qtquickcontrols2plugin.cpp

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// Copyright (C) 2017 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 <QtCore/private/qfileselector_p.h>
#include <QtCore/qloggingcategory.h>
#include <QtQml/qqmlengine.h>
#include <QtQml/qqmlextensionplugin.h>
#include <QtQuickTemplates2/private/qquicktheme_p_p.h>
#include <QtQuickControls2/private/qquickstyle_p.h>
#include <QtQuickControls2/private/qquickstyleplugin_p.h>
#include <QtQuickControls2/qquickstyle.h>
#include <QtQuickControls2/qtquickcontrols2global.h>
 
QT_BEGIN_NAMESPACE
 
Q_GHS_KEEP_REFERENCE(qml_register_types_QtQuick_Controls);
 
Q_LOGGING_CATEGORY(lcQtQuickControls2Plugin, "qt.quick.controls.qtquickcontrols2plugin")
 
class QtQuickControls2Plugin : public QQmlExtensionPlugin
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID QQmlExtensionInterface_iid)
 
public:
    QtQuickControls2Plugin(QObject *parent = nullptr);
    ~QtQuickControls2Plugin();
 
    void registerTypes(const char *uri) override;
    void unregisterTypes() override;
 
private:
    // We store these because the style plugins can be unregistered before
    // QtQuickControls2Plugin, and since QQuickStylePlugin calls QQuickStylePrivate::reset(),
    // the style information can be lost when it comes time to call qmlUnregisterModuleImport().
    // It also avoids unnecessarily resolving the style after resetting it just to get the style
    // name in unregisterTypes().
    bool customStyle = false;
    QString registeredStyleUri;
    QString registeredFallbackStyleUri;
    QString rawFallbackStyleName;
};
 
static const char *qtQuickControlsUri = "QtQuick.Controls";
 
QString styleUri()
{
    const QString style = QQuickStyle::name();
    if (!QQuickStylePrivate::isCustomStyle()) {
        // The style set is a built-in style.
        const QString styleName = QQuickStylePrivate::effectiveStyleName(style);
        return QString::fromLatin1("QtQuick.Controls.%1").arg(styleName);
    }
 
    // This is a custom style, so just use the name as the import uri.
    QString styleName = style;
    if (styleName.startsWith(QLatin1String(":/")))
        styleName.remove(0, 2);
    return styleName;
}
 
QString fallbackStyleUri()
{
    // The fallback style must be a built-in style, so we don't need to check for custom styles here.
    const QString fallbackStyle = QQuickStylePrivate::fallbackStyle();
    const QString fallbackStyleName = QQuickStylePrivate::effectiveStyleName(fallbackStyle);
    return QString::fromLatin1("QtQuick.Controls.%1").arg(fallbackStyleName);
}
 
QtQuickControls2Plugin::QtQuickControls2Plugin(QObject *parent) : QQmlExtensionPlugin(parent)
{
    volatile auto registration = &qml_register_types_QtQuick_Controls;
    Q_UNUSED(registration);
}
 
QtQuickControls2Plugin::~QtQuickControls2Plugin()
{
    // Intentionally empty: we use register/unregisterTypes() to do
    // initialization and cleanup, as plugins are not unloaded on macOS.
}
 
void QtQuickControls2Plugin::registerTypes(const char *uri)
{
    qCDebug(lcQtQuickControls2Plugin) << "registerTypes() called with uri" << uri;
 
    // It's OK that the style is resolved more than once; some accessors like name() cause it to be called, for example.
    QQuickStylePrivate::init();
 
    // The fallback style that was set via env var/.conf/C++.
    rawFallbackStyleName = QQuickStylePrivate::fallbackStyle();
    // The style that was set via env var/.conf/C++, or Basic if none was set.
    const QString styleName = QQuickStylePrivate::effectiveStyleName(QQuickStyle::name());
    // The effective fallback style: rawFallbackStyleName, or Basic if empty.
    const QString fallbackStyleName = QQuickStylePrivate::effectiveStyleName(rawFallbackStyleName);
    qCDebug(lcQtQuickControls2Plugin) << "style:" << QQuickStyle::name() << "effective style:" << styleName
        << "fallback style:" << rawFallbackStyleName << "effective fallback style:" << fallbackStyleName;
 
    customStyle = QQuickStylePrivate::isCustomStyle();
    // The URI of the current style. For built-in styles, the style name is appended to "QtQuick.Controls.".
    // For custom styles that are embedded in resources, we need to remove the ":/" prefix.
    registeredStyleUri = ::styleUri();
 
    // If the style is Basic, we don't need to register the fallback because the Basic style
    // provides all controls. Also, if we didn't return early here, we can get an infinite import loop
    // when the style is set to Basic.
    if (styleName != fallbackStyleName && styleName != QLatin1String("Basic")) {
        // If no specific fallback is given, the fallback is of lower precedence than recursive
        // imports of the main style (i.e. IMPORTS in a style's CMakeLists.txt).
        // If a specific fallback is given, it is of higher precedence.
 
