Refactor GUI

* Make error handling more clear
* Get rid of useless mutex (sync is done
  by QMetaObject::invokeMethod() already)
* Improve details

dbquery/dbquery.cpp

@@ -40,11 +40,11 @@ void QueryResultsModel::setFetchingCover(bool fetchingCover)
     m_fetchingCover = fetchingCover;
 }
 
-#define returnValue(field) return qstringToTagValue(res.field, TagTextEncoding::Utf16LittleEndian)
-
 void QueryResultsModel::abort()
 {}
 
+#define returnValue(field) return qstringToTagValue(res.field, TagTextEncoding::Utf16LittleEndian)
+
 TagValue QueryResultsModel::fieldValue(int row, KnownField knownField) const
 {
     if(row < m_results.size()) {

dbquery/dbquery.h

@@ -2,6 +2,7 @@
 #define DBQUERY_H
 
 #include <c++utilities/application/global.h>
+#include <c++utilities/conversion/types.h>
 
 #include <QAbstractTableModel>
 #include <QNetworkReply>
@@ -29,9 +30,9 @@ struct SongDescription
     QString artist;
     QString year;
     QString genre;
-    unsigned int track;
-    unsigned int totalTracks;
-    unsigned int disk;
+    int32 track;
+    int32 totalTracks;
+    int32 disk;
     QByteArray cover;
     QString lyrics;
 };

gui/mainwindow.cpp

@@ -55,9 +55,9 @@ enum LoadingResult : char
 /*!
  * \brief Shortcut to access file operation mutex of TagEditorWidget.
  */
-QMutex &MainWindow::fileOperationMutex()
+bool MainWindow::fileOperationOngoing() const
 {
-    return m_ui->tagEditorWidget->fileOperationMutex();
+    return m_ui->tagEditorWidget->fileOperationOngoing();
 }
 
 /*!
@@ -503,39 +503,41 @@ void MainWindow::showSaveAsDlg()
  */
 void MainWindow::saveFileInformation()
 {
-    TryLocker<> locker(fileOperationMutex());
-    if(locker) {
-        if(fileInfo().isOpen()) {
-            const QByteArray htmlData =
-        #ifndef TAGEDITOR_NO_WEBVIEW
-                   !m_ui->tagEditorWidget->fileInfoHtml().isEmpty() ?
-                        m_ui->tagEditorWidget->fileInfoHtml() :
-            #endif
-                        HtmlInfo::generateInfo(fileInfo(), m_ui->tagEditorWidget->originalNotifications());
-            if(!htmlData.isEmpty()) {
-                const QString path = QFileDialog::getSaveFileName(this, tr("Save file information - ") + QCoreApplication::applicationName());
-                if(!path.isEmpty()) {
-                    QFile file(path);
-                    if(file.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
-                        QTextStream stream(&file);
-                        stream.setCodec(QTextCodec::codecForName("UTF-8"));
-                        stream << htmlData;
-                        file.close();
-                        if(file.error() != QFileDevice::NoError) {
-                            QMessageBox::critical(this, QApplication::applicationName(), tr("Unable to write to file.\n%1").arg(file.errorString()));
-                        }
-                    } else {
-                        QMessageBox::critical(this, QApplication::applicationName(), tr("Unable to open file."));
-                    }
-                }
-            } else {
-                QMessageBox::information(this, QApplication::applicationName(), tr("No file information available."));
-            }
-        } else {
-            QMessageBox::information(this, QApplication::applicationName(), tr("No file is opened."));
-        }
-    } else {
+    if(fileOperationOngoing()) {
         m_ui->statusBar->showMessage(tr("Unable to save file information because the current process hasn't been finished yet."));
+        return;
+    }
+    if(!fileInfo().isOpen()) {
+        QMessageBox::information(this, QApplication::applicationName(), tr("No file is opened."));
+        return;
+    }
+
+    const QByteArray htmlData =
+        #ifndef TAGEDITOR_NO_WEBVIEW
+            !m_ui->tagEditorWidget->fileInfoHtml().isEmpty() ?
+                m_ui->tagEditorWidget->fileInfoHtml() :
+            #endif
+                HtmlInfo::generateInfo(fileInfo(), m_ui->tagEditorWidget->originalNotifications());
+    if(htmlData.isEmpty()) {
+        QMessageBox::information(this, QApplication::applicationName(), tr("No file information available."));
+        return;
+    }
+
+    const QString path = QFileDialog::getSaveFileName(this, tr("Save file information - ") + QCoreApplication::applicationName());
+    if(path.isEmpty()) {
+        QMessageBox::critical(this, QApplication::applicationName(), tr("Unable to open file."));
+        return;
+    }
+
+    QFile file(path);
+    if(file.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        QTextStream stream(&file);
+        stream.setCodec(QTextCodec::codecForName("UTF-8"));
+        stream << htmlData;
+        file.close();
+        if(file.error() != QFileDevice::NoError) {
+            QMessageBox::critical(this, QApplication::applicationName(), tr("Unable to write to file.\n%1").arg(file.errorString()));
+        }
     }
 }
 

gui/mainwindow.h

@@ -12,7 +12,6 @@
 
 QT_FORWARD_DECLARE_CLASS(QFileSystemModel)
 QT_FORWARD_DECLARE_CLASS(QItemSelectionModel)
-QT_FORWARD_DECLARE_CLASS(QMutex)
 
 namespace Media {
 DECLARE_ENUM_CLASS(TagType, unsigned int);
@@ -80,7 +79,7 @@ private slots:
     void toggleDbQueryWidget();
 
 private:
-    QMutex &fileOperationMutex();
+    bool fileOperationOngoing() const;
     Media::MediaFileInfo &fileInfo();
 
