qqmlcontext.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 "qqmlcontext_p.h"
#include "qqmlcomponentattached_p.h"
 
#include "qqmlcomponent_p.h"
#include "qqmlexpression_p.h"
#include "qqmlengine_p.h"
#include "qqmlengine.h"
#include "qqmlinfo.h"
#include "qqmlabstracturlinterceptor.h"
 
#include <qjsengine.h>
#include <QtCore/qvarlengtharray.h>
#include <private/qmetaobject_p.h>
#include <QtCore/qdebug.h>
 
QT_BEGIN_NAMESPACE
 
QQmlContext::QQmlContext(QQmlEngine *e, bool)
    : QObject(*(new QQmlContextPrivate(this, QQmlRefPointer<QQmlContextData>(), e)))
{
}
 
QQmlContext::QQmlContext(QQmlEngine *engine, QObject *parent)
    : QObject(*(new QQmlContextPrivate(this, engine
                                       ? QQmlContextData::get(engine->rootContext())
                                       : QQmlRefPointer<QQmlContextData>())), parent)
{
}
 
QQmlContext::QQmlContext(QQmlContext *parentContext, QObject *parent)
    : QObject(*(new QQmlContextPrivate(this, parentContext
                                       ? QQmlContextData::get(parentContext)
                                       : QQmlRefPointer<QQmlContextData>())), parent)
{
}
 
QQmlContext::QQmlContext(QQmlContextPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}
 
QQmlContext::~QQmlContext()
{
    Q_D(QQmlContext);
    d->m_data->clearPublicContext();
}
 
bool QQmlContext::isValid() const
{
    Q_D(const QQmlContext);
    return d->m_data->isValid();
}
 
QQmlEngine *QQmlContext::engine() const
{
    Q_D(const QQmlContext);
    return d->m_data->engine();
}
 
QQmlContext *QQmlContext::parentContext() const
{
    Q_D(const QQmlContext);
 
    if (QQmlRefPointer<QQmlContextData> parent = d->m_data->parent())
        return parent->asQQmlContext();
    return nullptr;
}
 
QObject *QQmlContext::contextObject() const
{
    Q_D(const QQmlContext);
    return d->m_data->contextObject();
}
 
void QQmlContext::setContextObject(QObject *object)
{
    Q_D(QQmlContext);
 
    QQmlRefPointer<QQmlContextData> data = d->m_data;
 
    if (data->isInternal()) {
        qWarning("QQmlContext: Cannot set context object for internal context.");
        return;
    }
 
    if (!data->isValid()) {
        qWarning("QQmlContext: Cannot set context object on invalid context.");
        return;
    }
 
    data->setContextObject(object);
    data->refreshExpressions();
}
 
void QQmlContext::setContextProperty(const QString &name, const QVariant &value)
{
    Q_D(QQmlContext);
    if (d->notifyIndex() == -1)
        d->setNotifyIndex(QMetaObjectPrivate::absoluteSignalCount(&QQmlContext::staticMetaObject));
 
    QQmlRefPointer<QQmlContextData> data = d->m_data;
 
    if (data->isInternal()) {
        qWarning("QQmlContext: Cannot set property on internal context.");
        return;
    }
 
    if (!data->isValid()) {
        qWarning("QQmlContext: Cannot set property on invalid context.");
        return;
    }
 
    if (bool isNumber = false; name.toUInt(&isNumber), isNumber) {
        qWarning("QQmlContext: Using numbers as context properties will be disallowed in a future Qt version.");
        QT7_ONLY(return;)
    }
 
    int idx = data->propertyIndex(name);
    if (idx == -1) {
        data->addPropertyNameAndIndex(name, data->numIdValues() + d->numPropertyValues());
        d->appendPropertyValue(value);
        data->refreshExpressions();
    } else {
        d->setPropertyValue(idx, value);
        QMetaObject::activate(this, d->notifyIndex(), idx, nullptr);
    }
 
    if (auto *obj = qvariant_cast<QObject *>(value)) {
        connect(obj, &QObject::destroyed, this, [d, name](QObject *destroyed) {
            d->dropDestroyedQObject(name, destroyed);
        });
    }
}
 
void QQmlContext::setContextProperty(const QString &name, QObject *value)
{
    setContextProperty(name, QVariant::fromValue(value));
}
 
void QQmlContext::setContextProperties(const QList<PropertyPair> &properties)
{
    Q_D(const QQmlContext);
 
    QQmlRefPointer<QQmlContextData> data = d->m_data;
    QQmlJavaScriptExpression *expressions = data->takeExpressions();
    QQmlRefPointer<QQmlContextData> childContexts = data->takeChildContexts();
 
    for (const auto &property : properties)
        setContextProperty(property.name, property.value);
 
    data->setExpressions(expressions);
    data->setChildContexts(childContexts);
    data->refreshExpressions();
}
 
static bool readObjectProperty(
        const QQmlRefPointer<QQmlContextData> &data, QObject *object, const QString &name,
        QVariant *target)
{
    QQmlPropertyData local;
    if (const QQmlPropertyData *property = QQmlPropertyCache::property(object, name, data, &local)) {
        *target = object->metaObject()->property(property->coreIndex()).read(object);
        return true;
    }
    return false;
}
 
