Simplify interface of classes in ClassViewPlugin

Allow for direct connections where signal emitter and
receiver live in the same thread.
Remove unneeded mutexState, as changes to state and
all queries of state are done in the same thread.
Remove some indirections by removing some signals
and by calling respective slots through
QMetaObject::invokeMethod() or directly.
Remove some unused methods.
Remove a code path of setState(false), as this was never called.
Remove an initial call to onProjectListChanged(), as initially
the state is false and a call is no-op.

This change doesn't influence the existing behavior.

Task-number: QTCREATORBUG-25317
Change-Id: I683525b49afaf04e155d1859bb85ee5dd8e26dd2
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

1 files changed, 52 insertions, 196 deletions

diff --git a/src/plugins/classview/classviewmanager.cpp b/src/plugins/classview/classviewmanager.cpp
index ca616f86ee..bf9ed8f58f 100644
--- a/src/plugins/classview/classviewmanager.cpp
+++ b/src/plugins/classview/classviewmanager.cpp
@@ -73,15 +73,6 @@ static Manager *managerInstance = nullptr;
 */
 
 /*!
-    \fn void ClassView::Internal::Manager::stateChanged(bool state)
-
-    Changes the internal manager state. \a state returns true if manager is
-    enabled, otherwise false.
-
-    \sa setState, state
-*/
-
-/*!
     \fn void ClassView::Internal::Manager::treeDataUpdate(QSharedPointer<QStandardItem> result)
 
     Emits a signal about a tree data update (to tree view). \a result holds the
@@ -89,49 +80,6 @@ static Manager *managerInstance = nullptr;
 */
 
 /*!
-    \fn void ClassView::Internal::Manager::requestTreeDataUpdate()
-
-    Emits a signal that a request for sending the tree view has to be handled by
-    listeners (the parser).
-
-    \sa onRequestTreeDataUpdate
-*/
-
-/*!
-    \fn void ClassView::Internal::Manager::requestDocumentUpdated(CPlusPlus::Document::Ptr doc)
-
-    Emits a signal that \a doc was updated and has to be reparsed.
-
-    \sa onDocumentUpdated
-*/
-
-/*!
-    \fn void ClassView::Internal::Manager::requestResetCurrentState()
-
-    Emits a signal that the parser has to reset its internal state to the
-    current state from the code manager.
-*/
-
-/*!
-    \fn void ClassView::Internal::Manager::requestClearCache()
-
-    Requests the parser to clear a cache.
-*/
-
-/*!
-    \fn void ClassView::Internal::Manager::requestClearCacheAll()
-
-    Requests the parser to clear a full cache.
-*/
-
-/*!
-    \fn void ClassView::Internal::Manager::requestSetFlatMode(bool flat)
-
-    Requests the manager to set the flat mode without subprojects. Set \a flat
-    to \c true to enable flat mode and to false to disable it.
-*/
-
-/*!
    \class ManagerPrivate
    \internal
    \brief The ManagerPrivate class contains private class data for the Manager
@@ -142,9 +90,6 @@ static Manager *managerInstance = nullptr;
 class ManagerPrivate
 {
 public:
-    //! State mutex
-    QMutex mutexState;
-
     //! code state/changes parser
     Parser parser;
 
@@ -174,9 +119,6 @@ Manager::Manager(QObject *parent)
     // start a separate thread for the parser
     d->parser.moveToThread(&d->parserThread);
     d->parserThread.start();
-
-    // initial setup
-    onProjectListChanged();
 }
 
 Manager::~Manager()
@@ -220,58 +162,62 @@ void Manager::initialize()
 {
     using ProjectExplorer::SessionManager;
 
-    // use Qt::QueuedConnection everywhere
-
-    // internal manager state is changed
-    connect(this, &Manager::stateChanged, this, &Manager::onStateChanged, Qt::QueuedConnection);
-
     // connections to enable/disable navi widget factory
     SessionManager *sessionManager = SessionManager::instance();
     connect(sessionManager, &SessionManager::projectAdded,
-            this, &Manager::onProjectListChanged, Qt::QueuedConnection);
+            this, &Manager::onProjectListChanged);
     connect(sessionManager, &SessionManager::projectRemoved,
-            this, &Manager::onProjectListChanged, Qt::QueuedConnection);
+            this, &Manager::onProjectListChanged);
 
