qgsfield.h

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/***************************************************************************
               qgsfield.h - Describes a field in a layer or table
                     --------------------------------------
               Date                 : 01-Jan-2004
               Copyright            : (C) 2004 by Gary E.Sherman
               email                : sherman at mrcc.com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSFIELD_H
#define QGSFIELD_H

#include <QString>
#include <QVariant>
#include <QVector>
#include <QSharedDataPointer>

typedef QList<int> QgsAttributeList;

class QgsExpression;
class QgsFieldPrivate;
class QgsFieldsPrivate;

/***************************************************************************
 * This class is considered CRITICAL and any change MUST be accompanied with
 * full unit tests in testqgsfield.cpp.
 * See details in QEP #17
 ****************************************************************************/

class CORE_EXPORT QgsField
{
    Q_GADGET

    Q_PROPERTY( bool isNumeric READ isNumeric )
    Q_PROPERTY( int length READ length WRITE setLength )
    Q_PROPERTY( int precision READ precision WRITE setPrecision )
    Q_PROPERTY( QString comment READ comment WRITE setComment )
    Q_PROPERTY( QString name READ name WRITE setName )
    Q_PROPERTY( QString alias READ alias WRITE setAlias )
    Q_PROPERTY( QString defaultValueExpression READ defaultValueExpression WRITE setDefaultValueExpression )

  public:
    QgsField( const QString& name = QString(),
              QVariant::Type type = QVariant::Invalid,
              const QString& typeName = QString(),
              int len = 0,
              int prec = 0,
              const QString& comment = QString() );

    QgsField( const QgsField& other );

    QgsField& operator =( const QgsField &other );

    virtual ~QgsField();

    bool operator==( const QgsField& other ) const;
    bool operator!=( const QgsField& other ) const;

    QString name() const;

    QString displayName() const;

    QVariant::Type type() const;

    QString typeName() const;

    int length() const;

    int precision() const;

    QString comment() const;

    bool isNumeric() const;

    void setName( const QString& name );

    void setType( QVariant::Type type );

    void setTypeName( const QString& typeName );

    void setLength( int len );

    void setPrecision( int precision );

    void setComment( const QString& comment );

    QString defaultValueExpression() const;

    void setDefaultValueExpression( const QString& expression );

    QString alias() const;

    void setAlias( const QString& alias );

    QString displayString( const QVariant& v ) const;

    bool convertCompatible( QVariant& v ) const;

    operator QVariant() const
    {
      return QVariant::fromValue( *this );
    }

  private:

    QSharedDataPointer<QgsFieldPrivate> d;


}; // class QgsField

Q_DECLARE_METATYPE( QgsField )


CORE_EXPORT QDataStream& operator<<( QDataStream& out, const QgsField& field );
CORE_EXPORT QDataStream& operator>>( QDataStream& in, QgsField& field );



/***************************************************************************
 * This class is considered CRITICAL and any change MUST be accompanied with
 * full unit tests in testqgsfields.cpp.
 * See details in QEP #17
 ****************************************************************************/

class CORE_EXPORT QgsFields
{
  public:

    enum FieldOrigin
    {
      OriginUnknown,   
      OriginProvider,  
      OriginJoin,      
      OriginEdit,      
      OriginExpression 
    };

    typedef struct Field
    {
      Field(): origin( OriginUnknown ), originIndex( -1 ) {}
      Field( const QgsField& f, FieldOrigin o, int oi ): field( f ), origin( o ), originIndex( oi ) {}

      bool operator==( const Field& other ) const { return field == other.field && origin == other.origin && originIndex == other.originIndex; }
      bool operator!=( const Field& other ) const { return !( *this == other ); }

      QgsField field;      
      FieldOrigin origin;  
      int originIndex;     
    } Field;

    QgsFields();

    QgsFields( const QgsFields& other );

    QgsFields& operator =( const QgsFields &other );

    virtual ~QgsFields();

    void clear();
    bool append( const QgsField& field, FieldOrigin origin = OriginProvider, int originIndex = -1 );
    bool appendExpressionField( const QgsField& field, int originIndex );
    void remove( int fieldIdx );
    void extend( const QgsFields& other );

    bool isEmpty() const;
    int count() const;
    int size() const;
    bool exists( int i ) const;

    const QgsField& operator[]( int i ) const;
    QgsField& operator[]( int i );
    const QgsField& at( int i ) const;
    const QgsField& field( int fieldIdx ) const;
    const QgsField& field( const QString& name ) const;

    FieldOrigin fieldOrigin( int fieldIdx ) const;
    int fieldOriginIndex( int fieldIdx ) const;

    int indexFromName( const QString& name ) const;

    int fieldNameIndex( const QString& fieldName ) const;

