qgslayoutexporter.h

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/***************************************************************************
                              qgslayoutexporter.h
                             -------------------
    begin                : October 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 QGSLAYOUTEXPORTER_H
#define QGSLAYOUTEXPORTER_H

#include "qgis_core.h"
#include "qgsmargins.h"
#include "qgslayoutrendercontext.h"
#include "qgslayoutreportcontext.h"
#include <QPointer>
#include <QSize>
#include <QRectF>
#include <QPrinter>

class QgsLayout;
class QPainter;
class QgsLayoutItemMap;
class QgsAbstractLayoutIterator;

class CORE_EXPORT QgsLayoutExporter
{

  public:

    struct PageExportDetails
    {
      QString directory;

      QString baseName;

      QString extension;

      int page = 0;
    };

    QgsLayoutExporter( QgsLayout *layout );

    virtual ~QgsLayoutExporter() = default;

    QgsLayout *layout() const;

    void renderPage( QPainter *painter, int page ) const;

    QImage renderPageToImage( int page, QSize imageSize = QSize(), double dpi = 0 ) const;

    void renderRegion( QPainter *painter, const QRectF &region ) const;

    QImage renderRegionToImage( const QRectF &region, QSize imageSize = QSize(), double dpi = 0 ) const;


    enum ExportResult
    {
      Success, 
      Canceled, 
      MemoryError, 
      FileError, 
      PrintError, 
      SvgLayerError, 
      IteratorError, 
    };

    struct ImageExportSettings
    {
      ImageExportSettings()
        : flags( QgsLayoutRenderContext::FlagAntialiasing | QgsLayoutRenderContext::FlagUseAdvancedEffects )
      {}

      double dpi = -1;

      QSize imageSize;

      bool cropToContents = false;

      QgsMargins cropMargins;

      QList< int > pages;

      bool generateWorldFile = false;

      QgsLayoutRenderContext::Flags flags = 0;

    };

    ExportResult exportToImage( const QString &filePath, const QgsLayoutExporter::ImageExportSettings &settings );


    static ExportResult exportToImage( QgsAbstractLayoutIterator *iterator, const QString &baseFilePath,
                                       const QString &extension, const QgsLayoutExporter::ImageExportSettings &settings,
                                       QString &error SIP_OUT, QgsFeedback *feedback = nullptr );


    struct PdfExportSettings
    {
      PdfExportSettings()
        : flags( QgsLayoutRenderContext::FlagAntialiasing | QgsLayoutRenderContext::FlagUseAdvancedEffects )
      {}

      double dpi = -1;

      bool rasterizeWholeImage = false;

      bool forceVectorOutput = false;

      QgsLayoutRenderContext::Flags flags = 0;

    };

    ExportResult exportToPdf( const QString &filePath, const QgsLayoutExporter::PdfExportSettings &settings );

    static ExportResult exportToPdf( QgsAbstractLayoutIterator *iterator, const QString &fileName,
                                     const QgsLayoutExporter::PdfExportSettings &settings,
                                     QString &error SIP_OUT, QgsFeedback *feedback = nullptr );

    static ExportResult exportToPdfs( QgsAbstractLayoutIterator *iterator, const QString &baseFilePath,
                                      const QgsLayoutExporter::PdfExportSettings &settings,
                                      QString &error SIP_OUT, QgsFeedback *feedback = nullptr );


    struct PrintExportSettings
    {
      PrintExportSettings()
        : flags( QgsLayoutRenderContext::FlagAntialiasing | QgsLayoutRenderContext::FlagUseAdvancedEffects )
      {}

      double dpi = -1;

      bool rasterizeWholeImage = false;

      QgsLayoutRenderContext::Flags flags = 0;

    };

    ExportResult print( QPrinter &printer, const QgsLayoutExporter::PrintExportSettings &settings );

    static ExportResult print( QgsAbstractLayoutIterator *iterator, QPrinter &printer,
                               const QgsLayoutExporter::PrintExportSettings &settings,
                               QString &error SIP_OUT, QgsFeedback *feedback = nullptr );


    struct SvgExportSettings
    {
      SvgExportSettings()
        : flags( QgsLayoutRenderContext::FlagAntialiasing | QgsLayoutRenderContext::FlagUseAdvancedEffects )
      {}

      double dpi = -1;

      bool forceVectorOutput = false;

      bool cropToContents = false;

      QgsMargins cropMargins;

      bool exportAsLayers = false;

      QgsLayoutRenderContext::Flags flags = 0;

    };

    ExportResult exportToSvg( const QString &filePath, const QgsLayoutExporter::SvgExportSettings &settings );

    static ExportResult exportToSvg( QgsAbstractLayoutIterator *iterator, const QString &baseFilePath,
                                     const QgsLayoutExporter::SvgExportSettings &settings,
                                     QString &error SIP_OUT, QgsFeedback *feedback = nullptr );


    QString errorFile() const { return mErrorFileName; }

    bool georeferenceOutput( const QString &file, QgsLayoutItemMap *referenceMap = nullptr,
                             const QRectF &exportRegion = QRectF(), double dpi = -1 ) const;

    void computeWorldFileParameters( double &a, double &b, double &c, double &d, double &e, double &f, double dpi = -1 ) const;

    void computeWorldFileParameters( const QRectF &region, double &a, double &b, double &c, double &d, double &e, double &f, double dpi = -1 ) const;

  protected:

    virtual QString generateFileName( const PageExportDetails &details ) const;

  private:

    QPointer< QgsLayout > mLayout;

    mutable QString mErrorFileName;

    QImage createImage( const ImageExportSettings &settings, int page, QRectF &bounds, bool &skipPage ) const;

    static bool saveImage( const QImage &image, const QString &imageFilename, const QString &imageFormat );

    std::unique_ptr<double[]> computeGeoTransform( const QgsLayoutItemMap *referenceMap = nullptr, const QRectF &exportRegion = QRectF(), double dpi = -1 ) const;

    void writeWorldFile( const QString &fileName, double a, double b, double c, double d, double e, double f ) const;

    static void preparePrintAsPdf( QgsLayout *layout, QPrinter &printer, const QString &filePath );

    static void preparePrint( QgsLayout *layout, QPrinter &printer, bool setFirstPageSize = false );

    ExportResult print( QPrinter &printer );

    ExportResult printPrivate( QPrinter &printer, QPainter &painter, bool startNewPage = false, double dpi = -1, bool rasterize = false );

    static void updatePrinterPageSize( QgsLayout *layout, QPrinter &printer, int page );

    ExportResult renderToLayeredSvg( const SvgExportSettings &settings, double width, double height, int page, QRectF bounds,
                                     const QString &filename, int svgLayerId, const QString &layerName,
                                     QDomDocument &svg, QDomNode &svgDocRoot ) const;

    friend class TestQgsLayout;

};

#endif //QGSLAYOUTEXPORTER_H