KDE4: evaluate frameWidth in the Qt thread

When opening a document via Java UNO without a running LO instance, one
gets the following Qt error messages:

CE>  QObject: Cannot create children for a parent that is in a different thread.
CE>  (Parent is Oxygen::WidgetStateEngine(0x8deb878), parent's thread is QThread(0x8d6cf70), current thread is QThread(0xa8fa7fc8)
CE>  QObject::installEventFilter(): Cannot filter events for objects in a different thread.
CE>  QObject::installEventFilter(): Cannot filter events for objects in a different thread.
CE>  QObject::installEventFilter(): Cannot filter events for objects in a different thread.

This happens, because the Java UNO call is processed in the first /
Qt thread while document loading happens in a second thread.

Document loading actually just calls getNativeControlRegion, which
should not involve any drawing. But the KDE4 backend does some style
processing to get the correct frame width (QWidget::ensurePolished(),
which uses GUI based events and need to be processed in the Qt
thread.

Change-Id: I344d5089d958963c48a9a8a84bfa9fe8f092b75a

vcl/unx/kde4/KDESalGraphics.cxx

@@ -31,10 +31,12 @@
 #undef Region
 
 #include "KDESalGraphics.hxx"
+#include "KDESalInstance.hxx"
 
 #include <vcl/settings.hxx>
 #include <vcl/decoview.hxx>
 #include <rtl/ustrbuf.hxx>
+#include <unx/saldata.hxx>
 
 using namespace ::rtl;
 
@@ -165,21 +167,6 @@ namespace
         kapp->style()->drawComplexControl(element, option, &painter);
     }
 
-    int getFrameWidth()
-    {
-        static int s_nFrameWidth = -1;
-        if( s_nFrameWidth < 0 )
-        {
-            // fill in a default
-            QFrame aFrame( NULL );
-            aFrame.setFrameRect( QRect(0, 0, 100, 30) );
-            aFrame.setFrameStyle( QFrame::StyledPanel | QFrame::Sunken );
-            aFrame.ensurePolished();
-            s_nFrameWidth = aFrame.frameWidth();
-        }
-        return s_nFrameWidth;
-    }
-
     void lcl_drawFrame(QStyle::PrimitiveElement element, QImage* image, QStyle::State state)
     {
     #if ( QT_VERSION >= QT_VERSION_CHECK( 4, 5, 0 ) )
@@ -554,7 +541,7 @@ bool KDESalGraphics::drawNativeControl( ControlType type, ControlPart part,
                        vclStateValue2StateFlag(nControlState, value) );
 
         // draw just the border, see http://qa.openoffice.org/issues/show_bug.cgi?id=107945
-        int fw = getFrameWidth();
+        int fw = static_cast< KDESalInstance* >(GetSalData()->m_pInstance)->getFrameWidth();
         clipRegion = new QRegion( QRegion( widgetRect ).subtracted( widgetRect.adjusted( fw, fw, -fw, -fw )));
     }
     else if (type == CTRL_WINDOW_BACKGROUND)
@@ -857,7 +844,7 @@ bool KDESalGraphics::getNativeControlRegion( ControlType type, ControlPart part,
         {
             if( part == PART_BORDER )
             {
-                int nFrameWidth = getFrameWidth();
+                int nFrameWidth = static_cast< KDESalInstance* >(GetSalData()->m_pInstance)->getFrameWidth();
                 sal_uInt16 nStyle = val.getNumericVal();
                 if( nStyle & FRAME_DRAW_NODRAW )
                 {

vcl/unx/kde4/KDESalInstance.cxx

@@ -38,4 +38,9 @@ uno::Reference< ui::dialogs::XFilePicker2 > KDESalInstance::createFilePicker(
         static_cast<KDEXLib*>( mpXLib )->createFilePicker(xMSF) );
 }
 
+int KDESalInstance::getFrameWidth()
+{
+    return static_cast<KDEXLib*>( mpXLib )->getFrameWidth();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/unx/kde4/KDESalInstance.hxx