     // connect to the progress manager for signals about Parsing tasks
     connect(ProgressManager::instance(), &ProgressManager::taskStarted,
-            this, &Manager::onTaskStarted, Qt::QueuedConnection);
-    connect(ProgressManager::instance(), &ProgressManager::allTasksFinished,
-            this, &Manager::onAllTasksFinished, Qt::QueuedConnection);
-
-    // when we signals that really document is updated - sent it to the parser
-    connect(this, &Manager::requestDocumentUpdated,
-            &d->parser, &Parser::parseDocument, Qt::QueuedConnection);
+            this, [this](Id type) {
+        if (type != CppTools::Constants::TASK_INDEX)
+            return;
 
-    // translate data update from the parser to listeners
-    connect(&d->parser, &Parser::treeDataUpdate,
-            this, &Manager::onTreeDataUpdate, Qt::QueuedConnection);
+        // disable tree updates to speed up
+        d->disableCodeParser = true;
+    });
+    connect(ProgressManager::instance(), &ProgressManager::allTasksFinished,
+            this, [this](Id type) {
+        if (type != CppTools::Constants::TASK_INDEX)
+            return;
 
-    // requet current state - immediately after a notification
-    connect(this, &Manager::requestTreeDataUpdate,
-            &d->parser, &Parser::requestCurrentState, Qt::QueuedConnection);
+        // parsing is finished, enable tree updates
+        d->disableCodeParser = false;
 
-    // full reset request to parser
-    connect(this, &Manager::requestResetCurrentState,
-            &d->parser, &Parser::resetDataToCurrentState, Qt::QueuedConnection);
+        // do nothing if Manager is disabled
+        if (!state())
+            return;
 
-    // clear cache request
-    connect(this, &Manager::requestClearCache,
-            &d->parser, &Parser::clearCache, Qt::QueuedConnection);
+        // any document might be changed, clear parser's cache
+        QMetaObject::invokeMethod(&d->parser, &Parser::clearCache, Qt::QueuedConnection);
 
-    // clear full cache request
-    connect(this, &Manager::requestClearCacheAll,
-            &d->parser, &Parser::clearCacheAll, Qt::QueuedConnection);
+        // request to update a tree to the current state
+        resetParser();
+    });
 
-    // flat mode request
-    connect(this, &Manager::requestSetFlatMode,
-            &d->parser, &Parser::setFlatMode, Qt::QueuedConnection);
+    // translate data update from the parser to listeners
+    connect(&d->parser, &Parser::treeDataUpdate,
+            this, &Manager::onTreeDataUpdate, Qt::QueuedConnection);
 
     // connect to the cpp model manager for signals about document updates
     CppTools::CppModelManager *codeModelManager = CppTools::CppModelManager::instance();
 
     // when code manager signals that document is updated - handle it by ourselves
     connect(codeModelManager, &CppTools::CppModelManager::documentUpdated,
-            this, &Manager::onDocumentUpdated, Qt::QueuedConnection);
+            this, [this](CPlusPlus::Document::Ptr doc) {
+        // do nothing if Manager is disabled
+        if (!state())
+            return;
+
+        // do nothing if updates are disabled
+        if (d->disableCodeParser)
+            return;
+
+        QMetaObject::invokeMethod(&d->parser, [this, doc]() {
+            d->parser.parseDocument(doc); }, Qt::QueuedConnection);
+    }, Qt::QueuedConnection);
     //
     connect(codeModelManager, &CppTools::CppModelManager::aboutToRemoveFiles,
             &d->parser, &Parser::removeFiles, Qt::QueuedConnection);
@@ -300,15 +246,18 @@ bool Manager::state() const
 
 void Manager::setState(bool state)
 {
-    QMutexLocker locker(&d->mutexState);
-
-    // boolean comparsion - should be done correctly by any compiler
     if (state == d->state)
         return;
 
     d->state = state;
 
