
                    if (role.type == ListLayout::Role::VariantMap)
                        e->setVariantMapFast(role, o);
                }
            }
        } else if (propertyValue->isNullOrUndefined()) {
            if (reason == SetElement::WasJustInserted) {
                QQmlError err;
                auto memberName = propertyName->toString(v4)->toQString();
                err.setDescription(QString::fromLatin1("%1 is %2. Adding an object with a %2 member does not create a role for it.").arg(memberName, propertyValue->isNull() ? QLatin1String("null") : QLatin1String("undefined")));
                qmlWarning(nullptr, err);
            } else {
                const ListLayout::Role *r = m_layout->getExistingRole(propertyName);
                if (r)
                    e->clearProperty(*r);
            }
        }
    }
}
 
QVector<std::function<void()>> ListModel::remove(int index, int count)
{
    QVector<std::function<void()>> toDestroy;
    auto layout = m_layout;
    for (int i=0 ; i < count ; ++i) {
        auto element = elements[index+i];
        toDestroy.append([element, layout](){
            element->destroy(layout);
            delete element;
        });
    }
    elements.remove(index, count);
    updateCacheIndices(index);
    return toDestroy;
}
 
void ListModel::insert(int elementIndex, QV4::Object *object)
{
    insertElement(elementIndex);
    set(elementIndex, object, SetElement::WasJustInserted);
}
 
int ListModel::append(QV4::Object *object)
{
    int elementIndex = appendElement();
    set(elementIndex, object, SetElement::WasJustInserted);
    return elementIndex;
}
 
int ListModel::setOrCreateProperty(int elementIndex, const QString &key, const QVariant &data)
{
    int roleIndex = -1;
 
    if (elementIndex >= 0 && elementIndex < elements.count()) {
        ListElement *e = elements[elementIndex];
 
        const ListLayout::Role *r = m_layout->getRoleOrCreate(key, data);
        if (r) {
            roleIndex = e->setVariantProperty(*r, data);
 
            ModelNodeMetaObject *cache = e->objectCache();
 
            if (roleIndex != -1 && cache)
                cache->updateValues(QVector<int>(1, roleIndex));
        }
    }
 
    return roleIndex;
}
 
int ListModel::setExistingProperty(int elementIndex, const QString &key, const QV4::Value &data, QV4::ExecutionEngine *eng)
{
    int roleIndex = -1;
 
    if (elementIndex >= 0 && elementIndex < elements.count()) {
        ListElement *e = elements[elementIndex];
        const ListLayout::Role *r = m_layout->getExistingRole(key);
        if (r)
            roleIndex = e->setJsProperty(*r, data, eng);
    }
 
    return roleIndex;
}
 
inline char *ListElement::getPropertyMemory(const ListLayout::Role &role)
{
    ListElement *e = this;
    int blockIndex = 0;
    while (blockIndex < role.blockIndex) {
        if (e->next == nullptr) {
            e->next = new ListElement;
            e->next->uid = uid;
        }
        e = e->next;
        ++blockIndex;
    }
 
    char *mem = &e->data[role.blockOffset];
    return mem;
}
 
ModelNodeMetaObject *ListElement::objectCache()
{
    if (!m_objectCache)
        return nullptr;
    return ModelNodeMetaObject::get(m_objectCache);
}
 
StringOrTranslation *ListElement::getStringProperty(const ListLayout::Role &role)
{
    char *mem = getPropertyMemory(role);
    StringOrTranslation *s = reinterpret_cast<StringOrTranslation *>(mem);
    return s;
}
 
QV4::QObjectWrapper *ListElement::getQObjectProperty(const ListLayout::Role &role)
{
    char *mem = getPropertyMemory(role);
    QV4::PersistentValue *g = reinterpret_cast<QV4::PersistentValue *>(mem);
    return g->as<QV4::QObjectWrapper>();
}
 
QVariantMap *ListElement::getVariantMapProperty(const ListLayout::Role &role)
{
    QVariantMap *map = nullptr;
 
    char *mem = getPropertyMemory(role);
    if (isMemoryUsed<QVariantMap>(mem))
        map = reinterpret_cast<QVariantMap *>(mem);
 
    return map;
}
 
QDateTime *ListElement::getDateTimeProperty(const ListLayout::Role &role)
{
    QDateTime *dt = nullptr;
 
    char *mem = getPropertyMemory(role);
    if (isMemoryUsed<QDateTime>(mem))
        dt = reinterpret_cast<QDateTime *>(mem);
 
    return dt;
}
 
QUrl *ListElement::getUrlProperty(const ListLayout::Role &role)
{
    QUrl *url = nullptr;
 
    char *mem = getPropertyMemory(role);
    if (isMemoryUsed<QUrl>(mem))
        url = reinterpret_cast<QUrl *>(mem);
 
    return url;
}
 
QJSValue *ListElement::getFunctionProperty(const ListLayout::Role &role)
{
    QJSValue *f = nullptr;
 
    char *mem = getPropertyMemory(role);
    if (isMemoryUsed<QJSValue>(mem))
        f = reinterpret_cast<QJSValue *>(mem);
 
    return f;
}
 
QV4::PersistentValue *
ListElement::getGuardProperty(const ListLayout::Role &role)
{
    char *mem = getPropertyMemory(role);
 
    bool existingGuard = false;
    for (size_t i = 0; i < sizeof(QV4::PersistentValue);
         ++i) {
        if (mem[i] != 0) {
            existingGuard = true;
            break;
        }
    }
 
    QV4::PersistentValue *g = nullptr;
 
    if (existingGuard)
        g = reinterpret_cast<QV4::PersistentValue *>(mem);
 
    return g;
}
 
ListModel *ListElement::getListProperty(const ListLayout::Role &role)
{
    char *mem = getPropertyMemory(role);
    ListModel **value = reinterpret_cast<ListModel **>(mem);
    return *value;
}
 
QVariant ListElement::getProperty(const ListLayout::Role &role, const QQmlListModel *owner, QV4::ExecutionEngine *eng)
{
    char *mem = getPropertyMemory(role);
 
    QVariant data;
 
    switch (role.type) {
        case ListLayout::Role::Number:
            {
                double *value = reinterpret_cast<double *>(mem);
                data = *value;
            }
            break;
        case ListLayout::Role::String:
            {
                StringOrTranslation *value = reinterpret_cast<StringOrTranslation *>(mem);
                if (value->isSet())
                    data = value->toString(owner);
                else
                    data = QString();
            }
            break;
        case ListLayout::Role::Bool:
            {
                bool *value = reinterpret_cast<bool *>(mem);
                data = *value;
            }
            break;
        case ListLayout::Role::List:
            {
                ListModel **value = reinterpret_cast<ListModel **>(mem);
                ListModel *model = *value;
 
                if (model) {
                    if (model->m_modelCache == nullptr) {
                        model->m_modelCache = new QQmlListModel(owner, model, eng);
                        QQmlEngine::setContextForObject(model->m_modelCache, QQmlEngine::contextForObject(owner));
                    }
 
