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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
commited5640d8b587fbcfed7dd7967f3de04b37a76f26 (patch)
tree7a5f7c6c9d02226d7471cb3cc8fbbf631b415303 /vcl/source/gdi/pdfobjectcopier.cxx
parentInitial commit. (diff)
downloadlibreoffice-upstream.tar.xz
libreoffice-upstream.zip
Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vcl/source/gdi/pdfobjectcopier.cxx')
-rw-r--r--vcl/source/gdi/pdfobjectcopier.cxx318
1 files changed, 318 insertions, 0 deletions
diff --git a/vcl/source/gdi/pdfobjectcopier.cxx b/vcl/source/gdi/pdfobjectcopier.cxx
new file mode 100644
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+++ b/vcl/source/gdi/pdfobjectcopier.cxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/log.hxx>
+#include <sal/types.h>
+#include <rtl/strbuf.hxx>
+#include <tools/stream.hxx>
+#include <tools/zcodec.hxx>
+
+#include <vcl/filter/pdfdocument.hxx>
+#include <vcl/filter/pdfobjectcontainer.hxx>
+
+#include <pdf/objectcopier.hxx>
+#include <pdf/pdfwriter_impl.hxx>
+
+namespace vcl
+{
+PDFObjectCopier::PDFObjectCopier(PDFObjectContainer& rContainer)
+ : m_rContainer(rContainer)
+{
+}
+
+void PDFObjectCopier::copyRecursively(OStringBuffer& rLine, filter::PDFElement& rInputElement,
+ SvMemoryStream& rDocBuffer,
+ std::map<sal_Int32, sal_Int32>& rCopiedResources)
+{
+ if (auto pReference = dynamic_cast<filter::PDFReferenceElement*>(&rInputElement))
+ {
+ filter::PDFObjectElement* pReferenced = pReference->LookupObject();
+ if (pReferenced)
+ {
+ // Copy the referenced object.
+ sal_Int32 nRef = copyExternalResource(rDocBuffer, *pReferenced, rCopiedResources);
+
+ // Write the updated reference.
+ rLine.append(nRef);
+ rLine.append(" 0 R");
+ }
+ }
+ else if (auto pInputArray = dynamic_cast<filter::PDFArrayElement*>(&rInputElement))
+ {
+ rLine.append("[ ");
+ for (auto const& pElement : pInputArray->GetElements())
+ {
+ copyRecursively(rLine, *pElement, rDocBuffer, rCopiedResources);
+ rLine.append(" ");
+ }
+ rLine.append("] ");
+ }
+ else if (auto pInputDictionary = dynamic_cast<filter::PDFDictionaryElement*>(&rInputElement))
+ {
+ rLine.append("<< ");
+ for (auto const& pPair : pInputDictionary->GetItems())
+ {
+ rLine.append("/");
+ rLine.append(pPair.first);
+ rLine.append(" ");
+ copyRecursively(rLine, *pPair.second, rDocBuffer, rCopiedResources);
+ rLine.append(" ");
+ }
+ rLine.append(">> ");
+ }
+ else
+ {
+ rInputElement.writeString(rLine);
+ }
+}
+
+sal_Int32 PDFObjectCopier::copyExternalResource(SvMemoryStream& rDocBuffer,
+ filter::PDFObjectElement& rObject,
+ std::map<sal_Int32, sal_Int32>& rCopiedResources)
+{
+ auto it = rCopiedResources.find(rObject.GetObjectValue());
+ if (it != rCopiedResources.end())
+ {
+ // This resource was already copied once, nothing to do.
+ return it->second;
+ }
+
+ 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", "PDFObjectCopier::copyExternalResource: " << rObject.GetObjectValue()
+ << " -> " << nObject);
+
+ OStringBuffer aLine;
+ aLine.append(nObject);
+ aLine.append(" 0 obj\n");
+
+ if (rObject.GetDictionary())
+ {
+ aLine.append("<< ");
+ bool bFirst = true;
+ for (auto const& rPair : rObject.GetDictionaryItems())
+ {
+ if (bFirst)
+ bFirst = false;
+ else
+ aLine.append(" ");
+
+ aLine.append("/");
+ aLine.append(rPair.first);
+ aLine.append(" ");
+ copyRecursively(aLine, *rPair.second, rDocBuffer, rCopiedResources);
+ }
+
+ aLine.append(" >>\n");
+ }
+
+ filter::PDFStreamElement* pStream = rObject.GetStream();
+ if (pStream)
+ {
+ aLine.append("stream\n");
+ }
+
+ if (filter::PDFArrayElement* pArray = rObject.GetArray())
+ {
+ aLine.append("[ ");
+
+ const std::vector<filter::PDFElement*>& rElements = pArray->GetElements();
+
+ bool bFirst = true;
+ for (auto const& pElement : rElements)
+ {
+ if (bFirst)
+ bFirst = false;
+ else
+ aLine.append(" ");
+ copyRecursively(aLine, *pElement, rDocBuffer, rCopiedResources);
+ }
+ aLine.append("]\n");
+ }
+
+ // If the object has a number element outside a dictionary or array, copy that.
