qgsfieldconstraints.h

Go to the documentation of this file.

/***************************************************************************
                     qgsfieldconstraints.h
                     ---------------------
               Date                 : November 2016
               Copyright            : (C) 2016 by Nyall Dawson
               email                : nyall dot dawson at gmail dot 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 QGSFIELDCONSTRAINTS_H
#define QGSFIELDCONSTRAINTS_H
 
#include <QString>
#include <QHash>
#include <QObject>
 
#include "qgis_core.h"
 
class CORE_EXPORT QgsFieldConstraints
{
    Q_GADGET
 
    Q_PROPERTY( Constraints constraints READ constraints )
 
  public:
 
    enum Constraint
    {
      ConstraintNotNull = 1, 
      ConstraintUnique = 1 << 1, 
      ConstraintExpression = 1 << 2, 
    };
    Q_DECLARE_FLAGS( Constraints, Constraint )
 
    
    enum ConstraintOrigin
    {
      ConstraintOriginNotSet = 0, 
      ConstraintOriginProvider, 
      ConstraintOriginLayer, 
    };
 
    enum ConstraintStrength
    {
      ConstraintStrengthNotSet = 0, 
      ConstraintStrengthHard, 
      ConstraintStrengthSoft, 
    };
 
    QgsFieldConstraints();
 
    Constraints constraints() const { return mConstraints; }
 
    ConstraintOrigin constraintOrigin( Constraint constraint ) const;
 
    ConstraintStrength constraintStrength( Constraint constraint ) const;
 
    void setConstraintStrength( Constraint constraint, ConstraintStrength strength );
 
    void setConstraint( Constraint constraint, ConstraintOrigin origin = ConstraintOriginLayer );
 
    void removeConstraint( Constraint constraint ) { mConstraints &= ~constraint; }
 
    QString constraintExpression() const;
 
    QString constraintDescription() const { return mExpressionConstraintDescription; }
 
    void setConstraintExpression( const QString &expression, const QString &description = QString() );
 
    // TODO c++20 - replace with = default
    bool operator==( const QgsFieldConstraints &other ) const;
 
  private:
 
    Constraints mConstraints;
 
    QHash< Constraint, ConstraintOrigin > mConstraintOrigins;
 
    QHash< Constraint, ConstraintStrength > mConstraintStrengths;
 
    QString mExpressionConstraint;
 
    QString mExpressionConstraintDescription;
};
 
Q_DECLARE_OPERATORS_FOR_FLAGS( QgsFieldConstraints::Constraints )
 
#endif //QGSFIELDCONSTRAINTS_H