tdf#142448 sw offapi: add custom color metadata field shading

using the new com::sun::star::rdf::URIs::LO_EXT_SHADING
URI (modelled after odf:prefix and odf:suffix).
Custom color field shading of text:meta annotated text
ranges and text:meta-field metadata fields allows
quick visual check of metadata categories.

For example, RDF triple

content.xml#id1753384014 urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading FF0000

sets red (FF0000) shading color for the text span
with xml:id="id1753384014".

Pressing Ctrl-F8 or View->Field Shadings can disable
custom color metadata field shading on the UI.

Note: neither LO_EXT_SHADING, nor odf:prefix and
odf:suffix changes invalidate the View (MetaPortion),
but run-time update of shading color can be triggered
without save and reload of the document e.g. by using
(temporary) bookmarks on the annotated text spans.

To run unit test with enabled visibility, use

(cd sw && make UITest_sw_styleInspector UITEST_TEST_NAME="styleInspector.styleNavigator.test_metadata_shading_color" SAL_USE_VCLPLUGIN=gen)

in Linux command line.

Change-Id: I5de93cfa32ac6793d7dbdc7b64e6f4beacb2e8d7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/116015
Tested-by: László Németh <nemeth@numbertext.org>
Reviewed-by: László Németh <nemeth@numbertext.org>

13 files changed, 243 insertions, 21 deletions

diff --git a/offapi/com/sun/star/rdf/URIs.idl b/offapi/com/sun/star/rdf/URIs.idl
index 6172fa87717a..ecb74f667ae8 100644
--- a/offapi/com/sun/star/rdf/URIs.idl
+++ b/offapi/com/sun/star/rdf/URIs.idl
@@ -314,6 +314,14 @@ constants URIs
 
     /// urn:oasis:names:tc:opendocument:xmlns:text:1.0meta-field
 //    const short TEXT_META_FIELD = 3000;
+
+    /** custom shading color of an annotated text range or metadata field
+        (replacement of the default field shading color)
+
+        @since LibreOffice 7.2
+     */
+    /// urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading
+    const short LO_EXT_SHADING      = 2106;
 };
 
 
diff --git a/schema/libreoffice/OpenDocument-v1.3+libreoffice-metadata.owl b/schema/libreoffice/OpenDocument-v1.3+libreoffice-metadata.owl
index 7fe1d94939b8..2c648cf6ce30 100644
--- a/schema/libreoffice/OpenDocument-v1.3+libreoffice-metadata.owl
+++ b/schema/libreoffice/OpenDocument-v1.3+libreoffice-metadata.owl
@@ -75,4 +75,27 @@
 	<range rdf:resource="http://www.w3.org/2001/XMLSchema-datatypes#string"/>
 	<label xml:lang="en">has suffix</label>
 </owl:DatatypeProperty>
+
+<owl:Class rdf:about="urn:oasis:names:tc:opendocument:xmlns:text:1.0meta">
+	<label xml:lang="en">OpenDocument Annotated text range Element</label>
+	<subClassOf rdf:resource="http://docs.oasis-open.org/ns/office/1.2/meta/odf#Element"/>
+</owl:Class>
+
+<owl:Class rdf:about="urn:oasis:names:tc:opendocument:xmlns:text:1.0nestedtextcontent">
+  <owl:equivalentClass>
+    <owl:Class>
+      <owl:unionOf rdf:parseType="Collection">
+        <owl:Class rdf:about="urn:oasis:names:tc:opendocument:xmlns:text:1.0meta">
+        <owl:Class rdf:about="urn:oasis:names:tc:opendocument:xmlns:text:1.0meta-field">
+      </owl:unionOf>
+    </owl:Class>
+  </owl:equivalentClass>
+</owl:Class>
+
+<owl:DatatypeProperty rdf:about="urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading">
+	<rdf:type rdf:resource="http://www.w3.org/2002/07/owl#FunctionalProperty"/>
+	<domain rdf:resource="urn:oasis:names:tc:opendocument:xmlns:text:1.0nestedtextcontent"/>
+	<range rdf:resource="http://www.w3.org/2001/XMLSchema-datatypes#string"/>
+	<label xml:lang="en">has shading color</label>
+</owl:DatatypeProperty>
 </rdf:RDF>
diff --git a/sw/inc/fmtmeta.hxx b/sw/inc/fmtmeta.hxx
index 17a160bc53e6..441a7d5e6e68 100644
--- a/sw/inc/fmtmeta.hxx
+++ b/sw/inc/fmtmeta.hxx
@@ -189,7 +189,7 @@ private:
 public:
     /// get prefix/suffix from the RDF repository. @throws RuntimeException
     void GetPrefixAndSuffix(
-        OUString *const o_pPrefix, OUString *const o_pSuffix);
+        OUString *const o_pPrefix, OUString *const o_pSuffix, OUString *const o_pShadingColor);
 };
 
