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Diffstat (limited to 'vcl/source/gdi/pdfobjectcopier.cxx')
| -rw-r--r-- | vcl/source/gdi/pdfobjectcopier.cxx | 318 |
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 index 000000000..93b7b4989 --- /dev/null +++ b/vcl/source/gdi/pdfobjectcopier.cxx @@ -0,0 +1,318 @@ +/* -*- 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: */ |