tdf#35798: Hide empty Database fields' paragraphs (+ compat option)

With this change, Database fields that expand to empty values behave
as if they are "Hidden Paragraph" fields.

A compatibility option to enable this behaviour is added. The option is
enabled by default, and for any non-native documents (for compatibility
with other office suites). For existing (F)ODT documents, the option is
disabled for those documents that don't have this setting set, to keep
the layout of legacy documents.

Change-Id: Ic5e8cb15a3a7d1a765a984eef4b0d97666df7dfd
Reviewed-on: https://gerrit.libreoffice.org/54552
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/54929
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>

9 files changed, 168 insertions, 95 deletions

diff --git a/sw/source/core/doc/DocumentSettingManager.cxx b/sw/source/core/doc/DocumentSettingManager.cxx
index 77de92017537..c900a985dee2 100644
--- a/sw/source/core/doc/DocumentSettingManager.cxx
+++ b/sw/source/core/doc/DocumentSettingManager.cxx
@@ -114,6 +114,8 @@ sw::DocumentSettingManager::DocumentSettingManager(SwDoc &rDoc)
         mbProtectForm                       = aOptions.GetDefault( SvtCompatibilityEntry::Index::ProtectForm );
         mbMsWordCompTrailingBlanks          = aOptions.GetDefault( SvtCompatibilityEntry::Index::MsWordTrailingBlanks );
         mbSubtractFlys                      = aOptions.GetDefault( SvtCompatibilityEntry::Index::SubtractFlysAnchoredAtFlys );
+        mbEmptyDbFieldHidesPara
+            = aOptions.GetDefault(SvtCompatibilityEntry::Index::EmptyDbFieldHidesPara);
     }
     else
     {
@@ -131,6 +133,7 @@ sw::DocumentSettingManager::DocumentSettingManager(SwDoc &rDoc)
         mbProtectForm                       = false;
         mbMsWordCompTrailingBlanks          = false;
         mbSubtractFlys                      = false;
+        mbEmptyDbFieldHidesPara             = true;
     }
 
     // COMPATIBILITY FLAGS END
@@ -204,6 +207,7 @@ bool sw::DocumentSettingManager::get(/*[in]*/ DocumentSettingId id) const
         case DocumentSettingId::EMBED_SYSTEM_FONTS: return mEmbedSystemFonts;
         case DocumentSettingId::APPLY_PARAGRAPH_MARK_FORMAT_TO_NUMBERING: return mApplyParagraphMarkFormatToNumbering;
         case DocumentSettingId::DISABLE_OFF_PAGE_POSITIONING: return mbDisableOffPagePositioning;
+        case DocumentSettingId::EMPTY_DB_FIELD_HIDES_PARA: return mbEmptyDbFieldHidesPara;
         default:
             OSL_FAIL("Invalid setting id");
     }
@@ -421,6 +425,9 @@ void sw::DocumentSettingManager::set(/*[in]*/ DocumentSettingId id, /*[in]*/ boo
         case DocumentSettingId::DISABLE_OFF_PAGE_POSITIONING:
             mbDisableOffPagePositioning = value;
             break;
+        case DocumentSettingId::EMPTY_DB_FIELD_HIDES_PARA:
+            mbEmptyDbFieldHidesPara = value;
+            break;
         default:
             OSL_FAIL("Invalid setting id");
     }
@@ -562,6 +569,7 @@ void sw::DocumentSettingManager::ReplaceCompatibilityOptions(const DocumentSetti
     mbTabRelativeToIndent = rSource.mbTabRelativeToIndent;
     mbTabAtLeftIndentForParagraphsInList = rSource.mbTabAtLeftIndentForParagraphsInList;
     mbMsWordCompTrailingBlanks = rSource.mbMsWordCompTrailingBlanks;
+    mbEmptyDbFieldHidesPara = rSource.mbEmptyDbFieldHidesPara;
 }
 
 sal_uInt32 sw::DocumentSettingManager::Getn32DummyCompatibilityOptions1() const
diff --git a/sw/source/core/doc/doc.cxx b/sw/source/core/doc/doc.cxx
index e9cdbc8b1174..d5b299373abd 100644
--- a/sw/source/core/doc/doc.cxx
+++ b/sw/source/core/doc/doc.cxx
@@ -1317,6 +1317,73 @@ void SwDoc::Summary( SwDoc* pExtDoc, sal_uInt8 nLevel, sal_uInt8 nPara, bool bIm
     }
 }
 
