tdf#119856 vcl: convert Qt5FilePicker and Qt5Menu to RunInMainThread

... and also convert KDE5FilePicker. And Qt5Frame.

The UNO methods in Qt5FilePicker/KDE5FilePicker have to ensure that the
thread actually owns SolarMutex, because if RunInMainThread() is
called without that it will deadlock.

Change-Id: Ie4d2f494ac81c799ec7c9a3acb3a9b0f77bb6361
Reviewed-on: https://gerrit.libreoffice.org/68357
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

vcl/inc/qt5/Qt5FilePicker.hxx

@@ -158,121 +158,6 @@ protected:
     virtual void addCustomControl(sal_Int16 controlId);
     void setCustomControlWidgetLayout(QGridLayout* pLayout) { m_pLayout = pLayout; }
 
-private Q_SLOTS:
-    // XExecutableDialog functions
-    /// @throws css::uno::RuntimeException
-    void setTitleSlot(const OUString& rTitle) { return setTitle(rTitle); }
-    /// @throws css::uno::RuntimeException
-    sal_Int16 executeSlot() { return execute(); }
-
-    // XFilePicker functions
-    /// @throws css::uno::RuntimeException
-    void setMultiSelectionModeSlot(bool bMode) { return setMultiSelectionMode(bMode); }
-    /// @throws css::uno::RuntimeException
-    void setDefaultNameSlot(const OUString& rName) { return setDefaultName(rName); }
-    /// @throws css::uno::RuntimeException
-    void setDisplayDirectorySlot(const OUString& rDirectory)
-    {
-        return setDisplayDirectory(rDirectory);
-    }
-    /// @throws css::uno::RuntimeException
-    OUString getDisplayDirectorySlot() { return getDisplayDirectory(); }
-    /// @throws css::uno::RuntimeException
-    css::uno::Sequence<OUString> getFilesSlot() { return getFiles(); }
-
-    // XFilterManager functions
-    /// @throws css::lang::IllegalArgumentException
-    /// @throws css::uno::RuntimeException
-    void appendFilterSlot(const OUString& rTitle, const OUString& rFilter)
-    {
-        return appendFilter(rTitle, rFilter);
-    }
-    /// @throws css::lang::IllegalArgumentException
-    /// @throws css::uno::RuntimeException
-    void setCurrentFilterSlot(const OUString& rTitle) { return setCurrentFilter(rTitle); }
-    /// @throws css::uno::RuntimeException
-    OUString getCurrentFilterSlot() { return getCurrentFilter(); }
-
-    // XFilterGroupManager functions
-    /// @throws css::lang::IllegalArgumentException
-    /// @throws css::uno::RuntimeException
-    void appendFilterGroupSlot(const OUString& rGroupTitle,
-                               const css::uno::Sequence<css::beans::StringPair>& rFilters)
-    {
-        return appendFilterGroup(rGroupTitle, rFilters);
-    }
-
-    // XFilePickerControlAccess functions
-    /// @throws css::uno::RuntimeException
-    void setValueSlot(sal_Int16 nControlId, sal_Int16 nControlAction, const css::uno::Any& rValue)
