qgslayoutatlas.h

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/***************************************************************************
                             qgslayoutatlas.h
                             ----------------
    begin                : December 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 QGSLAYOUTATLAS_H
#define QGSLAYOUTATLAS_H

#include "qgis_core.h"
#include "qgsvectorlayerref.h"
#include "qgslayoutserializableobject.h"
#include "qgsabstractlayoutiterator.h"
#include "qgsexpressioncontextgenerator.h"
#include <QObject>

class QgsLayout;

class CORE_EXPORT QgsLayoutAtlas : public QObject, public QgsAbstractLayoutIterator, public QgsLayoutSerializableObject, public QgsExpressionContextGenerator
{
    Q_OBJECT
  public:

    QgsLayoutAtlas( QgsLayout *layout SIP_TRANSFERTHIS );

    QString stringType() const override;
    QgsLayout *layout() override;

    const QgsLayout *layout() const SIP_SKIP;

    bool writeXml( QDomElement &parentElement, QDomDocument &document, const QgsReadWriteContext &context ) const override;
    bool readXml( const QDomElement &element, const QDomDocument &document, const QgsReadWriteContext &context ) override;

    bool enabled() const { return mEnabled; }

    void setEnabled( bool enabled );

    bool hideCoverage() const { return mHideCoverage; }

    void setHideCoverage( bool hide );

    QString filenameExpression() const { return mFilenameExpressionString; }

    bool setFilenameExpression( const QString &expression, QString &errorString SIP_OUT );

    QString currentFilename() const;

    QgsVectorLayer *coverageLayer() const { return mCoverageLayer.get(); }

    void setCoverageLayer( QgsVectorLayer *layer );

    QString pageNameExpression() const { return mPageNameExpression; }

    void setPageNameExpression( const QString &expression );

    QString nameForPage( int page ) const;

    bool sortFeatures() const { return mSortFeatures; }

    void setSortFeatures( bool enabled );

    bool sortAscending() const { return mSortAscending; }

    void setSortAscending( bool ascending );

    QString sortExpression() const { return mSortExpression; }

    void setSortExpression( const QString &expression );

    bool filterFeatures() const { return mFilterFeatures; }

    void setFilterFeatures( bool filtered );

    QString filterExpression() const { return mFilterExpression; }

    bool setFilterExpression( const QString &expression, QString &errorString SIP_OUT );

    int updateFeatures();

    bool beginRender() override;
    bool endRender() override;
    int count() const override;
    QString filePath( const QString &baseFilePath, const QString &extension ) override;

    int currentFeatureNumber() const { return mCurrentFeatureNo; }

    QgsExpressionContext createExpressionContext() const override;

  public slots:

    bool next() override;

    bool previous();

    bool last();

    bool first();

    bool seekTo( int feature );

    bool seekTo( const QgsFeature &feature );

    void refreshCurrentFeature();

  signals:

    void changed();

    void toggled( bool );

    void coverageLayerChanged( QgsVectorLayer *layer );

    void messagePushed( const QString &message );

    void numberFeaturesChanged( int numFeatures );

    void featureChanged( const QgsFeature &feature );

    void renderBegun();

    void renderEnded();

  private slots:
    void removeLayers( const QStringList &layers );

  private:

    bool updateFilenameExpression( QString &error );

    bool evalFeatureFilename( const QgsExpressionContext &context );

    bool prepareForFeature( int i );

    QPointer< QgsLayout > mLayout;

    bool mEnabled = false;
    bool mHideCoverage = false;
    QString mFilenameExpressionString;

    QgsExpression mFilenameExpression;
    QgsVectorLayerRef mCoverageLayer;

    QString mCurrentFilename;
    bool mSortFeatures = false;
    bool mSortAscending = true;

    typedef QMap< QgsFeatureId, QVariant > SorterKeys;
    // value of field that is used for ordering of features
    SorterKeys mFeatureKeys;

    QString mSortExpression;

    QString mPageNameExpression;

    bool mFilterFeatures = false;
    QString mFilterExpression;

    QString mFilterParserError;

    // id of each iterated feature (after filtering and sorting) paired with atlas page name
    QVector< QPair<QgsFeatureId, QString> > mFeatureIds;
    // current atlas feature number
    int mCurrentFeatureNo = -1;
    QgsFeature mCurrentFeature;


    friend class AtlasFeatureSorter;
};

#endif //QGSLAYOUTATLAS_H