qgsfeaturesource.h

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/***************************************************************************
                         qgsfeaturesource.h
                         ----------------
    begin                : May 2017
    copyright            : (C) 2017 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 QGSFEATURESOURCE_H
#define QGSFEATURESOURCE_H

#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsfeaturerequest.h"

class QgsFeatureIterator;
class QgsCoordinateReferenceSystem;
class QgsFields;
class QgsFeedback;

class CORE_EXPORT QgsFeatureSource
{
  public:

    enum FeatureAvailability
    {
      NoFeaturesAvailable, 
      FeaturesAvailable, 
      FeaturesMaybeAvailable 
    };

    virtual ~QgsFeatureSource() = default;

    virtual QgsFeatureIterator getFeatures( const QgsFeatureRequest &request = QgsFeatureRequest() ) const = 0;

    virtual QString sourceName() const = 0;

    virtual QgsCoordinateReferenceSystem sourceCrs() const = 0;

    virtual QgsFields fields() const = 0;

    virtual QgsWkbTypes::Type wkbType() const = 0;

#ifdef SIP_RUN

    int __len__() const;
    % MethodCode
    sipRes = sipCpp->featureCount();
    % End

    int __bool__() const;
    % MethodCode
    sipRes = true;
    % End
#endif

    virtual long featureCount() const = 0;

    virtual FeatureAvailability hasFeatures() const;

    virtual QSet<QVariant> uniqueValues( int fieldIndex, int limit = -1 ) const;

    virtual QVariant minimumValue( int fieldIndex ) const;

    virtual QVariant maximumValue( int fieldIndex ) const;

    virtual QgsRectangle sourceExtent() const;

    virtual QgsFeatureIds allFeatureIds() const;

    QgsVectorLayer *materialize( const QgsFeatureRequest &request,
                                 QgsFeedback *feedback = nullptr ) SIP_FACTORY;
};

Q_DECLARE_METATYPE( QgsFeatureSource * )

#endif // QGSFEATURESOURCE_H