qquickview.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 "qquickview.h"
#include "qquickview_p.h"
 
#include "qquickwindow_p.h"
#include "qquickitem_p.h"
#include "qquickitemchangelistener_p.h"
 
#include <QtQml/qqmlengine.h>
#include <private/qqmlengine_p.h>
#include <private/qv4qobjectwrapper_p.h>
#include <QtCore/qbasictimer.h>
 
#include <memory>
 
QT_BEGIN_NAMESPACE
 
void QQuickViewPrivate::init(QQmlEngine* e)
{
    Q_Q(QQuickView);
 
    engine = e;
 
    if (engine.isNull())
        engine = new QQmlEngine(q);
 
    QQmlEngine::setContextForObject(contentItem, engine.data()->rootContext());
 
    if (!engine.data()->incubationController())
        engine.data()->setIncubationController(q->incubationController());
 
    {
        // The content item has CppOwnership policy (set in QQuickWindow). Ensure the presence of a JS
        // wrapper so that the garbage collector can see the policy.
        QV4::ExecutionEngine *v4 = engine.data()->handle();
        QV4::QObjectWrapper::ensureWrapper(v4, contentItem);
    }
}
 
QQuickViewPrivate::QQuickViewPrivate()
    : component(nullptr), resizeMode(QQuickView::SizeViewToRootObject), initialSize(0,0)
{
}
 
QQuickViewPrivate::~QQuickViewPrivate()
{
}
 
QQuickViewPrivate::ExecuteState QQuickViewPrivate::executeHelper()
{
    if (!engine) {
        qWarning() << "QQuickView: invalid qml engine.";
        return Stop;
    }
 
    if (root)
        delete root;
    if (component) {
        delete component;
        component = nullptr;
    }
    return ExecuteState::Continue;
}
 
void QQuickViewPrivate::execute()
{
    if (executeHelper() == Stop)
        return;
    Q_Q(QQuickView);
    if (!source.isEmpty()) {
        component = new QQmlComponent(engine.data(), source, q);
        if (!component->isLoading()) {
            q->continueExecute();
        } else {
            QObject::connect(component, SIGNAL(statusChanged(QQmlComponent::Status)),
                             q, SLOT(continueExecute()));
        }
    }
}
 
void QQuickViewPrivate::execute(QAnyStringView uri, QAnyStringView typeName)
{
    if (executeHelper() == Stop)
        return;
    Q_Q(QQuickView);
 
    component = new QQmlComponent(engine.data(), uri, typeName, q);
    if (!component->isLoading()) {
        q->continueExecute();
    } else {
        QObject::connect(component, SIGNAL(statusChanged(QQmlComponent::Status)),
                         q, SLOT(continueExecute()));
    }
 
}
 
void QQuickViewPrivate::itemGeometryChanged(QQuickItem *resizeItem, QQuickGeometryChange change,
                                            const QRectF &oldGeometry)
{
    Q_Q(QQuickView);
    if (resizeItem == root && resizeMode == QQuickView::SizeViewToRootObject) {
        // wait for both width and height to be changed
        resizetimer.start(0,q);
    }
    QQuickItemChangeListener::itemGeometryChanged(resizeItem, change, oldGeometry);
}
 
QQuickView::QQuickView(QWindow *parent)
: QQuickWindow(*(new QQuickViewPrivate), parent)
{
    d_func()->init();
}
 
QQuickView::QQuickView(const QUrl &source, QWindow *parent)
    : QQuickView(parent)
{
    setSource(source);
}
 
QQuickView::QQuickView(QAnyStringView uri, QAnyStringView typeName, QWindow *parent)
    : QQuickView(parent)
{
    loadFromModule(uri, typeName);
}
 
QQuickView::QQuickView(QQmlEngine* engine, QWindow *parent)
    : QQuickWindow(*(new QQuickViewPrivate), parent)
{
    Q_ASSERT(engine);
    d_func()->init(engine);
}
 
QQuickView::QQuickView(const QUrl &source, QQuickRenderControl *control)
    : QQuickWindow(*(new QQuickViewPrivate), control)
{
    d_func()->init();
    setSource(source);
}
 