     // UI

gui/tageditorwidget.cpp

@@ -22,8 +22,6 @@
 #include <tagparser/ogg/oggcontainer.h>
 
 #include <qtutilities/misc/dialogutils.h>
-#include <qtutilities/misc/trylocker.h>
-#include <qtutilities/misc/adoptlocker.h>
 #include <qtutilities/widgets/clearlineedit.h>
 
 #include <c++utilities/conversion/stringconversion.h>
@@ -56,7 +54,6 @@ using namespace std::placeholders;
 using namespace Utility;
 using namespace Dialogs;
 using namespace Widgets;
-using namespace ThreadingUtils;
 using namespace Media;
 using namespace Models;
 
@@ -90,7 +87,8 @@ TagEditorWidget::TagEditorWidget(QWidget *parent) :
     m_infoTreeView(nullptr),
     m_nextFileAfterSaving(false),
     m_makingResultsAvailable(false),
-    m_abortClicked(false)
+    m_abortClicked(false),
+    m_fileOperationOngoing(false)
 {
     // setup UI
     m_ui->setupUi(this);
@@ -723,82 +721,80 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
     if(!forceRefresh && sameFile) {
         return true;
     }
-    TryLocker<> locker(fileOperationMutex());
-    if(locker) {
-        // clear previous results and status
-        m_tags.clear();
-        m_fileInfo.clearParsingResults();
-        m_fileInfo.invalidateStatus();
-        m_fileInfo.invalidateNotifications();
-        if(!sameFile) {
-            // close last file if possibly open
-            m_fileInfo.close();
-            // set path of file info
-            m_currentPath = path;
-            m_fileInfo.setSaveFilePath(string());
-            m_fileInfo.setPath(path.toLocal8Bit().data());
-            // update directory
-            m_lastDir = m_currentDir;
-            m_currentDir = QString::fromLocal8Bit(m_fileInfo.containingDirectory().c_str());
-        }
-        // update availability of making results
-        m_makingResultsAvailable &= sameFile;
-        if(!m_makingResultsAvailable) {
-            m_originalNotifications.clear();
-        }
-        // show filename
-        m_ui->fileNameLabel->setText(QString::fromLocal8Bit(m_fileInfo.fileName().c_str()));
-        // define function to parse the file
-        auto startThread = [this] {
-            m_fileOperationMutex.lock();
-            char result;
-            try { // credits for this nesting go to GCC regression 66145
+    if(m_fileOperationOngoing) {
+        emit statusMessage(tr("Unable to load the selected file \"%1\" because the current process hasn't finished yet.").arg(path));
+        return false;
+    }
+
+    // clear previous results and status
+    m_tags.clear();
+    m_fileInfo.clearParsingResults();
+    m_fileInfo.invalidateStatus();
+    m_fileInfo.invalidateNotifications();
+    if(!sameFile) {
+        // close last file if possibly open
+        m_fileInfo.close();
+        // set path of file info
+        m_currentPath = path;
+        m_fileInfo.setSaveFilePath(string());
+        m_fileInfo.setPath(path.toLocal8Bit().data());
+        // update directory
+        m_lastDir = m_currentDir;
+        m_currentDir = QString::fromLocal8Bit(m_fileInfo.containingDirectory().c_str());
+    }
+    // update availability of making results
+    m_makingResultsAvailable &= sameFile;
+    if(!m_makingResultsAvailable) {
+        m_originalNotifications.clear();
+    }
+    // show filename
+    m_ui->fileNameLabel->setText(QString::fromLocal8Bit(m_fileInfo.fileName().c_str()));
+    // define function to parse the file
+    auto startThread = [this] {
+        char result;
+        try { // credits for this nesting go to GCC regression 66145
+            try {
                 try {
-                    try {
-                        // try to open with write access
-                        m_fileInfo.reopen(false);
-                    } catch(...) {
-                        ::IoUtilities::catchIoFailure();
-                        // try to open read-only if opening with write access failed
-                        m_fileInfo.reopen(true);
-                    }
-                    m_fileInfo.setForceFullParse(Settings::values().editor.forceFullParse);
-                    m_fileInfo.parseEverything();
-                    result = ParsingSuccessful;
-                } catch(const Failure &) {
-                    // the file has been opened; parsing notifications will be shown in the info box
-                    result = FatalParsingError;
+                    // try to open with write access
+                    m_fileInfo.reopen(false);
                 } catch(...) {
                     ::IoUtilities::catchIoFailure();
-                    // the file could not be opened because an IO error occured
-                    m_fileInfo.close(); // ensure file is closed
-                    result = IoError;
+                    // try to open read-only if opening with write access failed
+                    m_fileInfo.reopen(true);
                 }
-            } catch(const exception &e) {
-                m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "parsing");
+                m_fileInfo.setForceFullParse(Settings::values().editor.forceFullParse);
+                m_fileInfo.parseEverything();
+                result = ParsingSuccessful;
+            } catch(const Failure &) {
+                // the file has been opened; parsing notifications will be shown in the info box
                 result = FatalParsingError;
             } catch(...) {
-                m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "parsing");
-                result = FatalParsingError;
+                ::IoUtilities::catchIoFailure();
+                // the file could not be opened because an IO error occured
+                m_fileInfo.close(); // ensure file is closed
+                result = IoError;
             }
-            m_fileInfo.unregisterAllCallbacks();
-            QMetaObject::invokeMethod(this, "showFile", Qt::QueuedConnection, Q_ARG(char, result));
-            // showFile() will unlock the mutex!
-        };
+        } catch(const exception &e) {
+            m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "parsing");
+            result = FatalParsingError;
+        } catch(...) {
+            m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "parsing");
+            result = FatalParsingError;
+        }
         m_fileInfo.unregisterAllCallbacks();
-        // perform the operation concurrently
-        QtConcurrent::run(startThread);
-        // inform user
-        static const QString statusMsg(tr("The file is beeing parsed ..."));
-        m_ui->parsingNotificationWidget->setNotificationType(NotificationType::Progress);
-        m_ui->parsingNotificationWidget->setText(statusMsg);
-        m_ui->parsingNotificationWidget->setVisible(true); // ensure widget is visible!
-        emit statusMessage(statusMsg);
-        return true;
-    } else {
-        emit statusMessage(tr("Unable to load the selected file \"%1\" because the current process hasn't finished yet.").arg(path));
-    }
-    return false;
+        QMetaObject::invokeMethod(this, "showFile", Qt::QueuedConnection, Q_ARG(char, result));
+    };
+    m_fileInfo.unregisterAllCallbacks();
+    m_fileOperationOngoing = true;
+    // perform the operation concurrently
+    QtConcurrent::run(startThread);
+    // inform user
+    static const QString statusMsg(tr("The file is beeing parsed ..."));
+    m_ui->parsingNotificationWidget->setNotificationType(NotificationType::Progress);
+    m_ui->parsingNotificationWidget->setText(statusMsg);
+    m_ui->parsingNotificationWidget->setVisible(true); // ensure widget is visible!
+    emit statusMessage(statusMsg);
+    return true;
 }
 
