Utils: Introduce GlobalFileChangeBlocker

Tracks application state, and signals when it is changed.

Supports forcing blocked state with reference counting.

Change-Id: Ic173d42446b1b08bd4a1e7c1acf38c68644d30b3
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/globalfilechangeblocker.cpp

@@ -0,0 +1,70 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Orgad Shaneh <orgads@gmail.com>
+** 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 "globalfilechangeblocker.h"
+#include "qtcassert.h"
+
+#include <QApplication>
+
+namespace Utils {
+
+GlobalFileChangeBlocker::GlobalFileChangeBlocker()
+{
+    m_blockedState = QApplication::applicationState() != Qt::ApplicationActive;
+    qApp->installEventFilter(this);
+}
+
+GlobalFileChangeBlocker *GlobalFileChangeBlocker::instance()
+{
+    static GlobalFileChangeBlocker blocker;
+    return &blocker;
+}
+
+void GlobalFileChangeBlocker::forceBlocked(bool blocked)
+{
+    if (blocked)
+        ++m_forceBlocked;
+    else if (QTC_GUARD(m_forceBlocked > 0))
+        --m_forceBlocked;
+    emitIfChanged();
+}
+
+bool GlobalFileChangeBlocker::eventFilter(QObject *obj, QEvent *e)
+{
+    if (obj == qApp && e->type() == QEvent::ApplicationStateChange)
+        emitIfChanged();
+    return false;
+}
+
+void GlobalFileChangeBlocker::emitIfChanged()
+{
+    const bool blocked = m_forceBlocked || (QApplication::applicationState() != Qt::ApplicationActive);
+    if (blocked != m_blockedState) {
+        emit stateChanged(blocked);
+        m_blockedState = blocked;
+    }
+}
+
+} // namespace Utils

src/libs/utils/globalfilechangeblocker.h

@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Orgad Shaneh <orgads@gmail.com>
+** 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 "utils_global.h"
+
+#include <QObject>
+
+namespace Utils {
+
+class QTCREATOR_UTILS_EXPORT GlobalFileChangeBlocker : public QObject
+{
+    Q_OBJECT
+
+public:
+    static GlobalFileChangeBlocker *instance();
+    void forceBlocked(bool blocked);
+    bool isBlocked() const { return m_blockedState; }
+
+signals:
+    void stateChanged(bool blocked);
+
+private:
+    GlobalFileChangeBlocker();
+    bool eventFilter(QObject *obj, QEvent *e) override;
+    void emitIfChanged();
+
+    int m_forceBlocked = 0;
+    bool m_blockedState = false;
+};
+
+} // namespace Utils

src/libs/utils/utils-lib.pri

@@ -22,6 +22,7 @@ win32: LIBS += -luser32 -lshell32
 win32: LIBS += -liphlpapi -lws2_32
 
 SOURCES += \
+    $$PWD/globalfilechangeblocker.cpp \
     $$PWD/benchmarker.cpp \
     $$PWD/environment.cpp \
     $$PWD/environmentmodel.cpp \
@@ -128,6 +129,7 @@ win32:SOURCES += $$PWD/consoleprocess_win.cpp
 else:SOURCES += $$PWD/consoleprocess_unix.cpp
 
 HEADERS += \
+    $$PWD/globalfilechangeblocker.h \
     $$PWD/benchmarker.h \
     $$PWD/environment.h \
     $$PWD/environmentmodel.h \

src/libs/utils/utils.qbs

@@ -122,6 +122,8 @@ Project {
             "functiontraits.h",
             "fuzzymatcher.cpp",
             "fuzzymatcher.h",
+            "globalfilechangeblocker.cpp",
+            "globalfilechangeblocker.h",
             "guard.cpp",
             "guard.h",
             "highlightingitemdelegate.cpp",

src/plugins/clangcodemodel/clangbackendcommunicator.cpp

@@ -48,6 +48,7 @@
 #include <clangsupport/filecontainer.h>
 #include <clangsupport/clangcodemodelservermessages.h>
 
+#include <utils/globalfilechangeblocker.h>
 #include <utils/qtcassert.h>
 
 #include <QDateTime>
@@ -104,6 +105,10 @@ BackendCommunicator::BackendCommunicator()
             this, &BackendCommunicator::onEditorAboutToClose);
     connect(Core::ICore::instance(), &Core::ICore::coreAboutToClose,
             this, &BackendCommunicator::setupDummySender);
+    auto globalFCB = ::Utils::GlobalFileChangeBlocker::instance();
+    m_postponeBackendJobs = globalFCB->isBlocked();
+    connect(globalFCB, &::Utils::GlobalFileChangeBlocker::stateChanged,
+            this, &BackendCommunicator::setBackendJobsPostponed);
 