QQuickView::~QQuickView()
{
    // Ensure that the component is destroyed before the engine; the engine may
    // be a child of the QQuickViewPrivate, and will be destroyed by its dtor
    Q_D(QQuickView);
    delete d->root;
}
 
void QQuickView::setSource(const QUrl& url)
{
    Q_D(QQuickView);
    d->source = url;
    d->execute();
}
 
void QQuickView::loadFromModule(QAnyStringView uri, QAnyStringView typeName)
{
    Q_D(QQuickView);
    d->source = {}; // clear URL
    d->execute(uri, typeName);
}
 
void QQuickView::setInitialProperties(const QVariantMap &initialProperties)
{
    Q_D(QQuickView);
    d->initialProperties = initialProperties;
}
 
void QQuickView::setContent(const QUrl& url, QQmlComponent *component, QObject* item)
{
    Q_D(QQuickView);
    d->source = url;
    d->component = component;
 
    if (d->component && d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    if (!d->setRootObject(item))
        delete item;
    emit statusChanged(status());
}
 
QUrl QQuickView::source() const
{
    Q_D(const QQuickView);
    return d->source;
}
 
QQmlEngine* QQuickView::engine() const
{
    Q_D(const QQuickView);
    return d->engine ? const_cast<QQmlEngine *>(d->engine.data()) : nullptr;
}
 
QQmlContext* QQuickView::rootContext() const
{
    Q_D(const QQuickView);
    return d->engine ? d->engine.data()->rootContext() : nullptr;
}
 
QQuickView::Status QQuickView::status() const
{
    Q_D(const QQuickView);
    if (!d->engine)
        return QQuickView::Error;
 
    if (!d->component)
        return QQuickView::Null;
 
    if (d->component->status() == QQmlComponent::Ready && !d->root)
        return QQuickView::Error;
 
    return QQuickView::Status(d->component->status());
}
 
QList<QQmlError> QQuickView::errors() const
{
    Q_D(const QQuickView);
    QList<QQmlError> errs;
 
    if (d->component)
        errs = d->component->errors();
 
    if (!d->engine) {
        QQmlError error;
        error.setDescription(QLatin1String("QQuickView: invalid qml engine."));
        errs << error;
    } else if (d->component && d->component->status() == QQmlComponent::Ready && !d->root) {
        QQmlError error;
        error.setDescription(QLatin1String("QQuickView: invalid root object."));
        errs << error;
    }
 
    return errs;
}
 
void QQuickView::setResizeMode(ResizeMode mode)
{
    Q_D(QQuickView);
    if (d->resizeMode == mode)
        return;
 
    if (d->root) {
        if (d->resizeMode == SizeViewToRootObject) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(d->root);
            p->removeItemChangeListener(d, QQuickItemPrivate::Geometry);
        }
    }
 
    d->resizeMode = mode;
    if (d->root) {
        d->initResize();
    }
}
 
void QQuickViewPrivate::initResize()
{
    if (root) {
        if (resizeMode == QQuickView::SizeViewToRootObject) {
            QQuickItemPrivate *p = QQuickItemPrivate::get(root);
            p->addItemChangeListener(this, QQuickItemPrivate::Geometry);
        }
    }
    updateSize();
}
 
void QQuickViewPrivate::updateSize()
{
    Q_Q(QQuickView);
    if (!root)
        return;
 
    if (resizeMode == QQuickView::SizeViewToRootObject) {
        QSize newSize = QSize(root->width(), root->height());
        if (newSize.isValid() && newSize != q->size()) {
            q->resize(newSize);
        }
    } else if (resizeMode == QQuickView::SizeRootObjectToView) {
        bool needToUpdateWidth = !qFuzzyCompare(q->width(), root->width());
        bool needToUpdateHeight = !qFuzzyCompare(q->height(), root->height());
 
        if (needToUpdateWidth && needToUpdateHeight)
            root->setSize(QSizeF(q->width(), q->height()));
        else if (needToUpdateWidth)
            root->setWidth(q->width());
        else if (needToUpdateHeight)
            root->setHeight(q->height());
    }
}
 
QSize QQuickViewPrivate::rootObjectSize() const
{
    QSize rootObjectSize(0,0);
    int widthCandidate = -1;
    int heightCandidate = -1;
    if (root) {
        widthCandidate = root->width();
        heightCandidate = root->height();
    }
    if (widthCandidate > 0) {
        rootObjectSize.setWidth(widthCandidate);
    }
    if (heightCandidate > 0) {
        rootObjectSize.setHeight(heightCandidate);
    }
    return rootObjectSize;
}
 