                    QObject *object = model->m_modelCache;
                    data = QVariant::fromValue(object);
                }
            }
            break;
        case ListLayout::Role::QObject:
            {
                QV4::PersistentValue *guard = reinterpret_cast<QV4::PersistentValue *>(mem);
                data = QVariant::fromValue(guard->as<QV4::QObjectWrapper>()->object());
            }
            break;
        case ListLayout::Role::VariantMap:
            {
                if (isMemoryUsed<QVariantMap>(mem)) {
                    QVariantMap *map = reinterpret_cast<QVariantMap *>(mem);
                    data = *map;
                }
            }
            break;
        case ListLayout::Role::DateTime:
            {
                if (isMemoryUsed<QDateTime>(mem)) {
                    QDateTime *dt = reinterpret_cast<QDateTime *>(mem);
                    data = *dt;
                }
            }
            break;
        case ListLayout::Role::Url:
            {
                if (isMemoryUsed<QUrl>(mem)) {
                    QUrl *url = reinterpret_cast<QUrl *>(mem);
                    data = *url;
                }
            }
            break;
        case ListLayout::Role::Function:
            {
                if (isMemoryUsed<QJSValue>(mem)) {
                    QJSValue *func = reinterpret_cast<QJSValue *>(mem);
                    data = QVariant::fromValue(*func);
                }
            }
            break;
        default:
            break;
    }
 
    return data;
}
 
int ListElement::setStringProperty(const ListLayout::Role &role, const QString &s)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::String) {
        char *mem = getPropertyMemory(role);
        StringOrTranslation *c = reinterpret_cast<StringOrTranslation *>(mem);
        bool changed;
        if (!c->isSet() || c->isTranslation())
            changed = true;
        else
            changed = c->asString().compare(s) != 0;
        c->setString(s);
        if (changed)
            roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setDoubleProperty(const ListLayout::Role &role, double d)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::Number) {
        char *mem = getPropertyMemory(role);
        double *value = reinterpret_cast<double *>(mem);
        bool changed = *value != d;
        *value = d;
        if (changed)
            roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setBoolProperty(const ListLayout::Role &role, bool b)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::Bool) {
        char *mem = getPropertyMemory(role);
        bool *value = reinterpret_cast<bool *>(mem);
        bool changed = *value != b;
        *value = b;
        if (changed)
            roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setListProperty(const ListLayout::Role &role, ListModel *m)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::List) {
        char *mem = getPropertyMemory(role);
        ListModel **value = reinterpret_cast<ListModel **>(mem);
        if (*value && *value != m) {
            (*value)->destroy();
            delete *value;
        }
        *value = m;
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setQObjectProperty(const ListLayout::Role &role, QV4::QObjectWrapper *o)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::QObject) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QVariantMap>(mem))
            reinterpret_cast<QV4::PersistentValue *>(mem)->set(o->engine(), *o);
        else
            new (mem) QV4::PersistentValue(o->engine(), o);
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setVariantMapProperty(const ListLayout::Role &role, QV4::Object *o)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::VariantMap) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QVariantMap>(mem)) {
            QVariantMap *map = reinterpret_cast<QVariantMap *>(mem);
            map->~QMap();
        }
        new (mem) QVariantMap(o->engine()->variantMapFromJS(o));
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setVariantMapProperty(const ListLayout::Role &role, QVariantMap *m)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::VariantMap) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QVariantMap>(mem)) {
            QVariantMap *map = reinterpret_cast<QVariantMap *>(mem);
            if (m && map->isSharedWith(*m))
                return roleIndex;
            map->~QMap();
        } else if (!m) {
            return roleIndex;
        }
        if (m)
            new (mem) QVariantMap(*m);
        else
            new (mem) QVariantMap;
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setDateTimeProperty(const ListLayout::Role &role, const QDateTime &dt)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::DateTime) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QDateTime>(mem)) {
            QDateTime *dt = reinterpret_cast<QDateTime *>(mem);
            dt->~QDateTime();
        }
        new (mem) QDateTime(dt);
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setUrlProperty(const ListLayout::Role &role, const QUrl &url)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::Url) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QUrl>(mem)) {
            QUrl *qurl = reinterpret_cast<QUrl *>(mem);
            qurl->~QUrl();
        }
        new (mem) QUrl(url);
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setFunctionProperty(const ListLayout::Role &role, const QJSValue &f)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::Function) {
        char *mem = getPropertyMemory(role);
        if (isMemoryUsed<QJSValue>(mem)) {
            QJSValue *f = reinterpret_cast<QJSValue *>(mem);
            f->~QJSValue();
        }
        new (mem) QJSValue(f);
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
int ListElement::setTranslationProperty(const ListLayout::Role &role, const QV4::CompiledData::Binding *b)
{
    int roleIndex = -1;
 
    if (role.type == ListLayout::Role::String) {
        char *mem = getPropertyMemory(role);
        StringOrTranslation *s = reinterpret_cast<StringOrTranslation *>(mem);
        s->setTranslation(b);
        roleIndex = role.index;
    }
 
    return roleIndex;
}
 
 
void ListElement::setStringPropertyFast(const ListLayout::Role &role, const QString &s)
{
    char *mem = getPropertyMemory(role);
    reinterpret_cast<StringOrTranslation *>(mem)->setString(s);
}
 
void ListElement::setDoublePropertyFast(const ListLayout::Role &role, double d)
{
    char *mem = getPropertyMemory(role);
    double *value = new (mem) double;
    *value = d;
}
 
void ListElement::setBoolPropertyFast(const ListLayout::Role &role, bool b)
{
    char *mem = getPropertyMemory(role);
    bool *value = new (mem) bool;
    *value = b;
}
 
void ListElement::setQObjectPropertyFast(const ListLayout::Role &role, QV4::QObjectWrapper *o)
{
    char *mem = getPropertyMemory(role);
    new (mem) QV4::PersistentValue(o->engine(), o);
}
 
void ListElement::setListPropertyFast(const ListLayout::Role &role, ListModel *m)
{
    char *mem = getPropertyMemory(role);
    ListModel **value = new (mem) ListModel *;
    *value = m;
}
 
void ListElement::setVariantMapFast(const ListLayout::Role &role, QV4::Object *o)
{
    char *mem = getPropertyMemory(role);
    QVariantMap *map = new (mem) QVariantMap;
    *map = o->engine()->variantMapFromJS(o);
}
 
void ListElement::setDateTimePropertyFast(const ListLayout::Role &role, const QDateTime &dt)
{
    char *mem = getPropertyMemory(role);
    new (mem) QDateTime(dt);
}
 
void ListElement::setUrlPropertyFast(const ListLayout::Role &role, const QUrl &url)
{
    char *mem = getPropertyMemory(role);
    new (mem) QUrl(url);
}
 
void ListElement::setFunctionPropertyFast(const ListLayout::Role &role, const QJSValue &f)
{
    char *mem = getPropertyMemory(role);
    new (mem) QJSValue(f);
}
 
void ListElement::clearProperty(const ListLayout::Role &role)
{
    switch (role.type) {
    case ListLayout::Role::String:
        setStringProperty(role, QString());
        break;
    case ListLayout::Role::Number:
        setDoubleProperty(role, 0.0);
        break;
    case ListLayout::Role::Bool:
        setBoolProperty(role, false);
        break;
    case ListLayout::Role::List:
        setListProperty(role, nullptr);
        break;
    case ListLayout::Role::QObject:
        setQObjectProperty(role, nullptr);
        break;
    case ListLayout::Role::DateTime:
        setDateTimeProperty(role, QDateTime());
        break;
    case ListLayout::Role::Url:
        setUrlProperty(role, QUrl());
        break;
    case ListLayout::Role::VariantMap:
        setVariantMapProperty(role, (QVariantMap *)nullptr);
        break;
    case ListLayout::Role::Function:
        setFunctionProperty(role, QJSValue());
        break;
    default:
        break;
    }
}
 
ListElement::ListElement()
{
    m_objectCache = nullptr;
    uid = uidCounter.fetchAndAddOrdered(1);
    next = nullptr;
    memset(data, 0, sizeof(data));
}
 
ListElement::ListElement(int existingUid)
{
    m_objectCache = nullptr;
    uid = existingUid;
    next = nullptr;
    memset(data, 0, sizeof(data));
}
 