     initializeBackend();
 }
@@ -210,13 +215,10 @@ bool BackendCommunicator::isNotWaitingForCompletion() const
 void BackendCommunicator::setBackendJobsPostponed(bool postponed)
 {
     if (postponed) {
-        if (!m_postponeBackendJobs)
         documentVisibilityChanged(Utf8String(), {});
-        ++m_postponeBackendJobs;
+        m_postponeBackendJobs = postponed;
     } else {
-        if (QTC_GUARD(m_postponeBackendJobs > 0))
-            --m_postponeBackendJobs;
-        if (!m_postponeBackendJobs)
+        m_postponeBackendJobs = postponed;
         documentVisibilityChanged();
     }
 }

src/plugins/clangcodemodel/clangbackendcommunicator.h

@@ -136,7 +136,7 @@ private:
     QTimer m_backendStartTimeOut;
     QScopedPointer<ClangBackEnd::ClangCodeModelServerInterface> m_sender;
     int m_connectedCount = 0;
-    int m_postponeBackendJobs = 1; // Initial application state is inactive, so no jobs should be run.
+    bool m_postponeBackendJobs = false;
 };
 
 } // namespace Internal

src/plugins/clangcodemodel/clangmodelmanagersupport.cpp

@@ -76,8 +76,6 @@ ClangModelManagerSupport::ClangModelManagerSupport()
     QTC_CHECK(!m_instance);
     m_instance = this;
 
-    QApplication::instance()->installEventFilter(this);
-
     CppTools::CppModelManager::instance()->setCurrentDocumentFilter(
                 std::make_unique<ClangCurrentDocumentFilter>());
 
@@ -141,11 +139,6 @@ std::unique_ptr<CppTools::AbstractOverviewModel> ClangModelManagerSupport::creat
     return std::make_unique<OverviewModel>();
 }
 
-void ClangModelManagerSupport::setBackendJobsPostponed(bool postponed)
-{
-    m_communicator.setBackendJobsPostponed(postponed);
-}
-
 CppTools::BaseEditorDocumentProcessor *ClangModelManagerSupport::createEditorDocumentProcessor(
         TextEditor::TextDocument *baseTextDocument)
 {
@@ -219,20 +212,6 @@ void ClangModelManagerSupport::connectToWidgetsMarkContextMenuRequested(QWidget
     }
 }
 
-bool ClangModelManagerSupport::eventFilter(QObject *obj, QEvent *e)
-{
-    if (obj == QApplication::instance() && e->type() == QEvent::ApplicationStateChange) {
-        switch (QApplication::applicationState()) {
-        case Qt::ApplicationInactive: setBackendJobsPostponed(true); break;
-        case Qt::ApplicationActive: setBackendJobsPostponed(false); break;
-        default:
-            QTC_CHECK(false && "Unexpected Qt::ApplicationState");
-        }
-    }
-
-    return false;
-}
-
 void ClangModelManagerSupport::onEditorOpened(Core::IEditor *editor)
 {
     QTC_ASSERT(editor, return);

src/plugins/clangcodemodel/clangmodelmanagersupport.h

@@ -72,7 +72,6 @@ public:
     CppTools::FollowSymbolInterface &followSymbolInterface() override;
     CppTools::RefactoringEngineInterface &refactoringEngineInterface() override;
     std::unique_ptr<CppTools::AbstractOverviewModel> createOverviewModel() override;
-    void setBackendJobsPostponed(bool postponed) override;
 
     BackendCommunicator &communicator();
     QString dummyUiHeaderOnDiskDirPath() const;
@@ -83,8 +82,6 @@ public:
     static ClangModelManagerSupport *instance();
 
 private:
-    bool eventFilter(QObject *obj, QEvent *e) override;
-
     void onEditorOpened(Core::IEditor *editor);
     void onEditorClosed(const QList<Core::IEditor *> &editors);
     void onCurrentEditorChanged(Core::IEditor *newCurrent);

src/plugins/coreplugin/documentmanager.cpp

@@ -44,6 +44,7 @@
 #include <extensionsystem/pluginmanager.h>
 
 #include <utils/fileutils.h>
+#include <utils/globalfilechangeblocker.h>
 #include <utils/hostosinfo.h>
 #include <utils/mimetypes/mimedatabase.h>
 #include <utils/qtcassert.h>
@@ -229,7 +230,13 @@ DocumentManager::DocumentManager(QObject *parent)
 {
     d = new DocumentManagerPrivate;
     m_instance = this;
-    qApp->installEventFilter(this);
+
+    connect(Utils::GlobalFileChangeBlocker::instance(), &Utils::GlobalFileChangeBlocker::stateChanged,
+            this, [this](bool blocked) {
+        d->m_postponeAutoReload = blocked;
+        if (!blocked)
+            QTimer::singleShot(500, m_instance, &DocumentManager::checkForReload);
+    });
 
     readSettings();
 
@@ -597,13 +604,6 @@ void DocumentManager::unexpectFileChange(const QString &fileName)
         updateExpectedState(filePathKey(fileName, ResolveLinks));
 }
 