QQuickView::ResizeMode QQuickView::resizeMode() const
{
    Q_D(const QQuickView);
    return d->resizeMode;
}
 
void QQuickView::continueExecute()
{
    Q_D(QQuickView);
    disconnect(d->component, SIGNAL(statusChanged(QQmlComponent::Status)), this, SLOT(continueExecute()));
 
    if (d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    std::unique_ptr<QObject> obj(d->initialProperties.empty()
                                 ? d->component->create()
                                 : d->component->createWithInitialProperties(d->initialProperties));
 
    if (d->component->isError()) {
        const QList<QQmlError> errorList = d->component->errors();
        for (const QQmlError &error : errorList) {
            QMessageLogger(error.url().toString().toLatin1().constData(), error.line(), nullptr).warning()
                    << error;
        }
        emit statusChanged(status());
        return;
    }
 
    // If we used loadFromModule, we might not have a URL so far.
    // Thus, query the component to retrieve the associated URL, if any
    if (d->source.isEmpty())
        d->source = d->component->url();
 
    if (d->setRootObject(obj.get()))
        Q_UNUSED(obj.release());
    emit statusChanged(status());
}
 
 
bool QQuickViewPrivate::setRootObject(QObject *obj)
{
    Q_Q(QQuickView);
    if (root == obj)
        return true;
 
    delete root;
    if (obj == nullptr)
        return true;
 
    if (QQuickItem *sgItem = qobject_cast<QQuickItem *>(obj)) {
        root = sgItem;
        root->setFlag(QQuickItem::ItemIsViewport);
        sgItem->setParentItem(q->QQuickWindow::contentItem());
        QQml_setParent_noEvent(sgItem, q->QQuickWindow::contentItem());
        initialSize = rootObjectSize();
        if ((resizeMode == QQuickView::SizeViewToRootObject || q->width() <= 1 || q->height() <= 1) &&
            initialSize != q->size()) {
            q->resize(initialSize);
        }
        initResize();
        return true;
    }
 
    if (qobject_cast<QWindow *>(obj)) {
        qWarning() << "QQuickView does not support using a window as a root item." << Qt::endl
                   << Qt::endl
                   << "If you wish to create your root window from QML, consider using QQmlApplicationEngine instead." << Qt::endl;
        return false;
    }
 
    qWarning() << "QQuickView only supports loading of root objects that derive from QQuickItem." << Qt::endl
               << Qt::endl
               << "Ensure your QML code is written for QtQuick 2, and uses a root that is or" << Qt::endl
               << "inherits from QtQuick's Item (not a Timer, QtObject, etc)." << Qt::endl;
    return false;
}
 
void QQuickView::timerEvent(QTimerEvent* e)
{
    Q_D(QQuickView);
    if (!e || e->timerId() == d->resizetimer.timerId()) {
        d->updateSize();
        d->resizetimer.stop();
    }
}
 
QSize QQuickView::sizeHint() const
{
    Q_D(const QQuickView);
    QSize rootObjectSize = d->rootObjectSize();
    if (rootObjectSize.isEmpty()) {
        return size();
    } else {
        return rootObjectSize;
    }
}
 
QSize QQuickView::initialSize() const
{
    Q_D(const QQuickView);
    return d->initialSize;
}
 
QQuickItem *QQuickView::rootObject() const
{
    Q_D(const QQuickView);
    return d->root;
}
 
void QQuickView::resizeEvent(QResizeEvent *e)
{
    Q_D(QQuickView);
    if (d->resizeMode == SizeRootObjectToView)
        d->updateSize();
 
    QQuickWindow::resizeEvent(e);
}
 
void QQuickView::keyPressEvent(QKeyEvent *e)
{
    QQuickWindow::keyPressEvent(e);
}
 
void QQuickView::keyReleaseEvent(QKeyEvent *e)
{
    QQuickWindow::keyReleaseEvent(e);
}
 
void QQuickView::mouseMoveEvent(QMouseEvent *e)
{
    QQuickWindow::mouseMoveEvent(e);
}
 
void QQuickView::mousePressEvent(QMouseEvent *e)
{
    QQuickWindow::mousePressEvent(e);
}
 
void QQuickView::mouseReleaseEvent(QMouseEvent *e)
{
    QQuickWindow::mouseReleaseEvent(e);
}
 
 
QT_END_NAMESPACE
 
#include "moc_qquickview.cpp"