-    {
-        return setValue(nControlId, nControlAction, rValue);
-    }
-    /// @throws css::uno::RuntimeException
-    css::uno::Any getValueSlot(sal_Int16 nControlId, sal_Int16 nControlAction)
-    {
-        return getValue(nControlId, nControlAction);
-    }
-    /// @throws css::uno::RuntimeException
-    void enableControlSlot(sal_Int16 nControlId, bool bEnable)
-    {
-        return enableControl(nControlId, bEnable);
-    }
-    /// @throws css::uno::RuntimeException
-    void setLabelSlot(sal_Int16 nControlId, const OUString& rLabel)
-    {
-        return setLabel(nControlId, rLabel);
-    }
-    /// @throws css::uno::RuntimeException
-    OUString getLabelSlot(sal_Int16 nControlId) { return getLabel(nControlId); }
-
-    // XFilePicker2 functions
-    /// @throws css::uno::RuntimeException
-    css::uno::Sequence<OUString> getSelectedFilesSlot() { return getSelectedFiles(); }
-
-    // XInitialization
-    /// @throws css::uno::Exception
-    /// @throws css::uno::RuntimeException
-    void initializeSlot(const css::uno::Sequence<css::uno::Any>& rArguments)
-    {
-        return initialize(rArguments);
-    }
-
-Q_SIGNALS:
-    // XExecutableDialog functions
-    void setTitleSignal(const OUString& rTitle);
-    sal_Int16 executeSignal();
-
-    // XFilePicker functions
-    void setMultiSelectionModeSignal(bool bMode);
-    void setDefaultNameSignal(const OUString& rName);
-    void setDisplayDirectorySignal(const OUString& rDirectory);
-    OUString getDisplayDirectorySignal();
-    css::uno::Sequence<OUString> getFilesSignal();
-
-    // XFilterManager functions
-    void appendFilterSignal(const OUString& rTitle, const OUString& rFilter);
-    void setCurrentFilterSignal(const OUString& rTitle);
-    OUString getCurrentFilterSignal();
-
-    // XFilterGroupManager functions
-    void appendFilterGroupSignal(const OUString& rGroupTitle,
-                                 const css::uno::Sequence<css::beans::StringPair>& rFilters);
-
-    // XFilePickerControlAccess functions
-    void setValueSignal(sal_Int16 nControlId, sal_Int16 nControlAction,
-                        const css::uno::Any& rValue);
-    css::uno::Any getValueSignal(sal_Int16 nControlId, sal_Int16 nControlAction);
-    void enableControlSignal(sal_Int16 nControlId, bool bEnable);
-    void setLabelSignal(sal_Int16 nControlId, const OUString& rLabel);
-    OUString getLabelSignal(sal_Int16 nControlId);
-
-    // XFilePicker2 functions
-    css::uno::Sequence<OUString> getSelectedFilesSignal();
-
-    // XInitialization
-    void initializeSignal(const css::uno::Sequence<css::uno::Any>& rArguments);
-
 private:
     Qt5FilePicker(const Qt5FilePicker&) = delete;
     Qt5FilePicker& operator=(const Qt5FilePicker&) = delete;

