qgsvectorlayerexporter.h

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/***************************************************************************
                          qgsvectorlayerexporter.h
                             -------------------
    begin                : Thu Aug 25 2011
    copyright            : (C) 2011 by Giuseppe Sucameli
    email                : brush.tyler at gmail.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 QGSVECTORLAYEREXPORTER_H
#define QGSVECTORLAYEREXPORTER_H

#include "qgis_core.h"
#include "qgis.h"
#include "qgsfeature.h"
#include "qgsfeaturesink.h"
#include "qgstaskmanager.h"
#include "qgsfeedback.h"
#include "qgsvectorlayer.h"

class QProgressDialog;
class QgsVectorDataProvider;
class QgsFields;

class CORE_EXPORT QgsVectorLayerExporter : public QgsFeatureSink
{
  public:

    enum ExportError
    {
      NoError = 0, 
      ErrCreateDataSource, 
      ErrCreateLayer, 
      ErrAttributeTypeUnsupported, 
      ErrAttributeCreationFailed, 
      ErrProjection, 
      ErrFeatureWriteFailed, 
      ErrInvalidLayer, 
      ErrInvalidProvider, 
      ErrProviderUnsupportedFeature, 
      ErrConnectionFailed, 
      ErrUserCanceled, 
    };

    static ExportError exportLayer( QgsVectorLayer *layer,
                                    const QString &uri,
                                    const QString &providerKey,
                                    const QgsCoordinateReferenceSystem &destCRS,
                                    bool onlySelected = false,
                                    QString *errorMessage SIP_OUT = nullptr,
                                    const QMap<QString, QVariant> &options = QMap<QString, QVariant>(),
                                    QgsFeedback *feedback = nullptr
                                  );

    QgsVectorLayerExporter( const QString &uri,
                            const QString &provider,
                            const QgsFields &fields,
                            QgsWkbTypes::Type geometryType,
                            const QgsCoordinateReferenceSystem &crs,
                            bool overwrite = false,
                            const QMap<QString, QVariant> &options = QMap<QString, QVariant>() );

    QgsVectorLayerExporter( const QgsVectorLayerExporter &rh ) = delete;
    QgsVectorLayerExporter &operator=( const QgsVectorLayerExporter &rh ) = delete;

    ExportError errorCode() const;

    QString errorMessage() const;

    int errorCount() const { return mErrorCount; }

    bool addFeatures( QgsFeatureList &features, QgsFeatureSink::Flags flags = nullptr ) override;
    bool addFeature( QgsFeature &feature, QgsFeatureSink::Flags flags = nullptr ) override;

    ~QgsVectorLayerExporter() override;

    bool flushBuffer() override;

  private:

    bool createSpatialIndex();

    ExportError mError;
    QString mErrorMessage;

    int mErrorCount;

    QgsVectorDataProvider *mProvider = nullptr;

    QMap<int, int> mOldToNewAttrIdx;
    int mAttributeCount;

    QgsFeatureList mFeatureBuffer;

#ifdef SIP_RUN
    QgsVectorLayerExporter( const QgsVectorLayerExporter &rh );
#endif

};


class CORE_EXPORT QgsVectorLayerExporterTask : public QgsTask
{
    Q_OBJECT

  public:

    QgsVectorLayerExporterTask( QgsVectorLayer *layer,
                                const QString &uri,
                                const QString &providerKey,
                                const QgsCoordinateReferenceSystem &destinationCrs,
                                const QMap<QString, QVariant> &options = QMap<QString, QVariant>(),
                                bool ownsLayer = false );

    static QgsVectorLayerExporterTask *withLayerOwnership( QgsVectorLayer *layer SIP_TRANSFER,
        const QString &uri,
        const QString &providerKey,
        const QgsCoordinateReferenceSystem &destinationCrs,
        const QMap<QString, QVariant> &options = QMap<QString, QVariant>() ) SIP_FACTORY;

    void cancel() override;

  signals:

    void exportComplete();

    void errorOccurred( int error, const QString &errorMessage );

  protected:

    bool run() override;
    void finished( bool result ) override;

  private:

    QPointer< QgsVectorLayer > mLayer = nullptr;
    bool mOwnsLayer = false;

    QString mDestUri;
    QString mDestProviderKey;
    QgsCoordinateReferenceSystem mDestCrs;
    QMap<QString, QVariant> mOptions;

    std::unique_ptr< QgsFeedback > mOwnedFeedback;

    QgsVectorLayerExporter::ExportError mError = QgsVectorLayerExporter::NoError;
    QString mErrorMessage;

};

#endif // QGSVECTORLAYEREXPORTER_H