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() );

    bool operator==( const QgsFieldConstraints &other ) const;

  private:

    Constraints mConstraints = nullptr;

    QHash< Constraint, ConstraintOrigin > mConstraintOrigins;

    QHash< Constraint, ConstraintStrength > mConstraintStrengths;

    QString mExpressionConstraint;

    QString mExpressionConstraintDescription;
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsFieldConstraints::Constraints )

#endif //QGSFIELDCONSTRAINTS_H