ListElement::~ListElement()
{
    delete next;
}
 
QVector<int> ListElement::sync(ListElement *src, ListLayout *srcLayout, ListElement *target, ListLayout *targetLayout)
{
    QVector<int> changedRoles;
    for (int i=0 ; i < srcLayout->roleCount() ; ++i) {
        const ListLayout::Role &srcRole = srcLayout->getExistingRole(i);
        const ListLayout::Role &targetRole = targetLayout->getExistingRole(i);
 
        int roleIndex = -1;
        switch (srcRole.type) {
            case ListLayout::Role::List:
                {
                    ListModel *srcSubModel = src->getListProperty(srcRole);
                    ListModel *targetSubModel = target->getListProperty(targetRole);
 
                    if (srcSubModel) {
                        if (targetSubModel == nullptr) {
                            targetSubModel = new ListModel(targetRole.subLayout, nullptr);
                            target->setListPropertyFast(targetRole, targetSubModel);
                        }
                        if (ListModel::sync(srcSubModel, targetSubModel))
                            roleIndex = targetRole.index;
                    }
                }
                break;
            case ListLayout::Role::QObject:
                {
                    QV4::QObjectWrapper *object = src->getQObjectProperty(srcRole);
                    roleIndex = target->setQObjectProperty(targetRole, object);
                }
                break;
            case ListLayout::Role::String:
            case ListLayout::Role::Number:
            case ListLayout::Role::Bool:
            case ListLayout::Role::DateTime:
            case ListLayout::Role::Function:
                {
                    QVariant v = src->getProperty(srcRole, nullptr, nullptr);
                    roleIndex = target->setVariantProperty(targetRole, v);
                }
                break;
            case ListLayout::Role::VariantMap:
                {
                    QVariantMap *map = src->getVariantMapProperty(srcRole);
                    roleIndex = target->setVariantMapProperty(targetRole, map);
                }
                break;
            default:
                break;
        }
        if (roleIndex >= 0)
            changedRoles << roleIndex;
    }
 
    return changedRoles;
}
 
void ListElement::destroy(ListLayout *layout)
{
    if (layout) {
        for (int i=0 ; i < layout->roleCount() ; ++i) {
            const ListLayout::Role &r = layout->getExistingRole(i);
 
            switch (r.type) {
                case ListLayout::Role::String:
                    {
                        StringOrTranslation *string = getStringProperty(r);
                        if (string)
                            string->~StringOrTranslation();
                    }
                    break;
                case ListLayout::Role::List:
                    {
                        ListModel *model = getListProperty(r);
                        if (model) {
                            model->destroy();
                            delete model;
                        }
                    }
                    break;
                case ListLayout::Role::QObject:
                    {
                        if (QV4::PersistentValue *guard = getGuardProperty(r))
                            guard->~PersistentValue();
                    }
                    break;
                case ListLayout::Role::VariantMap:
                    {
                        QVariantMap *map = getVariantMapProperty(r);
                        if (map)
                            map->~QMap();
                    }
                    break;
                case ListLayout::Role::DateTime:
                    {
                        QDateTime *dt = getDateTimeProperty(r);
                        if (dt)
                            dt->~QDateTime();
                    }
                    break;
                case ListLayout::Role::Url:
                    {
                        QUrl *url = getUrlProperty(r);
                        if (url)
                            url->~QUrl();
                        break;
                    }
                case ListLayout::Role::Function:
                    {
                        QJSValue *f = getFunctionProperty(r);
                        if (f)
                            f->~QJSValue();
                    }
                    break;
                default:
                    // other types don't need explicit cleanup.
                    break;
            }
        }
 
        if (m_objectCache) {
            m_objectCache->~QObject();
            operator delete(m_objectCache);
        }
    }
 
    if (next)
        next->destroy(nullptr);
    uid = -1;
}
 
int ListElement::setVariantProperty(const ListLayout::Role &role, const QVariant &d)
{
    int roleIndex = -1;
 
    switch (role.type) {
        case ListLayout::Role::Number:
            roleIndex = setDoubleProperty(role, d.toDouble());
            break;
        case ListLayout::Role::String:
            if (d.userType() == qMetaTypeId<const QV4::CompiledData::Binding *>())
                roleIndex = setTranslationProperty(role, d.value<const QV4::CompiledData::Binding*>());
            else
                roleIndex = setStringProperty(role, d.toString());
            break;
        case ListLayout::Role::Bool:
            roleIndex = setBoolProperty(role, d.toBool());
            break;
        case ListLayout::Role::List:
            roleIndex = setListProperty(role, d.value<ListModel *>());
            break;
        case ListLayout::Role::VariantMap: {
                QVariantMap map = d.toMap();
                roleIndex = setVariantMapProperty(role, &map);
            }
            break;
        case ListLayout::Role::DateTime:
            roleIndex = setDateTimeProperty(role, d.toDateTime());
            break;
        case ListLayout::Role::Url:
            roleIndex = setUrlProperty(role, d.toUrl());
            break;
        case ListLayout::Role::Function:
            roleIndex = setFunctionProperty(role, d.value<QJSValue>());
            break;
        default:
            break;
    }
 
    return roleIndex;
}
 
int ListElement::setJsProperty(const ListLayout::Role &role, const QV4::Value &d, QV4::ExecutionEngine *eng)
{
    // Check if this key exists yet
    int roleIndex = -1;
 
    QV4::Scope scope(eng);
 
    // Add the value now
    if (d.isString()) {
        QString qstr = d.toQString();
        roleIndex = setStringProperty(role, qstr);
    } else if (d.isNumber()) {
        roleIndex = setDoubleProperty(role, d.asDouble());
    } else if (d.as<QV4::ArrayObject>()) {
        QV4::ScopedArrayObject a(scope, d);
        if (role.type == ListLayout::Role::List) {
            QV4::Scope scope(a->engine());
            QV4::ScopedObject o(scope);
 
            ListModel *subModel = new ListModel(role.subLayout, nullptr);
            int arrayLength = a->getLength();
            for (int j=0 ; j < arrayLength ; ++j) {
                o = a->get(j);
                subModel->append(o);
            }
            roleIndex = setListProperty(role, subModel);
        } else {
            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(role.name).arg(roleTypeName(role.type)).arg(roleTypeName(ListLayout::Role::List));
        }
    } else if (d.isBoolean()) {
        roleIndex = setBoolProperty(role, d.booleanValue());
    } else if (d.as<QV4::DateObject>()) {
        QV4::Scoped<QV4::DateObject> dd(scope, d);
        QDateTime dt = dd->toQDateTime();
        roleIndex = setDateTimeProperty(role, dt);
    } else if (d.as<QV4::UrlObject>()) {
        QV4::Scoped<QV4::UrlObject> url(scope, d);
        QUrl qurl = QUrl(url->href());
        roleIndex = setUrlProperty(role, qurl);
    } else if (d.as<QV4::FunctionObject>()) {
        QV4::ScopedFunctionObject f(scope, d);
        QJSValue jsv;
        QJSValuePrivate::setValue(&jsv, f);
        roleIndex = setFunctionProperty(role, jsv);
    } else if (d.isObject()) {
        QV4::ScopedObject o(scope, d);
        QV4::QObjectWrapper *wrapper = o->as<QV4::QObjectWrapper>();
        if (role.type == ListLayout::Role::QObject && wrapper) {
            roleIndex = setQObjectProperty(role, wrapper);
        } else if (role.type == ListLayout::Role::VariantMap) {
            roleIndex = setVariantMapProperty(role, o);
        } else if (role.type == ListLayout::Role::Url) {
            QVariant maybeUrl = QV4::ExecutionEngine::toVariant(
                        o.asReturnedValue(), QMetaType::fromType<QUrl>(), true);
            if (maybeUrl.metaType() == QMetaType::fromType<QUrl>()) {
                roleIndex = setUrlProperty(role, maybeUrl.toUrl());
            }
        }
    } else if (d.isNullOrUndefined()) {
        clearProperty(role);
    }
 
    return roleIndex;
}
 
ModelNodeMetaObject::ModelNodeMetaObject(QObject *object, QQmlListModel *model, int elementIndex)
: QQmlOpenMetaObject(object), m_enabled(false), m_model(model), m_elementIndex(elementIndex), m_initialized(false)
{}
 
void ModelNodeMetaObject::initialize()
{
    const int roleCount = m_model->m_listModel->roleCount();
    QVector<QByteArray> properties;
    properties.reserve(roleCount);
    for (int i = 0 ; i < roleCount ; ++i) {
        const ListLayout::Role &role = m_model->m_listModel->getExistingRole(i);
        QByteArray name = role.name.toUtf8();
        properties << name;
    }
    type()->createProperties(properties);
    updateValues();
    m_enabled = true;
}
 
ModelNodeMetaObject::~ModelNodeMetaObject()
{
}
 
QMetaObject *ModelNodeMetaObject::toDynamicMetaObject(QObject *object)
{
    if (!m_initialized) {
        m_initialized = true;
        initialize();
    }
    return QQmlOpenMetaObject::toDynamicMetaObject(object);
}
 