-void DocumentManager::setAutoReloadPostponed(bool postponed)
-{
-    d->m_postponeAutoReload = postponed;
-    if (!postponed)
-        QTimer::singleShot(500, m_instance, &DocumentManager::checkForReload);
-}
-
 static bool saveModifiedFilesHelper(const QList<IDocument *> &documents,
                                     const QString &message, bool *cancelled, bool silently,
                                     const QString &alwaysSaveMessage, bool *alwaysSave,
@@ -1470,14 +1470,6 @@ void DocumentManager::notifyFilesChangedInternally(const QStringList &files)
     emit m_instance->filesChangedInternally(files);
 }
 
-bool DocumentManager::eventFilter(QObject *obj, QEvent *e)
-{
-    if (obj == qApp && e->type() == QEvent::ApplicationStateChange) {
-        QTimer::singleShot(0, this, &DocumentManager::checkForReload);
-    }
-    return false;
-}
-
 // -------------- FileChangeBlocker
 
 FileChangeBlocker::FileChangeBlocker(const QString &fileName)

src/plugins/coreplugin/documentmanager.h

@@ -69,8 +69,6 @@ public:
     static void expectFileChange(const QString &fileName);
     static void unexpectFileChange(const QString &fileName);
 
-    static void setAutoReloadPostponed(bool enabled);
-
     // recent files
     static void addToRecentFiles(const QString &fileName, Id editorId = Id());
     Q_SLOT void clearRecentFiles();
@@ -155,9 +153,6 @@ signals:
     void documentRenamed(Core::IDocument *document, const QString &from, const QString &to);
     void projectsDirectoryChanged(const Utils::FileName &directory);
 
-protected:
-    bool eventFilter(QObject *obj, QEvent *e) override;
-
 private:
     explicit DocumentManager(QObject *parent);
     ~DocumentManager() override;

src/plugins/cpptools/cppbuiltinmodelmanagersupport.h

@@ -47,7 +47,6 @@ public:
     FollowSymbolInterface &followSymbolInterface() final;
     RefactoringEngineInterface &refactoringEngineInterface() final;
     std::unique_ptr<AbstractOverviewModel> createOverviewModel() final;
-    void setBackendJobsPostponed(bool) final {}
 
 private:
     QScopedPointer<CppCompletionAssistProvider> m_completionAssistProvider;

src/plugins/cpptools/cppmodelmanager.cpp

@@ -1318,11 +1318,6 @@ void CppModelManager::renameIncludes(const QString &oldFileName, const QString &
     }
 }
 
-void CppModelManager::setBackendJobsPostponed(bool postponed)
-{
-    d->m_activeModelManagerSupport->setBackendJobsPostponed(postponed);
-}
-
 void CppModelManager::onCoreAboutToClose()
 {
     Core::ProgressManager::cancelTasks(CppTools::Constants::TASK_INDEX);

src/plugins/cpptools/cppmodelmanager.h

@@ -230,8 +230,6 @@ public:
 
     void renameIncludes(const QString &oldFileName, const QString &newFileName);
 
-    void setBackendJobsPostponed(bool postponed);
-
 signals:
     /// Project data might be locked while this is emitted.
     void aboutToRemoveFiles(const QStringList &files);

src/plugins/cpptools/cppmodelmanagersupport.h

@@ -60,7 +60,6 @@ public:
     virtual FollowSymbolInterface &followSymbolInterface() = 0;
     virtual RefactoringEngineInterface &refactoringEngineInterface() = 0;
     virtual std::unique_ptr<AbstractOverviewModel> createOverviewModel() = 0;
-    virtual void setBackendJobsPostponed(bool yesno) = 0;
 };
 
 class CPPTOOLS_EXPORT ModelManagerSupportProvider

src/plugins/vcsbase/vcscommand.cpp

@@ -29,7 +29,7 @@
 
 #include <coreplugin/documentmanager.h>
 #include <coreplugin/vcsmanager.h>
-#include <cpptools/cppmodelmanager.h>
+#include <utils/globalfilechangeblocker.h>
 #include <utils/synchronousprocess.h>
 
 #include <QProcessEnvironment>
@@ -61,16 +61,12 @@ VcsCommand::VcsCommand(const QString &workingDirectory,
         return proxy;
     });
     connect(this, &VcsCommand::started, this, [this] {
-        if (flags() & ExpectRepoChanges) {
-            Core::DocumentManager::setAutoReloadPostponed(true);
-            CppTools::CppModelManager::instance()->setBackendJobsPostponed(true);
-        }
+        if (flags() & ExpectRepoChanges)
+            Utils::GlobalFileChangeBlocker::instance()->forceBlocked(true);
     });
     connect(this, &VcsCommand::finished, this, [this] {
-        if (flags() & ExpectRepoChanges) {
-            Core::DocumentManager::setAutoReloadPostponed(false);
-            CppTools::CppModelManager::instance()->setBackendJobsPostponed(false);
-        }
+        if (flags() & ExpectRepoChanges)
+            Utils::GlobalFileChangeBlocker::instance()->forceBlocked(false);
     });
 }