CppTools: Extract ProjectPartChooser

...and put it under tests.

Change-Id: Id4bd2391abd1dfdc23640e871453558566cb0693
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/cppprojectpartchooser.h

@@ -0,0 +1,60 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 "projectpart.h"
+
+#include <functional>
+
+namespace CppTools {
+namespace Internal {
+
+class ProjectPartChooser
+{
+public:
+    using FallBackProjectPart = std::function<ProjectPart::Ptr()>;
+    using ProjectPartsForFile = std::function<QList<ProjectPart::Ptr>(const QString &filePath)>;
+    using ProjectPartsFromDependenciesForFile
+        = std::function<QList<ProjectPart::Ptr>(const QString &filePath)>;
+
+public:
+    void setFallbackProjectPart(const FallBackProjectPart &getter);
+    void setProjectPartsForFile(const ProjectPartsForFile &getter);
+    void setProjectPartsFromDependenciesForFile(const ProjectPartsFromDependenciesForFile &getter);
+
+    ProjectPart::Ptr choose(const QString &filePath,
+                            const ProjectPart::Ptr &currentProjectPart,
+                            const ProjectPart::Ptr &manuallySetProjectPart,
+                            bool stickToPreviousProjectPart) const;
+
+private:
+    FallBackProjectPart m_fallbackProjectPart;
+    ProjectPartsForFile m_projectPartsForFile;
+    ProjectPartsFromDependenciesForFile m_projectPartsFromDependenciesForFile;
+};
+
+} // namespace Internal
+} // namespace CppTools