    QgsAttributeList allAttributesList() const;

    QList<QgsField> toList() const;

    bool operator==( const QgsFields& other ) const;
    bool operator!=( const QgsFields& other ) const { return !( *this == other ); }
    QIcon iconForField( int fieldIdx ) const;

    operator QVariant() const
    {
      return QVariant::fromValue( *this );
    }


    class const_iterator;

    class iterator
    {
      public:
        QgsFields::Field* d;
        typedef std::random_access_iterator_tag  iterator_category;
        typedef qptrdiff difference_type;

        inline iterator()
            : d( nullptr )
        {}
        inline iterator( QgsFields::Field *n )
            : d( n )
        {}

        inline QgsField& operator*() const { return d->field; }
        inline QgsField* operator->() const { return &d->field; }
        inline QgsField& operator[]( difference_type j ) const { return d[j].field; }
        inline bool operator==( const iterator &o ) const noexcept { return d == o.d; }
        inline bool operator!=( const iterator &o ) const noexcept { return d != o.d; }
        inline bool operator<( const iterator& other ) const noexcept { return d < other.d; }
        inline bool operator<=( const iterator& other ) const noexcept { return d <= other.d; }
        inline bool operator>( const iterator& other ) const noexcept { return d > other.d; }
        inline bool operator>=( const iterator& other ) const noexcept { return d >= other.d; }

        inline iterator& operator++() { ++d; return *this; }
        inline iterator operator++( int ) { QgsFields::Field* n = d; ++d; return n; }
        inline iterator& operator--() { d--; return *this; }
        inline iterator operator--( int ) { QgsFields::Field* n = d; d--; return n; }
        inline iterator& operator+=( difference_type j ) { d += j; return *this; }
        inline iterator& operator-=( difference_type j ) { d -= j; return *this; }
        inline iterator operator+( difference_type j ) const { return iterator( d + j ); }
        inline iterator operator-( difference_type j ) const { return iterator( d -j ); }
        inline int operator-( iterator j ) const { return int( d - j.d ); }
    };
    friend class iterator;

    class const_iterator
    {
      public:
        const QgsFields::Field* d;

        typedef std::random_access_iterator_tag  iterator_category;
        typedef qptrdiff difference_type;

        inline const_iterator()
            : d( nullptr ) {}
        inline const_iterator( const QgsFields::Field* f )
            : d( f ) {}
        inline const_iterator( const const_iterator &o )
            : d( o.d ) {}
        inline explicit const_iterator( const iterator &o )
            : d( o.d ) {}
        inline const QgsField& operator*() const { return d->field; }
        inline const QgsField* operator->() const { return &d->field; }
        inline const QgsField& operator[]( difference_type j ) const noexcept { return d[j].field; }
        inline bool operator==( const const_iterator &o ) const noexcept { return d == o.d; }
        inline bool operator!=( const const_iterator &o ) const noexcept { return d != o.d; }
        inline bool operator<( const const_iterator& other ) const noexcept { return d < other.d; }
        inline bool operator<=( const const_iterator& other ) const noexcept { return d <= other.d; }
        inline bool operator>( const const_iterator& other ) const noexcept { return d > other.d; }
        inline bool operator>=( const const_iterator& other ) const noexcept { return d >= other.d; }
        inline const_iterator& operator++() { ++d; return *this; }
        inline const_iterator operator++( int ) { const QgsFields::Field* n = d; ++d; return n; }
        inline const_iterator& operator--() { d--; return *this; }
        inline const_iterator operator--( int ) { const QgsFields::Field* n = d; --d; return n; }
        inline const_iterator& operator+=( difference_type j ) { d += j; return *this; }
        inline const_iterator& operator-=( difference_type j ) { d -= j; return *this; }
        inline const_iterator operator+( difference_type j ) const { return const_iterator( d + j ); }
        inline const_iterator operator-( difference_type j ) const { return const_iterator( d -j ); }
        inline int operator-( const_iterator j ) const { return int( d - j.d ); }
    };
    friend class const_iterator;


    const_iterator constBegin() const noexcept;

    const_iterator constEnd() const noexcept;

    const_iterator begin() const noexcept;

    const_iterator end() const noexcept;

    iterator begin();


    iterator end();

  private:

    QSharedDataPointer<QgsFieldsPrivate> d;

};

Q_DECLARE_METATYPE( QgsFields )


CORE_EXPORT QDataStream& operator<<( QDataStream& out, const QgsFields& fields );
CORE_EXPORT QDataStream& operator>>( QDataStream& in, QgsFields& fields );

#endif