 /*!
@@ -806,17 +802,13 @@ bool TagEditorWidget::startParsing(const QString &path, bool forceRefresh)
  */
 bool TagEditorWidget::reparseFile()
 {
-    {
-        TryLocker<> locker(m_fileOperationMutex);
-        if(locker) {
-            if(!m_fileInfo.isOpen() || m_currentPath.isEmpty()) {
-                QMessageBox::warning(this, windowTitle(), tr("Currently is not file opened."));
-                return false;
-            }
-        } else {
-            emit statusMessage(tr("Unable to reload the file because the current process hasn't finished yet."));
-            return false;
-        }
+    if(m_fileOperationOngoing) {
+        emit statusMessage(tr("Unable to reload the file because the current process hasn't finished yet."));
+        return false;
+    }
+    if(!m_fileInfo.isOpen() || m_currentPath.isEmpty()) {
+        QMessageBox::warning(this, windowTitle(), tr("Currently is not file opened."));
+        return false;
     }
     return startParsing(m_currentPath, true);
 }
@@ -826,11 +818,10 @@ bool TagEditorWidget::reparseFile()
  * This private slot is invoked from the thread which performed the
  * parsing operation using Qt::QueuedConnection.
  * \param result Specifies whether the file could be load sucessfully.
- * \remarks Expects m_fileOperationMutex to be locked!
  */
 void TagEditorWidget::showFile(char result)
 {    
-    AdoptLocker<> locker(m_fileOperationMutex);
+    m_fileOperationOngoing = false;
     if(result == IoError) {
         // update status
         updateFileStatusStatus();
@@ -941,43 +932,39 @@ void TagEditorWidget::saveAndShowNextFile()
  */
 bool TagEditorWidget::applyEntriesAndSaveChangings()
 {
-    {
-        TryLocker<> locker(m_fileOperationMutex);
-        if(locker) {
-            m_ui->makingNotificationWidget->setNotificationType(NotificationType::Information);
-            m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::Saving);
-            m_ui->makingNotificationWidget->setHidden(false);
-            m_makingResultsAvailable = true;
-            if(m_fileInfo.isOpen()) {
-                // apply titles
-                if(AbstractContainer *container = m_fileInfo.container()) {
-                    if(container->supportsTitle()) {
-                        QLayout *docTitleLayout = m_ui->docTitleWidget->layout();
-                        for(int i = 0, count = min<int>(docTitleLayout->count() - 1, container->segmentCount()); i < count; ++i) {
-                            container->setTitle(static_cast<ClearLineEdit *>(docTitleLayout->itemAt(i + 1)->widget())->text().toUtf8().data(), i);
-                        }
-                    }
-                }
-                // apply all tags
-                foreachTagEdit([] (TagEdit *edit) {edit->apply();});
-                static const QString statusMsg(tr("Saving tags ..."));
-                m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::None);
-                m_ui->makingNotificationWidget->setNotificationType(NotificationType::Progress);
-                m_ui->makingNotificationWidget->setText(statusMsg);
-                emit statusMessage(statusMsg);
-            } else {
-                static const QString statusMsg(tr("No file has been opened."));
-                m_ui->makingNotificationWidget->setText(statusMsg);
-                QMessageBox::warning(this, QApplication::applicationName(), statusMsg);
-                return false;
+    if(m_fileOperationOngoing) {
+        static const QString statusMsg(tr("Unable to apply the entered tags to the file because the current process hasn't finished yet."));
+        emit statusMessage(statusMsg);
+        return false;
+    }
+
+    m_ui->makingNotificationWidget->setNotificationType(NotificationType::Information);
+    m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::Saving);
+    m_ui->makingNotificationWidget->setHidden(false);
+
+    if(!m_fileInfo.isOpen()) {
+        m_ui->makingNotificationWidget->setText(tr("No file has been opened, so tags can not be saved."));
+        return false;
+    }
+
+    m_makingResultsAvailable = true;
+
+    // apply titles
+    if(AbstractContainer *container = m_fileInfo.container()) {
+        if(container->supportsTitle()) {
+            QLayout *docTitleLayout = m_ui->docTitleWidget->layout();
+            for(int i = 0, count = min<int>(docTitleLayout->count() - 1, container->segmentCount()); i < count; ++i) {
+                container->setTitle(static_cast<ClearLineEdit *>(docTitleLayout->itemAt(i + 1)->widget())->text().toUtf8().data(), i);
             }
-        } else {
-            static const QString statusMsg(tr("Unable to apply the entered tags to the file because the current process hasn't finished yet."));
-            m_ui->makingNotificationWidget->setText(statusMsg);
-            emit statusMessage(statusMsg);
-            return false;
         }
     }
+    // apply all tags
+    foreachTagEdit([] (TagEdit *edit) {edit->apply();});
+    static const QString statusMsg(tr("Saving tags ..."));
+    m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::None);
+    m_ui->makingNotificationWidget->setNotificationType(NotificationType::Progress);
+    m_ui->makingNotificationWidget->setText(statusMsg);
+    emit statusMessage(statusMsg);
     return startSaving();
 }
 