+namespace
+{
+void RemoveOrDeleteContents(SwTextNode* pTextNd, IDocumentContentOperations& xOperations)
+{
+    SwPaM aPam(*pTextNd, 0, *pTextNd, pTextNd->GetText().getLength());
+
+    // Remove hidden paragraph or delete contents:
+    // Delete contents if
+    // 1. removing the paragraph would result in an empty section or
+    // 2. if the paragraph is the last paragraph in the section and
+    //    there is no paragraph in front of the paragraph:
+    if ((2 == pTextNd->EndOfSectionIndex() - pTextNd->StartOfSectionIndex())
+        || (1 == pTextNd->EndOfSectionIndex() - pTextNd->GetIndex()
+            && !pTextNd->GetNodes()[pTextNd->GetIndex() - 1]->GetTextNode()))
+    {
+        xOperations.DeleteRange(aPam);
+    }
+    else
+    {
+        aPam.DeleteMark();
+        xOperations.DelFullPara(aPam);
+    }
+}
+// Returns if the data was actually modified
+bool HandleHidingField(SwFormatField& rFormatField, const SwNodes& rNodes,
+                       IDocumentContentOperations& xOperations)
+{
+    SwTextNode* pTextNd;
+    if (rFormatField.GetTextField()
+        && nullptr != (pTextNd = rFormatField.GetTextField()->GetpTextNode())
+        && pTextNd->GetpSwpHints() && pTextNd->IsHiddenByParaField()
+        && &pTextNd->GetNodes() == &rNodes)
+    {
+        RemoveOrDeleteContents(pTextNd, xOperations);
+        return true;
+    }
+    return false;
+}
+}
+
+bool SwDoc::FieldCanHidePara(SwFieldIds eFieldId) const
+{
+    switch (eFieldId)
+    {
+        case SwFieldIds::HiddenPara:
+            return true;
+        case SwFieldIds::Database:
+            return GetDocumentSettingManager().get(
+                DocumentSettingId::EMPTY_DB_FIELD_HIDES_PARA);
+        default:
+            return false;
+    }
+}
+
+bool SwDoc::FieldHidesPara(const SwField& rField) const
+{
+    switch (rField.GetTyp()->Which())
+    {
+        case SwFieldIds::HiddenPara:
+            return static_cast<const SwHiddenParaField&>(rField).IsHidden();
+        case SwFieldIds::Database:
+            return FieldCanHidePara(SwFieldIds::Database) && rField.ExpandField(true).isEmpty();
+        default:
+            return false;
+    }
+}
+
 /// Remove the invisible content from the document e.g. hidden areas, hidden paragraphs
 bool SwDoc::RemoveInvisibleContent()
 {
@@ -1324,35 +1391,22 @@ bool SwDoc::RemoveInvisibleContent()
     GetIDocumentUndoRedo().StartUndo( SwUndoId::UI_DELETE_INVISIBLECNTNT, nullptr );
 
     {
-        SwTextNode* pTextNd;
-        SwIterator<SwFormatField,SwFieldType> aIter( *getIDocumentFieldsAccess().GetSysFieldType( SwFieldIds::HiddenPara )  );
-        for( SwFormatField* pFormatField = aIter.First(); pFormatField;  pFormatField = aIter.Next() )
+        // Removing some nodes for one SwFieldIds::Database type might remove the type from
+        // document's field types, invalidating iterators. So, we need to create own list of
+        // matching types prior to processing them.
+        std::vector<const SwFieldType*> aHidingFieldTypes;
+        for (const auto* pType : *getIDocumentFieldsAccess().GetFieldTypes())
         {
-            if( pFormatField->GetTextField() &&
-                nullptr != ( pTextNd = pFormatField->GetTextField()->GetpTextNode() ) &&
-                pTextNd->GetpSwpHints() && pTextNd->HasHiddenParaField() &&
-                &pTextNd->GetNodes() == &GetNodes() )
-            {
-                bRet = true;
-                SwPaM aPam(*pTextNd, 0, *pTextNd, pTextNd->GetText().getLength());
-
-                // Remove hidden paragraph or delete contents:
-                // Delete contents if
-                // 1. removing the paragraph would result in an empty section or
-                // 2. if the paragraph is the last paragraph in the section and
-                //    there is no paragraph in front of the paragraph:
-                if ( ( 2 == pTextNd->EndOfSectionIndex() - pTextNd->StartOfSectionIndex() ) ||
-                     ( 1 == pTextNd->EndOfSectionIndex() - pTextNd->GetIndex() &&
-                       !GetNodes()[ pTextNd->GetIndex() - 1 ]->GetTextNode() ) )
-                {
-                    getIDocumentContentOperations().DeleteRange( aPam );
-                }
-                else
-                {
-                    aPam.DeleteMark();
-                    getIDocumentContentOperations().DelFullPara( aPam );
-                }
-            }
+            if (FieldCanHidePara(pType->Which()))
+                aHidingFieldTypes.push_back(pType);
+        }
+        for (const auto* pType : aHidingFieldTypes)
+        {
+            SwIterator<SwFormatField, SwFieldType> aIter(*pType);
+            for (SwFormatField* pFormatField = aIter.First(); pFormatField;
+                 pFormatField = aIter.Next())
+                bRet |= HandleHidingField(*pFormatField, GetNodes(),
+                                          getIDocumentContentOperations());
         }
     }
 