QVariant QQmlContext::contextProperty(const QString &name) const
{
    Q_D(const QQmlContext);
 
    const QQmlRefPointer<QQmlContextData> data = d->m_data;
 
    const int idx = data->propertyIndex(name);
    if (idx == -1) {
        if (QObject *obj = data->contextObject()) {
            QVariant value;
            if (readObjectProperty(data, obj, name, &value))
                return value;
        }
 
        if (parentContext())
            return parentContext()->contextProperty(name);
    } else {
        if (idx >= d->numPropertyValues())
            return QVariant::fromValue(data->idValue(idx - d->numPropertyValues()));
        else
            return d->propertyValue(idx);
    }
 
    return QVariant();
}
 
QString QQmlContext::nameForObject(const QObject *object) const
{
    Q_D(const QQmlContext);
 
    return d->m_data->findObjectId(object);
}
 
QObject *QQmlContext::objectForName(const QString &name) const
{
    Q_D(const QQmlContext);
 
    QQmlRefPointer<QQmlContextData> data = d->m_data;
    if (const int propertyIndex = data->propertyIndex(name); propertyIndex >= 0) {
        const int numPropertyValues = d->numPropertyValues();
        if (propertyIndex < numPropertyValues)
            return qvariant_cast<QObject *>(d->propertyValue(propertyIndex));
        return data->idValue(propertyIndex - numPropertyValues);
    }
 
    if (QObject *obj = data->contextObject()) {
        QVariant result;
        if (readObjectProperty(data, obj, name, &result))
            return qvariant_cast<QObject *>(result);
    }
 
    return nullptr;
}
 
QUrl QQmlContext::resolvedUrl(const QUrl &src) const
{
    Q_D(const QQmlContext);
    return d->m_data->resolvedUrl(src);
}
 
void QQmlContext::setBaseUrl(const QUrl &baseUrl)
{
    Q_D(QQmlContext);
    d->m_data->setBaseUrl(baseUrl);
    d->m_data->setBaseUrlString(baseUrl.toString());
}
 
QUrl QQmlContext::baseUrl() const
{
    Q_D(const QQmlContext);
    return d->m_data->baseUrl();
}
 
QJSValue QQmlContext::importedScript(const QString &name) const
{
    Q_D(const QQmlContext);
 
    QQmlTypeNameCache::Result r = d->m_data->imports()->query(name, QQmlTypeLoader::get(engine()));
    QV4::Scope scope(engine()->handle());
    QV4::ScopedObject scripts(scope, d->m_data->importedScripts().valueRef());
    return scripts ? QJSValuePrivate::fromReturnedValue(scripts->get(r.scriptIndex))
                   : QJSValue(QJSValue::UndefinedValue);
}
 
qsizetype QQmlContextPrivate::context_count(QQmlListProperty<QObject> *prop)
{
    QQmlContext *context = static_cast<QQmlContext*>(prop->object);
    QQmlContextPrivate *d = QQmlContextPrivate::get(context);
    int contextProperty = (int)(quintptr)prop->data;
 
    if (d->propertyValue(contextProperty).userType() != qMetaTypeId<QList<QObject*> >())
        return 0;
    else
        return ((const QList<QObject> *)d->propertyValue(contextProperty).constData())->size();
}
 
QObject *QQmlContextPrivate::context_at(QQmlListProperty<QObject> *prop, qsizetype index)
{
    QQmlContext *context = static_cast<QQmlContext*>(prop->object);
    QQmlContextPrivate *d = QQmlContextPrivate::get(context);
    int contextProperty = (int)(quintptr)prop->data;
 
    if (d->propertyValue(contextProperty).userType() != qMetaTypeId<QList<QObject*> >())
        return nullptr;
    else
        return ((const QList<QObject*> *)d->propertyValue(contextProperty).constData())->at(index);
}
 
void QQmlContextPrivate::dropDestroyedQObject(const QString &name, QObject *destroyed)
{
    if (!m_data->isValid())
        return;
 
    const int idx = m_data->propertyIndex(name);
    Q_ASSERT(idx >= 0);
    if (qvariant_cast<QObject *>(propertyValue(idx)) != destroyed)
        return;
 
    setPropertyValue(idx, QVariant::fromValue<QObject *>(nullptr));
    QMetaObject::activate(q_func(), notifyIndex(), idx, nullptr);
}
 
void QQmlContextPrivate::emitDestruction()
{
    m_data->emitDestruction();
}
 
// m_data is owned by the public context. When the public context is reset to nullptr, it will be
// deref'd. It's OK to pass a half-created publicContext here. We will not dereference it during
// construction.
QQmlContextPrivate::QQmlContextPrivate(
        QQmlContext *publicContext, const QQmlRefPointer<QQmlContextData> &parent,
        QQmlEngine *engine) :
    m_data(new QQmlContextData(QQmlContextData::OwnedByPublicContext, publicContext,
                               parent, engine))
{
    Q_ASSERT(publicContext != nullptr);
}
 
QT_END_NAMESPACE
 
#include "moc_qqmlcontext.cpp"