@@ -987,148 +974,148 @@ bool TagEditorWidget::applyEntriesAndSaveChangings()
  */
 bool TagEditorWidget::deleteAllTagsAndSave()
 {
-    {
-        TryLocker<> locker(m_fileOperationMutex);
-        if(locker) {
-            if(Settings::values().editor.askBeforeDeleting) {
-                QMessageBox msgBox(this);
-                msgBox.setText(tr("Do you really want to delete all tags from the file?"));
-                msgBox.setIcon(QMessageBox::Warning);
-                msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
-                msgBox.setDefaultButton(QMessageBox::No);
+    if(m_fileOperationOngoing) {
+        static const QString statusMsg(tr("Unable to delete all tags from the file because the current process hasn't been finished yet."));
+        emit statusMessage(statusMsg);
+        return false;
+    }
+
+    m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::Saving);
+    m_ui->makingNotificationWidget->setNotificationType(NotificationType::Information);
+    m_ui->makingNotificationWidget->setHidden(false);
+
+    if(!m_fileInfo.isOpen()) {
+        m_ui->makingNotificationWidget->setText(tr("No file has been opened, so no tags can be deleted."));
+        return false;
+    }
+    if(!m_fileInfo.hasAnyTag()) {
+        m_ui->makingNotificationWidget->setText(tr("The selected file has no tag (at least no supported), so there is nothing to delete."));
+        return false;
+    }
+
+    if(Settings::values().editor.askBeforeDeleting) {
+        m_ui->makingNotificationWidget->setText(tr("Do you really want to delete all tags from the file?"));
+
+        QMessageBox msgBox(this);
+        msgBox.setText(m_ui->makingNotificationWidget->text());
+        msgBox.setIcon(QMessageBox::Warning);
+        msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
+        msgBox.setDefaultButton(QMessageBox::No);
 #if QT_VERSION >= 0x050200
-                auto *checkBox = new QCheckBox(&msgBox);
-                checkBox->setText(tr("don't show this message again"));
-                msgBox.setCheckBox(checkBox);
+        auto *checkBox = new QCheckBox(&msgBox);
+        checkBox->setText(tr("Don't show this message again"));
+        msgBox.setCheckBox(checkBox);
 #endif
-                int res = msgBox.exec();
+        int res = msgBox.exec();
 #if QT_VERSION >= 0x050200
-                if(checkBox->isChecked()) {
-                    Settings::values().editor.askBeforeDeleting = false;
-                }
+        if(checkBox->isChecked()) {
+            Settings::values().editor.askBeforeDeleting = false;
+        }
 #endif
-                if(res != QMessageBox::Yes) {
-                    return false;
-                }
-            }
-            m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::Saving);
-            m_ui->makingNotificationWidget->setNotificationType(NotificationType::Information);
-            m_ui->makingNotificationWidget->setHidden(false);
-            m_makingResultsAvailable = true;
-            if(m_fileInfo.isOpen()) {
-                if(m_fileInfo.hasAnyTag()) {
-                    foreachTagEdit([] (TagEdit *edit) {edit->clear();});
-                    m_fileInfo.removeAllTags();
-                    m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::None);
-                    m_ui->makingNotificationWidget->setNotificationType(NotificationType::Progress);
-                    static const QString statusMsg(tr("Deleting all tags ..."));
-                    m_ui->makingNotificationWidget->setText(statusMsg);
-                    emit statusMessage(statusMsg);
-                } else {
-                    m_ui->makingNotificationWidget->setText(tr("The selected file stores no tag (at least no supported), so there is nothing to delete."));
-                    return false;
-                }
-            } else {
-                m_ui->makingNotificationWidget->setText(tr("No file has been opened, so no tags can be deleted."));
-                return false;
-            }
-        } else {
-            static const QString statusMsg(tr("Unable to delete all tags from the file because the current process hasn't been finished yet."));
-            m_ui->makingNotificationWidget->setText(statusMsg);
-            emit statusMessage(statusMsg);
+        if(res != QMessageBox::Yes) {
+            m_ui->makingNotificationWidget->setText(tr("Deletion aborted."));
             return false;
         }
     }
+
+    m_makingResultsAvailable = true;
+
+    foreachTagEdit([] (TagEdit *edit) {edit->clear();});
+    m_fileInfo.removeAllTags();
+    m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::None);
+    m_ui->makingNotificationWidget->setNotificationType(NotificationType::Progress);
+    static const QString statusMsg(tr("Deleting all tags ..."));
+    m_ui->makingNotificationWidget->setText(statusMsg);
+    emit statusMessage(statusMsg);
     return startSaving();
 }
 
