SwFrmFmt::FindRealSdrObject() and stacking order

 Hello,

 could somebody more knowledgeable of Writer internals please review this?

 While working on support for stacking order in the .docx filter, I found out 
that setting z-order for an image using UNO and later trying to retrieve the 
value fails. The attached sw.patch fixes that for me, and I checked that .odt 
export/import (which uses it too) still works. But I have no idea what the 
difference actually is, besides making reading use the same value like 
writing.

-- 
 Lubos Lunak
 l.lunak@suse.cz

diff --git a/sw/source/core/unocore/unoframe.cxx b/sw/source/core/unocore/unoframe.cxx
index f8d2c90..91c8d89 100644
--- a/sw/source/core/unocore/unoframe.cxx
+++ b/sw/source/core/unocore/unoframe.cxx
@@ -1598,7 +1598,7 @@ uno::Any SwXFrame::getPropertyValue(const OUString& rPropertyName)
         }
         else if(FN_UNO_Z_ORDER == pEntry->nWID)
         {
-            const SdrObject* pObj = pFmt->FindRealSdrObject();
+            const SdrObject* pObj = pFmt->FindSdrObject();
             if( pObj )
             {
                 aAny <<= (sal_Int32)pObj->GetOrdNum();

diff --git a/writerfilter/inc/dmapper/DomainMapper.hxx b/writerfilter/inc/dmapper/DomainMapper.hxx
index 4713763..95ddc6f 100644
--- a/writerfilter/inc/dmapper/DomainMapper.hxx
+++ b/writerfilter/inc/dmapper/DomainMapper.hxx
@@ -36,6 +36,7 @@
 
 #include <map>
 #include <vector>
+#include <boost/scoped_ptr.hpp>
 
 namespace com{ namespace sun {namespace star{
     namespace beans{
@@ -65,6 +66,7 @@ class PropertyMap;
 class DomainMapper_Impl;
 class ListsManager;
 class StyleSheetTable;
+class GraphicZOrderHelper;
 
 // different context types require different sprm handling (e.g. names)
 enum SprmType
@@ -113,6 +115,7 @@ public:
 
     ::rtl::OUString getOrCreateCharStyle( PropertyValueVector_t& rCharProperties );
     boost::shared_ptr< StyleSheetTable > GetStyleSheetTable( );
+    GraphicZOrderHelper* graphicZOrderHelper();
 
 private:
     // Stream
@@ -150,6 +153,7 @@ private:
     sal_Unicode getFillCharFromValue(const sal_Int32 nIntValue);
     sal_Int32 mnBackgroundColor;
     bool mbIsHighlightSet;
+    boost::scoped_ptr< GraphicZOrderHelper > zOrderHelper;
 };
 
 } // namespace dmapper
diff --git a/writerfilter/source/dmapper/DomainMapper.cxx 
b/writerfilter/source/dmapper/DomainMapper.cxx
index 54fe0a0..dcc20cf 100644
--- a/writerfilter/source/dmapper/DomainMapper.cxx
+++ b/writerfilter/source/dmapper/DomainMapper.cxx
@@ -71,6 +71,7 @@
 #include <tools/color.hxx>
 #include <CellColorHandler.hxx>
 #include <SectionColumnHandler.hxx>
+#include <GraphicHelpers.hxx>
 
 using namespace ::com::sun::star;
 using namespace ::rtl;
@@ -3755,6 +3756,13 @@ StyleSheetTablePtr DomainMapper::GetStyleSheetTable( )
     return m_pImpl->GetStyleSheetTable( );
 }
 
+GraphicZOrderHelper* DomainMapper::graphicZOrderHelper()
+{
+    if( zOrderHelper.get() == NULL )
+        zOrderHelper.reset( new GraphicZOrderHelper );
+    return zOrderHelper.get();
+}
+
 } //namespace dmapper
 } //namespace writerfilter
 
diff --git a/writerfilter/source/dmapper/GraphicHelpers.cxx 
b/writerfilter/source/dmapper/GraphicHelpers.cxx
index cdafb8e..819dc6f 100644
--- a/writerfilter/source/dmapper/GraphicHelpers.cxx
+++ b/writerfilter/source/dmapper/GraphicHelpers.cxx
@@ -216,6 +216,47 @@ sal_Int32 WrapHandler::getWrapMode( )
     return nMode;
 }
 
+
+void GraphicZOrderHelper::addItem( uno::Reference< beans::XPropertySet > props, sal_Int32 
relativeHeight )
+{
+    items[ relativeHeight ] = props;
+}
+
+// The relativeHeight value in .docx is an arbitrary number, where only the relative ordering 
matters.
+// But in Writer, the z-order is index in 0..(numitems-1) range, so whenever a new item needs to be
+// added in the proper z-order, it is necessary to find the proper index.
+sal_Int32 GraphicZOrderHelper::findZOrder( sal_Int32 relativeHeight )
+{
+    Items::const_iterator it = items.begin();
+    while( it != items.end())
+    {
+        // std::map is iterated sorted by key
+        if( it->first > relativeHeight )
+            break; // this is the first one higher, we belong right before it
+        else
+            ++it;
+    }
+    if( it == items.end()) // we're topmost
+    {
+        if( items.empty())
+            return 0;
+        sal_Int32 itemZOrder;
+        --it;
+        if( it->second->getPropertyValue(PropertyNameSupplier::GetPropertyNameSupplier()
+            .GetName( PROP_Z_ORDER )) >>= itemZOrder )
+            return itemZOrder + 1; // after the topmost
+    }
+    else
+    {
+        sal_Int32 itemZOrder;
+        if( it->second->getPropertyValue(PropertyNameSupplier::GetPropertyNameSupplier()
+            .GetName( PROP_Z_ORDER )) >>= itemZOrder )
+            return itemZOrder; // before the item
+    }
+    SAL_WARN( "writerfilter", "findZOrder() didn't find item z-order" );
+    return 0; // this should not(?) happen
+}
+
 } }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/writerfilter/source/dmapper/GraphicHelpers.hxx 
b/writerfilter/source/dmapper/GraphicHelpers.hxx
index 80ddc93..f87b6f9 100644
--- a/writerfilter/source/dmapper/GraphicHelpers.hxx
+++ b/writerfilter/source/dmapper/GraphicHelpers.hxx
@@ -51,6 +51,16 @@ public:
 };
 typedef boost::shared_ptr<WrapHandler> WrapHandlerPtr;
 
