PdfDifferenceEncoding.h

// SPDX-FileCopyrightText: 2008 Dominik Seichter <domseichter@web.de>
// SPDX-FileCopyrightText: 2020 Francesco Pretto <ceztko@gmail.com>
// SPDX-License-Identifier: LGPL-2.0-or-later OR MPL-2.0
 
#ifndef PDF_DIFFERENCE_ENCODING_H
#define PDF_DIFFERENCE_ENCODING_H
 
#include "PdfEncodingMap.h"
#include "PdfArray.h"
 
namespace PoDoFo {
 
class PdfFontMetrics;
struct CodePointMapNode;
 
struct PODOFO_API PdfDifferenceMapping final
{
    PdfName Name;
    unsigned char Code = 0;
    CodePointSpan CodePoints;
};
 
class PODOFO_API PdfDifferenceMap final
{
    friend class PdfDifferenceEncoding;
public:
    using const_iterator = std::vector<PdfDifferenceMapping>::const_iterator;
 
public:
    PdfDifferenceMap();
 
    PdfDifferenceMap(const PdfDifferenceMap& rhs) = default;
    PdfDifferenceMap& operator=(const PdfDifferenceMap& rhs) = default;
 
    void AddDifference(unsigned char code, char32_t codePoint);
 
    void AddDifference(unsigned char code, const codepointview& codePoints);
 
    bool TryGetMappedName(unsigned char code, const PdfName*& name) const;
    bool TryGetMappedName(unsigned char code, const PdfName*& name, CodePointSpan& codePoints) const;
 
    void ToArray(PdfArray& arr) const;
 
    unsigned GetCount() const;
 
    const_iterator begin() const { return m_differences.begin(); }
 
    const_iterator end() const { return m_differences.end(); }
 
private:
    void AddDifference(unsigned char code, const std::string_view& name);
 
    void addDifference(unsigned char code, const codepointview& codepoints, const PdfName& name);
 
    struct DifferenceComparatorPredicate
    {
    public:
        bool operator()(const PdfDifferenceMapping& diff1, const PdfDifferenceMapping& diff2) const
        {
            return diff1.Code < diff2.Code;
        }
    };
 
    using DifferenceList = std::vector<PdfDifferenceMapping>;
 
private:
    DifferenceList m_differences;
};
 
class PODOFO_API PdfDifferenceEncoding final : public PdfEncodingMapSimple
{
    friend class PdfDifferenceMap;
 
public:
    PdfDifferenceEncoding(PdfEncodingMapConstPtr baseEncoding,
        PdfDifferenceMap differences);
 
    ~PdfDifferenceEncoding();
 
public:
    static bool TryCreateFromObject(const PdfObject& obj, const PdfFontMetrics& metrics,
        std::unique_ptr<PdfDifferenceEncoding>& encoding);
 
    static std::unique_ptr<PdfDifferenceEncoding> CreateFromObject(const PdfObject& obj, const PdfFontMetrics& metrics);
 
    static bool TryGetCodePointsFromCharName(const std::string_view& name, CodePointSpan& codepoints);
 
    const PdfDifferenceMap& GetDifferences() const { return m_differences; }
 
protected:
    void GetBaseEncoding(const PdfEncodingMap*& baseEncoding, const PdfDifferenceMap*& differences) const override;
 
    void getExportObject(PdfIndirectObjectList& objects, PdfName& name, PdfObject*& obj) const override;
    bool tryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const override;
    bool tryGetCharCodeSpan(const unicodeview& codePoints, PdfCharCode& codeUnit) const override;
    bool tryGetNextCharCode(std::string_view::iterator& it,
        const std::string_view::iterator& end, PdfCharCode& codeUnit) const override;
    bool tryGetCodePoints(const PdfCharCode& codeUnit, const unsigned* cidId, CodePointSpan& codePoints) const override;
 
private:
    static bool TryGetCodePointsFromCharName(std::string_view charName, CodePointSpan& codepoints, const PdfName*& actualName);
 
    void buildReverseMap();
 
private:
    PdfEncodingMapConstPtr m_baseEncoding;
    PdfDifferenceMap m_differences;
    CodePointMapNode* m_reverseMap;
};
 
};
 
#endif // PDF_DIFFERENCE_ENCODING_H