@@ -1368,23 +1422,7 @@ bool SwDoc::RemoveInvisibleContent()
             {
                 bRemoved = true;
                 bRet = true;
-
-                // Remove hidden paragraph or delete contents:
-                // Delete contents if
-                // 1. removing the paragraph would result in an empty section or
-                // 2. if the paragraph is the last paragraph in the section and
-                //    there is no paragraph in front of the paragraph:
-                if ( ( 2 == pTextNd->EndOfSectionIndex() - pTextNd->StartOfSectionIndex() ) ||
-                     ( 1 == pTextNd->EndOfSectionIndex() - pTextNd->GetIndex() &&
-                       !GetNodes()[ pTextNd->GetIndex() - 1 ]->GetTextNode() ) )
-                {
-                    getIDocumentContentOperations().DeleteRange( aPam );
-                }
-                else
-                {
-                    aPam.DeleteMark();
-                    getIDocumentContentOperations().DelFullPara( aPam );
-                }
+                RemoveOrDeleteContents(pTextNd, getIDocumentContentOperations());
             }
             else if ( pTextNd->HasHiddenCharAttribute( false ) )
             {
diff --git a/sw/source/core/doc/doctxm.cxx b/sw/source/core/doc/doctxm.cxx
index 71b961e1522b..7e635d76a04c 100644
--- a/sw/source/core/doc/doctxm.cxx
+++ b/sw/source/core/doc/doctxm.cxx
@@ -1153,7 +1153,7 @@ void SwTOXBaseSection::UpdateMarks( const SwTOXInternational& rIntl,
                 pTOXSrc->GetText().getLength() && pTOXSrc->HasWriterListeners() &&
                 pTOXSrc->getLayoutFrame( pDoc->getIDocumentLayoutAccess().GetCurrentLayout() ) &&
                (!IsFromChapter() || ::lcl_FindChapterNode( *pTOXSrc ) == pOwnChapterNode ) &&
-               !pTOXSrc->HasHiddenParaField() &&
+               !pTOXSrc->IsHiddenByParaField() &&
                !SwScriptInfo::IsInHiddenRange( *pTOXSrc, pTextMark->GetStart() ) )
             {
                 SwTOXSortTabBase* pBase = nullptr;
@@ -1206,7 +1206,7 @@ void SwTOXBaseSection::UpdateOutline( const SwTextNode* pOwnChapterNode )
         if( pTextNd && pTextNd->Len() && pTextNd->HasWriterListeners() &&
             sal_uInt16( pTextNd->GetAttrOutlineLevel()) <= GetLevel() &&
             pTextNd->getLayoutFrame( pDoc->getIDocumentLayoutAccess().GetCurrentLayout() ) &&
-           !pTextNd->HasHiddenParaField() &&
+           !pTextNd->IsHiddenByParaField() &&
            !pTextNd->HasHiddenCharAttribute( true ) &&
             ( !IsFromChapter() ||
                ::lcl_FindChapterNode( *pTextNd ) == pOwnChapterNode ))
diff --git a/sw/source/core/inc/DocumentSettingManager.hxx b/sw/source/core/inc/DocumentSettingManager.hxx
index 5f762d099ca8..1cf9a9d9fea9 100644
--- a/sw/source/core/inc/DocumentSettingManager.hxx
+++ b/sw/source/core/inc/DocumentSettingManager.hxx
@@ -155,6 +155,7 @@ class DocumentSettingManager :
 
     bool mbLastBrowseMode                           : 1;
     bool mbDisableOffPagePositioning; // tdf#112443
+    bool mbEmptyDbFieldHidesPara;
 
 public:
 
diff --git a/sw/source/core/text/txtfrm.cxx b/sw/source/core/text/txtfrm.cxx
index 05037aa7ead3..6cccb9653a3e 100644
--- a/sw/source/core/text/txtfrm.cxx
+++ b/sw/source/core/text/txtfrm.cxx
@@ -457,12 +457,11 @@ bool SwTextFrame::IsHiddenNow() const
         return true;
     }
 