+class WRITERFILTER_DLLPRIVATE GraphicZOrderHelper
+{
+public:
+    void addItem( uno::Reference< beans::XPropertySet > props, sal_Int32 relativeHeight );
+    sal_Int32 findZOrder( sal_Int32 relativeHeight );
+private:
+    typedef std::map< sal_Int32, uno::Reference< beans::XPropertySet > > Items;
+    Items items;
+};
+
 } }
 
 #endif
diff --git a/writerfilter/source/dmapper/GraphicImport.cxx 
b/writerfilter/source/dmapper/GraphicImport.cxx
index e74951b..5a0aded 100644
--- a/writerfilter/source/dmapper/GraphicImport.cxx
+++ b/writerfilter/source/dmapper/GraphicImport.cxx
@@ -210,6 +210,7 @@ public:
     sal_Int32 nBottomCrop;
 
     bool      bUseSimplePos;
+    sal_Int32 zOrder;
 
     sal_Int16 nHoriOrient;
     sal_Int16 nHoriRelation;
@@ -276,6 +277,7 @@ public:
         ,nRightCrop (0)
         ,nBottomCrop(0)
         ,bUseSimplePos(false)
+        ,zOrder(-1)
         ,nHoriOrient(   text::HoriOrientation::NONE )
         ,nHoriRelation( text::RelOrientation::FRAME )
         ,bPageToggle( false )
@@ -835,7 +837,7 @@ void GraphicImport::lcl_attribute(Id nName, Value & val)
             m_pImpl->bUseSimplePos = nIntValue > 0;
         break;
         case NS_ooxml::LN_CT_Anchor_relativeHeight: // 90988;
-            //z-order
+            m_pImpl->zOrder = nIntValue;
         break;
         case NS_ooxml::LN_CT_Anchor_behindDoc: // 90989; - in background
             if( nIntValue > 0 )
@@ -1454,6 +1456,14 @@ uno::Reference< text::XTextContent > GraphicImport::createGraphicObject( 
const b
                         uno::makeAny( m_pImpl->bVertFlip ));
                 xGraphicObjectProperties->setPropertyValue(rPropNameSupplier.GetName( 
PROP_BACK_COLOR ),
                     uno::makeAny( m_pImpl->nFillColor ));
+                
+                if( m_pImpl->zOrder >= 0 )
+                {
+                    GraphicZOrderHelper* zOrderHelper = 
m_pImpl->rDomainMapper.graphicZOrderHelper();
+                    xGraphicObjectProperties->setPropertyValue(rPropNameSupplier.GetName( 
PROP_Z_ORDER ),
+                        uno::makeAny( zOrderHelper->findZOrder( m_pImpl->zOrder )));
+                    zOrderHelper->addItem( xGraphicObjectProperties, m_pImpl->zOrder );
+                }
 
                 //there seems to be no way to detect the original size via _real_ API
                 uno::Reference< beans::XPropertySet > xGraphicProperties( xGraphic, 
uno::UNO_QUERY_THROW );
diff --git a/writerfilter/source/dmapper/PropertyIds.cxx 
b/writerfilter/source/dmapper/PropertyIds.cxx
index 64f562a..cc7bba7 100644
--- a/writerfilter/source/dmapper/PropertyIds.cxx
+++ b/writerfilter/source/dmapper/PropertyIds.cxx
@@ -322,6 +322,7 @@ const rtl::OUString& PropertyNameSupplier::GetName( PropertyIds eId ) const
             case PROP_FRM_DIRECTION:        sName = 
::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("FRMDirection")); break;
             case PROP_EMBEDDED_OBJECT           :    sName = 
::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("EmbeddedObject")); break;
             case PROP_IS_VISIBLE: sName = "IsVisible"; break;
+            case PROP_Z_ORDER: sName = "ZOrder"; break;
         }
         ::std::pair<PropertyNameMap_t::iterator,bool> aInsertIt =
                 m_pImpl->aNameMap.insert( PropertyNameMap_t::value_type( eId, sName ));
diff --git a/writerfilter/source/dmapper/PropertyIds.hxx 
b/writerfilter/source/dmapper/PropertyIds.hxx
index c6e5369..0c6c25b 100644
--- a/writerfilter/source/dmapper/PropertyIds.hxx
+++ b/writerfilter/source/dmapper/PropertyIds.hxx
@@ -295,6 +295,7 @@ enum PropertyIds
 /*253*/ ,PROP_FRM_DIRECTION
         ,PROP_EMBEDDED_OBJECT
         ,PROP_PARA_CONTEXT_MARGIN
+        ,PROP_Z_ORDER
     };
 struct PropertyNameSupplier_Impl;
 class PropertyNameSupplier