     /// knows all meta-fields in the document.
diff --git a/sw/qa/uitest/data/metacolor.odt b/sw/qa/uitest/data/metacolor.odt
new file mode 100644
index 000000000000..88cfb7212def
--- /dev/null
+++ b/sw/qa/uitest/data/metacolor.odt
diff --git a/sw/qa/uitest/styleInspector/styleInspector.py b/sw/qa/uitest/styleInspector/styleInspector.py
index 6afc4483e911..9c4abaf7191f 100644
--- a/sw/qa/uitest/styleInspector/styleInspector.py
+++ b/sw/qa/uitest/styleInspector/styleInspector.py
@@ -7,6 +7,7 @@
 from uitest.framework import UITestCase
 from uitest.uihelper.common import get_state_as_dict, get_url_for_data_file
 from libreoffice.uno.propertyvalue import mkPropertyValues
+from com.sun.star.rdf.URIs import RDF_TYPE, RDFS_COMMENT, RDFS_LABEL, ODF_PREFIX, ODF_SUFFIX, LO_EXT_SHADING
 
 class styleNavigator(UITestCase):
 
@@ -246,4 +247,110 @@ class styleNavigator(UITestCase):
         self.xUITest.executeCommand(".uno:Sidebar")
         self.ui_test.close_doc()
 