-    const bool bHiddenCharsHidePara = GetTextNode()->HasHiddenCharAttribute( true );
-    const bool bHiddenParaField = GetTextNode()->HasHiddenParaField();
-    const SwViewShell* pVsh = getRootFrame()->GetCurrShell();
-
-    if ( pVsh && ( bHiddenCharsHidePara || bHiddenParaField ) )
+    if ( const SwViewShell* pVsh = getRootFrame()->GetCurrShell() )
     {
+        const bool bHiddenCharsHidePara = GetTextNode()->HasHiddenCharAttribute(true);
+        const bool bHiddenParaField = GetTextNode()->IsHiddenByParaField();
+
         if (
              ( bHiddenParaField &&
                ( !pVsh->GetViewOptions()->IsShowHiddenPara() &&
diff --git a/sw/source/core/txtnode/atrfld.cxx b/sw/source/core/txtnode/atrfld.cxx
index c1ddb549defc..ceec40078ec0 100644
--- a/sw/source/core/txtnode/atrfld.cxx
+++ b/sw/source/core/txtnode/atrfld.cxx
@@ -379,18 +379,26 @@ void SwTextField::ExpandTextField(const bool bForceNotify) const
     const SwField* pField = GetFormatField().GetField();
     const OUString aNewExpand( pField->ExpandField(m_pTextNode->GetDoc()->IsClipBoard()) );
 
+    const SwFieldIds nWhich = pField->GetTyp()->Which();
+    const bool bSameExpandSimpleNotification
+        = SwFieldIds::Chapter != nWhich && SwFieldIds::PageNumber != nWhich
+          && SwFieldIds::RefPageGet != nWhich
+          // Page count fields to not use aExpand during formatting,
+          // therefore an invalidation of the text frame has to be triggered even if aNewExpand == aExpand:
+          && (SwFieldIds::DocStat != nWhich
+              || DS_PAGE != static_cast<const SwDocStatField*>(pField)->GetSubType())
+          && (SwFieldIds::GetExp != nWhich
+              || static_cast<const SwGetExpField*>(pField)->IsInBodyText());
+
+    bool bHiddenParaChanged = false;
+    if (aNewExpand != m_aExpand || bSameExpandSimpleNotification)
+        bHiddenParaChanged = m_pTextNode->CalcHiddenParaField();
+
     if (aNewExpand == m_aExpand)
     {
-        const SwFieldIds nWhich = pField->GetTyp()->Which();
-        if ( SwFieldIds::Chapter != nWhich
-             && SwFieldIds::PageNumber != nWhich
-             && SwFieldIds::RefPageGet != nWhich
-             // Page count fields to not use aExpand during formatting,
-             // therefore an invalidation of the text frame has to be triggered even if aNewExpand == aExpand:
-             && ( SwFieldIds::DocStat != nWhich || DS_PAGE != static_cast<const SwDocStatField*>(pField)->GetSubType() )
-             && ( SwFieldIds::GetExp != nWhich || static_cast<const SwGetExpField*>(pField)->IsInBodyText() ) )
+        if ( bSameExpandSimpleNotification )
         {
-            if( m_pTextNode->CalcHiddenParaField() )
+            if( bHiddenParaChanged )
             {
                 m_pTextNode->ModifyNotification( nullptr, nullptr );
             }
diff --git a/sw/source/core/txtnode/ndtxt.cxx b/sw/source/core/txtnode/ndtxt.cxx
index 193b3a654eb7..03fbb0c39da6 100644
--- a/sw/source/core/txtnode/ndtxt.cxx
+++ b/sw/source/core/txtnode/ndtxt.cxx
@@ -4168,7 +4168,7 @@ void SwTextNode::CalcHiddenCharFlags() const
 // #i12836# enhanced pdf export
 bool SwTextNode::IsHidden() const
 {
-    if ( HasHiddenParaField() || HasHiddenCharAttribute( true ) )
+    if ( IsHiddenByParaField() || HasHiddenCharAttribute( true ) )
         return true;
 
     const SwSectionNode* pSectNd = FindSectionNode();
diff --git a/sw/source/core/txtnode/thints.cxx b/sw/source/core/txtnode/thints.cxx
index e77276f1fc35..bc111093273b 100644
--- a/sw/source/core/txtnode/thints.cxx
+++ b/sw/source/core/txtnode/thints.cxx
@@ -19,6 +19,7 @@
 
