tdf#111895 writerfilter: avoid hiding shapes behind background

In MSO, page background is "in hell" zOrder, however
in LO, page background is at the same zOrder as the text,
so avoid hiding shapes behind the page background unless
doing so would hide text.

When importing gradients/pattern/hatch backgrounds are supported,
HasPageBackground will need to be expanded to include those as well.

Change-Id: I4496fd3f4c644ac9ac1854090658017078ce3e88
Reviewed-on: https://gerrit.libreoffice.org/41486
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Justin Luth <justin_luth@sil.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

sw/qa/extras/ooxmlexport/ooxmlexport9.cxx

@@ -229,6 +229,22 @@ DECLARE_OOXMLEXPORT_TEST(testTdf98700_keepWithNext, "tdf98700_keepWithNext.odt")
     CPPUNIT_ASSERT_EQUAL_MESSAGE("Text Body style toggled off keep with next", false, getProperty<bool>(getParagraph(5), "ParaKeepTogether"));
 }
 
+DECLARE_OOXMLEXPORT_TEST(testTdf111895_foregroundShape, "tdf111895_foregroundShape.docx")
+{
+    uno::Reference<beans::XPropertySet> xPageStyle(getStyles("PageStyles")->getByName("Standard"), uno::UNO_QUERY);
+    CPPUNIT_ASSERT_EQUAL_MESSAGE("Light yellow background", sal_Int32(0xFFFF66), getProperty<sal_Int32>(xPageStyle, "BackColor"));
+    // despite a behindDoc==1, put shape in foreground since the page background would have hidden it otherwise.
+    CPPUNIT_ASSERT_EQUAL_MESSAGE("Shape is in front of page background", true, getProperty<bool>(getShape(1), "Opaque"));
+}
+
+DECLARE_OOXMLEXPORT_TEST(testTdf111895_foregroundShape2, "tdf111895_foregroundShape2.docx")
+{
+    uno::Reference<beans::XPropertySet> xPageStyle(getStyles("PageStyles")->getByName("Standard"), uno::UNO_QUERY);
+    CPPUNIT_ASSERT_EQUAL_MESSAGE("Light yellow background", sal_Int32(0xFFFF66), getProperty<sal_Int32>(xPageStyle, "BackColor"));
+    // despite a page background, don't show behindDoc==1 shape in front since it would have hidden wrap_THROUGH text.
+    CPPUNIT_ASSERT_EQUAL_MESSAGE("Shape is in front of page background", false, getProperty<bool>(getShape(1), "Opaque"));
+}
+
 // base class to supply a helper method for testHFLinkToPrev
 class testHFBase : public Test
 {

writerfilter/source/dmapper/DomainMapper.cxx

@@ -3775,6 +3775,11 @@ bool DomainMapper::IsStyleSheetImport() const
     return m_pImpl->IsStyleSheetImport();
 }
 
+bool DomainMapper::HasPageBackground() const
+{
+    return (bool)m_pImpl->m_oBackgroundColor;
+}
+
 void DomainMapper::enableInteropGrabBag(const OUString& aName)
 {
     m_pImpl->m_aInteropGrabBagName = aName;

writerfilter/source/dmapper/DomainMapper.hxx

@@ -110,6 +110,7 @@ public:
     bool IsInHeaderFooter() const;
     bool IsInTable() const;
     bool IsStyleSheetImport() const;
+    bool HasPageBackground() const;
     /**
      @see DomainMapper_Impl::processDeferredCharacterProperties()
     */

writerfilter/source/dmapper/GraphicImport.cxx

@@ -197,6 +197,7 @@ public:
     text::WrapTextMode nWrap;
     bool      bLayoutInCell;
     bool      bOpaque;
+    bool      bBehindDoc;
     bool      bContour;
     bool      bContourOutside;
     WrapPolygon::Pointer_t mpWrapPolygon;
@@ -266,6 +267,7 @@ public:
         ,nWrap(text::WrapTextMode_NONE)
         ,bLayoutInCell(false)
         ,bOpaque( !rDMapper.IsInHeaderFooter() )
+        ,bBehindDoc( false )
         ,bContour(false)
         ,bContourOutside(true)
         ,nLeftMargin(319)
@@ -365,6 +367,10 @@ public:
             GraphicZOrderHelper* pZOrderHelper = rDomainMapper.graphicZOrderHelper();
             xGraphicObjectProperties->setPropertyValue(getPropertyName(PROP_Z_ORDER), uno::makeAny(pZOrderHelper->findZOrder(zOrder)));
             pZOrderHelper->addItem(xGraphicObjectProperties, zOrder);
+
+            // use opaque setting unless it would hide text that should be in front of the shape.
+            const bool bPutInForeground = bOpaque && !(bBehindDoc && nWrap == text::WrapTextMode_THROUGH);
+            xGraphicObjectProperties->setPropertyValue(getPropertyName( PROP_OPAQUE ), uno::makeAny( bPutInForeground ) );
         }
     }
 
@@ -598,7 +604,15 @@ void GraphicImport::lcl_attribute(Id nName, Value& rValue)
         break;
         case NS_ooxml::LN_CT_Anchor_behindDoc: // 90989; - in background
             if( nIntValue > 0 )
-                m_pImpl->bOpaque = false;
+            {
+                m_pImpl->bBehindDoc = true;
+
+                // In MSO, page background is "in hell" zOrder, however
+                // in LO, page background is at the same zOrder as the text,
+                // so avoid hiding shapes behind the page background.
+                if( !m_pImpl->rDomainMapper.HasPageBackground() )
+                    m_pImpl->bOpaque = false;
+            }
         break;
         case NS_ooxml::LN_CT_Anchor_locked: // 90990; - ignored
         break;