+    def test_metadata_shading_color(self):
+        writer_doc = self.ui_test.load_file(get_url_for_data_file("metacolor.odt"))
+        xWriterDoc = self.xUITest.getTopFocusWindow()
+        xWriterEdit = xWriterDoc.getChild("writer_edit")
+
+        self.xUITest.executeCommand(".uno:Sidebar")
+        xWriterEdit.executeAction("SIDEBAR", mkPropertyValues({"PANEL": "InspectorTextPanel"}))
+
+        xListBox = xWriterEdit.getChild('listbox_fonts')
+
+        # The cursor is on text without metadata
+        self.assertEqual(1, len(xListBox.getChild('0').getChildren()))
+        self.assertEqual("Default Paragraph Style\t", get_state_as_dict(xListBox.getChild('0').getChild('0'))['Text'])
+        self.assertEqual(136, len(xListBox.getChild('0').getChild('0').getChildren()))
+        self.assertEqual(0, len(xListBox.getChild('1').getChildren()))
+        self.assertEqual(0, len(xListBox.getChild('2').getChildren()))
+
+        # go to next word with RDF annotation
+        self.xUITest.executeCommand(".uno:GoToNextWord")
+        self.xUITest.executeCommand(".uno:GoRight")
+
+        # FIXME jump over the control character (not visible in getString(), but it affects
+        # cursor position and availability of NestedTextContent)
+        self.xUITest.executeCommand(".uno:GoRight")
+
+        # The cursor is on text with annotated text range
+        xDirFormatting = xListBox.getChild('3')
+        self.assertEqual(2, len(xDirFormatting.getChildren()))
+        self.assertEqual("Metadata Reference\t", get_state_as_dict(xDirFormatting.getChild('0'))['Text'])
+        self.assertEqual("Nested Text Content\tipsum", get_state_as_dict(xDirFormatting.getChild('1'))['Text'])
+
+        xMetadata = xDirFormatting.getChild('0')
+        self.assertEqual(2, len(xMetadata.getChildren()))
+        self.assertEqual("xml:id\tID-f1a8a096-7a43-4bda-a462-d73c2800dd9a", get_state_as_dict(xMetadata.getChild('0'))['Text'])
+        # RGB code of the custom shading color of the annotated text range is FFB7E9
+        self.assertEqual("urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading\tFFB7E9", get_state_as_dict(xMetadata.getChild('1'))['Text'])
+
+        self.assertEqual(0, len(xListBox.getChild('1').getChildren()))
+        self.assertEqual(0, len(xListBox.getChild('2').getChildren()))
+
+        # go to next word with RDF annotation
+        self.xUITest.executeCommand(".uno:GoToNextWord")
+        self.xUITest.executeCommand(".uno:GoToNextWord")
+        self.xUITest.executeCommand(".uno:GoToNextWord")
+        self.xUITest.executeCommand(".uno:GoRight")
+
+        # The cursor is on text with annotated text range
+        xDirFormatting = xListBox.getChild('3')
+        self.assertEqual(2, len(xDirFormatting.getChildren()))
+        self.assertEqual("Metadata Reference\t", get_state_as_dict(xDirFormatting.getChild('0'))['Text'])
+        self.assertEqual("Nested Text Content\tames", get_state_as_dict(xDirFormatting.getChild('1'))['Text'])
+
+        xMetadata = xDirFormatting.getChild('0')
+        print(get_state_as_dict(xMetadata))
+        self.assertEqual(2, len(xMetadata.getChildren()))
+        self.assertEqual("xml:id\tID-24478193-9630-4d03-8976-9e097c843a0b", get_state_as_dict(xMetadata.getChild('0'))['Text'])
+        # RGB code of the custom shading color of the annotated text range is 97E1E9 (the code can be lower case, see STRtoRGB)
+        self.assertEqual("urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading\t97e1e9", get_state_as_dict(xMetadata.getChild('1'))['Text'])
+
+        self.assertEqual(0, len(xListBox.getChild('1').getChildren()))
+        self.assertEqual(0, len(xListBox.getChild('2').getChildren()))
+
+        # add a new annotated text range and check it in the Style Inspector
+        self.xUITest.executeCommand(".uno:GoToStartOfDoc")
+
+        # create annotated text range on "Lorem"
+        viewCursor = writer_doc.CurrentController.getViewCursor()
+        viewCursor.goRight(5, True)
+        rdf = writer_doc.createInstance("com.sun.star.text.InContentMetadata")
+        writer_doc.Text.insertTextContent(viewCursor, rdf, True)
+
+        # set its custom shading color using the new URI const LO_EXT_SHADING
+        repository = writer_doc.getRDFRepository()
+        # get metadata graph of file "custom.rdf" stored in the test document
+        xCustomGraph = [repository.getGraph(i) for i in repository.getGraphNames() if i.LocalName == "custom.rdf"]
+        self.assertEqual(1, len(xCustomGraph))
+
+        smgr = self.xContext.ServiceManager
+        xShadingURI = smgr.createInstance('com.sun.star.rdf.URI')
+        xShadingURI.initialize((LO_EXT_SHADING,))
+        xShadingColor = smgr.createInstance('com.sun.star.rdf.Literal')
+        xShadingColor.initialize(('BBFF88',))
+        xCustomGraph[0].addStatement(rdf, xShadingURI, xShadingColor)
+
+        # remove the selection
+        self.xUITest.executeCommand(".uno:GoLeft")
+
+        # FIXME: neither LO_EXT_SHADING, nor odf:prefix/odf:suffix changes update the View,
+        # so add a temporary bookmark to the text range to trigger the color change immediately
+        self.ui_test.execute_dialog_through_command(".uno:InsertBookmark")
+        xBookDlg = self.xUITest.getTopFocusWindow()
+        xInsertBtn = xBookDlg.getChild("insert")
+        xInsertBtn.executeAction("CLICK", tuple()) # first bookmark
+        self.xUITest.executeCommand(".uno:Undo")
+
+        xDirFormatting = xListBox.getChild('3')
+        xMetadata = xDirFormatting.getChild('0')
+        self.assertEqual(2, len(xMetadata.getChildren()))
+        # RGB code of the custom shading color of the annotated text range is BBFF88
+        self.assertEqual("urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#shading\tBBFF88", get_state_as_dict(xMetadata.getChild('1'))['Text'])
+
+        self.xUITest.executeCommand(".uno:Sidebar")
+        self.ui_test.close_doc()
+
+
+
 # vim: set shiftwidth=4 softtabstop=4 expandtab:
diff --git a/sw/source/core/inc/unometa.hxx b/sw/source/core/inc/unometa.hxx
index ea4c3e66836c..ca298fcd8f63 100644
--- a/sw/source/core/inc/unometa.hxx
+++ b/sw/source/core/inc/unometa.hxx
@@ -263,7 +263,7 @@ public:
 void getPrefixAndSuffix(
         const css::uno::Reference< css::frame::XModel>& xModel,
         const css::uno::Reference< css::rdf::XMetadatable>& xMetaField,
-        OUString *const o_pPrefix, OUString *const o_pSuffix);
+        OUString *const o_pPrefix, OUString *const o_pSuffix, OUString *const o_pShadowColor);
 