 /*!
  * \brief Starts saving. This method is called by applyEntriesAndSaveChangings() and deleteAllTagsAndSave().
+ *
  * The actual process is performed in another thread.
+ *
  * \remarks Will start a new thread to perform the operation. Then showSavingResult() is called
- *          using Qt::QueuedConnection in the main thread. m_fileOperationMutex will remain locked when saving is
- *          finished and will be unlocked in showSavingResult(). This way any method which might be called after
- *          the operation thread ends and before the invokation of showSavingResult() will see a locked mutex and
- *          hence not mutate the current file.
+ *          using Qt::QueuedConnection in the main thread.
  */
 bool TagEditorWidget::startSaving()
 {
-    TryLocker<> locker(m_fileOperationMutex);
-    if(locker) {
-        // tags might get invalidated
-        m_tags.clear();
-        foreachTagEdit([] (TagEdit *edit) { edit->setTag(nullptr, false); });
-        // show abort button
-        m_ui->abortButton->setHidden(false);
-        m_ui->abortButton->setEnabled(true);
-        m_abortClicked = false;
-        // remove current path from file watcher
-        m_fileWatcher->removePath(m_currentPath);
-        // use current configuration
-        const auto &settings = Settings::values().tagPocessing.fileLayout;
-        m_fileInfo.setForceRewrite(settings.forceRewrite);
-        m_fileInfo.setTagPosition(settings.preferredTagPosition);
-        m_fileInfo.setForceTagPosition(settings.forceTagPosition);
-        m_fileInfo.setIndexPosition(settings.preferredIndexPosition);
-        m_fileInfo.setForceIndexPosition(settings.forceIndexPosition);
-        m_fileInfo.setMinPadding(settings.minPadding);
-        m_fileInfo.setMaxPadding(settings.maxPadding);
-        m_fileInfo.setPreferredPadding(settings.preferredPadding);
-        // define functions to show the saving progress and to actually applying the changes
-        auto showProgress = [this] (StatusProvider &sender) -> void {
-            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setPercentage", Qt::QueuedConnection, Q_ARG(int, static_cast<int>(sender.currentPercentage() * 100.0)));
-            if(m_abortClicked) {
-                QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, tr("Cancelling ...")));
-                m_fileInfo.tryToAbort();
-            } else {
-                QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, QString::fromStdString(sender.currentStatus())));
-            }
-        };
-        auto startThread = [this] {
-            m_fileOperationMutex.lock();
-            bool processingError = false, ioError = false;
-            try {
-                try {
-                    m_fileInfo.applyChanges();
-                } catch(const Failure &) {
-                    processingError = true;
-                } catch(...) {
-                    ::IoUtilities::catchIoFailure();
-                    ioError = true;
-                }
-            } catch(const exception &e) {
-                m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "making");
-                processingError = true;
-            } catch(...) {
-                m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "making");
-                processingError = true;
-            }
-            m_fileInfo.unregisterAllCallbacks();
-            QMetaObject::invokeMethod(this, "showSavingResult", Qt::QueuedConnection, Q_ARG(bool, processingError), Q_ARG(bool, ioError));
-            // showSavingResult() will unlock the mutex!
-        };
-        m_fileInfo.unregisterAllCallbacks();
-        m_fileInfo.registerCallback(showProgress);
-        // use another thread to perform the operation
-        QtConcurrent::run(startThread);
-        return true;
-    } else {
+    if(m_fileOperationOngoing) {
         static const QString errorMsg(tr("Unable to start saving process because there an other process hasn't finished yet."));
         emit statusMessage(errorMsg);
         QMessageBox::warning(this, QApplication::applicationName(), errorMsg);
         return false;
     }
+
+    // tags might get invalidated
+    m_tags.clear();
+    foreachTagEdit([] (TagEdit *edit) { edit->setTag(nullptr, false); });
+    // show abort button
+    m_ui->abortButton->setHidden(false);
+    m_ui->abortButton->setEnabled(true);
+    m_abortClicked = false;
+    // remove current path from file watcher
+    m_fileWatcher->removePath(m_currentPath);
+    // use current configuration
+    const auto &settings = Settings::values().tagPocessing.fileLayout;
+    m_fileInfo.setForceRewrite(settings.forceRewrite);
+    m_fileInfo.setTagPosition(settings.preferredTagPosition);
+    m_fileInfo.setForceTagPosition(settings.forceTagPosition);
+    m_fileInfo.setIndexPosition(settings.preferredIndexPosition);
+    m_fileInfo.setForceIndexPosition(settings.forceIndexPosition);
+    m_fileInfo.setMinPadding(settings.minPadding);
+    m_fileInfo.setMaxPadding(settings.maxPadding);
+    m_fileInfo.setPreferredPadding(settings.preferredPadding);
+    // define functions to show the saving progress and to actually applying the changes
+    auto showProgress = [this] (StatusProvider &sender) -> void {
+        QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setPercentage", Qt::QueuedConnection, Q_ARG(int, static_cast<int>(sender.currentPercentage() * 100.0)));
+        if(m_abortClicked) {
+            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, tr("Cancelling ...")));
+            m_fileInfo.tryToAbort();
+        } else {
+            QMetaObject::invokeMethod(m_ui->makingNotificationWidget, "setText", Qt::QueuedConnection, Q_ARG(QString, QString::fromStdString(sender.currentStatus())));
+        }
+    };
+    auto startThread = [this] {
+        bool processingError = false, ioError = false;
+        try {
+            try {
+                m_fileInfo.applyChanges();
+            } catch(const Failure &) {
+                processingError = true;
+            } catch(...) {
+                ::IoUtilities::catchIoFailure();
+                ioError = true;
+            }
+        } catch(const exception &e) {
+            m_fileInfo.addNotification(Media::NotificationType::Critical, string("Something completely unexpected happened: ") + e.what(), "making");
+            processingError = true;
+        } catch(...) {
+            m_fileInfo.addNotification(Media::NotificationType::Critical, "Something completely unexpected happened", "making");
+            processingError = true;
+        }
+        m_fileInfo.unregisterAllCallbacks();
+        QMetaObject::invokeMethod(this, "showSavingResult", Qt::QueuedConnection, Q_ARG(bool, processingError), Q_ARG(bool, ioError));
+    };
+    m_fileInfo.unregisterAllCallbacks();
+    m_fileInfo.registerCallback(showProgress);
+    m_fileOperationOngoing = true;
+    // use another thread to perform the operation
+    QtConcurrent::run(startThread);
+    return true;
 }
 