vcl/inc/qt5/Qt5Frame.hxx

@@ -107,11 +107,10 @@ class VCLPLUG_QT5_PUBLIC Qt5Frame : public QObject, public SalFrame
     void TriggerPaintEvent();
     void TriggerPaintEvent(QRect aRect);
 
-private Q_SLOTS:
+private:
     void setVisible(bool);
 
 Q_SIGNALS:
-    void setVisibleSignal(bool);
     void tooltipRequest(const OUString& rTooltip);
 
 public:

vcl/qt5/Qt5FilePicker.cxx

@@ -101,62 +101,6 @@ Qt5FilePicker::Qt5FilePicker(QFileDialog::FileMode eMode, bool bShowFileExtensio
 
     setMultiSelectionMode(false);
 
-    // XExecutableDialog functions
-    connect(this, SIGNAL(setTitleSignal(const OUString&)), this,
-            SLOT(setTitleSlot(const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(executeSignal()), this, SLOT(executeSlot()), Qt::BlockingQueuedConnection);
-
-    // XFilePicker functions
-    connect(this, SIGNAL(setMultiSelectionModeSignal(bool)), this,
-            SLOT(setMultiSelectionModeSlot(bool)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(setDefaultNameSignal(const OUString&)), this,
-            SLOT(setDefaultNameSlot(const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(setDisplayDirectorySignal(const OUString&)), this,
-            SLOT(setDisplayDirectorySlot(const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(getDisplayDirectorySignal()), this, SLOT(getDisplayDirectorySlot()),
-            Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(getFilesSignal()), this, SLOT(getFilesSlot()),
-            Qt::BlockingQueuedConnection);
-
-    // XFilterManager functions
-    connect(this, SIGNAL(appendFilterSignal(const OUString&, const OUString&)), this,
-            SLOT(appendFilterSlot(const OUString&, const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(setCurrentFilterSignal(const OUString&)), this,
-            SLOT(setCurrentFilterSlot(const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(getCurrentFilterSignal()), this, SLOT(getCurrentFilterSlot()),
-            Qt::BlockingQueuedConnection);
-
-    // XFilterGroupManager functions
-    connect(this,
-            SIGNAL(appendFilterGroupSignal(const OUString&,
-                                           const css::uno::Sequence<css::beans::StringPair>&)),
-            this,
-            SLOT(appendFilterGroupSlot(const OUString&,
-                                       const css::uno::Sequence<css::beans::StringPair>&)),
-            Qt::BlockingQueuedConnection);
-
-    // XFilePickerControlAccess functions
-    connect(this, SIGNAL(setValueSignal(sal_Int16, sal_Int16, const css::uno::Any&)), this,
-            SLOT(setValueSlot(sal_Int16, sal_Int16, const css::uno::Any&)),
-            Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(getValueSignal(sal_Int16, sal_Int16)), this,
-            SLOT(getValueSlot(sal_Int16, sal_Int16)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(enableControlSignal(sal_Int16, bool)), this,
-            SLOT(enableControlSlot(sal_Int16, bool)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(setLabelSignal(sal_Int16, const OUString&)), this,
-            SLOT(setLabelSlot(sal_Int16, const OUString&)), Qt::BlockingQueuedConnection);
-    connect(this, SIGNAL(getLabelSignal(sal_Int16)), this, SLOT(getLabelSlot(sal_Int16)),
-            Qt::BlockingQueuedConnection);
-
-    // XFilePicker2 functions
-    connect(this, SIGNAL(getSelectedFilesSignal()), this, SLOT(getSelectedFilesSlot()),
-            Qt::BlockingQueuedConnection);
-
-    // XInitialization
-    connect(this, SIGNAL(initializeSignal(const css::uno::Sequence<css::uno::Any>&)), this,
-            SLOT(initializeSlot(const css::uno::Sequence<css::uno::Any>&)),
-            Qt::BlockingQueuedConnection);
-
     // XFilePickerListener notifications
     connect(m_pFileDialog.get(), SIGNAL(filterSelected(const QString&)), this,
             SLOT(filterSelected(const QString&)));
@@ -170,6 +114,7 @@ Qt5FilePicker::Qt5FilePicker(QFileDialog::FileMode eMode, bool bShowFileExtensio
 
 Qt5FilePicker::~Qt5FilePicker()
 {
+    SolarMutexGuard g;
     auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
     assert(pSalInst);
     pSalInst->RunInMainThread([this]() {
@@ -194,21 +139,23 @@ void SAL_CALL Qt5FilePicker::removeFilePickerListener(const uno::Reference<XFile
 
 void SAL_CALL Qt5FilePicker::setTitle(const OUString& title)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setTitleSignal(title);
-    }
-
-    m_pFileDialog->setWindowTitle(toQString(title));
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread(
+        [this, &title]() { m_pFileDialog->setWindowTitle(toQString(title)); });
 }
 
 sal_Int16 SAL_CALL Qt5FilePicker::execute()
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT executeSignal();
+        sal_uInt16 ret;
+        pSalInst->RunInMainThread([&ret, this]() { ret = execute(); });
+        return ret;
     }
 
     vcl::Window* pWindow = ::Application::GetActiveTopWindow();
@@ -247,58 +194,50 @@ sal_Int16 SAL_CALL Qt5FilePicker::execute()
 
 void SAL_CALL Qt5FilePicker::setMultiSelectionMode(sal_Bool multiSelect)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setMultiSelectionModeSignal(multiSelect);
-    }
-
-    if (m_bIsFolderPicker || m_pFileDialog->acceptMode() == QFileDialog::AcceptSave)
-        return;
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, multiSelect]() {
+        if (m_bIsFolderPicker || m_pFileDialog->acceptMode() == QFileDialog::AcceptSave)
+            return;
 