 #endif // INCLUDED_SW_SOURCE_CORE_INC_UNOMETA_HXX
 
diff --git a/sw/source/core/text/inftxt.cxx b/sw/source/core/text/inftxt.cxx
index c399ac758a24..6e5318097e2b 100644
--- a/sw/source/core/text/inftxt.cxx
+++ b/sw/source/core/text/inftxt.cxx
@@ -1125,7 +1125,7 @@ void SwTextPaintInfo::DrawCheckBox(const SwFieldFormCheckboxPortion &rPor, bool
     m_pOut->Pop();
 }
 
-void SwTextPaintInfo::DrawBackground( const SwLinePortion &rPor ) const
+void SwTextPaintInfo::DrawBackground( const SwLinePortion &rPor, const Color *pColor ) const
 {
     OSL_ENSURE( OnWin(), "SwTextPaintInfo::DrawBackground: printer pollution ?" );
 
@@ -1145,7 +1145,11 @@ void SwTextPaintInfo::DrawBackground( const SwLinePortion &rPor ) const
     }
     else
     {
-        pOut->SetFillColor( SwViewOption::GetFieldShadingsColor() );
+        if ( pColor )
+            pOut->SetFillColor( *pColor );
+        else
+            pOut->SetFillColor( SwViewOption::GetFieldShadingsColor() );
+
         pOut->SetLineColor();
     }
 
@@ -1313,7 +1317,7 @@ void SwTextPaintInfo::DrawBorder( const SwLinePortion &rPor ) const
 }
 
 void SwTextPaintInfo::DrawViewOpt( const SwLinePortion &rPor,
-                                   PortionType nWhich ) const
+                                   PortionType nWhich, const Color *pColor ) const
 {
     if( !OnWin() || IsMulti() )
         return;
@@ -1366,7 +1370,7 @@ void SwTextPaintInfo::DrawViewOpt( const SwLinePortion &rPor,
         }
     }
     if ( bDraw )
-        DrawBackground( rPor );
+        DrawBackground( rPor, pColor );
 }
 
 static void lcl_InitHyphValues( PropertyValues &rVals,
diff --git a/sw/source/core/text/inftxt.hxx b/sw/source/core/text/inftxt.hxx
index bb245d5b031f..f11ea65ed918 100644
--- a/sw/source/core/text/inftxt.hxx
+++ b/sw/source/core/text/inftxt.hxx
@@ -399,8 +399,8 @@ public:
     void DrawLineBreak( const SwLinePortion &rPor ) const;
     void DrawRedArrow( const SwLinePortion &rPor ) const;
     void DrawPostIts( bool bScript ) const;
-    void DrawBackground( const SwLinePortion &rPor ) const;
-    void DrawViewOpt( const SwLinePortion &rPor, PortionType nWhich ) const;
+    void DrawBackground( const SwLinePortion &rPor, const Color *pColor=nullptr ) const;
+    void DrawViewOpt( const SwLinePortion &rPor, PortionType nWhich, const Color *pColor=nullptr ) const;
     void DrawBackBrush( const SwLinePortion &rPor ) const;
 