 #include <sal/config.h>
 
+#include <DocumentSettingManager.hxx>
 #include <hintids.hxx>
 #include <editeng/xmlcnitm.hxx>
 #include <editeng/rsiditem.hxx>
@@ -88,11 +89,12 @@
 
 using namespace ::com::sun::star::i18n;
 
-SwpHints::SwpHints()
-    : m_pHistory(nullptr)
+SwpHints::SwpHints(const SwTextNode& rParent)
+    : m_rParent(rParent)
+    , m_pHistory(nullptr)
     , m_bInSplitNode(false)
     , m_bCalcHiddenParaField(false)
-    , m_bHasHiddenParaField(false)
+    , m_bHiddenByParaField(false)
     , m_bFootnote(false)
     , m_bDDEFields(false)
 {
@@ -1145,19 +1147,21 @@ void SwTextNode::DestroyAttr( SwTextAttr* pAttr )
             if( !pDoc->IsInDtor() )
             {
                 SwTextField *const pTextField(static_txtattr_cast<SwTextField*>(pAttr));
-                const SwField* pField = pAttr->GetFormatField().GetField();
+                SwFieldType* pFieldType = pAttr->GetFormatField().GetField()->GetTyp();
 
                 //JP 06-08-95: DDE-fields are an exception
-                assert(SwFieldIds::Dde == pField->GetTyp()->Which() ||
+                assert(SwFieldIds::Dde == pFieldType->Which() ||
                        this == pTextField->GetpTextNode());
 
                 // certain fields must update the SwDoc's calculation flags
-                switch( pField->GetTyp()->Which() )
+
+                // Certain fields (like HiddenParaField) must trigger recalculation of visible flag
+                if (FieldCanHidePara(pFieldType->Which()))
+                    SetCalcHiddenParaField();
+
+                switch( pFieldType->Which() )
                 {
                 case SwFieldIds::HiddenPara:
-                // HiddenParaField must trigger recalculation of visible flag
-                    SetCalcHiddenParaField();
-                    SAL_FALLTHROUGH;
                 case SwFieldIds::DbSetNumber:
                 case SwFieldIds::GetExp:
                 case SwFieldIds::Database:
@@ -1170,7 +1174,7 @@ void SwTextNode::DestroyAttr( SwTextAttr* pAttr )
                     break;
                 case SwFieldIds::Dde:
                     if (GetNodes().IsDocNodes() && pTextField->GetpTextNode())
-                        static_cast<SwDDEFieldType*>(pField->GetTyp())->DecRefCnt();
+                        static_cast<SwDDEFieldType*>(pFieldType)->DecRefCnt();
                     break;
                 case SwFieldIds::Postit:
                     {
@@ -1461,8 +1465,8 @@ bool SwTextNode::InsertHint( SwTextAttr * const pAttr, const SetAttrMode nMode )
 
             case RES_TXTATR_FIELD:
                 {
-                    // trigger notification for HiddenParaFields
-                    if( SwFieldIds::HiddenPara == pAttr->GetFormatField().GetField()->GetTyp()->Which() )
+                    // trigger notification for relevant fields, like HiddenParaFields
+                    if (FieldCanHidePara(pAttr->GetFormatField().GetField()->GetTyp()->Which()))
                     {
                         bHiddenPara = true;
                     }
@@ -2586,38 +2590,32 @@ void SwpHints::CalcFlags()
     }
 }
 
-bool SwpHints::CalcHiddenParaField()
+bool SwpHints::CalcHiddenParaField() const
 {
     m_bCalcHiddenParaField = false;
-    bool bOldHasHiddenParaField = m_bHasHiddenParaField;
-    bool bNewHasHiddenParaField  = false;
+    const bool bOldHiddenByParaField = m_bHiddenByParaField;
+    bool bNewHiddenByParaField = false;
     const size_t nSize = Count();
-    const SwTextAttr *pTextHt;
+    const SwTextAttr* pTextHt;
 