+ if (filter::PDFNumberElement* pNumber = rObject.GetNumberElement())
+ {
+ pNumber->writeString(aLine);
+ aLine.append("\n");
+ }
+
+ // We have the whole object, now write it to the output.
+ if (!m_rContainer.updateObject(nObject))
+ return -1;
+ if (!m_rContainer.writeBuffer(aLine.getStr(), aLine.getLength()))
+ return -1;
+ aLine.setLength(0);
+
+ if (pStream)
+ {
+ SvMemoryStream& rStream = pStream->GetMemory();
+ m_rContainer.checkAndEnableStreamEncryption(nObject);
+ aLine.append(static_cast<const char*>(rStream.GetData()), rStream.GetSize());
+ if (!m_rContainer.writeBuffer(aLine.getStr(), aLine.getLength()))
+ return -1;
+ aLine.setLength(0);
+ m_rContainer.disableStreamEncryption();
+
+ aLine.append("\nendstream\n");
+ if (!m_rContainer.writeBuffer(aLine.getStr(), aLine.getLength()))
+ return -1;
+ aLine.setLength(0);
+ }
+
+ aLine.append("endobj\n\n");
+ if (!m_rContainer.writeBuffer(aLine.getStr(), aLine.getLength()))
+ return -1;
+
+ return nObject;
+}
+
+OString PDFObjectCopier::copyExternalResources(filter::PDFObjectElement& rPage,
+ const OString& rKind,
+ std::map<sal_Int32, sal_Int32>& rCopiedResources)
+{
+ // A name - object ID map, IDs as they appear in our output, not the
+ // original ones.
+ std::map<OString, sal_Int32> aRet;
+
+ // Get the rKind subset of the resource dictionary.
+ std::map<OString, filter::PDFElement*> aItems;
+ if (auto pResources = dynamic_cast<filter::PDFDictionaryElement*>(rPage.Lookup("Resources")))
+ {
+ // Resources is a direct dictionary.
+ filter::PDFElement* pLookup = pResources->LookupElement(rKind);
+ if (auto pDictionary = dynamic_cast<filter::PDFDictionaryElement*>(pLookup))
+ {
+ // rKind is an inline dictionary.
+ aItems = pDictionary->GetItems();
+ }
+ else if (auto pReference = dynamic_cast<filter::PDFReferenceElement*>(pLookup))
+ {
+ // rKind refers to a dictionary.
+ filter::PDFObjectElement* pReferenced = pReference->LookupObject();
+ if (!pReferenced)
+ {
+ return {};
+ }
+
+ aItems = pReferenced->GetDictionaryItems();
+ }
+ }
+ else if (filter::PDFObjectElement* pPageResources = rPage.LookupObject("Resources"))
+ {
+ // Resources is an indirect object.
+ filter::PDFElement* pValue = pPageResources->Lookup(rKind);
+ if (auto pDictionary = dynamic_cast<filter::PDFDictionaryElement*>(pValue))
+ // Kind is a direct dictionary.
+ aItems = pDictionary->GetItems();
+ else if (filter::PDFObjectElement* pObject = pPageResources->LookupObject(rKind))
+ // Kind is an indirect object.
+ aItems = pObject->GetDictionaryItems();
+ }
+ if (aItems.empty())
+ return {};
+
+ SvMemoryStream& rDocBuffer = rPage.GetDocument().GetEditBuffer();
+
+ for (const auto& rItem : aItems)
+ {
+ // For each item copy it over to our output then insert it into aRet.
+ auto pReference = dynamic_cast<filter::PDFReferenceElement*>(rItem.second);
+ if (!pReference)
+ continue;
+
+ filter::PDFObjectElement* pValue = pReference->LookupObject();
+ if (!pValue)
+ continue;
+
+ // Then copying over an object copy its dictionary and its stream.
+ sal_Int32 nObject = copyExternalResource(rDocBuffer, *pValue, rCopiedResources);
+ aRet[rItem.first] = nObject;
+ }
+
+ // Build the dictionary entry string.
+ OStringBuffer sRet("/" + rKind + "<<");
+ for (const auto& rPair : aRet)
+ {
+ sRet.append("/" + rPair.first + " " + OString::number(rPair.second) + " 0 R");
+ }
+ sRet.append(">>");
+
+ 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;
+ copyPageResources(pPage, rLine, aCopiedResources);
+}
+
+void PDFObjectCopier::copyPageResources(filter::PDFObjectElement* pPage, OStringBuffer& rLine,
+ std::map<sal_Int32, sal_Int32>& rCopiedResources)
+{
+ 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, rCopiedResources));
+ }
+ 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: */