-    m_pFileDialog->setFileMode(multiSelect ? QFileDialog::ExistingFiles
-                                           : QFileDialog::ExistingFile);
+        m_pFileDialog->setFileMode(multiSelect ? QFileDialog::ExistingFiles
+                                               : QFileDialog::ExistingFile);
+    });
 }
 
 void SAL_CALL Qt5FilePicker::setDefaultName(const OUString& name)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setDefaultNameSignal(name);
-    }
-    m_pFileDialog->selectFile(toQString(name));
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, &name]() { m_pFileDialog->selectFile(toQString(name)); });
 }
 
 void SAL_CALL Qt5FilePicker::setDisplayDirectory(const OUString& dir)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setDisplayDirectorySignal(dir);
-    }
-
-    QString qDir(toQString(dir));
-    m_pFileDialog->setDirectoryUrl(QUrl(qDir));
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, &dir]() {
+        QString qDir(toQString(dir));
+        m_pFileDialog->setDirectoryUrl(QUrl(qDir));
+    });
 }
 
 OUString SAL_CALL Qt5FilePicker::getDisplayDirectory()
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getDisplayDirectorySignal();
-    }
-    return toOUString(m_pFileDialog->directoryUrl().toString());
+    SolarMutexGuard g;
+    OUString ret;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread(
+        [&ret, this]() { ret = toOUString(m_pFileDialog->directoryUrl().toString()); });
+    return ret;
 }
 
 uno::Sequence<OUString> SAL_CALL Qt5FilePicker::getFiles()
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getFilesSignal();
-    }
     uno::Sequence<OUString> seq = getSelectedFiles();
     if (seq.getLength() > 1)
         seq.realloc(1);
@@ -307,12 +246,12 @@ uno::Sequence<OUString> SAL_CALL Qt5FilePicker::getFiles()
 
 uno::Sequence<OUString> SAL_CALL Qt5FilePicker::getSelectedFiles()
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getSelectedFilesSignal();
-    }
-    QList<QUrl> urls = m_pFileDialog->selectedUrls();
+    SolarMutexGuard g;
+    QList<QUrl> urls;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([&urls, this]() { urls = m_pFileDialog->selectedUrls(); });
+
     uno::Sequence<OUString> seq(urls.size());
 
     size_t i = 0;
@@ -324,10 +263,13 @@ uno::Sequence<OUString> SAL_CALL Qt5FilePicker::getSelectedFiles()
 
 void SAL_CALL Qt5FilePicker::appendFilter(const OUString& title, const OUString& filter)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT appendFilterSignal(title, filter);
+        pSalInst->RunInMainThread([this, &title, &filter]() { appendFilter(title, filter); });
+        return;
     }
 
     // '/' need to be escaped else they are assumed to be mime types
@@ -357,24 +299,24 @@ void SAL_CALL Qt5FilePicker::appendFilter(const OUString& title, const OUString&
 
 void SAL_CALL Qt5FilePicker::setCurrentFilter(const OUString& title)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setCurrentFilterSignal(title);
-    }
-
-    m_aCurrentFilter = m_aTitleToFilterMap.value(toQString(title).replace("/", "\\/"));
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, &title]() {
+        m_aCurrentFilter = m_aTitleToFilterMap.value(toQString(title).replace("/", "\\/"));
+    });
 }
 
 OUString SAL_CALL Qt5FilePicker::getCurrentFilter()
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getCurrentFilterSignal();
-    }
+    SolarMutexGuard g;
+    QString filter;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([&filter, this]() {
+        filter = m_aTitleToFilterMap.key(m_pFileDialog->selectedNameFilter());
+    });
 
-    QString filter = m_aTitleToFilterMap.key(m_pFileDialog->selectedNameFilter());
     if (filter.isEmpty())
         filter = "ODF Text Document (.odt)";
     return toOUString(filter);
@@ -383,10 +325,14 @@ OUString SAL_CALL Qt5FilePicker::getCurrentFilter()
 void SAL_CALL Qt5FilePicker::appendFilterGroup(const OUString& rGroupTitle,
                                                const uno::Sequence<beans::StringPair>& filters)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT appendFilterGroupSignal(rGroupTitle, filters);
+        pSalInst->RunInMainThread(
+            [this, &rGroupTitle, &filters]() { appendFilterGroup(rGroupTitle, filters); });
+        return;
     }
 
     const sal_uInt16 length = filters.getLength();
@@ -476,10 +422,15 @@ void Qt5FilePicker::handleSetListValue(QComboBox* pWidget, sal_Int16 nControlAct
 void SAL_CALL Qt5FilePicker::setValue(sal_Int16 controlId, sal_Int16 nControlAction,
                                       const uno::Any& value)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setValueSignal(controlId, nControlAction, value);
+        pSalInst->RunInMainThread([this, controlId, nControlAction, &value]() {
+            setValue(controlId, nControlAction, value);
+        });
+        return;
     }
 