-    for( size_t nPos = 0; nPos < nSize; ++nPos )
+    for (size_t nPos = 0; nPos < nSize; ++nPos)
     {
         pTextHt = Get(nPos);
         const sal_uInt16 nWhich = pTextHt->Which();
 
-        if( RES_TXTATR_FIELD == nWhich )
+        if (RES_TXTATR_FIELD == nWhich)
         {
             const SwFormatField& rField = pTextHt->GetFormatField();
-            if( SwFieldIds::HiddenPara == rField.GetField()->GetTyp()->Which() )
+            if (m_rParent.FieldCanHidePara(rField.GetField()->GetTyp()->Which())
+                && !(bNewHiddenByParaField = m_rParent.FieldHidesPara(*rField.GetField())))
             {
-                if( !static_cast<const SwHiddenParaField*>(rField.GetField())->IsHidden() )
-                {
-                    SetHiddenParaField(false);
-                    return bOldHasHiddenParaField != bNewHasHiddenParaField;
-                }
-                else
-                {
-                    bNewHasHiddenParaField = true;
-                }
+                // If there's at least one field telling not to hide, so be it
+                break;
             }
         }
     }
-    SetHiddenParaField( bNewHasHiddenParaField );
-    return bOldHasHiddenParaField != bNewHasHiddenParaField;
+    SetHiddenByParaField(bNewHiddenByParaField);
+    return bOldHiddenByParaField != bNewHiddenByParaField;
 }
 
 void SwpHints::NoteInHistory( SwTextAttr *pAttr, const bool bNew )
@@ -3285,7 +3283,8 @@ void SwpHints::DeleteAtPos( const size_t nPos )
     if( pHint->Which() == RES_TXTATR_FIELD )
     {
         SwTextField *const pTextField(static_txtattr_cast<SwTextField*>(pHint));
-        const SwFieldType* pFieldTyp = pTextField->GetFormatField().GetField()->GetTyp();
+        const SwField* pField = pTextField->GetFormatField().GetField();
+        const SwFieldType* pFieldTyp = pField->GetTyp();
         if( SwFieldIds::Dde == pFieldTyp->Which() )
         {
             const SwTextNode* pNd = pTextField->GetpTextNode();
@@ -3293,8 +3292,8 @@ void SwpHints::DeleteAtPos( const size_t nPos )
                 const_cast<SwDDEFieldType*>(static_cast<const SwDDEFieldType*>(pFieldTyp))->DecRefCnt();
             pTextField->ChgTextNode(nullptr);
         }
-        else if ( m_bHasHiddenParaField &&
-                 SwFieldIds::HiddenPara == pFieldTyp->Which() )
+        else if (m_bHiddenByParaField
+                 && m_rParent.FieldCanHidePara(pField->GetTyp()->Which()))
         {
             m_bCalcHiddenParaField = true;
         }
diff --git a/sw/source/core/view/viewsh.cxx b/sw/source/core/view/viewsh.cxx
index bb1ab6b3f454..fa81d1736f2c 100644
--- a/sw/source/core/view/viewsh.cxx
+++ b/sw/source/core/view/viewsh.cxx
@@ -923,6 +923,26 @@ void SwViewShell::SetSubtractFlysAnchoredAtFlys(bool bSubtractFlysAnchoredAtFlys
     rIDSA.set(DocumentSettingId::SUBTRACT_FLYS, bSubtractFlysAnchoredAtFlys);
 }
 
+void SwViewShell::SetEmptyDbFieldHidesPara(bool bEmptyDbFieldHidesPara)
+{
+    IDocumentSettingAccess& rIDSA = getIDocumentSettingAccess();
+    if (rIDSA.get(DocumentSettingId::EMPTY_DB_FIELD_HIDES_PARA) != bEmptyDbFieldHidesPara)
+    {
+        SwWait aWait(*GetDoc()->GetDocShell(), true);
+        rIDSA.set(DocumentSettingId::EMPTY_DB_FIELD_HIDES_PARA, bEmptyDbFieldHidesPara);
+        StartAction();
+        GetDoc()->getIDocumentState().SetModified();
+        for (auto* pFieldType : *GetDoc()->getIDocumentFieldsAccess().GetFieldTypes())
+        {
+            if (pFieldType->Which() == SwFieldIds::Database)
+            {
+                pFieldType->ModifyNotification(nullptr, nullptr);
+            }
+        }
+        EndAction();
+    }
+}
+
 void SwViewShell::Reformat()
 {
     SwWait aWait( *GetDoc()->GetDocShell(), true );