ModelNodeMetaObject *ModelNodeMetaObject::get(QObject *obj)
{
    QObjectPrivate *op = QObjectPrivate::get(obj);
    return static_cast<ModelNodeMetaObject*>(op->metaObject);
}
 
void ModelNodeMetaObject::updateValues()
{
    const int roleCount = m_model->m_listModel->roleCount();
    if (!m_initialized) {
        if (roleCount) {
            Q_ALLOCA_VAR(int, changedRoles, roleCount * sizeof(int));
            for (int i = 0; i < roleCount; ++i)
                changedRoles[i] = i;
            emitDirectNotifies(changedRoles, roleCount);
        }
        return;
    }
    for (int i=0 ; i < roleCount ; ++i) {
        const ListLayout::Role &role = m_model->m_listModel->getExistingRole(i);
        QByteArray name = role.name.toUtf8();
        const QVariant &data = m_model->data(m_elementIndex, i);
        setValue(name, data, role.type == ListLayout::Role::List);
    }
}
 
void ModelNodeMetaObject::updateValues(const QVector<int> &roles)
{
    if (!m_initialized) {
        emitDirectNotifies(roles.constData(), roles.size());
        return;
    }
    int roleCount = roles.size();
    for (int i=0 ; i < roleCount ; ++i) {
        int roleIndex = roles.at(i);
        const ListLayout::Role &role = m_model->m_listModel->getExistingRole(roleIndex);
        QByteArray name = role.name.toUtf8();
        const QVariant &data = m_model->data(m_elementIndex, roleIndex);
        setValue(name, data, role.type == ListLayout::Role::List);
    }
}
 
void ModelNodeMetaObject::propertyWritten(int index)
{
    if (!m_enabled)
        return;
 
    QString propName = QString::fromUtf8(name(index));
    const QVariant value = this->value(index);
 
    QV4::Scope scope(m_model->engine());
    QV4::ScopedValue v(scope, scope.engine->fromVariant(value));
 
    int roleIndex = m_model->m_listModel->setExistingProperty(m_elementIndex, propName, v, scope.engine);
    if (roleIndex != -1)
        m_model->emitItemsChanged(m_elementIndex, 1, QVector<int>(1, roleIndex));
}
 
// Does the emission of the notifiers when we haven't created the meta-object yet
void ModelNodeMetaObject::emitDirectNotifies(const int *changedRoles, int roleCount)
{
    Q_ASSERT(!m_initialized);
    QQmlData *ddata = QQmlData::get(object(), /*create*/false);
    if (!ddata)
        return;
    // There's nothing to emit if we're a list model in a worker thread.
    if (!qmlEngine(m_model))
        return;
    for (int i = 0; i < roleCount; ++i) {
        const int changedRole = changedRoles[i];
        QQmlNotifier::notify(ddata, changedRole);
    }
}
 
namespace QV4 {
 
bool ModelObject::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
{
    if (!id.isString())
        return Object::virtualPut(m, id, value, receiver);
    QString propName = id.toQString();
 
    ModelObject *that = static_cast<ModelObject*>(m);
 
    ExecutionEngine *eng = that->engine();
    const int elementIndex = that->d()->elementIndex();
    int roleIndex = that->d()->m_model->m_listModel->setExistingProperty(elementIndex, propName, value, eng);
    if (roleIndex != -1)
        that->d()->m_model->emitItemsChanged(elementIndex, 1, QVector<int>(1, roleIndex));
 
    ModelNodeMetaObject *mo = ModelNodeMetaObject::get(that->object());
    if (mo->initialized())
        mo->emitPropertyNotification(propName.toUtf8());
    return true;
}
 
ReturnedValue ModelObject::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
{
    if (!id.isString())
        return QObjectWrapper::virtualGet(m, id, receiver, hasProperty);
 
    const ModelObject *that = static_cast<const ModelObject*>(m);
    Scope scope(that);
    ScopedString name(scope, id.asStringOrSymbol());
    const ListLayout::Role *role = that->d()->m_model->m_listModel->getExistingRole(name);
    if (!role)
        return QObjectWrapper::virtualGet(m, id, receiver, hasProperty);
    if (hasProperty)
        *hasProperty = true;
 
    if (QQmlEngine *qmlEngine = that->engine()->qmlEngine()) {
        QQmlEnginePrivate *ep = QQmlEnginePrivate::get(qmlEngine);
        if (ep && ep->propertyCapture)
            ep->propertyCapture->captureProperty(that->object(), -1, role->index, /*doNotify=*/ false);
    }
 
    const int elementIndex = that->d()->elementIndex();
    QVariant value = that->d()->m_model->data(elementIndex, role->index);
    return that->engine()->fromVariant(value);
}
 
ReturnedValue ModelObject::virtualResolveLookupGetter(const Object *object, ExecutionEngine *engine, Lookup *lookup)
{
    lookup->getter = Lookup::getterFallback;
    return lookup->getter(lookup, engine, *object);
}
 
struct ModelObjectOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
{
    int roleNameIndex = 0;
    ~ModelObjectOwnPropertyKeyIterator() override = default;
    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
 
};
 
PropertyKey ModelObjectOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
{
    const ModelObject *that = static_cast<const ModelObject *>(o);
 
    ExecutionEngine *v4 = that->engine();
    if (roleNameIndex < that->listModel()->roleCount()) {
        Scope scope(that->engine());
        const ListLayout::Role &role = that->listModel()->getExistingRole(roleNameIndex);
        ++roleNameIndex;
        ScopedString roleName(scope, v4->newString(role.name));
        if (attrs)
            *attrs = QV4::Attr_Data;
        if (pd) {
 
            QVariant value = that->d()->m_model->data(that->d()->elementIndex(), role.index);
            if (auto recursiveListModel = qvariant_cast<QQmlListModel*>(value)) {
                auto size = recursiveListModel->count();
                auto array = ScopedArrayObject{scope, v4->newArrayObject(size)};
                for (auto i = 0; i < size; i++) {
                    array->arrayPut(i, QJSValuePrivate::convertToReturnedValue(
                                        v4, recursiveListModel->get(i)));
                }
                pd->value = array;
            } else {
                pd->value = v4->fromVariant(value);
            }
        }
        return roleName->toPropertyKey();
    }
 
    // Fall back to QV4::Object as opposed to QV4::QObjectWrapper otherwise it will add
    // unnecessary entries that relate to the roles used. These just create extra work
    // later on as they will just be ignored.
    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
}
 
OwnPropertyKeyIterator *ModelObject::virtualOwnPropertyKeys(const Object *m, Value *target)
{
    *target = *m;
    return new ModelObjectOwnPropertyKeyIterator;
}
 
DEFINE_OBJECT_VTABLE(ModelObject);
 
} // namespace QV4
 
DynamicRoleModelNode::DynamicRoleModelNode(QQmlListModel *owner, int uid) : m_owner(owner), m_uid(uid), m_meta(new DynamicRoleModelNodeMetaObject(this))
{
    setNodeUpdatesEnabled(true);
}
 
DynamicRoleModelNode *DynamicRoleModelNode::create(const QVariantMap &obj, QQmlListModel *owner)
{
    DynamicRoleModelNode *object = new DynamicRoleModelNode(owner, uidCounter.fetchAndAddOrdered(1));
    QVector<int> roles;
    object->updateValues(obj, roles);
    return object;
}
 
QVector<int> DynamicRoleModelNode::sync(DynamicRoleModelNode *src, DynamicRoleModelNode *target)
{
    QVector<int> changedRoles;
    for (int i = 0; i < src->m_meta->count(); ++i) {
        const QByteArray &name = src->m_meta->name(i);
        QVariant value = src->m_meta->value(i);
 
        QQmlListModel *srcModel = qobject_cast<QQmlListModel *>(value.value<QObject *>());
        QQmlListModel *targetModel = qobject_cast<QQmlListModel *>(target->m_meta->value(i).value<QObject *>());
 
        bool modelHasChanges = false;
        if (srcModel) {
            if (targetModel == nullptr)
                targetModel = QQmlListModel::createWithOwner(target->m_owner);
 
            modelHasChanges = QQmlListModel::sync(srcModel, targetModel);
 
