File indexing completed on 2024-05-12 15:55:36

 /* SPDX-FileCopyrightText: 2003-2010 Jesper K. Pedersen <blackie@kde.org>
 
    SPDX-License-Identifier: GPL-2.0-or-later
 */
 #ifndef DATABASEELEMENT_H
 #define DATABASEELEMENT_H
 
 #include <QString>
 #include <QVariant>
 
 namespace Exiv2
 {
 class ExifData;
 }
 
 namespace Exif
 {
 
 class DatabaseElement
 {
 public:
     virtual ~DatabaseElement() { }
     virtual QString columnName() const = 0;
     /**
      * @brief createString
      * Create a string containing the field name and field data type.
      * E.g.: "Exif_Photo_FNumber_denominator int", "Exif_Photo_FNumber_nominator int"
      * @return a string suitable for usage in a create table query
      */
     virtual QString createString() const = 0;
     /**
      * @brief queryString
      * @return a placeholder string ("?") for the column.
      */
     virtual QString queryString() const = 0;
     /**
      * @brief exifAsValue interprets the ExifData value and creates a QVariant suitable for QSqlQuery::bindValue.
      * @param data
      * @return The converted value, or an empty QVariant if the necessary data is not available.
      */
     virtual QVariant valueFromExif(Exiv2::ExifData &data) const = 0;
     /**
      * @brief value
      * @see Database::readFields
      * @return The bound value, or an empty QVariant if setValue was never called.
      */
     QVariant value() const;
     void setValue(QVariant val);
 
 protected:
     DatabaseElement();
 
 private:
     QVariant m_value;
 };
 
 class StringExifElement : public DatabaseElement
 {
 public:
     explicit StringExifElement(const char *tag);
     QString columnName() const override;
     QString createString() const override;
     QString queryString() const override;
     QVariant valueFromExif(Exiv2::ExifData &data) const override;
 
 private:
     const char *m_tag;
 };
 
 class IntExifElement : public DatabaseElement
 {
 public:
     explicit IntExifElement(const char *tag);
     QString columnName() const override;
     QString createString() const override;
     QString queryString() const override;
     QVariant valueFromExif(Exiv2::ExifData &data) const override;
 
 private:
     const char *m_tag;
 };
 
 /**
  * @brief The RationalExifElement class
  * This has support for the exif rational type.
  *
  * Currently, only simple (one component) rationals and
  * the 3-component rationals used for GPS data (hour-minute-second)
  * are supported.
  */
 class RationalExifElement : public DatabaseElement
 {
 public:
     explicit RationalExifElement(const char *tag);
     QString columnName() const override;
     QString createString() const override;
     QString queryString() const override;
     QVariant valueFromExif(Exiv2::ExifData &data) const override;
 
 private:
     const char *m_tag;
 };
 
 /**
  * @brief The LensExifElement class
  * This class provides a wrapper around the Exif.Photo.LensModel exif tag.
  * Besides this tag, there are several other legacy exif tags with similar information.
  * This class transparently falls back to a legacy tag when the LensModel is not available.
  */
 class LensExifElement : public DatabaseElement
 {
 public:
     explicit LensExifElement();
     QString columnName() const override;
     QString createString() const override;
     QString queryString() const override;
     QVariant valueFromExif(Exiv2::ExifData &data) const override;
 
 private:
     const char *m_tag;
 };
 
 }
 
 #endif /* DATABASEELEMENT_H */
 
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