tdf#91383: sw: prevent style preview from actually creating styles

The dialog/sidebar should not actually create styles that don't exist yet,
because it messes up Undo and the (unused) styles are then unnecessarily
exported to documents.

Due to Writer's ... unusual SwDocStyleSheet class this is a bit tricky.

Add a new function GetItemSetForPreview() and use it from the style preview
code.

The implementation does not use FillPhysical so will temporarily create and
then delete any non-existing styles.

Skip page and numbering styles for now since they don't have a useful preview.

(regression from ca95307638207db5d662059aa61594151a13e927)

(cherry picked from commit 93067f37cf22aa119db5878c4345fea500cbbb42)

-Werror,-Wreturn-type
(cherry picked from commit 0ed64030f17849ea943800343003c5ec3f4f1388)

Change-Id: Id6ee30ea467fc24c991547a4c23a9ce14fdd86c7
Reviewed-on: https://gerrit.libreoffice.org/18381
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>

2 files changed, 38 insertions, 33 deletions

diff --git a/svx/source/styles/CommonStylePreviewRenderer.cxx b/svx/source/styles/CommonStylePreviewRenderer.cxx
index ab1271ac8fe0..67f9b89670a5 100644
--- a/svx/source/styles/CommonStylePreviewRenderer.cxx
+++ b/svx/source/styles/CommonStylePreviewRenderer.cxx
@@ -60,65 +60,67 @@ CommonStylePreviewRenderer::~CommonStylePreviewRenderer()
 
 bool CommonStylePreviewRenderer::recalculate()
 {
-    const SfxItemSet& aItemSet = mpStyle->GetItemSet();
-
     maFont = SvxFont();
 
+    std::unique_ptr<SfxItemSet> pItemSet(mpStyle->GetItemSetForPreview());
+
+    if (!pItemSet) return false;
+
     const SfxPoolItem* pItem;
 
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_WEIGHT)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_WEIGHT)) != nullptr)
     {
         maFont.SetWeight(static_cast<const SvxWeightItem*>(pItem)->GetWeight());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_POSTURE)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_POSTURE)) != nullptr)
     {
         maFont.SetItalic(static_cast<const SvxPostureItem*>(pItem)->GetPosture());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_CONTOUR)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_CONTOUR)) != nullptr)
     {
         maFont.SetOutline(static_cast< const SvxContourItem*>(pItem)->GetValue());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_SHADOWED)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_SHADOWED)) != nullptr)
     {
         maFont.SetShadow(static_cast<const SvxShadowedItem*>(pItem)->GetValue());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_RELIEF)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_RELIEF)) != nullptr)
     {
         maFont.SetRelief(static_cast<FontRelief>(static_cast<const SvxCharReliefItem*>(pItem)->GetValue()));
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_UNDERLINE)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_UNDERLINE)) != nullptr)
     {
         maFont.SetUnderline(static_cast< const SvxUnderlineItem*>(pItem)->GetLineStyle());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_OVERLINE)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_OVERLINE)) != nullptr)
     {
         maFont.SetOverline(static_cast<FontUnderline>(static_cast<const SvxOverlineItem*>(pItem)->GetValue()));
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_STRIKEOUT)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_STRIKEOUT)) != nullptr)
     {
         maFont.SetStrikeout(static_cast<const SvxCrossedOutItem*>(pItem)->GetStrikeout());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_CASEMAP)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_CASEMAP)) != nullptr)
     {
         maFont.SetCaseMap(static_cast<const SvxCaseMapItem*>(pItem)->GetCaseMap());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_EMPHASISMARK)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_EMPHASISMARK)) != nullptr)
     {
         maFont.SetEmphasisMark(static_cast<const SvxEmphasisMarkItem*>(pItem)->GetEmphasisMark());
     }
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_COLOR)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_COLOR)) != nullptr)
     {
         maFontColor = Color(static_cast<const SvxColorItem*>(pItem)->GetValue());
     }
 
     if (mpStyle->GetFamily() == SFX_STYLE_FAMILY_PARA)
     {
-        if ((pItem = aItemSet.GetItem(XATTR_FILLSTYLE)) != nullptr)
+        if ((pItem = pItemSet->GetItem(XATTR_FILLSTYLE)) != nullptr)
         {
             sal_uInt16 aFillStyle = static_cast<const XFillStyleItem*>(pItem)->GetValue();
             if (aFillStyle == drawing::FillStyle_SOLID)
             {
-                if ((pItem = aItemSet.GetItem(XATTR_FILLCOLOR)) != nullptr)
+                if ((pItem = pItemSet->GetItem(XATTR_FILLCOLOR)) != nullptr)
                 {
                     maBackgroundColor = Color(static_cast<const XFillColorItem*>(pItem)->GetColorValue());
                 }
@@ -126,7 +128,7 @@ bool CommonStylePreviewRenderer::recalculate()
         }
     }
 
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_FONT)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_FONT)) != nullptr)
     {
         const SvxFontItem* pFontItem = static_cast<const SvxFontItem*>(pItem);
         maFont.SetName(pFontItem->GetFamilyName());
@@ -137,7 +139,7 @@ bool CommonStylePreviewRenderer::recalculate()
         return false;
     }
 
