ProjectExplorer: Delay-create TaskHub

Effectively only by a few lines.

Change-Id: Ieb548d0a2f5ced033881106c76adc9a5e3e16663
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

9 files changed, 42 insertions, 51 deletions

diff --git a/src/plugins/cppeditor/cppprojectinfogenerator.cpp b/src/plugins/cppeditor/cppprojectinfogenerator.cpp
index 54713999cc..b92393f0e2 100644
--- a/src/plugins/cppeditor/cppprojectinfogenerator.cpp
+++ b/src/plugins/cppeditor/cppprojectinfogenerator.cpp
@@ -37,7 +37,7 @@ ProjectInfo::ConstPtr ProjectInfoGenerator::generate(const QPromise<ProjectInfo:
     const auto projectInfo = ProjectInfo::create(m_projectUpdateInfo, projectParts);
 
     static const auto showWarning = [](const QString &message) {
-        QTimer::singleShot(0, TaskHub::instance(), [message] {
+        QTimer::singleShot(0, &taskHub(), [message] {
             TaskHub::addTask(BuildSystemTask(Task::Warning, message));
         });
     };
diff --git a/src/plugins/projectexplorer/outputparser_test.cpp b/src/plugins/projectexplorer/outputparser_test.cpp
index 0b466c74fd..6e5f1bc45f 100644
--- a/src/plugins/projectexplorer/outputparser_test.cpp
+++ b/src/plugins/projectexplorer/outputparser_test.cpp
@@ -46,14 +46,14 @@ static inline QByteArray msgFileComparisonFail(const Utils::FilePath &f1, const
 // test functions:
 OutputParserTester::OutputParserTester()
 {
-    connect(TaskHub::instance(), &TaskHub::taskAdded, this, [this](const Task &t) {
+    connect(&taskHub(), &TaskHub::taskAdded, this, [this](const Task &t) {
         m_receivedTasks.append(t);
     });
 }
 
 OutputParserTester::~OutputParserTester()
 {
-    TaskHub::instance()->disconnect(this);
+    taskHub().disconnect(this);
 }
 
 void OutputParserTester::testParsing(const QString &lines,
diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index 3b17379e1f..3d77ad8c89 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -660,8 +660,6 @@ public:
 
     ToolChainOptionsPage m_toolChainOptionsPage;
 
-    TaskHub m_taskHub;
-
     ProjectWelcomePage m_welcomePage;
 
     CustomWizardMetaFactory<CustomProjectWizard> m_customProjectWizard{IWizardFactory::ProjectWizard};
diff --git a/src/plugins/projectexplorer/taskhub.cpp b/src/plugins/projectexplorer/taskhub.cpp
index e7ec30d477..09b7d49e7b 100644
--- a/src/plugins/projectexplorer/taskhub.cpp
+++ b/src/plugins/projectexplorer/taskhub.cpp
@@ -13,8 +13,6 @@
 #include <utils/threadutils.h>
 #include <utils/utilsicons.h>
 
-#include <QApplication>
-
 using namespace Utils;
 
 namespace ProjectExplorer {
@@ -23,8 +21,7 @@ namespace ProjectExplorer {
 const char TASK_MARK_WARNING[] = "Task.Mark.Warning";
 const char TASK_MARK_ERROR[] = "Task.Mark.Error";
 
-static TaskHub *m_instance = nullptr;
-QVector<Utils::Id> TaskHub::m_registeredCategories;
+static QVector<Id> s_registeredCategories;
 
 static TextEditor::TextMarkCategory categoryForType(Task::TaskType type)
 {
@@ -45,8 +42,8 @@ public:
         TextMark(task.file, task.line, categoryForType(task.type)),
         m_task(task)
     {
-        setColor(task.type == Task::Error ? Utils::Theme::ProjectExplorer_TaskError_TextMarkColor
-                                          : Utils::Theme::ProjectExplorer_TaskWarn_TextMarkColor);
+        setColor(task.type == Task::Error ? Theme::ProjectExplorer_TaskError_TextMarkColor
+                                          : Theme::ProjectExplorer_TaskWarn_TextMarkColor);
         setDefaultToolTip(task.type == Task::Error ? Tr::tr("Error")
                                                    : Tr::tr("Warning"));
         setPriority(task.type == Task::Error ? TextEditor::TextMark::NormalPriority
@@ -97,30 +94,21 @@ void TaskMark::clicked()
 