            QObject *targetModelObject = targetModel;
            value = QVariant::fromValue(targetModelObject);
        } else if (targetModel) {
            delete targetModel;
        }
 
        if (target->setValue(name, value) || modelHasChanges)
            changedRoles << target->m_owner->m_roles.indexOf(QString::fromUtf8(name));
    }
    return changedRoles;
}
 
void DynamicRoleModelNode::updateValues(const QVariantMap &object, QVector<int> &roles)
{
    for (auto it = object.cbegin(), end = object.cend(); it != end; ++it) {
        const QString &key = it.key();
 
        int roleIndex = m_owner->m_roles.indexOf(key);
        if (roleIndex == -1) {
            roleIndex = m_owner->m_roles.size();
            m_owner->m_roles.append(key);
        }
 
        QVariant value = it.value();
 
        // A JS array/object is translated into a (hierarchical) QQmlListModel,
        // so translate to a variant map/list first with toVariant().
        if (value.userType() == qMetaTypeId<QJSValue>())
            value = value.value<QJSValue>().toVariant();
 
        if (value.userType() == QMetaType::QVariantList) {
            QQmlListModel *subModel = QQmlListModel::createWithOwner(m_owner);
 
            QVariantList subArray = value.toList();
            QVariantList::const_iterator subIt = subArray.cbegin();
            QVariantList::const_iterator subEnd = subArray.cend();
            while (subIt != subEnd) {
                const QVariantMap &subObject = subIt->toMap();
                subModel->m_modelObjects.append(DynamicRoleModelNode::create(subObject, subModel));
                ++subIt;
            }
 
            QObject *subModelObject = subModel;
            value = QVariant::fromValue(subModelObject);
        }
 
        const QByteArray &keyUtf8 = key.toUtf8();
 
        QQmlListModel *existingModel = qobject_cast<QQmlListModel *>(m_meta->value(keyUtf8).value<QObject *>());
        delete existingModel;
 
        if (m_meta->setValue(keyUtf8, value))
            roles << roleIndex;
    }
}
 
DynamicRoleModelNodeMetaObject::DynamicRoleModelNodeMetaObject(DynamicRoleModelNode *object)
    : QQmlOpenMetaObject(object), m_enabled(false), m_owner(object)
{
}
 
DynamicRoleModelNodeMetaObject::~DynamicRoleModelNodeMetaObject()
{
    for (int i=0 ; i < count() ; ++i) {
        QQmlListModel *subModel = qobject_cast<QQmlListModel *>(value(i).value<QObject *>());
        delete subModel;
    }
}
 
void DynamicRoleModelNodeMetaObject::propertyWrite(int index)
{
    if (!m_enabled)
        return;
 
    QVariant v = value(index);
    QQmlListModel *model = qobject_cast<QQmlListModel *>(v.value<QObject *>());
    delete model;
}
 
void DynamicRoleModelNodeMetaObject::propertyWritten(int index)
{
    if (!m_enabled)
        return;
 
    QQmlListModel *parentModel = m_owner->m_owner;
 
    QVariant v = value(index);
 
    // A JS array/object is translated into a (hierarchical) QQmlListModel,
    // so translate to a variant map/list first with toVariant().
    if (v.userType() == qMetaTypeId<QJSValue>())
        v= v.value<QJSValue>().toVariant();
 
    if (v.userType() == QMetaType::QVariantList) {
        QQmlListModel *subModel = QQmlListModel::createWithOwner(parentModel);
 
        QVariantList subArray = v.toList();
        QVariantList::const_iterator subIt = subArray.cbegin();
        QVariantList::const_iterator subEnd = subArray.cend();
        while (subIt != subEnd) {
            const QVariantMap &subObject = subIt->toMap();
            subModel->m_modelObjects.append(DynamicRoleModelNode::create(subObject, subModel));
            ++subIt;
        }
 
        QObject *subModelObject = subModel;
        v = QVariant::fromValue(subModelObject);
 
        setValue(index, v);
    }
 
    int elementIndex = parentModel->m_modelObjects.indexOf(m_owner);
    if (elementIndex != -1) {
        int roleIndex = parentModel->m_roles.indexOf(QString::fromLatin1(name(index).constData()));
        if (roleIndex != -1)
            parentModel->emitItemsChanged(elementIndex, 1, QVector<int>(1, roleIndex));
    }
}
 
QQmlListModel::QQmlListModel(QObject *parent)
: QAbstractListModel(parent)
{
    m_mainThread = true;
    m_primary = true;
    m_agent = nullptr;
    m_dynamicRoles = false;
 
    m_layout = new ListLayout;
    m_listModel = new ListModel(m_layout, this);
 
    m_engine = nullptr;
}
 
QQmlListModel::QQmlListModel(const QQmlListModel *owner, ListModel *data, QV4::ExecutionEngine *engine, QObject *parent)
: QAbstractListModel(parent)
{
    m_mainThread = owner->m_mainThread;
    m_primary = false;
    m_agent = owner->m_agent;
 
    Q_ASSERT(owner->m_dynamicRoles == false);
    m_dynamicRoles = false;
    m_layout = nullptr;
    m_listModel = data;
 
    m_engine = engine;
    m_compilationUnit = owner->m_compilationUnit;
}
 
QQmlListModel::QQmlListModel(QQmlListModel *orig, QQmlListModelWorkerAgent *agent)
: QAbstractListModel(agent)
{
    m_mainThread = false;
    m_primary = true;
    m_agent = agent;
    m_dynamicRoles = orig->m_dynamicRoles;
 
    m_layout = new ListLayout(orig->m_layout);
    m_listModel = new ListModel(m_layout, this);
 
    if (m_dynamicRoles)
        sync(orig, this);
    else
        ListModel::sync(orig->m_listModel, m_listModel);
 
    m_engine = nullptr;
    m_compilationUnit = orig->m_compilationUnit;
}
 
QQmlListModel::~QQmlListModel()
{
    qDeleteAll(m_modelObjects);
 
    if (m_primary) {
        m_listModel->destroy();
        delete m_listModel;
 
        if (m_mainThread && m_agent) {
            m_agent->modelDestroyed();
            m_agent->release();
        }
    }
 
    m_listModel = nullptr;
 
    delete m_layout;
    m_layout = nullptr;
}
 
QQmlListModel *QQmlListModel::createWithOwner(QQmlListModel *newOwner)
{
    QQmlListModel *model = new QQmlListModel;
 
    model->m_mainThread = newOwner->m_mainThread;
    model->m_engine = newOwner->m_engine;
    model->m_agent = newOwner->m_agent;
    model->m_dynamicRoles = newOwner->m_dynamicRoles;
 
    if (model->m_mainThread && model->m_agent)
        model->m_agent->addref();
 
    QQmlEngine::setContextForObject(model, QQmlEngine::contextForObject(newOwner));
 
    return model;
}
 
QV4::ExecutionEngine *QQmlListModel::engine() const
{
    if (m_engine == nullptr) {
        m_engine  = qmlEngine(this)->handle();
    }
 
    return m_engine;
}
 
bool QQmlListModel::sync(QQmlListModel *src, QQmlListModel *target)
{
    Q_ASSERT(src->m_dynamicRoles && target->m_dynamicRoles);
 
    bool hasChanges = false;
 
    target->m_roles = src->m_roles;
 
    // Build hash of elements <-> uid for each of the lists
    QHash<int, ElementSync> elementHash;
    for (int i = 0 ; i < target->m_modelObjects.size(); ++i) {
        DynamicRoleModelNode *e = target->m_modelObjects.at(i);
        int uid = e->getUid();
        ElementSync sync;
        sync.target = e;
        sync.targetIndex = i;
        elementHash.insert(uid, sync);
    }
    for (int i = 0 ; i < src->m_modelObjects.size(); ++i) {
        DynamicRoleModelNode *e = src->m_modelObjects.at(i);
        int uid = e->getUid();
 
