VCL fix shutdown when run via system loop

Adds DoQuit and SAL_USE_SYSTEM_LOOP to complement DoExecute.
Makes it easier to switch between a LO with and without nested
event processing. Unfortunatly the recovery dialogs run outside
of Application::Execute(), so this currently also disables
recovery handling.

Follow-up (and no more Emscripten-specific) change to commit
93133585b5b52e38defc3162eeb1e7704dceafcb ("WASM optionally run
any app via system loop").

Change-Id: I1b622065d7fa0c5ad03a7c7daaf8241dcc3f09a3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128717
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

2 files changed, 18 insertions, 12 deletions

diff --git a/vcl/qt5/QtInstance.cxx b/vcl/qt5/QtInstance.cxx
index a03b71e46bd2..a52f6529c3bc 100644
--- a/vcl/qt5/QtInstance.cxx
+++ b/vcl/qt5/QtInstance.cxx
@@ -259,6 +259,8 @@ QtInstance::QtInstance(std::unique_ptr<QApplication>& pQApp, bool bUseCairo)
 
 #ifndef EMSCRIPTEN
     m_bSupportsOpenGL = true;
+#else
+    ImplGetSVData()->maAppData.m_bUseSystemLoop = true;
 #endif
 }
 
@@ -726,13 +728,16 @@ std::unique_ptr<QApplication> QtInstance::CreateQApplication(int& nArgc, char**
 
 bool QtInstance::DoExecute(int& nExitCode)
 {
-#ifdef EMSCRIPTEN
-    nExitCode = m_pQApplication->exec();
-    return true;
-#else
-    (void)nExitCode;
-    return false;
-#endif
+    const bool bIsOnSystemEventLoop = Application::IsOnSystemEventLoop();
+    if (bIsOnSystemEventLoop)
+        nExitCode = QApplication::exec();
+    return bIsOnSystemEventLoop;
+}
+
+void QtInstance::DoQuit()
+{
+    if (Application::IsOnSystemEventLoop())
+        QApplication::quit();
 }
 
 extern "C" {
diff --git a/vcl/qt5/QtTimer.cxx b/vcl/qt5/QtTimer.cxx
index 6568ca8ac1b8..1a34213977dc 100644
--- a/vcl/qt5/QtTimer.cxx
+++ b/vcl/qt5/QtTimer.cxx
@@ -42,11 +42,12 @@ QtTimer::QtTimer()
 void QtTimer::timeoutActivated()
 {
     SolarMutexGuard aGuard;
-#ifdef EMSCRIPTEN
-    const ImplSVData* pSVData = ImplGetSVData();
-    assert(pSVData->mpDefInst);
-    static_cast<QtInstance*>(pSVData->mpDefInst)->DispatchUserEvents(true);
-#endif
+    if (Application::IsOnSystemEventLoop())
+    {
+        const ImplSVData* pSVData = ImplGetSVData();
+        assert(pSVData && pSVData->mpDefInst);
+        static_cast<QtInstance*>(pSVData->mpDefInst)->DispatchUserEvents(true);
+    }
     CallCallback();
 }