     /**
diff --git a/sw/source/core/text/itrform2.cxx b/sw/source/core/text/itrform2.cxx
index e672eabb3fce..2eddba6c1c6e 100644
--- a/sw/source/core/text/itrform2.cxx
+++ b/sw/source/core/text/itrform2.cxx
@@ -54,8 +54,15 @@
 #include <IDocumentSettingAccess.hxx>
 #include <IMark.hxx>
 #include <IDocumentMarkAccess.hxx>
-
-#include <vector>
+#include <comphelper/processfactory.hxx>
+#include <docsh.hxx>
+#include <unocrsrhelper.hxx>
+#include <com/sun/star/rdf/Statement.hpp>
+#include <com/sun/star/rdf/URI.hpp>
+#include <com/sun/star/rdf/URIs.hpp>
+#include <com/sun/star/rdf/XDocumentMetadataAccess.hpp>
+#include <com/sun/star/rdf/XLiteral.hpp>
+#include <com/sun/star/text/XTextContent.hpp>
 
 using namespace ::com::sun::star;
 
@@ -842,9 +849,11 @@ namespace {
 
 class SwMetaPortion : public SwTextPortion
 {
+    Color m_aShadowColor;
 public:
     SwMetaPortion() { SetWhichPor( PortionType::Meta ); }
     virtual void Paint( const SwTextPaintInfo &rInf ) const override;
+    void SetShadowColor(const Color& rCol ) { m_aShadowColor = rCol; }
 };
 
