sd signature line: extract page resource / content copy code

So the "sign existing pdf" code can reuse it.

Change-Id: I63a811f0c6f2bc2eeb29507aff9bc35e92a081cd
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/96617
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

3 files changed, 78 insertions, 53 deletions

diff --git a/vcl/inc/pdf/objectcopier.hxx b/vcl/inc/pdf/objectcopier.hxx
index 5372019a6fe9..364fffbf1548 100644
--- a/vcl/inc/pdf/objectcopier.hxx
+++ b/vcl/inc/pdf/objectcopier.hxx
@@ -10,7 +10,9 @@
 #pragma once
 
 #include <map>
+#include <vector>
 
+#include <rtl/strbuf.hxx>
 #include <rtl/string.hxx>
 #include <sal/types.h>
 #include <vcl/dllapi.h>
@@ -42,6 +44,13 @@ public:
     /// object ID in our document.
     sal_Int32 copyExternalResource(SvMemoryStream& rDocBuffer, filter::PDFObjectElement& rObject,
                                    std::map<sal_Int32, sal_Int32>& rCopiedResources);
+
+    /// Copies resources of pPage into rLine.
+    void copyPageResources(filter::PDFObjectElement* pPage, OStringBuffer& rLine);
+
+    /// Copies page one or more page streams from rContentStreams into rStream.
+    static sal_Int32 copyPageStreams(std::vector<filter::PDFObjectElement*>& rContentStreams,
+                                     SvMemoryStream& rStream, bool& rCompressed);
 };
 }
 
diff --git a/vcl/source/gdi/pdfobjectcopier.cxx b/vcl/source/gdi/pdfobjectcopier.cxx
index c5ff2eecab19..5e54ee68c289 100644
--- a/vcl/source/gdi/pdfobjectcopier.cxx
+++ b/vcl/source/gdi/pdfobjectcopier.cxx
@@ -13,9 +13,12 @@
 #include <sal/log.hxx>
 #include <sal/types.h>
 #include <tools/stream.hxx>
+#include <tools/zcodec.hxx>
 #include <vcl/filter/pdfdocument.hxx>
 #include <vcl/filter/pdfobjectcontainer.hxx>
 
+#include "pdfwriter_impl.hxx"
+
 namespace vcl
 {
 PDFObjectCopier::PDFObjectCopier(PDFObjectContainer& rContainer)
@@ -35,8 +38,8 @@ sal_Int32 PDFObjectCopier::copyExternalResource(SvMemoryStream& rDocBuffer,
     sal_Int32 nObject = m_rContainer.createObject();
     // Remember what is the ID of this object in our output.
     rCopiedResources[rObject.GetObjectValue()] = nObject;
-    SAL_INFO("vcl.pdfwriter", "PDFWriterImpl::copyExternalResource: " << rObject.GetObjectValue()
-                                                                      << " -> " << nObject);
+    SAL_INFO("vcl.pdfwriter", "PDFObjectCopier::copyExternalResource: " << rObject.GetObjectValue()
+                                                                        << " -> " << nObject);
 
     OStringBuffer aLine;
     aLine.append(nObject);
@@ -267,6 +270,67 @@ OString PDFObjectCopier::copyExternalResources(filter::PDFObjectElement& rPage,
 