-    if ((pItem = aItemSet.GetItem(SID_ATTR_CHAR_FONTHEIGHT)) != nullptr)
+    if ((pItem = pItemSet->GetItem(SID_ATTR_CHAR_FONTHEIGHT)) != nullptr)
     {
         const SvxFontHeightItem* pFontHeightItem = static_cast<const SvxFontHeightItem*>(pItem);
         Size aFontSize(0, pFontHeightItem->GetHeight());
diff --git a/svx/source/tbxctrls/tbcontrl.cxx b/svx/source/tbxctrls/tbcontrl.cxx
index e22c6c67aa98..5e15ccd61f25 100644
--- a/svx/source/tbxctrls/tbcontrl.cxx
+++ b/svx/source/tbxctrls/tbcontrl.cxx
@@ -639,10 +639,13 @@ void SvxStyleBox_Impl::SetupEntry(vcl::RenderContext& rRenderContext, vcl::Windo
 
         if (pStyle )
         {
-            const SfxItemSet& aItemSet = pStyle->GetItemSet();
+            std::unique_ptr<const SfxItemSet> const pItemSet(pStyle->GetItemSetForPreview());
+            if (!pItemSet) return;
 
-            const SvxFontItem *pFontItem = static_cast< const SvxFontItem* >( aItemSet.GetItem( SID_ATTR_CHAR_FONT ) );
-            const SvxFontHeightItem *pFontHeightItem = static_cast< const SvxFontHeightItem* >( aItemSet.GetItem( SID_ATTR_CHAR_FONTHEIGHT ) );
+            const SvxFontItem * const pFontItem =
+                static_cast<const SvxFontItem*>(pItemSet->GetItem(SID_ATTR_CHAR_FONT));
+            const SvxFontHeightItem * const pFontHeightItem =
+                static_cast<const SvxFontHeightItem*>(pItemSet->GetItem(SID_ATTR_CHAR_FONTHEIGHT));
 
             if ( pFontItem && pFontHeightItem )
             {
@@ -655,43 +658,43 @@ void SvxStyleBox_Impl::SetupEntry(vcl::RenderContext& rRenderContext, vcl::Windo
                 aFont.SetStyleName(pFontItem->GetStyleName());
                 aFont.SetSize(aPixelSize);
 
-                const SfxPoolItem *pItem = aItemSet.GetItem( SID_ATTR_CHAR_WEIGHT );
+                const SfxPoolItem *pItem = pItemSet->GetItem( SID_ATTR_CHAR_WEIGHT );
                 if ( pItem )
                     aFont.SetWeight( static_cast< const SvxWeightItem* >( pItem )->GetWeight() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_POSTURE );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_POSTURE );
                 if ( pItem )
                     aFont.SetItalic( static_cast< const SvxPostureItem* >( pItem )->GetPosture() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_CONTOUR );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_CONTOUR );
                 if ( pItem )
                     aFont.SetOutline( static_cast< const SvxContourItem* >( pItem )->GetValue() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_SHADOWED );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_SHADOWED );
                 if ( pItem )
                     aFont.SetShadow( static_cast< const SvxShadowedItem* >( pItem )->GetValue() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_RELIEF );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_RELIEF );
                 if ( pItem )
                     aFont.SetRelief( static_cast< FontRelief >( static_cast< const SvxCharReliefItem* >( pItem )->GetValue() ) );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_UNDERLINE );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_UNDERLINE );
                 if ( pItem )
                     aFont.SetUnderline( static_cast< const SvxUnderlineItem* >( pItem )->GetLineStyle() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_OVERLINE );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_OVERLINE );
                 if ( pItem )
                     aFont.SetOverline( static_cast< FontUnderline >( static_cast< const SvxOverlineItem* >( pItem )->GetValue() ) );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_STRIKEOUT );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_STRIKEOUT );
                 if ( pItem )
                     aFont.SetStrikeout( static_cast< const SvxCrossedOutItem* >( pItem )->GetStrikeout() );
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_CASEMAP );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_CASEMAP );
                 if ( pItem )
                     aFont.SetCaseMap(static_cast<const SvxCaseMapItem*>(pItem)->GetCaseMap());
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_EMPHASISMARK );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_EMPHASISMARK );
                 if ( pItem )
                     aFont.SetEmphasisMark( static_cast< const SvxEmphasisMarkItem* >( pItem )->GetEmphasisMark() );
 
@@ -702,14 +705,14 @@ void SvxStyleBox_Impl::SetupEntry(vcl::RenderContext& rRenderContext, vcl::Windo
 
                 rRenderContext.SetFont(aFont);
 
-                pItem = aItemSet.GetItem( SID_ATTR_CHAR_COLOR );
+                pItem = pItemSet->GetItem( SID_ATTR_CHAR_COLOR );
                 // text color, when nothing is selected
                 if ( (NULL != pItem) && bIsNotSelected)
                     aFontCol = Color( static_cast< const SvxColorItem* >( pItem )->GetValue() );
 
                 sal_uInt16 style = drawing::FillStyle_NONE;
                 // which kind of Fill style is selected
-                pItem = aItemSet.GetItem( XATTR_FILLSTYLE );
+                pItem = pItemSet->GetItem( XATTR_FILLSTYLE );
                 // only when ok and not selected
                 if ( (NULL != pItem) && bIsNotSelected)
                     style = static_cast< const XFillStyleItem* >( pItem )->GetValue();
@@ -719,7 +722,7 @@ void SvxStyleBox_Impl::SetupEntry(vcl::RenderContext& rRenderContext, vcl::Windo
                     case drawing::FillStyle_SOLID:
                     {
                         // set background color
-                        pItem = aItemSet.GetItem( XATTR_FILLCOLOR );
+                        pItem = pItemSet->GetItem( XATTR_FILLCOLOR );
                         if ( NULL != pItem )
                             aBackCol = Color( static_cast< const XFillColorItem* >( pItem )->GetColorValue() );