 }
@@ -853,7 +862,12 @@ void SwMetaPortion::Paint( const SwTextPaintInfo &rInf ) const
 {
     if ( Width() )
     {
-        rInf.DrawViewOpt( *this, PortionType::Meta );
+        rInf.DrawViewOpt( *this, PortionType::Meta,
+                // custom shading (RDF metadata)
+                COL_BLACK == m_aShadowColor
+                    ? nullptr
+                    : &m_aShadowColor );
+
         SwTextPortion::Paint( rInf );
     }
 }
@@ -919,7 +933,50 @@ SwTextPortion *SwTextFormatter::WhichTextPor( SwTextFormatInfo &rInf ) const
             pPor = new SwRefPortion;
         else if (GetFnt()->IsMeta())
         {
-            pPor = new SwMetaPortion;
+            auto pMetaPor = new SwMetaPortion;
+
+            // set custom LO_EXT_SHADING color, if it exists
+            SwTextFrame const*const pFrame(rInf.GetTextFrame());
+            SwPosition aPosition(pFrame->MapViewToModelPos(rInf.GetIdx()));
+            SwPaM aPam(aPosition);
+            uno::Reference<text::XTextContent> const xRet(
+                SwUnoCursorHelper::GetNestedTextContent(
+                    *aPam.GetNode().GetTextNode(), aPosition.nContent.GetIndex(), false) );
+            if (xRet.is())
+            {
+                const SwDoc & rDoc = rInf.GetTextFrame()->GetDoc();
+                static uno::Reference< uno::XComponentContext > xContext(
+                    ::comphelper::getProcessComponentContext());
+
+                static uno::Reference< rdf::XURI > xODF_SHADING(
+                    rdf::URI::createKnown(xContext, rdf::URIs::LO_EXT_SHADING), uno::UNO_SET_THROW);
+
+                uno::Reference<rdf::XDocumentMetadataAccess> xDocumentMetadataAccess(
+                    rDoc.GetDocShell()->GetBaseModel(), uno::UNO_QUERY);
+
+                const css::uno::Reference<css::rdf::XResource> xSubject(xRet, uno::UNO_QUERY);
+                const uno::Reference<rdf::XRepository>& xRepository =
+                    xDocumentMetadataAccess->getRDFRepository();
+                const uno::Reference<container::XEnumeration> xEnum(
+                    xRepository->getStatements(xSubject, xODF_SHADING, nullptr), uno::UNO_SET_THROW);
+
+                while (xEnum->hasMoreElements())
+                {
+                    rdf::Statement stmt;
+                    if (!(xEnum->nextElement() >>= stmt)) {
+                        throw uno::RuntimeException();
+                    }
+                    const uno::Reference<rdf::XLiteral> xObject(stmt.Object, uno::UNO_QUERY);
+                    if (!xObject.is()) continue;
+                    if (xEnum->hasMoreElements()) {
+                        SAL_INFO("sw.uno", "ignoring other odf:shading statements");
+                    }
+                    Color rColor = Color::STRtoRGB(xObject->getValue());
+                    pMetaPor->SetShadowColor(rColor);
+                    break;
+                }
+            }
+            pPor = pMetaPor;
         }
         else
         {
diff --git a/sw/source/core/text/txtfld.cxx b/sw/source/core/text/txtfld.cxx
index e150f7f489f1..c1375b52fe09 100644
--- a/sw/source/core/text/txtfld.cxx
+++ b/sw/source/core/text/txtfld.cxx
@@ -304,7 +304,8 @@ static SwFieldPortion * lcl_NewMetaPortion(SwTextAttr & rHint, const bool bPrefi
     OSL_ENSURE(pField, "lcl_NewMetaPortion: no meta field?");
     if (pField)
     {
-        pField->GetPrefixAndSuffix(bPrefix ? &fix : nullptr, bPrefix ? nullptr : &fix);
+        OUString color;
+        pField->GetPrefixAndSuffix(bPrefix ? &fix : nullptr, bPrefix ? nullptr : &fix, &color);
     }
     return new SwFieldPortion( fix );
 }
diff --git a/sw/source/core/txtnode/fmtatr2.cxx b/sw/source/core/txtnode/fmtatr2.cxx
index 73eb992c5c97..afc82565c515 100644
--- a/sw/source/core/txtnode/fmtatr2.cxx
+++ b/sw/source/core/txtnode/fmtatr2.cxx
@@ -730,7 +730,7 @@ MetaField::MetaField(SwFormatMeta * const i_pFormat,
 }
 
 void MetaField::GetPrefixAndSuffix(
-        OUString *const o_pPrefix, OUString *const o_pSuffix)
+        OUString *const o_pPrefix, OUString *const o_pSuffix, OUString *const o_pShadowsColor)
 {
     try
     {
@@ -743,7 +743,7 @@ void MetaField::GetPrefixAndSuffix(
             SwDocShell const * const pShell(pTextNode->GetDoc().GetDocShell());
             const uno::Reference<frame::XModel> xModel(
                 pShell ? pShell->GetModel() : nullptr,  uno::UNO_SET_THROW);
-            getPrefixAndSuffix(xModel, xMetaField, o_pPrefix, o_pSuffix);
+            getPrefixAndSuffix(xModel, xMetaField, o_pPrefix, o_pSuffix, o_pShadowsColor);
         }
     }
     catch (const uno::Exception&)
diff --git a/sw/source/core/unocore/unorefmk.cxx b/sw/source/core/unocore/unorefmk.cxx
index a88d2d4f8a98..3156ef10ed35 100644
--- a/sw/source/core/unocore/unorefmk.cxx
+++ b/sw/source/core/unocore/unorefmk.cxx
@@ -1422,7 +1422,7 @@ SwXMetaField::removeVetoableChangeListener(
 }
 