 /*!
  * \brief Shows the saving results.
+ *
  * This private slot is invoked from the thread which performed the
  * saving operation using Qt::QueuedConnection.
+ *
  * \param sucess Specifies whether the file could be saved sucessfully.
- * \remarks Expects m_fileOperationMutex to be locked!
  */
 void TagEditorWidget::showSavingResult(bool processingError, bool ioError)
 {
+    m_fileOperationOngoing = false;
     m_ui->abortButton->setHidden(true);
     m_ui->makingNotificationWidget->setNotificationType(NotificationType::TaskComplete);
     m_ui->makingNotificationWidget->setNotificationSubject(NotificationSubject::Saving);
@@ -1166,7 +1153,6 @@ void TagEditorWidget::showSavingResult(bool processingError, bool ioError)
         }
         m_ui->makingNotificationWidget->setText(statusMsg);
         emit statusMessage(statusMsg);
-        m_fileOperationMutex.unlock();
         // let the main window know that the current file has been saved
         // -> the main window will ensure the current file is still selected
         emit currentPathChanged(m_currentPath);
@@ -1193,7 +1179,6 @@ void TagEditorWidget::showSavingResult(bool processingError, bool ioError)
         // -> reset "save as path" in any case after fatal error
         m_fileInfo.setSaveFilePath(string());
 
