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.h"
#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsfeature.h"
#include "qgsfeaturesink.h"
#include "qgsfeedback.h"
#include "qgsreferencedgeometry.h"
#include "qgstaskmanager.h"
#include "qgsvectorlayer.h"
 
#include <QPointer>
 
class QProgressDialog;
class QgsVectorDataProvider;
class QgsFields;

class CORE_EXPORT QgsVectorLayerExporter : public QgsFeatureSink
{
  public:
    static Qgis::VectorExportResult 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
    );
 

    struct CORE_EXPORT OutputField
    {
        OutputField( const QgsField &field, const QString &expression )
          : field( field )
          , expression( expression )
        {}

        QgsField field;
        QString expression;
    };

    class CORE_EXPORT ExportOptions
    {
      public:
        void setSelectedOnly( bool selected ) { mSelectedOnly = selected; }

        bool selectedOnly() const { return mSelectedOnly; }

        void setTransformContext( const QgsCoordinateTransformContext &context );

        QgsCoordinateTransformContext transformContext() const;

        void setDestinationCrs( const QgsCoordinateReferenceSystem &crs );

        QgsCoordinateReferenceSystem destinationCrs() const;

        void setExtent( const QgsReferencedRectangle &extent );

        QgsReferencedRectangle extent() const;

        void setFilterExpression( const QString &expression );

        QString filterExpression() const;

        void setExpressionContext( const QgsExpressionContext &context );

        const QgsExpressionContext &expressionContext() const;

        QList<QgsVectorLayerExporter::OutputField> outputFields() const;

        void setOutputFields( const QList<QgsVectorLayerExporter::OutputField> &fields );
 
      private:
        bool mSelectedOnly = false;
 
        QgsCoordinateReferenceSystem mDestinationCrs;
 
        QgsCoordinateTransformContext mTransformContext;
 
        QgsReferencedRectangle mExtent;
 
        QString mFilterExpression;
        QgsExpressionContext mExpressionContext;
 
        QList< QgsVectorLayerExporter::OutputField > mOutputFields;
    };

    static Qgis::VectorExportResult exportLayer(
      QgsVectorLayer *layer,
      const QString &uri,
      const QString &providerKey,
      const QgsVectorLayerExporter::ExportOptions &exportOptions,
      QString *errorMessage SIP_OUT = nullptr,
      const QMap<QString, QVariant> &providerOptions = QMap<QString, QVariant>(),
      QgsFeedback *feedback = nullptr
    );

    QgsVectorLayerExporter(
      const QString &uri,
      const QString &provider,
      const QgsFields &fields,
      Qgis::WkbType geometryType,
      const QgsCoordinateReferenceSystem &crs,
      bool overwrite = false,
      const QMap<QString, QVariant> &options = QMap<QString, QVariant>(),
      QgsFeatureSink::SinkFlags sinkFlags = QgsFeatureSink::SinkFlags()
    );
 
    QgsVectorLayerExporter( const QgsVectorLayerExporter &rh ) = delete;
    QgsVectorLayerExporter &operator=( const QgsVectorLayerExporter &rh ) = delete;

    Qgis::VectorExportResult errorCode() const;

    QString errorMessage() const;

    int errorCount() const { return mErrorCount; }

    Qgis::VectorDataProviderAttributeEditCapabilities attributeEditCapabilities() const;
 
    using QgsFeatureSink::addFeatures;
    bool addFeatures( QgsFeatureList &features, QgsFeatureSink::Flags flags = QgsFeatureSink::Flags() ) override;
    bool addFeature( QgsFeature &feature, QgsFeatureSink::Flags flags = QgsFeatureSink::Flags() ) override;
    QString lastError() const override;

    ~QgsVectorLayerExporter() override;
 
    bool flushBuffer() override;
 
  private:
    bool createSpatialIndex();

    Qgis::VectorExportResult mError;
    QString mErrorMessage;
 
    int mErrorCount = 0;
 
    QgsVectorDataProvider *mProvider = nullptr;

    QMap<int, int> mOldToNewAttrIdx;
    int mAttributeCount = -1;
 
    QgsFeatureList mFeatureBuffer;
    int mFeatureBufferMemoryUsage = 0;
 
    bool mCreateSpatialIndex = true;
 
#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
    );

    QgsVectorLayerExporterTask(
      QgsVectorLayer *layer,
      const QString &uri,
      const QString &providerKey,
      const QgsVectorLayerExporter::ExportOptions &exportOptions,
      const QMap<QString, QVariant> &providerOptions = 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( Qgis::VectorExportResult 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;
    QgsVectorLayerExporter::ExportOptions mExportOptions;
    QMap<QString, QVariant> mOptions;
 
    std::unique_ptr< QgsFeedback > mOwnedFeedback;
 
    Qgis::VectorExportResult mError = Qgis::VectorExportResult::Success;
    QString mErrorMessage;
};
 
#endif // QGSVECTORLAYEREXPORTER_H