 TaskHub::TaskHub()
 {
-    m_instance = this;
     qRegisterMetaType<ProjectExplorer::Task>("ProjectExplorer::Task");
     qRegisterMetaType<Tasks >("Tasks");
 }
 
-TaskHub::~TaskHub()
-{
-    m_instance = nullptr;
-}
+TaskHub::~TaskHub() = default;
 
 void TaskHub::addCategory(const TaskCategory &category)
 {
     QTC_CHECK(!category.displayName.isEmpty());
-    QTC_ASSERT(!m_registeredCategories.contains(category.id), return);
-    m_registeredCategories.push_back(category.id);
-    emit m_instance->categoryAdded(category);
+    QTC_ASSERT(!s_registeredCategories.contains(category.id), return);
+    s_registeredCategories.push_back(category.id);
+    emit taskHub().categoryAdded(category);
 }
 
-TaskHub *TaskHub::instance()
-{
-    return m_instance;
-}
-
-void TaskHub::addTask(Task::TaskType type, const QString &description, Utils::Id category)
+void TaskHub::addTask(Task::TaskType type, const QString &description, Id category)
 {
     addTask(Task(type, description, {}, -1, category));
 }
@@ -135,7 +123,7 @@ void TaskHub::addTask(Task task)
         return;
     }
 
-    QTC_ASSERT(m_registeredCategories.contains(task.category), return);
+    QTC_ASSERT(s_registeredCategories.contains(task.category), return);
     QTC_ASSERT(!task.description().isEmpty(), return);
     QTC_ASSERT(!task.isNull(), return);
     QTC_ASSERT(task.m_mark.isNull(), return);
@@ -146,49 +134,55 @@ void TaskHub::addTask(Task task)
 
     if ((task.options & Task::AddTextMark) && task.line != -1 && task.type != Task::Unknown)
         task.setMark(new TaskMark(task));
-    emit m_instance->taskAdded(task);
+    emit taskHub().taskAdded(task);
 }
 
-void TaskHub::clearTasks(Utils::Id categoryId)
+void TaskHub::clearTasks(Id categoryId)
 {
-    QTC_ASSERT(!categoryId.isValid() || m_registeredCategories.contains(categoryId), return);
-    emit m_instance->tasksCleared(categoryId);
+    QTC_ASSERT(!categoryId.isValid() || s_registeredCategories.contains(categoryId), return);
+    emit taskHub().tasksCleared(categoryId);
 }
 
 void TaskHub::removeTask(const Task &task)
 {
-    emit m_instance->taskRemoved(task);
+    emit taskHub().taskRemoved(task);
 }
 
 void TaskHub::updateTaskFileName(const Task &task, const QString &fileName)
 {
-    emit m_instance->taskFileNameUpdated(task, fileName);
+    emit taskHub().taskFileNameUpdated(task, fileName);
 }
 
 void TaskHub::updateTaskLineNumber(const Task &task, int line)
 {
-    emit m_instance->taskLineNumberUpdated(task, line);
+    emit taskHub().taskLineNumberUpdated(task, line);
 }
 
 void TaskHub::taskMarkClicked(const Task &task)
 {
-    emit m_instance->showTask(task);
+    emit taskHub().showTask(task);
 }
 
 void TaskHub::showTaskInEditor(const Task &task)
 {
-    emit m_instance->openTask(task);
+    emit taskHub().openTask(task);
 }
 
-void TaskHub::setCategoryVisibility(Utils::Id categoryId, bool visible)
+void TaskHub::setCategoryVisibility(Id categoryId, bool visible)
 {
-    QTC_ASSERT(m_registeredCategories.contains(categoryId), return);
-    emit m_instance->categoryVisibilityChanged(categoryId, visible);
+    QTC_ASSERT(s_registeredCategories.contains(categoryId), return);
+    emit taskHub().categoryVisibilityChanged(categoryId, visible);
 }
 
 void TaskHub::requestPopup()
 {
-    emit m_instance->popupRequested(Core::IOutputPane::NoModeSwitch);
+    emit taskHub().popupRequested(Core::IOutputPane::NoModeSwitch);
+}
+
+TaskHub &taskHub()
+{
+    static TaskHub theTaskHub;
+    return theTaskHub;
 }
 
 } // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/taskhub.h b/src/plugins/projectexplorer/taskhub.h
index 0afc8d51f4..439ddcd79e 100644
--- a/src/plugins/projectexplorer/taskhub.h
+++ b/src/plugins/projectexplorer/taskhub.h
@@ -22,12 +22,11 @@ public:
     int priority = 0;
 };
 
-class PROJECTEXPLORER_EXPORT TaskHub : public QObject
+class PROJECTEXPLORER_EXPORT TaskHub final : public QObject
 {
     Q_OBJECT
-public:
-    static TaskHub *instance();
 
+public:
     // Convenience overload
     static void addTask(Task::TaskType type, const QString &description,
                         Utils::Id category);
@@ -60,12 +59,12 @@ signals:
     void openTask(const Task &task);
 
 private:
-    TaskHub();
-    ~TaskHub() override;
+    friend TaskHub &taskHub();
 
-    static QVector<Utils::Id> m_registeredCategories;
-
-    friend class ProjectExplorerPluginPrivate;
+    TaskHub();
+    ~TaskHub() final;
 };
 
+PROJECTEXPLORER_EXPORT TaskHub &taskHub();
+
 } // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/taskwindow.cpp b/src/plugins/projectexplorer/taskwindow.cpp
index fe5fb350c2..9567982502 100644
--- a/src/plugins/projectexplorer/taskwindow.cpp
+++ b/src/plugins/projectexplorer/taskwindow.cpp
@@ -233,7 +233,7 @@ TaskWindow::TaskWindow() : d(std::make_unique<TaskWindowPrivate>())
     setupFilterUi("IssuesPane.Filter");
     setFilteringEnabled(true);
 
-    TaskHub *hub = TaskHub::instance();
+    TaskHub *hub = &taskHub();
     connect(hub, &TaskHub::categoryAdded, this, &TaskWindow::addCategory);
     connect(hub, &TaskHub::taskAdded, this, &TaskWindow::addTask);
     connect(hub, &TaskHub::taskRemoved, this, &TaskWindow::removeTask);
diff --git a/src/plugins/qmldesigner/assetexporterplugin/assetexportdialog.cpp b/src/plugins/qmldesigner/assetexporterplugin/assetexportdialog.cpp
index 3f60925d1e..a4509c38a6 100644
--- a/src/plugins/qmldesigner/assetexporterplugin/assetexportdialog.cpp
+++ b/src/plugins/qmldesigner/assetexporterplugin/assetexportdialog.cpp
@@ -135,7 +135,7 @@ AssetExportDialog::AssetExportDialog(const FilePath &exportPath,
     connect(&m_assetExporter, &AssetExporter::exportProgressChanged,
             this, &AssetExportDialog::updateExportProgress);
 
-    connect(TaskHub::instance(), &TaskHub::taskAdded, this, &AssetExportDialog::onTaskAdded);
+    connect(&taskHub(), &TaskHub::taskAdded, this, &AssetExportDialog::onTaskAdded);
 
     using namespace Layouting;
 
diff --git a/src/plugins/qtsupport/profilereader.cpp b/src/plugins/qtsupport/profilereader.cpp
index 6e8877566b..3232aaafaa 100644
--- a/src/plugins/qtsupport/profilereader.cpp
+++ b/src/plugins/qtsupport/profilereader.cpp
@@ -43,7 +43,7 @@ static void addTask(Task::TaskType type,
                     const Utils::FilePath &file = {},
                     int line = -1)
 {
-    QMetaObject::invokeMethod(TaskHub::instance(), [=]() {
+    QMetaObject::invokeMethod(&taskHub(), [=] {
         TaskHub::addTask(BuildSystemTask(type, description, file, line));
     });
 }
diff --git a/src/tools/buildoutputparser/outputprocessor.cpp b/src/tools/buildoutputparser/outputprocessor.cpp
index ed02736897..f8aa03d612 100644
--- a/src/tools/buildoutputparser/outputprocessor.cpp
+++ b/src/tools/buildoutputparser/outputprocessor.cpp
@@ -50,7 +50,7 @@ void CompilerOutputProcessor::start()
         break;
     }
 
-    connect(ProjectExplorer::TaskHub::instance(), &ProjectExplorer::TaskHub::taskAdded,
+    connect(&ProjectExplorer::taskHub(), &ProjectExplorer::TaskHub::taskAdded,
             this, &CompilerOutputProcessor::handleTask);
     while (!m_source.atEnd()) {
         parser.appendMessage(QString::fromLocal8Bit(m_source.readLine().trimmed()),