-    emit stateChanged(d->state);
+    if (state) // enabled - request a current snapshots etc?..
+        resetParser();
+}
+
+void Manager::resetParser()
+{
+    QMetaObject::invokeMethod(&d->parser, &Parser::resetDataToCurrentState, Qt::QueuedConnection);
 }
 
 /*!
@@ -321,26 +270,10 @@ void Manager::setState(bool state)
 void Manager::onWidgetVisibilityIsChanged(bool visibility)
 {
     // activate data handling - when 1st time 'Class View' will be open
-    if (visibility)
-        setState(true);
-}
-
-/*!
-    Reacts to the state changed signal for the current manager \a state.
-    For example, requests the currect code snapshot if needed.
-
-    \sa setState, state, stateChanged
-*/
-
-void Manager::onStateChanged(bool state)
-{
-    if (state) {
-        // enabled - request a current snapshots etc?..
-        emit requestResetCurrentState();
-    } else {
-        // disabled - clean parsers internal cache
-        emit requestClearCacheAll();
-    }
+    if (!visibility)
+        return;
+    setState(true);
+    onProjectListChanged();
 }
 
 /*!
@@ -354,70 +287,7 @@ void Manager::onProjectListChanged()
     if (!state())
         return;
 
-    // update to the latest state
-    emit requestTreeDataUpdate();
-}
-
-/*!
-    Handles parse tasks started by the progress manager. \a type holds the
-    task index, which should be \c CppTools::Constants::TASK_INDEX.
-
-   \sa CppTools::Constants::TASK_INDEX
-*/
-
-void Manager::onTaskStarted(Id type)
-{
-    if (type != CppTools::Constants::TASK_INDEX)
-        return;
-
-    // disable tree updates to speed up
-    d->disableCodeParser = true;
-}
-
-/*!
-    Handles parse tasks finished by the progress manager.\a type holds the
-    task index, which should be \c CppTools::Constants::TASK_INDEX.
-
-   \sa CppTools::Constants::TASK_INDEX
-*/
-
-void Manager::onAllTasksFinished(Id type)
-{
-    if (type != CppTools::Constants::TASK_INDEX)
-        return;
-
-    // parsing is finished, enable tree updates
-    d->disableCodeParser = false;
-
-    // do nothing if Manager is disabled
-    if (!state())
-        return;
-
-    // any document might be changed, emit signal to clear cache
-    emit requestClearCache();
-
-    // request to update a tree to the current state
-    emit requestResetCurrentState();
-}
-
-/*!
-    Emits the signal \c documentUpdated when the code model manager state is
-    changed for \a doc.
-
-    \sa documentUpdated
-*/
-
-void Manager::onDocumentUpdated(CPlusPlus::Document::Ptr doc)
-{
-    // do nothing if Manager is disabled
-    if (!state())
-        return;
-
-    // do nothing if updates are disabled
-    if (d->disableCodeParser)
-        return;
-
-    emit requestDocumentUpdated(doc);
+    QMetaObject::invokeMethod(&d->parser, &Parser::requestCurrentState, Qt::QueuedConnection);
 }
 
 /*!
@@ -472,28 +342,14 @@ void Manager::gotoLocations(const QList<QVariant> &list)
 }
 
 /*!
-    Emits the signal \c requestTreeDataUpdate if the latest tree info is
-    requested and if parsing is enabled.
-
-   \sa requestTreeDataUpdate, NavigationWidget::requestDataUpdate
-*/
-
-void Manager::onRequestTreeDataUpdate()
-{
-    // do nothing if Manager is disabled
-    if (!state())
-        return;
-
-    emit requestTreeDataUpdate();
-}
-
-/*!
     Switches to flat mode (without subprojects) if \a flat is set to \c true.
 */
 
 void Manager::setFlatMode(bool flat)
 {
-    emit requestSetFlatMode(flat);
+    QMetaObject::invokeMethod(&d->parser, [this, flat]() {
+        d->parser.setFlatMode(flat);
+    }, Qt::QueuedConnection);
 }
 
 /*!