        QHash<int, ElementSync>::iterator it = elementHash.find(uid);
        if (it == elementHash.end()) {
            ElementSync sync;
            sync.src = e;
            sync.srcIndex = i;
            elementHash.insert(uid, sync);
        } else {
            ElementSync &sync = it.value();
            sync.src = e;
            sync.srcIndex = i;
        }
    }
 
    // Get list of elements that are in the target but no longer in the source. These get deleted first.
    int rowsRemoved = 0;
    for (int i = 0 ; i < target->m_modelObjects.size() ; ++i) {
        DynamicRoleModelNode *element = target->m_modelObjects.at(i);
        ElementSync &s = elementHash.find(element->getUid()).value();
        Q_ASSERT(s.targetIndex >= 0);
        // need to update the targetIndex, to keep it correct after removals
        s.targetIndex -= rowsRemoved;
        if (s.src == nullptr) {
            Q_ASSERT(s.targetIndex == i);
            hasChanges = true;
            target->beginRemoveRows(QModelIndex(), i, i);
            target->m_modelObjects.remove(i, 1);
            target->endRemoveRows();
            delete s.target;
            ++rowsRemoved;
            --i;
            continue;
        }
    }
 
    // Clear the target list, and append in correct order from the source
    target->m_modelObjects.clear();
    for (int i = 0 ; i < src->m_modelObjects.size() ; ++i) {
        DynamicRoleModelNode *element = src->m_modelObjects.at(i);
        ElementSync &s = elementHash.find(element->getUid()).value();
        Q_ASSERT(s.srcIndex >= 0);
        DynamicRoleModelNode *targetElement = s.target;
        if (targetElement == nullptr) {
            targetElement = new DynamicRoleModelNode(target, element->getUid());
        }
        s.changedRoles = DynamicRoleModelNode::sync(element, targetElement);
        target->m_modelObjects.append(targetElement);
    }
 
    // now emit the change notifications required. This can be safely done, as we're only emitting changes, moves and inserts,
    // so the model indices can't be out of bounds
    //
    // to ensure things are kept in the correct order, emit inserts and moves first. This shouls ensure all persistent
    // model indices are updated correctly
    int rowsInserted = 0;
    for (int i = 0 ; i < target->m_modelObjects.size() ; ++i) {
        DynamicRoleModelNode *element = target->m_modelObjects.at(i);
        ElementSync &s = elementHash.find(element->getUid()).value();
        Q_ASSERT(s.srcIndex >= 0);
        s.srcIndex += rowsInserted;
        if (s.srcIndex != s.targetIndex) {
            if (s.targetIndex == -1) {
                target->beginInsertRows(QModelIndex(), i, i);
                target->endInsertRows();
            } else {
                target->beginMoveRows(QModelIndex(), i, i, QModelIndex(), s.srcIndex);
                target->endMoveRows();
            }
            hasChanges = true;
            ++rowsInserted;
        }
        if (s.targetIndex != -1 && !s.changedRoles.isEmpty()) {
            QModelIndex idx = target->createIndex(i, 0);
            emit target->dataChanged(idx, idx, s.changedRoles);
            hasChanges = true;
        }
    }
    return hasChanges;
}
 
void QQmlListModel::emitItemsChanged(int index, int count, const QVector<int> &roles)
{
    if (count <= 0)
        return;
 
    if (m_mainThread)
        emit dataChanged(createIndex(index, 0), createIndex(index + count - 1, 0), roles);;
}
 
void QQmlListModel::emitItemsAboutToBeInserted(int index, int count)
{
    Q_ASSERT(index >= 0 && count >= 0);
    if (m_mainThread)
        beginInsertRows(QModelIndex(), index, index + count - 1);
}
 
void QQmlListModel::emitItemsInserted()
{
    if (m_mainThread) {
        endInsertRows();
        emit countChanged();
    }
}
 
QQmlListModelWorkerAgent *QQmlListModel::agent()
{
    if (m_agent)
        return m_agent;
 
    m_agent = new QQmlListModelWorkerAgent(this);
    return m_agent;
}
 
QModelIndex QQmlListModel::index(int row, int column, const QModelIndex &parent) const
{
    return row >= 0 && row < count() && column == 0 && !parent.isValid()
            ? createIndex(row, column)
            : QModelIndex();
}
 
int QQmlListModel::rowCount(const QModelIndex &parent) const
{
    return !parent.isValid() ? count() : 0;
}
 
QVariant QQmlListModel::data(const QModelIndex &index, int role) const
{
    return data(index.row(), role);
}
 
bool QQmlListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    const int row = index.row();
    if (row >= count() || row < 0)
        return false;
 
    if (m_dynamicRoles) {
        const QByteArray property = m_roles.at(role).toUtf8();
        if (m_modelObjects[row]->setValue(property, value)) {
            emitItemsChanged(row, 1, QVector<int>(1, role));
            return true;
        }
    } else {
        const ListLayout::Role &r = m_listModel->getExistingRole(role);
        const int roleIndex = m_listModel->setOrCreateProperty(row, r.name, value);
        if (roleIndex != -1) {
            emitItemsChanged(row, 1, QVector<int>(1, role));
            return true;
        }
    }
 
    return false;
}
 
QVariant QQmlListModel::data(int index, int role) const
{
    QVariant v;
 
    if (index >= count() || index < 0)
        return v;
 
    if (m_dynamicRoles)
        v = m_modelObjects[index]->getValue(m_roles[role]);
    else
        v = m_listModel->getProperty(index, role, this, engine());
 
    return v;
}
 
QHash<int, QByteArray> QQmlListModel::roleNames() const
{
    QHash<int, QByteArray> roleNames;
 
    if (m_dynamicRoles) {
        for (int i = 0 ; i < m_roles.size() ; ++i)
            roleNames.insert(i, m_roles.at(i).toUtf8());
    } else {
        for (int i = 0 ; i < m_listModel->roleCount() ; ++i) {
            const ListLayout::Role &r = m_listModel->getExistingRole(i);
            roleNames.insert(i, r.name.toUtf8());
        }
    }
 
    return roleNames;
}
 
void QQmlListModel::setDynamicRoles(bool enableDynamicRoles)
{
    if (m_mainThread && m_agent == nullptr) {
        if (enableDynamicRoles) {
            if (m_layout->roleCount())
                qmlWarning(this) << tr("unable to enable dynamic roles as this model is not empty");
            else
                m_dynamicRoles = true;
        } else {
            if (m_roles.size()) {
                qmlWarning(this) << tr("unable to enable static roles as this model is not empty");
            } else {
                m_dynamicRoles = false;
            }
        }
    } else {
        qmlWarning(this) << tr("dynamic role setting must be made from the main thread, before any worker scripts are created");
    }
}
 
int QQmlListModel::count() const
{
    return m_dynamicRoles ? m_modelObjects.size() : m_listModel->elementCount();
}
 
void QQmlListModel::clear()
{
    removeElements(0, count());
}
 
void QQmlListModel::remove(QQmlV4FunctionPtr args)
{
    int argLength = args->length();
 
    if (argLength == 1 || argLength == 2) {
        QV4::Scope scope(args->v4engine());
        int index = QV4::ScopedValue(scope, (*args)[0])->toInt32();
        int removeCount = (argLength == 2 ? QV4::ScopedValue(scope, (*args)[1])->toInt32() : 1);
 
        if (index < 0 || index+removeCount > count() || removeCount <= 0) {
            qmlWarning(this) << tr("remove: indices [%1 - %2] out of range [0 - %3]").arg(index).arg(index+removeCount).arg(count());
            return;
        }
 
        removeElements(index, removeCount);
    } else {
        qmlWarning(this) << tr("remove: incorrect number of arguments");
    }
}
 
void QQmlListModel::removeElements(int index, int removeCount)
{
    Q_ASSERT(index >= 0 && removeCount >= 0);
 
    if (!removeCount)
        return;
 
    if (m_mainThread)
        beginRemoveRows(QModelIndex(), index, index + removeCount - 1);
 