     if (m_aCustomWidgetsMap.contains(controlId))
@@ -501,10 +452,16 @@ void SAL_CALL Qt5FilePicker::setValue(sal_Int16 controlId, sal_Int16 nControlAct
 
 uno::Any SAL_CALL Qt5FilePicker::getValue(sal_Int16 controlId, sal_Int16 nControlAction)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getValueSignal(controlId, nControlAction);
+        uno::Any ret;
+        pSalInst->RunInMainThread([&ret, this, controlId, nControlAction]() {
+            ret = getValue(controlId, nControlAction);
+        });
+        return ret;
     }
 
     uno::Any res(false);
@@ -529,24 +486,26 @@ uno::Any SAL_CALL Qt5FilePicker::getValue(sal_Int16 controlId, sal_Int16 nContro
 
 void SAL_CALL Qt5FilePicker::enableControl(sal_Int16 controlId, sal_Bool enable)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT enableControlSignal(controlId, enable);
-    }
-
-    if (m_aCustomWidgetsMap.contains(controlId))
-        m_aCustomWidgetsMap.value(controlId)->setEnabled(enable);
-    else
-        SAL_WARN("vcl.qt5", "enable unknown control " << controlId);
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, controlId, enable]() {
+        if (m_aCustomWidgetsMap.contains(controlId))
+            m_aCustomWidgetsMap.value(controlId)->setEnabled(enable);
+        else
+            SAL_WARN("vcl.qt5", "enable unknown control " << controlId);
+    });
 }
 
 void SAL_CALL Qt5FilePicker::setLabel(sal_Int16 controlId, const OUString& label)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setLabelSignal(controlId, label);
+        pSalInst->RunInMainThread([this, controlId, label]() { setLabel(controlId, label); });
+        return;
     }
 
     if (m_aCustomWidgetsMap.contains(controlId))
@@ -561,10 +520,14 @@ void SAL_CALL Qt5FilePicker::setLabel(sal_Int16 controlId, const OUString& label
 
 OUString SAL_CALL Qt5FilePicker::getLabel(sal_Int16 controlId)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getLabelSignal(controlId);
+        OUString ret;
+        pSalInst->RunInMainThread([&ret, this, controlId]() { ret = getLabel(controlId); });
+        return ret;
     }
 
     QString label;
@@ -696,16 +659,6 @@ void Qt5FilePicker::addCustomControl(sal_Int16 controlId)
 
 void SAL_CALL Qt5FilePicker::initialize(const uno::Sequence<uno::Any>& args)
 {
-    if (qApp->thread() != QThread::currentThread())
-    {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT initializeSignal(args);
-    }
-
-    m_aNamedFilterList.clear();
-    m_aTitleToFilterMap.clear();
-    m_aCurrentFilter.clear();
-
     // parameter checking
     uno::Any arg;
     if (args.getLength() == 0)
@@ -722,6 +675,19 @@ void SAL_CALL Qt5FilePicker::initialize(const uno::Sequence<uno::Any>& args)
                                              static_cast<XFilePicker2*>(this), 1);
     }
 
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
+    {
+        pSalInst->RunInMainThread([this, args]() { initialize(args); });
+        return;
+    }
+
+    m_aNamedFilterList.clear();
+    m_aTitleToFilterMap.clear();
+    m_aCurrentFilter.clear();
+
     sal_Int16 templateId = -1;
     arg >>= templateId;
 

vcl/qt5/Qt5Frame.cxx

@@ -128,7 +128,6 @@ Qt5Frame::Qt5Frame(Qt5Frame* pParent, SalFrameStyleFlags nStyle, bool bUseCairo)
     else
         m_pQWidget = new Qt5Widget(*this, aWinFlags);
 
-    connect(this, SIGNAL(setVisibleSignal(bool)), SLOT(setVisible(bool)));
     connect(this, &Qt5Frame::tooltipRequest, static_cast<Qt5Widget*>(m_pQWidget),
             &Qt5Widget::showTooltip);
 
