tdf#163483: implement export of Math formula's fallback image to PPTX

This was left as a TODO in commit cb890ae43bacd2be24bc74fad2e2e5cce8910995
(oox: export Math objects to PPTX files, 2016-01-15). Now after commit
7cfff4751befd678b3db4b6f16b020d38f4e9c32 (Related: tdf#129061 Avoid formula
import and use fallback for now, 2024-09-11), that relied on the fallback
being present, our exported documents lost the formulas completely on load.
So the fallback export became a necessity.

Change-Id: I52d4ef0400ce72ee10fda10a1131b4ba29ea56be
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/177564
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Jenkins

1 files changed, 34 insertions, 4 deletions

diff --git a/oox/source/export/shapes.cxx b/oox/source/export/shapes.cxx
index 38c76ef59952..0bb8d1ebeecc 100644
--- a/oox/source/export/shapes.cxx
+++ b/oox/source/export/shapes.cxx
@@ -77,6 +77,7 @@
 #include <vcl/graph.hxx>
 #include <vcl/outdev.hxx>
 #include <filter/msfilter/escherex.hxx>
+#include <svtools/embedhlp.hxx>
 #include <svx/svdoashp.hxx>
 #include <svx/svdoole2.hxx>
 #include <comphelper/diagnose_ex.hxx>
@@ -2657,6 +2658,8 @@ void ShapeExport::WriteMathShape(Reference<XShape> const& xShape)
     assert(xMathModel.is());
     assert(GetDocumentType() != DOCUMENT_DOCX); // should be written in DocxAttributeOutput
     SAL_WARN_IF(GetDocumentType() == DOCUMENT_XLSX, "oox.shape", "Math export to XLSX isn't tested, should it happen here?");
+    const OString cNvPr_id = OString::number(GetNewShapeID(xShape));
+    const OUString shapeName = GetShapeName(xShape);
 
     // ECMA standard does not actually allow oMath outside of
     // WordProcessingML so write a MCE like PPT 2010 does
@@ -2666,9 +2669,7 @@ void ShapeExport::WriteMathShape(Reference<XShape> const& xShape)
         XML_Requires, "a14");
     mpFS->startElementNS(mnXmlNamespace, XML_sp);
     mpFS->startElementNS(mnXmlNamespace, XML_nvSpPr);
-    mpFS->startElementNS(mnXmlNamespace, XML_cNvPr,
-         XML_id, OString::number(GetNewShapeID(xShape)),
-         XML_name, GetShapeName(xShape));
+    mpFS->startElementNS(mnXmlNamespace, XML_cNvPr, XML_id, cNvPr_id, XML_name, shapeName);
     AddExtLst(mpFS, xPropSet);
     mpFS->endElementNS(mnXmlNamespace, XML_cNvPr);
     mpFS->singleElementNS(mnXmlNamespace, XML_cNvSpPr, XML_txBox, "1");
@@ -2696,7 +2697,36 @@ void ShapeExport::WriteMathShape(Reference<XShape> const& xShape)
     mpFS->endElementNS(mnXmlNamespace, XML_sp);
     mpFS->endElementNS(XML_mc, XML_Choice);
     mpFS->startElementNS(XML_mc, XML_Fallback);
-    // TODO: export bitmap shape as fallback
+
+    svt::EmbeddedObjectRef ref(
+        xPropSet->getPropertyValue(u"EmbeddedObject"_ustr).query<css::embed::XEmbeddedObject>(),
+        embed::Aspects::MSOLE_CONTENT);
+    if (auto* graphic = ref.GetGraphic(); graphic && graphic->GetType() != GraphicType::NONE)
+    {
+        if (OUString r_id = writeGraphicToStorage(*graphic); !r_id.isEmpty())
+        {
+            mpFS->startElementNS(mnXmlNamespace, XML_sp);
+            mpFS->startElementNS(mnXmlNamespace, XML_nvSpPr);
+            mpFS->startElementNS(mnXmlNamespace, XML_cNvPr, XML_id, cNvPr_id, XML_name, shapeName);
+            AddExtLst(mpFS, xPropSet);
+            mpFS->endElementNS(mnXmlNamespace, XML_cNvPr);
+            mpFS->singleElementNS(mnXmlNamespace, XML_cNvSpPr, XML_txBox, "1");
+            mpFS->singleElementNS(mnXmlNamespace, XML_nvPr);
+            mpFS->endElementNS(mnXmlNamespace, XML_nvSpPr);
+            mpFS->startElementNS(mnXmlNamespace, XML_spPr);
+            WriteShapeTransformation(xShape, XML_a);
+            WritePresetShape("rect"_ostr);
+            mpFS->startElementNS(XML_a, XML_blipFill);
+            mpFS->singleElementNS(XML_a, XML_blip, FSNS(XML_r, XML_embed), r_id);
+            mpFS->startElementNS(XML_a, XML_stretch);
+            mpFS->singleElementNS(XML_a, XML_fillRect);
+            mpFS->endElementNS(XML_a, XML_stretch);
+            mpFS->endElementNS(XML_a, XML_blipFill);
+            mpFS->endElementNS(mnXmlNamespace, XML_spPr);
+            mpFS->endElementNS(mnXmlNamespace, XML_sp);
+        }
+    }
+
     mpFS->endElementNS(XML_mc, XML_Fallback);
     mpFS->endElementNS(XML_mc, XML_AlternateContent);
 }