-        m_fileOperationMutex.unlock();
         startParsing(m_currentPath, true);
     }
 }
@@ -1230,18 +1215,18 @@ void TagEditorWidget::fileChangedOnDisk(const QString &path)
  */
 void TagEditorWidget::closeFile()
 {
-    TryLocker<> locker(m_fileOperationMutex);
-    if(locker) {
-        // close file
-        m_fileInfo.close();
-        // remove current path from file watcher
-        m_fileWatcher->removePath(m_currentPath);
-        // update ui
-        emit statusMessage("The file has been closed.");
-        updateFileStatusStatus();
-    } else {
+    if(m_fileOperationOngoing) {
         emit statusMessage("Unable to close the file because the current process hasn't been finished yet.");
+        return;
     }
+
+    // close file
+    m_fileInfo.close();
+    // remove current path from file watcher
+    m_fileWatcher->removePath(m_currentPath);
+    // update ui
+    emit statusMessage("The file has been closed.");
+    updateFileStatusStatus();
 }
 
 /*!
@@ -1300,28 +1285,29 @@ void TagEditorWidget::applySettingsFromDialog()
  */
 void TagEditorWidget::addTag(const function<Media::Tag *(Media::MediaFileInfo &)> &createTag)
 {
-    TryLocker<> locker(m_fileOperationMutex);
-    if(locker) {
-        if(!m_fileInfo.isOpen()) {
-            emit statusMessage("Unable to add a tag because no file is opened.");
+    if(m_fileOperationOngoing) {
+        emit statusMessage("Unable to add a tag because the current process hasn't been finished yet.");
+        return;
+    }
+    if(!m_fileInfo.isOpen()) {
+        emit statusMessage("Unable to add a tag because no file is opened.");
+        return;
+    }
+
+    if(Tag *tag = createTag(m_fileInfo)) {
+        if(std::find(m_tags.cbegin(), m_tags.cend(), tag) != m_tags.cend()) {
+            QMessageBox::warning(this, windowTitle(), tr("A tag (with the selected target) already exists."));
             return;
         }
-        if(Tag *tag = createTag(m_fileInfo)) {
-            if(std::find(m_tags.cbegin(), m_tags.cend(), tag) == m_tags.cend()) {
-                m_tags.push_back(tag);
-                updateTagEditsAndAttachmentEdits(true, m_tags.size() > 1 ? PreviousValueHandling::Keep : PreviousValueHandling::Auto);
-                updateTagSelectionComboBox();
-                updateTagManagementMenu();
-                updateFileStatusStatus();
-                insertTitleFromFilename();
-            } else {
-                QMessageBox::warning(this, windowTitle(), tr("A tag (with the selected target) already exists."));
-            }
-        } else {
-            QMessageBox::warning(this, windowTitle(), tr("The tag can not be created."));
-        }
+
+        m_tags.push_back(tag);
+        updateTagEditsAndAttachmentEdits(true, m_tags.size() > 1 ? PreviousValueHandling::Keep : PreviousValueHandling::Auto);
+        updateTagSelectionComboBox();
+        updateTagManagementMenu();
+        updateFileStatusStatus();
+        insertTitleFromFilename();
     } else {
-        emit statusMessage("Unable to add a tag because the current process hasn't been finished yet.");
+        QMessageBox::warning(this, windowTitle(), tr("The tag can not be created."));
     }
 }
 