@@ -358,7 +357,9 @@ void Qt5Frame::Show(bool bVisible, bool /*bNoActivate*/)
     if (m_bDefaultSize)
         SetDefaultSize();
 
-    Q_EMIT setVisibleSignal(bVisible);
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    pSalInst->RunInMainThread([this, bVisible]() { setVisible(bVisible); });
 }
 
 void Qt5Frame::SetMinClientSize(long nWidth, long nHeight)

vcl/qt5/Qt5Menu.cxx

@@ -12,6 +12,7 @@
 #include <Qt5Bitmap.hxx>
 #include <Qt5Menu.hxx>
 #include <Qt5Menu.moc>
+#include <Qt5Instance.hxx>
 
 #include <QtWidgets/QtWidgets>
 
@@ -390,10 +391,12 @@ void Qt5Menu::SetSubMenu(SalMenuItem* pSalMenuItem, SalMenu* pSubMenu, unsigned
 
 void Qt5Menu::SetFrame(const SalFrame* pFrame)
 {
-    if (qApp->thread() != QThread::currentThread())
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT setFrameSignal(pFrame);
+        pSalInst->RunInMainThread([this, pFrame]() { SetFrame(pFrame); });
+        return;
     }
 
     SolarMutexGuard aGuard;

vcl/unx/kde5/KDE5FilePicker.hxx

@@ -92,9 +92,6 @@ private:
 
 protected:
     bool eventFilter(QObject* watched, QEvent* event) override;
-
-Q_SIGNALS:
-    sal_Int16 executeSignal();
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/unx/kde5/KDE5FilePicker2.cxx

@@ -36,6 +36,7 @@
 
 #include <unx/geninst.h>
 #include <qt5/Qt5Tools.hxx>
+#include <qt5/Qt5Instance.hxx>
 
 #include <QtCore/QDebug>
 #include <QtCore/QThread>
@@ -107,19 +108,20 @@ KDE5FilePicker::KDE5FilePicker(QFileDialog::FileMode eMode)
         QStringLiteral("smb"),
     });
 
-    connect(this, &KDE5FilePicker::executeSignal, this, &KDE5FilePicker::execute,
-            Qt::BlockingQueuedConnection);
-
     // used to set the custom controls
     qApp->installEventFilter(this);
 }
 
 sal_Int16 SAL_CALL KDE5FilePicker::execute()
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        //SolarMutexReleaser aReleaser;
-        return Q_EMIT executeSignal();
+        sal_Int16 ret;
+        pSalInst->RunInMainThread([&ret, this] { ret = execute(); });
+        return ret;
     }
 
     if (!m_aNamedFilterList.isEmpty())
@@ -145,10 +147,16 @@ void SAL_CALL KDE5FilePicker::setValue(sal_Int16 controlId, sal_Int16 nControlAc
 
 uno::Any SAL_CALL KDE5FilePicker::getValue(sal_Int16 controlId, sal_Int16 nControlAction)
 {
-    if (qApp->thread() != QThread::currentThread())
+    SolarMutexGuard g;
+    auto* pSalInst(static_cast<Qt5Instance*>(GetSalData()->m_pInstance));
+    assert(pSalInst);
+    if (!pSalInst->IsMainThread())
     {
-        SolarMutexReleaser aReleaser;
-        return Q_EMIT getValueSignal(controlId, nControlAction);
+        uno::Any ret;
+        pSalInst->RunInMainThread([&ret, this, controlId, nControlAction]() {
+            ret = getValue(controlId, nControlAction);
+        });
+        return ret;
     }
 
     if (CHECKBOX_AUTOEXTENSION == controlId)

vcl/unx/kde5/KDE5SalInstance.cxx

@@ -61,6 +61,7 @@ KDE5SalInstance::createFilePicker(const uno::Reference<uno::XComponentContext>&
 {
     if (!IsMainThread())
     {
+        SolarMutexGuard g;
         uno::Reference<ui::dialogs::XFilePicker2> xRet;
         RunInMainThread(
             std::function([&xRet, this, xMSF]() { xRet = this->createFilePicker(xMSF); }));