        QString parentModule;
        QString fallbackModule;
 
        // The fallback style has to be a built-in style, so it will become "QtQuick.Controls.<fallback>".
        registeredFallbackStyleUri = ::fallbackStyleUri();
 
        if (!rawFallbackStyleName.isEmpty()) {
            parentModule = qtQuickControlsUri;
            fallbackModule = registeredFallbackStyleUri;
        } else if (customStyle) {
            // Since we don't know the versioning scheme of custom styles, but we want the
            // version of QtQuick.Controls to be propagated, we need to do our own indirection.
            // QtQuick.Controls.IndirectBasic indirectly imports QtQuick.Controls.Basic
            Q_ASSERT(registeredFallbackStyleUri == QLatin1String("QtQuick.Controls.Basic"));
            parentModule = qtQuickControlsUri;
            fallbackModule = QLatin1String("QtQuick.Controls.IndirectBasic");
        } else {
            parentModule = registeredStyleUri;
            fallbackModule = registeredFallbackStyleUri;
        }
 
        qCDebug(lcQtQuickControls2Plugin)
                << "calling qmlRegisterModuleImport() to register fallback style with"
                << " uri \"" << parentModule << "\" moduleMajor" << QQmlModuleImportModuleAny
                << "import" << fallbackModule << "importMajor" << QQmlModuleImportAuto;
        // Whenever parentModule is imported, registeredFallbackStyleUri will be imported too.
        // The fallback style must be a built-in style, so we match the version number.
        qmlRegisterModuleImport(parentModule.toUtf8().constData(), QQmlModuleImportModuleAny,
                                fallbackModule.toUtf8().constData(),
                                QQmlModuleImportAuto, QQmlModuleImportAuto);
    }
 
    // If the user imports QtQuick.Controls 2.15, and they're using the Material style, we should import version 2.15.
    // However, if they import QtQuick.Controls 2.15, but are using a custom style, we want to use the latest version
    // number of their style.
    const int importMajor = customStyle ? QQmlModuleImportLatest : QQmlModuleImportAuto;
    qCDebug(lcQtQuickControls2Plugin).nospace()
            << "calling qmlRegisterModuleImport() to register primary style with"
            << " uri \"" << qtQuickControlsUri << "\" moduleMajor " << importMajor
            << " import " << registeredStyleUri << " importMajor " << importMajor;
    // When QtQuick.Controls is imported, the selected style will be imported too.
    qmlRegisterModuleImport(qtQuickControlsUri, QQmlModuleImportModuleAny,
                            registeredStyleUri.toUtf8().constData(), importMajor);
 
    if (customStyle)
        QFileSelectorPrivate::addStatics(QStringList() << styleName);
}
 
void QtQuickControls2Plugin::unregisterTypes()
{
    qCDebug(lcQtQuickControls2Plugin) << "unregisterTypes() called";
 
    const int importMajor = customStyle ? QQmlModuleImportLatest : QQmlModuleImportAuto;
    qCDebug(lcQtQuickControls2Plugin).nospace()
            << "calling qmlUnregisterModuleImport() to unregister primary style with"
            << " uri \"" << qtQuickControlsUri << "\" moduleMajor " << importMajor
            << " import " << registeredStyleUri << " importMajor " << importMajor;
    qmlUnregisterModuleImport(qtQuickControlsUri, QQmlModuleImportModuleAny,
                              registeredStyleUri.toUtf8().constData(), importMajor);
 
    if (!registeredFallbackStyleUri.isEmpty()) {
        QString parentModule;
        QString fallbackModule;
 
        if (!rawFallbackStyleName.isEmpty()) {
            parentModule = qtQuickControlsUri;
            fallbackModule = registeredFallbackStyleUri;
            rawFallbackStyleName.clear();
        } else if (customStyle) {
            parentModule = qtQuickControlsUri;
            fallbackModule = QLatin1String("QtQuick.Controls.IndirectBasic");
        } else {
            parentModule = registeredStyleUri;
            fallbackModule = registeredFallbackStyleUri;
        }
 
        qCDebug(lcQtQuickControls2Plugin)
                << "calling qmlUnregisterModuleImport() to unregister fallback style with"
                << " uri \"" << parentModule << "\" moduleMajor" << QQmlModuleImportModuleAny
                << "import" << fallbackModule << "importMajor" << QQmlModuleImportAuto;
        qmlUnregisterModuleImport(parentModule.toUtf8().constData(), QQmlModuleImportModuleAny,
                                  fallbackModule.toUtf8().constData(),
                                  QQmlModuleImportAuto, QQmlModuleImportAuto);
 
        registeredFallbackStyleUri.clear();
    }
 
    customStyle = false;
    registeredStyleUri.clear();
}
 
QT_END_NAMESPACE
 
#include "qtquickcontrols2plugin.moc"