PDF4QT/Pdf4QtLib/sources/pdfpage.cpp

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2021-09-27 11:14:20 +02:00
// Copyright (C) 2018-2021 Jakub Melka
//
// This file is part of PDF4QT.
//
// PDF4QT is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// with the written consent of the copyright owner, any later version.
//
// PDF4QT is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with PDF4QT. If not, see <https://www.gnu.org/licenses/>.
#include "pdfpage.h"
#include "pdfdocument.h"
#include "pdfexception.h"
#include "pdfencoding.h"
namespace pdf
{
PDFPageInheritableAttributes PDFPageInheritableAttributes::parse(const PDFPageInheritableAttributes& templateAttributes,
const PDFObject& dictionary,
const PDFObjectStorage* storage)
{
PDFPageInheritableAttributes result(templateAttributes);
const PDFObject& dereferencedDictionary = storage->getObject(dictionary);
if (dereferencedDictionary.isDictionary())
{
PDFDocumentDataLoaderDecorator loader(storage);
const PDFDictionary* dictionary = dereferencedDictionary.getDictionary();
if (dictionary->hasKey("MediaBox"))
{
result.m_mediaBox = loader.readRectangle(dictionary->get("MediaBox"), result.getMediaBox());
}
if (dictionary->hasKey("CropBox"))
{
result.m_cropBox = loader.readRectangle(dictionary->get("CropBox"), result.getCropBox());
}
if (dictionary->hasKey("Resources"))
{
result.m_resources = dictionary->get("Resources");
}
if (dictionary->hasKey("Rotate"))
{
PDFInteger rotation = loader.readInteger(dictionary->get("Rotate"), 0);
// PDF specification says, that angle can be multiple of 90, so we can have here
// for example, 450° (90° * 5), or even negative angles. We must get rid of them.
PDFInteger fullCircles = rotation / 360;
if (fullCircles != 0)
{
rotation = rotation - fullCircles * 360;
}
if (rotation < 0)
{
rotation += 360;
}
switch (rotation)
{
case 0:
{
result.m_pageRotation = PageRotation::None;
break;
}
case 90:
{
result.m_pageRotation = PageRotation::Rotate90;
break;
}
case 180:
{
result.m_pageRotation = PageRotation::Rotate180;
break;
}
case 270:
{
result.m_pageRotation = PageRotation::Rotate270;
break;
}
default:
{
throw PDFException(PDFTranslationContext::tr("Invalid page rotation."));
}
}
}
}
return result;
}
PageRotation PDFPageInheritableAttributes::getPageRotation() const
{
if (m_pageRotation)
{
return m_pageRotation.value();
}
return PageRotation::None;
}
std::vector<PDFPage> PDFPage::parse(const PDFObjectStorage* storage, const PDFObject& root)
{
std::vector<PDFPage> result;
std::set<PDFObjectReference> visited;
parseImpl(result, visited, PDFPageInheritableAttributes(), root, storage);
return result;
}
QRectF PDFPage::getRectMM(const QRectF& rect) const
{
return QRectF(convertPDFPointToMM(rect.left()),
convertPDFPointToMM(rect.top()),
convertPDFPointToMM(rect.width()),
convertPDFPointToMM(rect.height()));
}
QRectF PDFPage::getRotatedMediaBox() const
{
return getRotatedBox(getMediaBox(), getPageRotation());
}
QRectF PDFPage::getRotatedMediaBoxMM() const
{
return getRotatedBox(getMediaBoxMM(), getPageRotation());
}
QRectF PDFPage::getRotatedCropBox() const
{
return getRotatedBox(getCropBox(), getPageRotation());
}
PDFObject PDFPage::getObjectFromPageDictionary(const PDFObjectStorage* storage, const char* key) const
{
if (const PDFDictionary* dictionary = storage->getDictionaryFromObject(m_pageObject))
{
return dictionary->get(key);
}
return PDFObject();
}
PDFObject PDFPage::getBoxColorInfo(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "BoxColorInfo");
}
PDFObject PDFPage::getTransparencyGroup(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "Group");
}
PDFObject PDFPage::getThumbnail(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "Thumb");
}
PDFObject PDFPage::getTransition(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "Trans");
}
PDFObject PDFPage::getAdditionalActions(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "AA");
}
PDFObject PDFPage::getMetadata(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "Metadata");
}
PDFObject PDFPage::getPieceDictionary(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "PieceInfo");
}
PDFObject PDFPage::getColorSeparationInfo(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "SeparationInfo");
}
PDFObject PDFPage::getFirstSubpageNavigationNode(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "PresSteps");
}
PDFObject PDFPage::getViewports(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "VP");
}
PDFObject PDFPage::getAssociatedFiles(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "AF");
}
PDFObject PDFPage::getOutputIntents(const PDFObjectStorage* storage) const
{
return getObjectFromPageDictionary(storage, "OutputIntents");
}
QSizeF PDFPage::getRotatedSize(const QSizeF& size, PageRotation rotation)
{
switch (rotation)
{
case PageRotation::None:
case PageRotation::Rotate180:
// Preserve rotation
break;
case PageRotation::Rotate90:
case PageRotation::Rotate270:
return size.transposed();
}
return size;
}
QRectF PDFPage::getRotatedBox(const QRectF& rect, PageRotation rotation)
{
switch (rotation)
{
case PageRotation::None:
case PageRotation::Rotate180:
// Preserve rotation
break;
case PageRotation::Rotate90:
case PageRotation::Rotate270:
return rect.transposed();
}
return rect;
}
void PDFPage::parseImpl(std::vector<PDFPage>& pages,
std::set<PDFObjectReference>& visitedReferences,
const PDFPageInheritableAttributes& templateAttributes,
const PDFObject& root,
const PDFObjectStorage* storage)
{
// Are we in internal node, or leaf (page object)?
