PDF4QT/Pdf4QtLib/sources/pdfobject.cpp
2021-08-10 19:22:56 +02:00

580 lines
18 KiB
C++

// 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 "pdfobject.h"
#include "pdfvisitor.h"
namespace pdf
{
QByteArray PDFObject::getString() const
{
PDFStringRef stringRef = getStringObject();
Q_ASSERT(stringRef.inplaceString || stringRef.memoryString);
return stringRef.inplaceString ? stringRef.inplaceString->getString() : stringRef.memoryString->getString();
}
const PDFDictionary* PDFObject::getDictionary() const
{
const PDFObjectContentPointer& objectContent = std::get<PDFObjectContentPointer>(m_data);
Q_ASSERT(dynamic_cast<const PDFDictionary*>(objectContent.get()));
return static_cast<const PDFDictionary*>(objectContent.get());
}
PDFStringRef PDFObject::getStringObject() const
{
if (std::holds_alternative<PDFInplaceString>(m_data))
{
return { &std::get<PDFInplaceString>(m_data) , nullptr };
}
else
{
const PDFObjectContentPointer& objectContent = std::get<PDFObjectContentPointer>(m_data);
Q_ASSERT(dynamic_cast<const PDFString*>(objectContent.get()));
return { nullptr, static_cast<const PDFString*>(objectContent.get()) };
}
}
const PDFStream* PDFObject::getStream() const
{
const PDFObjectContentPointer& objectContent = std::get<PDFObjectContentPointer>(m_data);
Q_ASSERT(dynamic_cast<const PDFStream*>(objectContent.get()));
return static_cast<const PDFStream*>(objectContent.get());
}
const PDFArray* PDFObject::getArray() const
{
const PDFObjectContentPointer& objectContent = std::get<PDFObjectContentPointer>(m_data);
Q_ASSERT(dynamic_cast<const PDFArray*>(objectContent.get()));
return static_cast<const PDFArray*>(objectContent.get());
}
bool PDFObject::operator==(const PDFObject& other) const
{
if (m_type == other.m_type)
{
if (m_type == Type::String || m_type == Type::Name)
{
PDFStringRef leftString = getStringObject();
PDFStringRef rightString = other.getStringObject();
if (leftString.inplaceString && rightString.inplaceString)
{
return *leftString.inplaceString == *rightString.inplaceString;
}
else if (leftString.memoryString && rightString.memoryString)
{
return leftString.memoryString->equals(rightString.memoryString);
}
// We have inplace string in one object and memory string in the other.
// So they are not equal, because memory strings have always greater
// size, than inplace strings.
return false;
}
Q_ASSERT(std::holds_alternative<PDFObjectContentPointer>(m_data) == std::holds_alternative<PDFObjectContentPointer>(other.m_data));
// If we have content object defined, then use its equal operator,
// otherwise use default compare operator. The only problem with
// default compare operator can occur, when we have a double
// with NaN value. Then operator == can return false, even if
// values are "equal" (NaN == NaN returns false)
if (std::holds_alternative<PDFObjectContentPointer>(m_data))
{
Q_ASSERT(std::get<PDFObjectContentPointer>(m_data));
return std::get<PDFObjectContentPointer>(m_data)->equals(std::get<PDFObjectContentPointer>(other.m_data).get());
}
return m_data == other.m_data;
}
return false;
}
void PDFObject::accept(PDFAbstractVisitor* visitor) const
{
switch (m_type)
{
case Type::Null:
visitor->visitNull();
break;
case Type::Bool:
visitor->visitBool(getBool());
break;
case Type::Int:
visitor->visitInt(getInteger());
break;
case Type::Real:
visitor->visitReal(getReal());
break;
case Type::String:
visitor->visitString(getStringObject());
break;
case Type::Name:
visitor->visitName(getStringObject());
break;
case Type::Array:
visitor->visitArray(getArray());
break;
case Type::Dictionary:
visitor->visitDictionary(getDictionary());
break;
case Type::Stream:
visitor->visitStream(getStream());
break;
case Type::Reference:
visitor->visitReference(getReference());
break;
default:
Q_ASSERT(false);
}
}
PDFObject PDFObject::createName(QByteArray name)
{
if (name.size() > PDFInplaceString::MAX_STRING_SIZE)
{
return PDFObject(Type::Name, std::make_shared<PDFString>(qMove(name)));
}
else
{
return PDFObject(Type::Name, PDFInplaceString(qMove(name)));
}
}
PDFObject PDFObject::createString(QByteArray name)
{
if (name.size() > PDFInplaceString::MAX_STRING_SIZE)
{
return PDFObject(Type::String, std::make_shared<PDFString>(qMove(name)));
}
else
{
return PDFObject(Type::String, PDFInplaceString(qMove(name)));
}
}
PDFObject PDFObject::createName(PDFStringRef name)
{
if (name.memoryString)
{
return PDFObject(Type::Name, std::make_shared<PDFString>(name.getString()));
}
else
{
return PDFObject(Type::Name, *name.inplaceString);
}
}
PDFObject PDFObject::createString(PDFStringRef name)
{
if (name.memoryString)
{
return PDFObject(Type::String, std::make_shared<PDFString>(name.getString()));
}
else
{
return PDFObject(Type::String, *name.inplaceString);
}
}
bool PDFString::equals(const PDFObjectContent* other) const
{
Q_ASSERT(dynamic_cast<const PDFString*>(other));
const PDFString* otherString = static_cast<const PDFString*>(other);
return m_string == otherString->m_string;
}
void PDFString::setString(const QByteArray& string)
{
m_string = string;
}
void PDFString::optimize()
{
m_string.shrink_to_fit();
}
bool PDFArray::equals(const PDFObjectContent* other) const
{
Q_ASSERT(dynamic_cast<const PDFArray*>(other));
const PDFArray* otherArray = static_cast<const PDFArray*>(other);
return m_objects == otherArray->m_objects;
}
void PDFArray::appendItem(PDFObject object)
{
m_objects.push_back(std::move(object));
}
void PDFArray::optimize()
{
m_objects.shrink_to_fit();
}
bool PDFDictionary::equals(const PDFObjectContent* other) const
{
Q_ASSERT(dynamic_cast<const PDFDictionary*>(other));
const PDFDictionary* otherStream = static_cast<const PDFDictionary*>(other);
return m_dictionary == otherStream->m_dictionary;
}
const PDFObject& PDFDictionary::get(const QByteArray& key) const
{
auto it = find(key);
if (it != m_dictionary.cend())
{
return it->second;
}
else
{
static PDFObject dummy;
return dummy;
}
}
const PDFObject& PDFDictionary::get(const char* key) const
{
auto it = find(key);
if (it != m_dictionary.cend())
{
return it->second;
}
else
{
static PDFObject dummy;
return dummy;
}
}
const PDFObject& PDFDictionary::get(const PDFInplaceOrMemoryString& key) const
{
auto it = find(key);
if (it != m_dictionary.cend())
{
return it->second;
}
else
{
static PDFObject dummy;
return dummy;
}
}
void PDFDictionary::removeEntry(const char* key)
{
auto it = find(key);
if (it != m_dictionary.end())
{
m_dictionary.erase(it);
}
}
void PDFDictionary::setEntry(const PDFInplaceOrMemoryString& key, PDFObject&& value)
{
auto it = find(key);
if (it != m_dictionary.end())
{
it->second = qMove(value);
}
else
{
addEntry(key, qMove(value));
}
}
void PDFDictionary::removeNullObjects()
{
m_dictionary.erase(std::remove_if(m_dictionary.begin(), m_dictionary.end(), [](const DictionaryEntry& entry) { return entry.second.isNull(); }), m_dictionary.end());
m_dictionary.shrink_to_fit();
}
void PDFDictionary::optimize()
{
m_dictionary.shrink_to_fit();
}
std::vector<PDFDictionary::DictionaryEntry>::const_iterator PDFDictionary::find(const QByteArray& key) const
{
return std::find_if(m_dictionary.cbegin(), m_dictionary.cend(), [&key](const DictionaryEntry& entry) { return entry.first == key; });
}
std::vector<PDFDictionary::DictionaryEntry>::iterator PDFDictionary::find(const QByteArray& key)
{
return std::find_if(m_dictionary.begin(), m_dictionary.end(), [&key](const DictionaryEntry& entry) { return entry.first == key; });
}
std::vector<PDFDictionary::DictionaryEntry>::const_iterator PDFDictionary::find(const char* key) const
{
return std::find_if(m_dictionary.cbegin(), m_dictionary.cend(), [key](const DictionaryEntry& entry) { return entry.first == key; });
}
std::vector<PDFDictionary::DictionaryEntry>::const_iterator PDFDictionary::find(const PDFInplaceOrMemoryString& key) const
{
return std::find_if(m_dictionary.cbegin(), m_dictionary.cend(), [&key](const DictionaryEntry& entry) { return entry.first == key; });
}
std::vector<PDFDictionary::DictionaryEntry>::iterator PDFDictionary::find(const PDFInplaceOrMemoryString& key)
{
return std::find_if(m_dictionary.begin(), m_dictionary.end(), [&key](const DictionaryEntry& entry) { return entry.first == key; });
}
std::vector<PDFDictionary::DictionaryEntry>::iterator PDFDictionary::find(const char* key)
{
return std::find_if(m_dictionary.begin(), m_dictionary.end(), [key](const DictionaryEntry& entry) { return entry.first == key; });
}
bool PDFStream::equals(const PDFObjectContent* other) const
{
Q_ASSERT(dynamic_cast<const PDFStream*>(other));
const PDFStream* otherStream = static_cast<const PDFStream*>(other);
return m_dictionary.equals(&otherStream->m_dictionary) && m_content == otherStream->m_content;
}
PDFObject PDFObjectManipulator::merge(PDFObject left, PDFObject right, MergeFlags flags)
{
const bool leftHasDictionary = left.isDictionary() || left.isStream();
if (left.getType() != right.getType() && (leftHasDictionary != right.isDictionary()))
{
return right;
}
if (left.isStream())
{
Q_ASSERT(right.isDictionary() || right.isStream());
const PDFStream* leftStream = left.getStream();
const PDFStream* rightStream = right.isStream() ? right.getStream() : nullptr;
PDFDictionary targetDictionary = *leftStream->getDictionary();
const PDFDictionary& sourceDictionary = rightStream ? *rightStream->getDictionary() : *right.getDictionary();
for (size_t i = 0, count = sourceDictionary.getCount(); i < count; ++i)
{
const auto& key = sourceDictionary.getKey(i);
PDFObject value = merge(targetDictionary.get(key), sourceDictionary.getValue(i), flags);
targetDictionary.setEntry(key, qMove(value));
}
if (flags.testFlag(RemoveNullObjects))
{
targetDictionary.removeNullObjects();
}
return PDFObject::createStream(std::make_shared<PDFStream>(qMove(targetDictionary), QByteArray(rightStream ? *rightStream->getContent() : *leftStream->getContent())));
}
if (left.isDictionary())
{
Q_ASSERT(right.isDictionary());
PDFDictionary targetDictionary = *left.getDictionary();
const PDFDictionary& sourceDictionary = *right.getDictionary();
for (size_t i = 0, count = sourceDictionary.getCount(); i < count; ++i)
{
const auto& key = sourceDictionary.getKey(i);
PDFObject value = merge(targetDictionary.get(key), sourceDictionary.getValue(i), flags);
targetDictionary.setEntry(key, qMove(value));
}
if (flags.testFlag(RemoveNullObjects))
{
targetDictionary.removeNullObjects();
}
return PDFObject::createDictionary(std::make_shared<PDFDictionary>(qMove(targetDictionary)));
}
else if (left.isArray() && flags.testFlag(ConcatenateArrays))
{
// Concatenate arrays
const PDFArray* leftArray = left.getArray();
const PDFArray* rightArray = right.getArray();
std::vector<PDFObject> objects;
objects.reserve(leftArray->getCount() + rightArray->getCount());
for (size_t i = 0, count = leftArray->getCount(); i < count; ++i)
{
objects.emplace_back(leftArray->getItem(i));
}
for (size_t i = 0, count = rightArray->getCount(); i < count; ++i)
{
objects.emplace_back(rightArray->getItem(i));
}
return PDFObject::createArray(std::make_shared<PDFArray>(qMove(objects)));
}
return right;
}
PDFObject PDFObjectManipulator::removeNullObjects(PDFObject object)
{
return merge(object, object, RemoveNullObjects);
}
PDFObject PDFObjectManipulator::removeDuplicitReferencesInArrays(PDFObject object)
{
switch (object.getType())
{
case PDFObject::Type::Stream:
{
const PDFStream* stream = object.getStream();
PDFDictionary dictionary = *stream->getDictionary();
for (size_t i = 0, count = dictionary.getCount(); i < count; ++i)
{
dictionary.setEntry(dictionary.getKey(i), removeDuplicitReferencesInArrays(dictionary.getValue(i)));
}
return PDFObject::createStream(std::make_shared<PDFStream>(qMove(dictionary), QByteArray(*stream->getContent())));
}
case PDFObject::Type::Dictionary:
{
PDFDictionary dictionary = *object.getDictionary();
for (size_t i = 0, count = dictionary.getCount(); i < count; ++i)
{
dictionary.setEntry(dictionary.getKey(i), removeDuplicitReferencesInArrays(dictionary.getValue(i)));
}
return PDFObject::createDictionary(std::make_shared<PDFDictionary>(qMove(dictionary)));
}
case PDFObject::Type::Array:
{
PDFArray array;
std::set<PDFObjectReference> usedReferences;
for (const PDFObject& object : *object.getArray())
{
if (object.isReference())
{
PDFObjectReference reference = object.getReference();
if (!usedReferences.count(reference))
{
usedReferences.insert(reference);
array.appendItem(PDFObject::createReference(reference));
}
}
else
{
array.appendItem(removeDuplicitReferencesInArrays(object));
}
}
return PDFObject::createArray(std::make_shared<PDFArray>(qMove(array)));
}
default:
return object;
}
}
QByteArray PDFStringRef::getString() const
{
if (inplaceString)
{
return inplaceString->getString();
}
if (memoryString)
{
return memoryString->getString();
}
return QByteArray();
}
PDFInplaceOrMemoryString::PDFInplaceOrMemoryString(const char* string)
{
const int size = static_cast<int>(qMin(std::strlen(string), size_t(std::numeric_limits<int>::max())));
if (size > PDFInplaceString::MAX_STRING_SIZE)
{
m_value = QByteArray(string, size);
}
else
{
m_value = PDFInplaceString(string, size);
}
}
PDFInplaceOrMemoryString::PDFInplaceOrMemoryString(QByteArray string)
{
const int size = string.size();
if (size > PDFInplaceString::MAX_STRING_SIZE)
{
m_value = qMove(string);
}
else
{
m_value = PDFInplaceString(qMove(string));
}
}
bool PDFInplaceOrMemoryString::equals(const char* value, size_t length) const
{
if (std::holds_alternative<PDFInplaceString>(m_value))
{
const PDFInplaceString& string = std::get<PDFInplaceString>(m_value);
return std::equal(string.string.data(), string.string.data() + string.size, value, value + length);
}
if (std::holds_alternative<QByteArray>(m_value))
{
const QByteArray& string = std::get<QByteArray>(m_value);
return std::equal(string.constData(), string.constData() + string.size(), value, value + length);
}
return length == 0;
}
bool PDFInplaceOrMemoryString::isInplace() const
{
return std::holds_alternative<PDFInplaceString>(m_value);
}
QByteArray PDFInplaceOrMemoryString::getString() const
{
if (std::holds_alternative<PDFInplaceString>(m_value))
{
return std::get<PDFInplaceString>(m_value).getString();
}
if (std::holds_alternative<QByteArray>(m_value))
{
return std::get<QByteArray>(m_value);
}
return QByteArray();
}
} // namespace pdf