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 "qgsfeature.h"
#include "qgspointlocator.h"
#include "qgsexpressioncontext.h"
#include "qgsmeshdataprovider.h"
 
#include <QString>
#include <QVariantMap>
 
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 QgsExpressionContextScope *globalScope() SIP_FACTORY;
 
    static QgsExpressionContextScope *formScope( const QgsFeature &formFeature = QgsFeature( ), const QString &formMode = QString() ) SIP_FACTORY;
 
    static QgsExpressionContextScope *parentFormScope( const QgsFeature &formFeature = QgsFeature( ), const QString &formMode = QString() ) SIP_FACTORY;
 
    static void setGlobalVariable( const QString &name, const QVariant &value );
 
    static void setGlobalVariables( const QVariantMap &variables );
 
    static void removeGlobalVariable( const QString &name );
 
    static QgsExpressionContextScope *projectScope( const QgsProject *project ) SIP_FACTORY;
 
    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 QgsExpressionContextScope *layerScope( const QgsMapLayer *layer ) SIP_FACTORY;
 
    static QList<QgsExpressionContextScope *> globalProjectLayerScopes( const QgsMapLayer *layer ) SIP_FACTORY;
 
    static void setLayerVariable( QgsMapLayer *layer, const QString &name, const QVariant &value );
 
    static void setLayerVariables( QgsMapLayer *layer, const QVariantMap &variables );
 
    static QgsExpressionContextScope *mapSettingsScope( const QgsMapSettings &mapSettings ) SIP_FACTORY;
 
    static QgsExpressionContextScope *mapToolCaptureScope( const QList<QgsPointLocator::Match> &matches ) SIP_FACTORY;
 
    static QgsExpressionContextScope *mapLayerPositionScope( const QgsPointXY &position ) SIP_FACTORY;
 
    static QgsExpressionContextScope *updateSymbolScope( const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope = nullptr );
 
    static QgsExpressionContextScope *layoutScope( const QgsLayout *layout ) SIP_FACTORY;
 
    static void setLayoutVariable( QgsLayout *layout, const QString &name, const QVariant &value );
 
    static void setLayoutVariables( QgsLayout *layout, const QVariantMap &variables );
 
    static QgsExpressionContextScope *atlasScope( const QgsLayoutAtlas *atlas ) SIP_FACTORY;
 
    static QgsExpressionContextScope *layoutItemScope( const QgsLayoutItem *item ) SIP_FACTORY;
 
    static void setLayoutItemVariable( QgsLayoutItem *item, const QString &name, const QVariant &value );
 
    static void setLayoutItemVariables( QgsLayoutItem *item, const QVariantMap &variables );
 
    static QgsExpressionContextScope *multiFrameScope( const QgsLayoutMultiFrame *frame ) SIP_FACTORY;
 
    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 QgsExpressionContextScope *processingAlgorithmScope( const QgsProcessingAlgorithm *algorithm, const QVariantMap &parameters, QgsProcessingContext &context ) SIP_FACTORY;
 
    static QgsExpressionContextScope *processingModelAlgorithmScope( const QgsProcessingModelAlgorithm *model, const QVariantMap &parameters, QgsProcessingContext &context ) SIP_FACTORY;
 
    static QgsExpressionContextScope *notificationScope( const QString &message = QString() ) SIP_FACTORY;
 
    static void registerContextFunctions();
 
    static QgsExpressionContextScope *meshExpressionScope( QgsMesh::ElementType elementType ) SIP_FACTORY;
 
  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( QStringLiteral( "load_layer" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "uri" ) ) << QgsExpressionFunction::Parameter( QStringLiteral( "provider" ) ), QStringLiteral( "Map Layers" ) )
    {}
 
    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