standard_decoder.h

#ifndef STANDARD_DECODER_H
#define STANDARD_DECODER_H
 
// Shared Library Support
#include "pxcrypt/pxcrypt_codec_export.h"
 
// Qt Includes
#include <QImage>
 
// Qx Includes
#include <qx/core/qx-abstracterror.h>
 
// Project Includes
#include "pxcrypt/codec/decoder.h"
 
namespace PxCrypt
{
 
class StandardDecoderPrivate;
 
class PXCRYPT_CODEC_EXPORT StandardDecoder final : public Decoder
{
    Q_DECLARE_PRIVATE(StandardDecoder);
//-Inner Classes----------------------------------------------------------------------------------------------
public:
    class Error;
 
//-Constructor---------------------------------------------------------------------------------------------------
public:
    StandardDecoder();
 
//-Instance Functions----------------------------------------------------------------------------------------------
public:
    QString tag() const;
    Error decode(QByteArray& decoded, const QImage& encoded, const QImage& medium = QImage());
};
 
class PXCRYPT_CODEC_EXPORT QX_ERROR_TYPE(StandardDecoder::Error, "PxCrypt::StandardDecoder::Error", 6878)
{
//-Class Enums-------------------------------------------------------------
public:
    enum Type
    {
        NoError,
        InvalidSource,
        MissingMedium,
        DimensionMismatch,
        NotLargeEnough,
        InvalidMeta,
        SkimFailed
    };
 
//-Class Variables-------------------------------------------------------------
private:
    static inline const QString PREFIX_STRING = u"Decoding failed."_s;
    static inline const QHash<Type, QString> ERR_STRINGS{
        {NoError, u""_s},
        {InvalidSource, u"The encoded image is invalid."_s},
        {MissingMedium, u"The encoded image requires a medium to be decoded but none was provided."_s},
        {DimensionMismatch, u"The required medium image has different dimensions than the encoded image."_s},
        {NotLargeEnough, u"The provided image is not large enough to be an encoded image."_s},
        {InvalidMeta, u"The provided image is not encoded."_s},
        {SkimFailed, u"There was an error while skimming data."_s}
    };
 
//-Instance Variables-------------------------------------------------------------
private:
    Type mType;
    QString mSpecific;
 
//-Constructor-------------------------------------------------------------
public:
    Error(Type t = NoError, const QString& s = {});
 
//-Instance Functions-------------------------------------------------------------
public:
    bool isValid() const;
    Type type() const;
    QString specific() const;
    QString errorString() const;
 
private:
    quint32 deriveValue() const override;
    QString derivePrimary() const override;
    QString deriveSecondary() const override;
};
 
}
 
#endif // STANDARD_DECODER_H