@@ -36,6 +36,7 @@ class KDESalInstance : public X11SalInstance
         virtual com::sun::star::uno::Reference< com::sun::star::ui::dialogs::XFilePicker2 >
             createFilePicker( const com::sun::star::uno::Reference<
                                   com::sun::star::uno::XComponentContext >& );
+        int getFrameWidth();
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/unx/kde4/KDEXLib.cxx

@@ -59,7 +59,7 @@ KDEXLib::KDEXLib() :
     SalXLib(),  m_bStartupDone(false), m_pApplication(0),
     m_pFreeCmdLineArgs(0), m_pAppCmdLineArgs(0), m_nFakeCmdLineArgs( 0 ),
     eventLoopType( LibreOfficeEventLoop ),
-    m_bYieldFrozen( false )
+    m_bYieldFrozen( false ), m_frameWidth( -1 )
 {
     // the timers created here means they belong to the main thread
     connect( &timeoutTimer, SIGNAL( timeout()), this, SLOT( timeoutActivated()));
@@ -82,6 +82,9 @@ KDEXLib::KDEXLib() :
              this, SLOT( createFilePicker( const com::sun::star::uno::Reference<
                                                  com::sun::star::uno::XComponentContext >&) ),
              Qt::BlockingQueuedConnection );
+
+    connect( this, SIGNAL( getFrameWidthSignal() ),
+             this, SLOT( getFrameWidth() ), Qt::BlockingQueuedConnection );
 }
 
 KDEXLib::~KDEXLib()
@@ -405,6 +408,27 @@ uno::Reference< ui::dialogs::XFilePicker2 > KDEXLib::createFilePicker(
     return uno::Reference< ui::dialogs::XFilePicker2 >( new KDE4FilePicker( xMSF, this ) );
 }
 
+#define Region QtXRegion
+#include <qframe.h>
+#undef Region
+
+int KDEXLib::getFrameWidth()
+{
+    if( m_frameWidth >= 0 )
+        return m_frameWidth;
+    if( qApp->thread() != QThread::currentThread()) {
+        SalYieldMutexReleaser aReleaser;
+        return Q_EMIT getFrameWidthSignal();
+    }
+
+    // fill in a default
+    QFrame aFrame( NULL );
+    aFrame.setFrameStyle( QFrame::StyledPanel | QFrame::Sunken );
+    aFrame.ensurePolished();
+    m_frameWidth = aFrame.frameWidth();
+    return m_frameWidth;
+}
+
 #include "KDEXLib.moc"
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/unx/kde4/KDEXLib.hxx

@@ -53,6 +53,7 @@ class KDEXLib : public QObject, public SalXLib
         QTimer userEventTimer;
         enum { LibreOfficeEventLoop, GlibEventLoop, QtUnixEventLoop } eventLoopType;
         bool m_bYieldFrozen;
+        int m_frameWidth;
 
     private:
         void setupEventLoop();
@@ -71,6 +72,7 @@ class KDEXLib : public QObject, public SalXLib
         com::sun::star::uno::Reference< com::sun::star::ui::dialogs::XFilePicker2 >
             createFilePickerSignal( const com::sun::star::uno::Reference<
                                           com::sun::star::uno::XComponentContext >& );
+        int getFrameWidthSignal();
 
     public:
         KDEXLib();
@@ -89,9 +91,10 @@ class KDEXLib : public QObject, public SalXLib
         void doStartup();
 
     public Q_SLOTS:
-        virtual com::sun::star::uno::Reference< com::sun::star::ui::dialogs::XFilePicker2 >
+        com::sun::star::uno::Reference< com::sun::star::ui::dialogs::XFilePicker2 >
             createFilePicker( const com::sun::star::uno::Reference<
                                   com::sun::star::uno::XComponentContext >& );
+        int getFrameWidth();
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */