qgsexpressioncontextutils.h

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/***************************************************************************
     qgsexpressioncontextutils.h
     ---------------------------
    Date                 : April 2015
    Copyright            : (C) 2015 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 QGSEXPRESSIONCONTEXTUTILS_H
#define QGSEXPRESSIONCONTEXTUTILS_H
 
#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsexpressioncontext.h"
#include "qgsfeature.h"
#include "qgsmeshdataprovider.h"
#include "qgspointlocator.h"
 
#include <QString>
#include <QVariantMap>
 
using namespace Qt::StringLiterals;
 
class QgsExpressionContextScope;
class QgsProject;
class QgsLayout;
class QgsSymbol;
class QgsLayoutAtlas;
class QgsLayoutItem;
class QgsMapSettings;
class QgsProcessingAlgorithm;
class QgsProcessingModelAlgorithm;
class QgsProcessingContext;
class QgsLayoutMultiFrame;

 
class CORE_EXPORT QgsExpressionContextUtils
{
  public:
    static std::unique_ptr<QgsExpressionContextScope> globalScope();

    static std::unique_ptr<QgsExpressionContextScope> formScope( const QgsFeature &formFeature = QgsFeature(), const QString &formMode = QString() );

    static std::unique_ptr<QgsExpressionContextScope> parentFormScope( const QgsFeature &formFeature = QgsFeature(), const QString &formMode = QString() );

    static void setGlobalVariable( const QString &name, const QVariant &value );

    static void setGlobalVariables( const QVariantMap &variables );

    static void removeGlobalVariable( const QString &name );

    static std::unique_ptr<QgsExpressionContextScope> projectScope( const QgsProject *project );

    static void setProjectVariable( QgsProject *project, const QString &name, const QVariant &value );

    static void setProjectVariables( QgsProject *project, const QVariantMap &variables );

    static void removeProjectVariable( QgsProject *project, const QString &name );

    static std::unique_ptr<QgsExpressionContextScope> layerScope( const QgsMapLayer *layer );

    static std::vector<std::unique_ptr<QgsExpressionContextScope>> globalProjectLayerScopes( const QgsMapLayer *layer );

    static void setLayerVariable( QgsMapLayer *layer, const QString &name, const QVariant &value );

    static void setLayerVariables( QgsMapLayer *layer, const QVariantMap &variables );

    static std::unique_ptr<QgsExpressionContextScope> mapSettingsScope( const QgsMapSettings &mapSettings );

    static std::unique_ptr<QgsExpressionContextScope> mapToolCaptureScope( const QList<QgsPointLocator::Match> &matches );

    static std::unique_ptr<QgsExpressionContextScope> mapLayerPositionScope( const QgsPointXY &position );

    static QgsExpressionContextScope *updateSymbolScope( const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope = nullptr );

    static std::unique_ptr<QgsExpressionContextScope> layoutScope( const QgsLayout *layout );

    static void setLayoutVariable( QgsLayout *layout, const QString &name, const QVariant &value );

    static void setLayoutVariables( QgsLayout *layout, const QVariantMap &variables );

    static std::unique_ptr<QgsExpressionContextScope> atlasScope( const QgsLayoutAtlas *atlas );

    static std::unique_ptr<QgsExpressionContextScope> layoutItemScope( const QgsLayoutItem *item );

    static void setLayoutItemVariable( QgsLayoutItem *item, const QString &name, const QVariant &value );

    static void setLayoutItemVariables( QgsLayoutItem *item, const QVariantMap &variables );

    static std::unique_ptr<QgsExpressionContextScope> multiFrameScope( const QgsLayoutMultiFrame *frame );

    static void setLayoutMultiFrameVariable( QgsLayoutMultiFrame *frame, const QString &name, const QVariant &value );

    static void setLayoutMultiFrameVariables( QgsLayoutMultiFrame *frame, const QVariantMap &variables );

    static QgsExpressionContext createFeatureBasedContext( const QgsFeature &feature, const QgsFields &fields );

    static std::unique_ptr<QgsExpressionContextScope> processingAlgorithmScope( const QgsProcessingAlgorithm *algorithm, const QVariantMap &parameters, QgsProcessingContext &context );

    static std::unique_ptr<QgsExpressionContextScope> processingModelAlgorithmScope( const QgsProcessingModelAlgorithm *model, const QVariantMap &parameters, QgsProcessingContext &context );

    static std::unique_ptr<QgsExpressionContextScope> notificationScope( const QString &message = QString() );

    SIP_SKIP static void registerContextFunctions( QgsExpression::SharedFunctionPtrList &functions );

    static std::unique_ptr<QgsExpressionContextScope> meshExpressionScope( QgsMesh::ElementType elementType );
 
  private:
    class GetLayerVisibility : public QgsScopedExpressionFunction
    {
      public:
        GetLayerVisibility( const QList<QgsMapLayer *> &layers, double scale = 0 );
        QVariant func( const QVariantList &values, const QgsExpressionContext *, QgsExpression *, const QgsExpressionNodeFunction * ) override;
        QgsScopedExpressionFunction *clone() const override;
 
      private:
        GetLayerVisibility();
 
        QList< QPointer< QgsMapLayer > > mLayers;
        QMap< QPointer< QgsMapLayer >, QPair< double, double > > mScaleBasedVisibilityDetails;
        double mScale = 0.0;
    };
 
    friend class QgsLayoutItemMap; // needs access to GetLayerVisibility
};

#ifndef SIP_RUN
class LoadLayerFunction : public QgsScopedExpressionFunction
{
  public:
    LoadLayerFunction()
      : QgsScopedExpressionFunction( u"load_layer"_s, QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( u"uri"_s ) << QgsExpressionFunction::Parameter( u"provider"_s ), u"Map Layers"_s )
    {}
 
    QVariant func( const QVariantList &, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * ) override;
    bool isStatic( const QgsExpressionNodeFunction *node, QgsExpression *parent, const QgsExpressionContext *context ) const override;
 
    QgsScopedExpressionFunction *clone() const override;
};
#endif
 
#ifndef SIP_RUN

class QgsExpressionContextScopePopper
{
  public:
    QgsExpressionContextScopePopper( QgsExpressionContext &context, QgsExpressionContextScope *scope )
      : mContext( context )
    {
      mContext.appendScope( scope );
    }
 
    ~QgsExpressionContextScopePopper() { delete mContext.popScope(); }
 
  private:
    QgsExpressionContext &mContext;
};
#endif
 
#endif // QGSEXPRESSIONCONTEXTUTILS_H