tdf#135638 drawinglayer,svx,sw: PDF/UA export: put SdrObjects on anchor

... frame in the structure tree.

The problem is that in sw, the anchored objects are painted
outside of the call to paint the page frame, which is what generates the
/Document structure element.

For Writer fly frames, this is handled via their SwFlyDrawObj painting,
where SwTaggedPDFHelper::CheckReopenTag() finds the anchor frame and
temporarily sets it as the structure parent, even if it's on a previous
page.

But all the SdrObjects on a page are painted by 2 calls to PaintLayer()
and there isn't a call back into Writer now.

Somehow this even causes a spurious line like "/Document<</MCID 7>>BDC"
to be emitted outside any PDF object, which looks clearly wrong.

Try to extend the SdrObjUserCall to get a way to retrieve the anchor
frame's structure element index.

Another option would be to extend ViewObjectContactRedirector to return
the PDF Id in its subclass SwViewObjectContactRedirector, and it seems
possible since its only one caller is
ViewObjectContact::getPrimitive2DSequence(), but Armin adivses that the
ViewObjectContactRedirector might go away in the future so it's better
to use SdrObjUserCall.

It's annoying that the mapping is a static members of
SwEnhancedPDFExportHelper; possibly it could be in OutputDevice's
PDFExtOutDevData instead?

Change-Id: Id61faae469aba4f0bd278ab2324aae06c1fdde64
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/143027
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

2 files changed, 14 insertions, 1 deletions

diff --git a/svx/source/sdr/contact/viewobjectcontact.cxx b/svx/source/sdr/contact/viewobjectcontact.cxx
index 15dea8262a5b..74c78868b80e 100644
--- a/svx/source/sdr/contact/viewobjectcontact.cxx
+++ b/svx/source/sdr/contact/viewobjectcontact.cxx
@@ -412,13 +412,21 @@ drawinglayer::primitive2d::Primitive2DContainer const & ViewObjectContact::getPr
             {
                 const bool bBackground(pSdrPage->IsMasterPage());
                 const bool bImage(SdrObjKind::Graphic == pSdrObj->GetObjIdentifier());
+                // note: there must be output device here, in PDF export
+                sal_Int32 nAnchorId(-1);
+                if (auto const pUserCall = pSdrObj->GetUserCall())
+                {
+                    nAnchorId = pUserCall->GetPDFAnchorStructureElementId(
+                        *pSdrObj, *GetObjectContact().TryToGetOutputDevice());
+                }
 
                 drawinglayer::primitive2d::Primitive2DReference xReference(
                     new drawinglayer::primitive2d::StructureTagPrimitive2D(
                         eElement,
                         bBackground,
                         bImage,
-                        std::move(xNewPrimitiveSequence)));
+                        std::move(xNewPrimitiveSequence),
+                        nAnchorId));
                 xNewPrimitiveSequence = drawinglayer::primitive2d::Primitive2DContainer { xReference };
             }
         }
diff --git a/svx/source/svdraw/svdobj.cxx b/svx/source/svdraw/svdobj.cxx
index 34688e501eae..4bcd7c386270 100644
--- a/svx/source/svdraw/svdobj.cxx
+++ b/svx/source/svdraw/svdobj.cxx
@@ -136,6 +136,11 @@ void SdrObjUserCall::Changed(const SdrObject& /*rObj*/, SdrUserCallType /*eType*
 {
 }
 
+sal_Int32 SdrObjUserCall::GetPDFAnchorStructureElementId(SdrObject const&, OutputDevice const&)
+{
+    return -1;
+}
+
 SdrObjMacroHitRec::SdrObjMacroHitRec() :
     pVisiLayer(nullptr),
     pPageView(nullptr),