     return sRet.makeStringAndClear();
 }
+
+void PDFObjectCopier::copyPageResources(filter::PDFObjectElement* pPage, OStringBuffer& rLine)
+{
+    // Maps from source object id (PDF image) to target object id (export result).
+    std::map<sal_Int32, sal_Int32> aCopiedResources;
+
+    rLine.append(" /Resources <<");
+    static const std::initializer_list<OString> aKeys
+        = { "ColorSpace", "ExtGState", "Font", "XObject", "Shading" };
+    for (const auto& rKey : aKeys)
+    {
+        rLine.append(copyExternalResources(*pPage, rKey, aCopiedResources));
+    }
+    rLine.append(">>");
+}
+
+sal_Int32 PDFObjectCopier::copyPageStreams(std::vector<filter::PDFObjectElement*>& rContentStreams,
+                                           SvMemoryStream& rStream, bool& rCompressed)
+{
+    for (auto pContent : rContentStreams)
+    {
+        filter::PDFStreamElement* pPageStream = pContent->GetStream();
+        if (!pPageStream)
+        {
+            SAL_WARN("vcl.pdfwriter", "PDFObjectCopier::copyPageStreams: contents has no stream");
+            continue;
+        }
+
+        SvMemoryStream& rPageStream = pPageStream->GetMemory();
+
+        auto pFilter = dynamic_cast<filter::PDFNameElement*>(pContent->Lookup("Filter"));
+        if (pFilter)
+        {
+            if (pFilter->GetValue() != "FlateDecode")
+            {
+                continue;
+            }
+
+            SvMemoryStream aMemoryStream;
+            ZCodec aZCodec;
+            rPageStream.Seek(0);
+            aZCodec.BeginCompression();
+            aZCodec.Decompress(rPageStream, aMemoryStream);
+            if (!aZCodec.EndCompression())
+            {
+                SAL_WARN("vcl.pdfwriter", "PDFObjectCopier::copyPageStreams: decompression failed");
+                continue;
+            }
+
+            rStream.WriteBytes(aMemoryStream.GetData(), aMemoryStream.GetSize());
+        }
+        else
+        {
+            rStream.WriteBytes(rPageStream.GetData(), rPageStream.GetSize());
+        }
+    }
+
+    rCompressed = PDFWriterImpl::compressStream(&rStream);
+
+    return rStream.Tell();
+}
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index 44c21afb2214..47a697785564 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -8417,9 +8417,6 @@ void PDFWriterImpl::writeReferenceXObject(ReferenceXObjectEmit& rEmit)
             return;
         }
 
-        // Maps from source object id (PDF image) to target object id (export result).
-        std::map<sal_Int32, sal_Int32> aCopiedResources;
-
         nWrappedFormObject = createObject();
         // Write the form XObject wrapped below. This is a separate object from
         // the wrapper, this way there is no need to alter the stream contents.
@@ -8457,19 +8454,8 @@ void PDFWriterImpl::writeReferenceXObject(ReferenceXObjectEmit& rEmit)
             }
         }
 
-        aLine.append(" /Resources <<");
-        static const std::initializer_list<OString> aKeys =
-        {
-            "ColorSpace",
-            "ExtGState",
-            "Font",
-            "XObject",
-            "Shading"
-        };
         PDFObjectCopier aCopier(*this);
-        for (const auto& rKey : aKeys)
-            aLine.append(aCopier.copyExternalResources(*pPage, rKey, aCopiedResources));
-        aLine.append(">>");
+        aCopier.copyPageResources(pPage, aLine);
         aLine.append(" /BBox [ 0 0 ");
         aLine.append(nWidth);
         aLine.append(" ");
@@ -8481,42 +8467,8 @@ void PDFWriterImpl::writeReferenceXObject(ReferenceXObjectEmit& rEmit)
         aLine.append(" /Length ");
 
         SvMemoryStream aStream;
-        for (auto pContent : aContentStreams)
-        {
-            filter::PDFStreamElement* pPageStream = pContent->GetStream();
-            if (!pPageStream)
-            {
-                SAL_WARN("vcl.pdfwriter", "PDFWriterImpl::writeReferenceXObject: contents has no stream");
-                continue;
-            }
-
-            SvMemoryStream& rPageStream = pPageStream->GetMemory();
-
-            auto pFilter = dynamic_cast<filter::PDFNameElement*>(pContent->Lookup("Filter"));
-            if (pFilter)
-            {
-                if (pFilter->GetValue() != "FlateDecode")
-                    continue;
-
-                SvMemoryStream aMemoryStream;
-                ZCodec aZCodec;
-                rPageStream.Seek(0);
-                aZCodec.BeginCompression();
-                aZCodec.Decompress(rPageStream, aMemoryStream);
-                if (!aZCodec.EndCompression())
-                {
-                    SAL_WARN("vcl.pdfwriter", "PDFWriterImpl::writeReferenceXObject: decompression failed");
-                    continue;
-                }
-
-                aStream.WriteBytes(aMemoryStream.GetData(), aMemoryStream.GetSize());
-            }
-            else
-                aStream.WriteBytes(rPageStream.GetData(), rPageStream.GetSize());
-        }
-
-        compressStream(&aStream);
-        sal_Int32 nLength = aStream.Tell();
+        bool bCompressed = false;
+        sal_Int32 nLength = PDFObjectCopier::copyPageStreams(aContentStreams, aStream, bCompressed);
         aLine.append(nLength);
 
         aLine.append(">>\nstream\n");