CppTools: Extract ProjectPartChooser

...and put it under tests.

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

src/plugins/cpptools/cppprojectpartchooser.cpp

@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** 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.
+**
+****************************************************************************/
+
+#include "cppprojectpartchooser.h"
+
+#include <utils/qtcassert.h>
+
+namespace CppTools {
+namespace Internal {
+
+ProjectPart::Ptr ProjectPartChooser::choose(const QString &filePath,
+                                            const ProjectPart::Ptr &currentProjectPart,
+                                            const ProjectPart::Ptr &manuallySetProjectPart,
+                                            bool stickToPreviousProjectPart) const
+{
+    QTC_CHECK(m_projectPartsForFile);
+    QTC_CHECK(m_projectPartsFromDependenciesForFile);
+    QTC_CHECK(m_fallbackProjectPart);
+
+    if (manuallySetProjectPart)
+        return manuallySetProjectPart;
+
+    ProjectPart::Ptr projectPart = currentProjectPart;
+
+    QList<ProjectPart::Ptr> projectParts = m_projectPartsForFile(filePath);
+    if (projectParts.isEmpty()) {
+        if (projectPart && stickToPreviousProjectPart)
+            // File is not directly part of any project, but we got one before. We will re-use it,
+            // because re-calculating this can be expensive when the dependency table is big.
+            return projectPart;
+
+        // Fall-back step 1: Get some parts through the dependency table:
+        projectParts = m_projectPartsFromDependenciesForFile(filePath);
+        if (projectParts.isEmpty())
+            // Fall-back step 2: Use fall-back part from the model manager:
+            projectPart = m_fallbackProjectPart();
+        else
+            projectPart = projectParts.first();
+    } else {
+        if (!projectParts.contains(projectPart))
+            // Apparently the project file changed, so update our project part.
+            projectPart = projectParts.first();
+    }
+
+    return projectPart;
+}
+
+void ProjectPartChooser::setFallbackProjectPart(const FallBackProjectPart &getter)
+{
+    m_fallbackProjectPart = getter;
+}
+
+void ProjectPartChooser::setProjectPartsForFile(const ProjectPartsForFile &getter)
+{
+    m_projectPartsForFile = getter;
+}
+
+void ProjectPartChooser::setProjectPartsFromDependenciesForFile(
+        const ProjectPartsFromDependenciesForFile &getter)
+{
+    m_projectPartsFromDependenciesForFile = getter;
+}
+
+} // namespace Internal
+} // namespace CppTools