    QVector<std::function<void()>> toDestroy;
    if (m_dynamicRoles) {
        for (int i=0 ; i < removeCount ; ++i) {
            auto modelObject = m_modelObjects[index+i];
            toDestroy.append([modelObject](){
                delete modelObject;
            });
        }
        m_modelObjects.remove(index, removeCount);
    } else {
        toDestroy = m_listModel->remove(index, removeCount);
    }
 
    if (m_mainThread) {
        endRemoveRows();
        emit countChanged();
    }
    for (const auto &destroyer : toDestroy)
        destroyer();
}
 
void QQmlListModel::updateTranslations()
{
    // assumption: it is impossible to have retranslatable strings in a
    // dynamic list model, as they would already have "decayed" to strings
    // when they were inserted
    if (m_dynamicRoles)
        return;
    Q_ASSERT(m_listModel);
 
    QList<int> roles;
    for (int i = 0, end = m_listModel->roleCount(); i != end; ++i) {
        if (m_listModel->getExistingRole(i).type == ListLayout::Role::String)
            roles.append(i);
    }
 
    if (!roles.isEmpty())
        emitItemsChanged(0, rowCount(QModelIndex()), roles);
 
    m_listModel->updateTranslations();
}
 
void QQmlListModel::insert(QQmlV4FunctionPtr args)
{
    if (args->length() == 2) {
        QV4::Scope scope(args->v4engine());
        QV4::ScopedValue arg0(scope, (*args)[0]);
        int index = arg0->toInt32();
 
        if (index < 0 || index > count()) {
            qmlWarning(this) << tr("insert: index %1 out of range").arg(index);
            return;
        }
 
        QV4::ScopedObject argObject(scope, (*args)[1]);
        QV4::ScopedArrayObject objectArray(scope, (*args)[1]);
        if (objectArray) {
            QV4::ScopedObject argObject(scope);
 
            int objectArrayLength = objectArray->getLength();
            emitItemsAboutToBeInserted(index, objectArrayLength);
            for (int i=0 ; i < objectArrayLength ; ++i) {
                argObject = objectArray->get(i);
 
                if (m_dynamicRoles) {
                    m_modelObjects.insert(index+i, DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
                } else {
                    m_listModel->insert(index+i, argObject);
                }
            }
            emitItemsInserted();
        } else if (argObject) {
            emitItemsAboutToBeInserted(index, 1);
 
            if (m_dynamicRoles) {
                m_modelObjects.insert(index, DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
            } else {
                m_listModel->insert(index, argObject);
            }
 
            emitItemsInserted();
        } else {
            qmlWarning(this) << tr("insert: value is not an object");
        }
    } else {
        qmlWarning(this) << tr("insert: value is not an object");
    }
}
 
void QQmlListModel::move(int from, int to, int n)
{
    if (n == 0 || from == to)
        return;
    if (!canMove(from, to, n)) {
        qmlWarning(this) << tr("move: out of range");
        return;
    }
 
    if (m_mainThread)
        beginMoveRows(QModelIndex(), from, from + n - 1, QModelIndex(), to > from ? to + n : to);
 
    if (m_dynamicRoles) {
 
        int realFrom = from;
        int realTo = to;
        int realN = n;
 
        if (from > to) {
            // Only move forwards - flip if backwards moving
            int tfrom = from;
            int tto = to;
            realFrom = tto;
            realTo = tto+n;
            realN = tfrom-tto;
        }
 
        QPODVector<DynamicRoleModelNode *, 4> store;
        for (int i=0 ; i < (realTo-realFrom) ; ++i)
            store.append(m_modelObjects[realFrom+realN+i]);
        for (int i=0 ; i < realN ; ++i)
            store.append(m_modelObjects[realFrom+i]);
        for (int i=0 ; i < store.count() ; ++i)
            m_modelObjects[realFrom+i] = store[i];
 
    } else {
        m_listModel->move(from, to, n);
    }
 
    if (m_mainThread)
        endMoveRows();
}
 
void QQmlListModel::append(QQmlV4FunctionPtr args)
{
    if (args->length() == 1) {
        QV4::Scope scope(args->v4engine());
        QV4::ScopedObject argObject(scope, (*args)[0]);
        QV4::ScopedArrayObject objectArray(scope, (*args)[0]);
 
        if (objectArray) {
            QV4::ScopedObject argObject(scope);
 
            int objectArrayLength = objectArray->getLength();
            if (objectArrayLength > 0) {
                int index = count();
                emitItemsAboutToBeInserted(index, objectArrayLength);
 
                for (int i=0 ; i < objectArrayLength ; ++i) {
                    argObject = objectArray->get(i);
 
                    if (m_dynamicRoles) {
                        m_modelObjects.append(DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
                    } else {
                        m_listModel->append(argObject);
                    }
                }
 
                emitItemsInserted();
            }
        } else if (argObject) {
            int index;
 
            if (m_dynamicRoles) {
                index = m_modelObjects.size();
                emitItemsAboutToBeInserted(index, 1);
                m_modelObjects.append(DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
            } else {
                index = m_listModel->elementCount();
                emitItemsAboutToBeInserted(index, 1);
                m_listModel->append(argObject);
            }
 
            emitItemsInserted();
        } else {
            qmlWarning(this) << tr("append: value is not an object");
        }
    } else {
        qmlWarning(this) << tr("append: value is not an object");
    }
}
 
QJSValue QQmlListModel::get(int index) const
{
    QV4::Scope scope(engine());
    QV4::ScopedValue result(scope, QV4::Value::undefinedValue());
 
    if (index >= 0 && index < count()) {
 
        if (m_dynamicRoles) {
            DynamicRoleModelNode *object = m_modelObjects[index];
            result = QV4::QObjectWrapper::wrap(scope.engine, object);
        } else {
            QObject *object = m_listModel->getOrCreateModelObject(const_cast<QQmlListModel *>(this), index);
            QQmlData *ddata = QQmlData::get(object);
            if (ddata->jsWrapper.isNullOrUndefined()) {
                result = scope.engine->memoryManager->allocate<QV4::ModelObject>(object, const_cast<QQmlListModel *>(this));
                // Keep track of the QObjectWrapper in persistent value storage
                ddata->jsWrapper.set(scope.engine, result);
            } else {
                result = ddata->jsWrapper.value();
            }
        }
    }
 
    return QJSValuePrivate::fromReturnedValue(result->asReturnedValue());
}
 
void QQmlListModel::set(int index, const QJSValue &value)
{
    QV4::Scope scope(engine());
    QV4::ScopedObject object(scope, QJSValuePrivate::asReturnedValue(&value));
 
    if (!object) {
        qmlWarning(this) << tr("set: value is not an object");
        return;
    }
    if (index > count() || index < 0) {
        qmlWarning(this) << tr("set: index %1 out of range").arg(index);
        return;
    }
 
 
    if (index == count()) {
        emitItemsAboutToBeInserted(index, 1);
 
        if (m_dynamicRoles) {
            m_modelObjects.append(DynamicRoleModelNode::create(scope.engine->variantMapFromJS(object), this));
        } else {
            m_listModel->insert(index, object);
        }
 
        emitItemsInserted();
    } else {
 
        QVector<int> roles;
 
        if (m_dynamicRoles) {
            m_modelObjects[index]->updateValues(scope.engine->variantMapFromJS(object), roles);
        } else {
            m_listModel->set(index, object, &roles);
        }
 
        if (roles.size())
            emitItemsChanged(index, 1, roles);
    }
}
 
void QQmlListModel::setProperty(int index, const QString& property, const QVariant& value)
{
    if (count() == 0 || index >= count() || index < 0) {
        qmlWarning(this) << tr("set: index %1 out of range").arg(index);
        return;
    }
 
    if (m_dynamicRoles) {
        int roleIndex = m_roles.indexOf(property);
        if (roleIndex == -1) {
            roleIndex = m_roles.size();
            m_roles.append(property);
        }
        if (m_modelObjects[index]->setValue(property.toUtf8(), value))
            emitItemsChanged(index, 1, QVector<int>(1, roleIndex));
    } else {
        int roleIndex = m_listModel->setOrCreateProperty(index, property, value);
        if (roleIndex != -1)
            emitItemsChanged(index, 1, QVector<int>(1, roleIndex));
    }
}
 
