qml: introduce QmlMultiLanguageAspect

This aspect is only available if the special multilanguage
plugin is available.
Translation changes in that plugin changes this aspect,
which results in environment variables which activate the use
of a multilanguage created sqlite to provide the translations.

Change-Id: I38250b69165eb7ec3e4f82dc34b3cc4ba0a33f8f
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmlprojectmanager/qmlmultilanguageaspect.h

@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include "qmlprojectmanager_global.h"
+
+#include <qmlprojectmanager/qmlprojectmanagerconstants.h>
+
+#include <projectexplorer/runconfigurationaspects.h>
+
+namespace QmlProjectManager {
+
+class QMLPROJECTMANAGER_EXPORT QmlMultiLanguageAspect : public ProjectExplorer::BaseBoolAspect
+{
+    Q_OBJECT
+public:
+    explicit QmlMultiLanguageAspect(ProjectExplorer::Target *target);
+    ~QmlMultiLanguageAspect() override;
+
+    QString lastUsedLanguage() const;
+    Utils::FilePath databaseFilePath() const;
+    void toMap(QVariantMap &map) const final;
+    void fromMap(const QVariantMap &map) final;
+
+public slots:
+    void setLastUsedLanguage(const QString &language);
+
+private:
+    ProjectExplorer::Target *m_target = nullptr;
+    mutable Utils::FilePath m_databaseFilePath;
+    QString m_lastUsedLanguage;
+};
+
+} // namespace QmlProjectManager