PDFObjectReference objectReference = root.isReference() ? root.getReference() : PDFObjectReference();
const PDFObject& dereferenced = storage->getObject(root);
if (dereferenced.isDictionary())
{
const PDFDictionary* dictionary = dereferenced.getDictionary();
const PDFObject& typeObject = storage->getObject(dictionary->get("Type"));
if (typeObject.isName())
{
PDFPageInheritableAttributes currentInheritableAttributes = PDFPageInheritableAttributes::parse(templateAttributes, root, storage);
QByteArray typeString = typeObject.getString();
if (typeString == "Pages")
{
const PDFObject& kids = storage->getObject(dictionary->get("Kids"));
if (kids.isArray())
{
const PDFArray* kidsArray = kids.getArray();
const size_t count = kidsArray->getCount();
for (size_t i = 0; i < count; ++i)
{
const PDFObject& kid = kidsArray->getItem(i);
// Check reference
if (!kid.isReference())
{
throw PDFException(PDFTranslationContext::tr("Expected valid kids in page tree."));
}
// Check cycles
if (visitedReferences.count(kid.getReference()))
{
throw PDFException(PDFTranslationContext::tr("Detected cycles in page tree."));
}
visitedReferences.insert(kid.getReference());
parseImpl(pages, visitedReferences, currentInheritableAttributes, kid, storage);
}
}
else
{
throw PDFException(PDFTranslationContext::tr("Expected valid kids in page tree."));
}
}
else if (typeString == "Page")
{
PDFPage page;
page.m_pageObject = dereferenced;
page.m_pageReference = objectReference;
page.m_mediaBox = currentInheritableAttributes.getMediaBox();
page.m_cropBox = currentInheritableAttributes.getCropBox();
page.m_resources = storage->getObject(currentInheritableAttributes.getResources());
page.m_pageRotation = currentInheritableAttributes.getPageRotation();
if (!page.m_cropBox.isValid())
{
page.m_cropBox = page.m_mediaBox;
}
PDFDocumentDataLoaderDecorator loader(storage);
page.m_bleedBox = loader.readRectangle(dictionary->get("BleedBox"), page.getCropBox());
page.m_trimBox = loader.readRectangle(dictionary->get("TrimBox"), page.getCropBox());
page.m_artBox = loader.readRectangle(dictionary->get("ArtBox"), page.getCropBox());
page.m_contents = storage->getObject(dictionary->get("Contents"));
page.m_annots = loader.readReferenceArrayFromDictionary(dictionary, "Annots");
page.m_lastModified = PDFEncoding::convertToDateTime(loader.readStringFromDictionary(dictionary, "LastModified"));
page.m_thumbnailReference = loader.readReferenceFromDictionary(dictionary, "Thumb");
page.m_beads = loader.readReferenceArrayFromDictionary(dictionary, "B");
page.m_duration = loader.readIntegerFromDictionary(dictionary, "Dur", 0);
page.m_structParent = loader.readIntegerFromDictionary(dictionary, "StructParents", 0);
page.m_webCaptureContentSetId = loader.readStringFromDictionary(dictionary, "ID");
page.m_preferredZoom = loader.readNumberFromDictionary(dictionary, "PZ", 0.0);
constexpr const std::array<std::pair<const char*, PageTabOrder>, 5> tabStops =
{
std::pair<const char*, PageTabOrder>{ "R", PageTabOrder::Row },
std::pair<const char*, PageTabOrder>{ "C", PageTabOrder::Column },
std::pair<const char*, PageTabOrder>{ "S", PageTabOrder::Structure },
std::pair<const char*, PageTabOrder>{ "A", PageTabOrder::Array },
std::pair<const char*, PageTabOrder>{ "W", PageTabOrder::Widget }
};
page.m_pageTabOrder = loader.readEnumByName(dictionary->get("Tabs"), tabStops.cbegin(), tabStops.cend(), PageTabOrder::Invalid);
page.m_templateName = loader.readNameFromDictionary(dictionary, "TemplateInstantiated");
page.m_userUnit = loader.readNumberFromDictionary(dictionary, "UserUnit", 1.0);
page.m_documentPart = loader.readReferenceFromDictionary(dictionary, "DPart");
pages.emplace_back(std::move(page));
}
else
{
throw PDFException(PDFTranslationContext::tr("Expected valid type item in page tree."));
}
}
else
{
throw PDFException(PDFTranslationContext::tr("Expected valid type item in page tree."));
}
}
else
{
throw PDFException(PDFTranslationContext::tr("Expected dictionary in page tree."));
}
}
} // namespace pdf