 static uno::Reference<rdf::XURI> const&
-lcl_getURI(const bool bPrefix)
+lcl_getURI(const sal_Int16 eKnown)
 {
     static uno::Reference< uno::XComponentContext > xContext(
         ::comphelper::getProcessComponentContext());
@@ -1432,7 +1432,18 @@ lcl_getURI(const bool bPrefix)
     static uno::Reference< rdf::XURI > xOdfSuffix(
         rdf::URI::createKnown(xContext, rdf::URIs::ODF_SUFFIX),
         uno::UNO_SET_THROW);
-    return bPrefix ? xOdfPrefix : xOdfSuffix;
+    static uno::Reference< rdf::XURI > xOdfShading(
+        rdf::URI::createKnown(xContext, rdf::URIs::LO_EXT_SHADING),
+        uno::UNO_SET_THROW);
+    switch (eKnown)
+    {
+        case rdf::URIs::ODF_PREFIX:
+            return xOdfPrefix;
+        case rdf::URIs::ODF_SUFFIX:
+            return xOdfSuffix;
+        default:
+            return xOdfShading;
+    }
 }
 
 static OUString
@@ -1464,7 +1475,7 @@ void
 getPrefixAndSuffix(
         const uno::Reference<frame::XModel>& xModel,
         const uno::Reference<rdf::XMetadatable>& xMetaField,
-        OUString *const o_pPrefix, OUString *const o_pSuffix)
+        OUString *const o_pPrefix, OUString *const o_pSuffix, OUString *const o_pShadingColor)
 {
     try {
         const uno::Reference<rdf::XRepositorySupplier> xRS(
@@ -1475,11 +1486,15 @@ getPrefixAndSuffix(
                 xMetaField, uno::UNO_QUERY_THROW);
         if (o_pPrefix)
         {
-            *o_pPrefix = lcl_getPrefixOrSuffix(xRepo, xMeta, lcl_getURI(true));
+            *o_pPrefix = lcl_getPrefixOrSuffix(xRepo, xMeta, lcl_getURI(rdf::URIs::ODF_PREFIX));
         }
         if (o_pSuffix)
         {
-            *o_pSuffix = lcl_getPrefixOrSuffix(xRepo, xMeta, lcl_getURI(false));
+            *o_pSuffix = lcl_getPrefixOrSuffix(xRepo, xMeta, lcl_getURI(rdf::URIs::ODF_SUFFIX));
+        }
+        if (o_pShadingColor)
+        {
+            *o_pShadingColor = lcl_getPrefixOrSuffix(xRepo, xMeta, lcl_getURI(rdf::URIs::LO_EXT_SHADING));
         }
     } catch (uno::RuntimeException &) {
         throw;
@@ -1506,7 +1521,7 @@ SwXMetaField::getPresentation(sal_Bool bShowCommand)
         const OUString content( getString() );
         OUString prefix;
         OUString suffix;
-        getPrefixAndSuffix(GetModel(), this, &prefix, &suffix);
+        getPrefixAndSuffix(GetModel(), this, &prefix, &suffix, nullptr);
         return prefix + content + suffix;
     }
 }
diff --git a/unoxml/source/rdf/CURI.cxx b/unoxml/source/rdf/CURI.cxx
index 0a154d037f8e..9a5a5b677831 100644
--- a/unoxml/source/rdf/CURI.cxx
+++ b/unoxml/source/rdf/CURI.cxx
@@ -94,6 +94,8 @@ const char s_nsPkg      [] =
     "http://docs.oasis-open.org/ns/office/1.2/meta/pkg#";
 const char s_nsODF      [] =
     "http://docs.oasis-open.org/ns/office/1.2/meta/odf#";
+const char s_nsLO_EXT   [] =
+    "urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0odf#";
 
 void CURI::initFromConstant(const sal_Int16 i_Constant)
 {
@@ -697,6 +699,11 @@ void CURI::initFromConstant(const sal_Int16 i_Constant)
             ln = "StylesFile";
             break;
 
+        case css::rdf::URIs::LO_EXT_SHADING:
+            ns = s_nsLO_EXT;
+            ln = "shading";
+            break;
+
         default:
             throw css::lang::IllegalArgumentException(
                 "CURI::initialize: invalid URIs constant argument", *this, 0);