From 9861a58400ba16d1f85537baf5d555613e0bdb1b Mon Sep 17 00:00:00 2001
From: Nikolai Kosjar <nikolai.kosjar@qt.io>
Date: Fri, 16 Dec 2016 15:30:08 +0100
Subject: [PATCH] CppTools: Prioritize project parts with
 selectedForBuilding=true

...when selecting one for the editor document.

This flag is only set by the QmakeProject.

Change-Id: I648886e12148bd1ebeccca52d9faaf4b528597c9
Reviewed-by: David Schulz <david.schulz@qt.io>
---
 .../cpptools/cppprojectpartchooser.cpp        | 31 ++++++++++++++-----
 .../unittest/cppprojectpartchooser-test.cpp   | 14 +++++++++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/src/plugins/cpptools/cppprojectpartchooser.cpp b/src/plugins/cpptools/cppprojectpartchooser.cpp
index 11e4ad01f25..19c40c5fe0f 100644
--- a/src/plugins/cpptools/cppprojectpartchooser.cpp
+++ b/src/plugins/cpptools/cppprojectpartchooser.cpp
@@ -31,12 +31,29 @@
 namespace CppTools {
 namespace Internal {
 
-static ProjectPart::Ptr selectFromActiveProject(const QList<ProjectPart::Ptr> &projectParts,
-                                                const ProjectExplorer::Project *activeProject)
+static int priority(const ProjectPart &projectPart, const ProjectExplorer::Project *activeProject)
 {
-    return Utils::findOr(projectParts, projectParts.first(), [&](const ProjectPart::Ptr &projectPart){
-        return projectPart->project == activeProject;
-    });
+    int thePriority = 0;
+
+    if (projectPart.project == activeProject)
+        thePriority += 10;
+
+    if (projectPart.selectedForBuilding)
+        thePriority += 1;
+
+    return thePriority;
+}
+
+static ProjectPart::Ptr chooseFromMultiple(const QList<ProjectPart::Ptr> &projectParts,
+                                           const ProjectExplorer::Project *activeProject)
+{
+    QList<ProjectPart::Ptr> projectPartsPrioritized = projectParts;
+    const auto lessThan = [activeProject] (const ProjectPart::Ptr &p1, const ProjectPart::Ptr &p2) {
+        return priority(*p1, activeProject) > priority(*p2, activeProject);
+    };
+    std::stable_sort(projectPartsPrioritized.begin(), projectPartsPrioritized.end(), lessThan);
+
+    return projectPartsPrioritized.first();
 }
 
 ProjectPart::Ptr ProjectPartChooser::choose(const QString &filePath,
@@ -68,10 +85,10 @@ ProjectPart::Ptr ProjectPartChooser::choose(const QString &filePath,
             // Fall-back step 2: Use fall-back part from the model manager:
             projectPart = m_fallbackProjectPart();
         else
-            projectPart = selectFromActiveProject(projectParts, activeProject);
+            projectPart = chooseFromMultiple(projectParts, activeProject);
     } else {
         if (projectHasChanged || !projectParts.contains(projectPart))
-            projectPart = selectFromActiveProject(projectParts, activeProject);
+            projectPart = chooseFromMultiple(projectParts, activeProject);
     }
 
     return projectPart;
diff --git a/tests/unit/unittest/cppprojectpartchooser-test.cpp b/tests/unit/unittest/cppprojectpartchooser-test.cpp
index fd1456a038d..a8b47d6a85a 100644
--- a/tests/unit/unittest/cppprojectpartchooser-test.cpp
+++ b/tests/unit/unittest/cppprojectpartchooser-test.cpp
@@ -89,6 +89,20 @@ TEST_F(ProjectPartChooser, ForMultipleChooseFromActiveProject)
     ASSERT_THAT(chosen, Eq(secondProjectPart));
 }
 
+TEST_F(ProjectPartChooser, ForMultiplePreferSelectedForBuilding)
+{
+    const ProjectPart::Ptr firstProjectPart{new ProjectPart};
+    const ProjectPart::Ptr secondProjectPart{new ProjectPart};
+    firstProjectPart->selectedForBuilding = false;
+    secondProjectPart->selectedForBuilding = true;
+    projectPartsForFile += firstProjectPart;
+    projectPartsForFile += secondProjectPart;
+
+    const ProjectPart::Ptr chosen = choose();
+
+    ASSERT_THAT(chosen, Eq(secondProjectPart));
+}
+
 TEST_F(ProjectPartChooser, ForMultipleFromDependenciesChooseFromActiveProject)
 {
     const QList<ProjectPart::Ptr> projectParts = createProjectPartsWithDifferentProjects();