@@ -1333,53 +1319,51 @@ void TagEditorWidget::addTag(const function<Media::Tag *(Media::MediaFileInfo &)
 void TagEditorWidget::removeTag(Tag *tag)
 {
     if(tag) {
-        TryLocker<> locker(m_fileOperationMutex);
-        if(locker) {
-            if(!m_fileInfo.isOpen()) {
-                emit statusMessage(tr("Unable to remove the tag because no file is opened."));
-                return;
-            }
-            if(m_fileInfo.isOpen()) {
-                m_fileInfo.removeTag(tag);
-                // remove tag from m_tags
-                m_tags.erase(remove(m_tags.begin(), m_tags.end(), tag), m_tags.end());
-                // remove tag from all TagEdit widgets
-                vector<TagEdit *> toRemove;
-                for(int index = 0, count = m_ui->stackedWidget->count(); index < count; ++index) {
-                    TagEdit *edit = qobject_cast<TagEdit *>(m_ui->stackedWidget->widget(index));
-                    if(edit && edit->tags().contains(tag)) {
-                        QList<Tag *> tagsOfEdit = edit->tags();
-                        tagsOfEdit.removeAll(tag);
-                        if(tagsOfEdit.empty()) {
-                            // no tags left in the edit
-                            if(m_tags.empty()) {
-                                // there are no other tag edits -> just disable the edit
-                                edit->setTag(nullptr, false);
-                            } else {
-                                // there are still other tag edits -> remove the edit
-                                toRemove.push_back(edit);
-                            }
-                        } else {
-                            // there are still tags left, reassign remaining tags (keeping the previous values)
-                            edit->setPreviousValueHandling(PreviousValueHandling::Keep);
-                            edit->setTags(tagsOfEdit, true);
-                        }
-                    }
-                }
-                // remove TagEdit widgets
-                for(TagEdit *edit : toRemove) {
-                    m_ui->tagSelectionComboBox->removeItem(m_ui->stackedWidget->indexOf(edit));
-                    m_ui->stackedWidget->removeWidget(edit);
-                    delete edit;
-                }
-                // update affected widgets
-                updateTagSelectionComboBox();
-                updateTagManagementMenu();
-                updateFileStatusStatus();
-            }
-        } else {
+        if(m_fileOperationOngoing) {
             emit statusMessage(tr("Unable to remove the tag because the current process hasn't been finished yet."));
+            return;
         }
+        if(!m_fileInfo.isOpen()) {
+            emit statusMessage(tr("Unable to remove the tag because no file is opened."));
+            return;
+        }
+
+        m_fileInfo.removeTag(tag);
+        // remove tag from m_tags
+        m_tags.erase(remove(m_tags.begin(), m_tags.end(), tag), m_tags.end());
+        // remove tag from all TagEdit widgets
+        vector<TagEdit *> toRemove;
+        for(int index = 0, count = m_ui->stackedWidget->count(); index < count; ++index) {
+            TagEdit *edit = qobject_cast<TagEdit *>(m_ui->stackedWidget->widget(index));
+            if(edit && edit->tags().contains(tag)) {
+                QList<Tag *> tagsOfEdit = edit->tags();
+                tagsOfEdit.removeAll(tag);
+                if(tagsOfEdit.empty()) {
+                    // no tags left in the edit
+                    if(m_tags.empty()) {
+                        // there are no other tag edits -> just disable the edit
+                        edit->setTag(nullptr, false);
+                    } else {
+                        // there are still other tag edits -> remove the edit
+                        toRemove.push_back(edit);
+                    }
+                } else {
+                    // there are still tags left, reassign remaining tags (keeping the previous values)
+                    edit->setPreviousValueHandling(PreviousValueHandling::Keep);
+                    edit->setTags(tagsOfEdit, true);
+                }
+            }
+        }
+        // remove TagEdit widgets
+        for(TagEdit *edit : toRemove) {
+            m_ui->tagSelectionComboBox->removeItem(m_ui->stackedWidget->indexOf(edit));
+            m_ui->stackedWidget->removeWidget(edit);
+            delete edit;
+        }
+        // update affected widgets
+        updateTagSelectionComboBox();
+        updateTagManagementMenu();
+        updateFileStatusStatus();
     }
 }
 
@@ -1391,27 +1375,25 @@ void TagEditorWidget::removeTag(Tag *tag)
 void TagEditorWidget::changeTarget(Tag *tag)
 {
     if(tag) {
-        TryLocker<> locker(m_fileOperationMutex);
-        if(locker) {
-            if(!m_fileInfo.isOpen()) {
-                emit statusMessage(tr("Unable to change the target because no file is opened."));
-                return;
-            }
-            if(m_fileInfo.isOpen()) {
-                if(tag->supportsTarget()) {
-                    EnterTargetDialog targetDlg(this);
-                    targetDlg.setTarget(tag->target(), &m_fileInfo);
-                    if(targetDlg.exec() == QDialog::Accepted) {
-                        tag->setTarget(targetDlg.target());
-                        updateTagSelectionComboBox();
-                        updateTagManagementMenu();
-                    }
-                } else {
-                    QMessageBox::warning(this, windowTitle(), tr("Can not change the target of the selected tag because the tag does not support targets."));
-                }
-            }
-        } else {
+        if(m_fileOperationOngoing) {
             emit statusMessage(tr("Unable to change the target because the current process hasn't been finished yet."));
+            return;
+        }
+        if(!m_fileInfo.isOpen()) {
+            emit statusMessage(tr("Unable to change the target because no file is opened."));
+            return;
+        }
+        if(!tag->supportsTarget()) {
+            QMessageBox::warning(this, windowTitle(), tr("Can not change the target of the selected tag because the tag does not support targets."));
+            return;
+        }
+
+        EnterTargetDialog targetDlg(this);
+        targetDlg.setTarget(tag->target(), &m_fileInfo);
+        if(targetDlg.exec() == QDialog::Accepted) {
+            tag->setTarget(targetDlg.target());
+            updateTagSelectionComboBox();
+            updateTagManagementMenu();
         }
     }
 }

gui/tageditorwidget.h

@@ -7,7 +7,6 @@
 
 #include <QWidget>
 #include <QByteArray>
-#include <QMutex>
 
 #include <functional>
 
@@ -55,7 +54,7 @@ public:
     ~TagEditorWidget();
 
 public:
-    QMutex &fileOperationMutex();
+    bool fileOperationOngoing() const;
     const QString &currentPath() const;
     const QString &currentDir() const;
     Media::MediaFileInfo &fileInfo();
@@ -151,15 +150,15 @@ private:
     bool m_makingResultsAvailable;
     Media::NotificationList m_originalNotifications;
     bool m_abortClicked;
-    QMutex m_fileOperationMutex;
+    bool m_fileOperationOngoing;
 };
 
 /*!
  * \brief Returns the mutex which is internally used for thread-synchronization.
  */
-inline QMutex &TagEditorWidget::fileOperationMutex()
+inline bool TagEditorWidget::fileOperationOngoing() const
 {
-    return m_fileOperationMutex;
+    return m_fileOperationOngoing;
 }
 
 /*!