void QQmlListModel::sync()
{
    // This is just a dummy method to make it look like sync() exists in
    // ListModel (and not just QQmlListModelWorkerAgent) and to let
    // us document sync().
    qmlWarning(this) << "List sync() can only be called from a WorkerScript";
}
 
bool QQmlListModelParser::verifyProperty(const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding)
{
    if (binding->type() >= QV4::CompiledData::Binding::Type_Object) {
        const quint32 targetObjectIndex = binding->value.objectIndex;
        const QV4::CompiledData::Object *target = compilationUnit->objectAt(targetObjectIndex);
        QString objName = compilationUnit->stringAt(target->inheritedTypeNameIndex);
        if (objName != listElementTypeName) {
            const QMetaObject *mo = resolveType(objName);
            if (mo != &QQmlListElement::staticMetaObject) {
                error(target, QQmlListModel::tr("ListElement: cannot contain nested elements"));
                return false;
            }
            listElementTypeName = objName; // cache right name for next time
        }
 
        if (!compilationUnit->stringAt(target->idNameIndex).isEmpty()) {
            error(target->locationOfIdProperty, QQmlListModel::tr("ListElement: cannot use reserved \"id\" property"));
            return false;
        }
 
        const QV4::CompiledData::Binding *binding = target->bindingTable();
        for (quint32 i = 0; i < target->nBindings; ++i, ++binding) {
            QString propName = compilationUnit->stringAt(binding->propertyNameIndex);
            if (propName.isEmpty()) {
                error(binding, QQmlListModel::tr("ListElement: cannot contain nested elements"));
                return false;
            }
            if (!verifyProperty(compilationUnit, binding))
                return false;
        }
    } else if (binding->type() == QV4::CompiledData::Binding::Type_Script) {
        QString scriptStr = compilationUnit->bindingValueAsScriptString(binding);
        if (!binding->isFunctionExpression() && !definesEmptyList(scriptStr)) {
            bool ok;
            evaluateEnum(scriptStr, &ok);
            if (!ok) {
                error(binding, QQmlListModel::tr("ListElement: cannot use script for property value"));
                return false;
            }
        }
    }
 
    return true;
}
 
bool QQmlListModelParser::applyProperty(
        const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit,
        const QV4::CompiledData::Binding *binding, ListModel *model, int outterElementIndex)
{
    const QString elementName = compilationUnit->stringAt(binding->propertyNameIndex);
 
    bool roleSet = false;
    const QV4::CompiledData::Binding::Type bindingType = binding->type();
    if (bindingType >= QV4::CompiledData::Binding::Type_Object) {
        const quint32 targetObjectIndex = binding->value.objectIndex;
        const QV4::CompiledData::Object *target = compilationUnit->objectAt(targetObjectIndex);
 
        ListModel *subModel = nullptr;
        if (outterElementIndex == -1) {
            subModel = model;
        } else {
            const ListLayout::Role &role = model->getOrCreateListRole(elementName);
            if (role.type == ListLayout::Role::List) {
                subModel = model->getListProperty(outterElementIndex, role);
                if (subModel == nullptr) {
                    subModel = new ListModel(role.subLayout, nullptr);
                    QVariant vModel = QVariant::fromValue(subModel);
                    model->setOrCreateProperty(outterElementIndex, elementName, vModel);
                }
            }
        }
 
        int elementIndex = subModel ? subModel->appendElement() : -1;
 
        const QV4::CompiledData::Binding *subBinding = target->bindingTable();
        for (quint32 i = 0; i < target->nBindings; ++i, ++subBinding) {
            roleSet |= applyProperty(compilationUnit, subBinding, subModel, elementIndex);
        }
 
    } else {
        QVariant value;
 
        const bool isTranslationBinding = binding->isTranslationBinding();
        if (isTranslationBinding) {
            value = QVariant::fromValue<const QV4::CompiledData::Binding*>(binding);
        } else if (binding->evaluatesToString()) {
            value = compilationUnit->bindingValueAsString(binding);
        } else if (bindingType == QV4::CompiledData::Binding::Type_Number) {
            value = compilationUnit->bindingValueAsNumber(binding);
        } else if (bindingType == QV4::CompiledData::Binding::Type_Boolean) {
            value = binding->valueAsBoolean();
        } else if (bindingType == QV4::CompiledData::Binding::Type_Null) {
            value = QVariant::fromValue(nullptr);
        } else if (bindingType == QV4::CompiledData::Binding::Type_Script) {
            QString scriptStr = compilationUnit->bindingValueAsScriptString(binding);
            if (definesEmptyList(scriptStr)) {
                const ListLayout::Role &role = model->getOrCreateListRole(elementName);
                ListModel *emptyModel = new ListModel(role.subLayout, nullptr);
                value = QVariant::fromValue(emptyModel);
            } else if (binding->isFunctionExpression()) {
                QQmlBinding::Identifier id = binding->value.compiledScriptIndex;
                Q_ASSERT(id != QQmlBinding::Invalid);
 
                auto v4 = compilationUnit->engine;
                QV4::Scope scope(v4);
                // for now we do not provide a context object; data from the ListElement must be passed to the function
                QV4::ScopedContext context(scope, QV4::QmlContext::create(v4->rootContext(), QQmlContextData::get(qmlContext(model->m_modelCache)), nullptr));
                QV4::ScopedFunctionObject function(scope, QV4::FunctionObject::createScriptFunction(context, compilationUnit->runtimeFunctions[id]));
 
                QJSValue v;
                QV4::ScopedValue result(scope, function->call(v4->globalObject, nullptr, 0));
                if (v4->hasException)
                    v4->catchException();
                else
                    QJSValuePrivate::setValue(&v, result->asReturnedValue());
                value.setValue(v);
            } else {
                bool ok;
                value = evaluateEnum(scriptStr, &ok);
            }
        } else {
            Q_UNREACHABLE();
        }
 
        if (!model)
            return roleSet;
        model->setOrCreateProperty(outterElementIndex, elementName, value);
        auto listModel = model->m_modelCache;
        if (isTranslationBinding && listModel) {
            if (!listModel->translationChangeHandler) {
                auto ep = QQmlEnginePrivate::get(compilationUnit->engine);
                model->m_modelCache->translationChangeHandler = std::make_unique<QPropertyNotifier>(
                            ep->translationLanguage.addNotifier([listModel](){ listModel->updateTranslations(); }));
            }
        }
        roleSet = true;
    }
    return roleSet;
}
 
void QQmlListModelParser::verifyBindings(const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
{
    listElementTypeName = QString(); // unknown
 
    for (const QV4::CompiledData::Binding *binding : bindings) {
        QString propName = compilationUnit->stringAt(binding->propertyNameIndex);
        if (!propName.isEmpty()) { // isn't default property
            error(binding, QQmlListModel::tr("ListModel: undefined property '%1'").arg(propName));
            return;
        }
        if (!verifyProperty(compilationUnit, binding))
            return;
    }
}
 
void QQmlListModelParser::applyBindings(QObject *obj, const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
{
    QQmlListModel *rv = static_cast<QQmlListModel *>(obj);
 
    rv->m_engine = qmlEngine(rv)->handle();
    rv->m_compilationUnit = compilationUnit;
 
    bool setRoles = false;
 
    for (const QV4::CompiledData::Binding *binding : bindings) {
        if (binding->type() != QV4::CompiledData::Binding::Type_Object)
            continue;
        setRoles |= applyProperty(compilationUnit, binding, rv->m_listModel, /*outter element index*/-1);
    }
 
    if (setRoles == false)
        qmlWarning(obj) << "All ListElement declarations are empty, no roles can be created unless dynamicRoles is set.";
}
 
bool QQmlListModelParser::definesEmptyList(const QString &s)
{
    if (s.startsWith(QLatin1Char('[')) && s.endsWith(QLatin1Char(']'))) {
        for (int i=1; i<s.size()-1; i++) {
            if (!s[i].isSpace())
                return false;
        }
        return true;
    }
    return false;
}
 
 
QT_END_NAMESPACE
 
#include "moc_qqmllistmodel_p_p.cpp"
 
#include "moc_qqmllistmodel_p.cpp"