qgsprocessingcontext.h

Go to the documentation of this file.

/***************************************************************************
                         qgsprocessingcontext.h
                         ----------------------
    begin                : April 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 QGSPROCESSINGCONTEXT_H
#define QGSPROCESSINGCONTEXT_H

#include "qgis_core.h"
#include "qgis.h"
#include "qgsproject.h"
#include "qgsexpressioncontext.h"
#include "qgsfeaturerequest.h"
#include "qgsmaplayerlistutils.h"
#include "qgsexception.h"
#include "qgsprocessingfeedback.h"

class QgsProcessingLayerPostProcessorInterface;

class CORE_EXPORT QgsProcessingContext
{
  public:

    enum Flag
    {
      // UseSelectionIfPresent = 1 << 0,
    };
    Q_DECLARE_FLAGS( Flags, Flag )

    
    QgsProcessingContext()
    {
      auto callback = [ = ]( const QgsFeature & feature )
      {
        if ( mFeedback )
          mFeedback->reportError( QObject::tr( "Encountered a transform error when reprojecting feature with id %1." ).arg( feature.id() ) );
      };
      mTransformErrorCallback = callback;
    }

    QgsProcessingContext( const QgsProcessingContext &other ) = delete;
    QgsProcessingContext &operator=( const QgsProcessingContext &other ) = delete;

    ~QgsProcessingContext();

    void copyThreadSafeSettings( const QgsProcessingContext &other )
    {
      mFlags = other.mFlags;
      mProject = other.mProject;
      mTransformContext = other.mTransformContext;
      mExpressionContext = other.mExpressionContext;
      mInvalidGeometryCallback = other.mInvalidGeometryCallback;
      mInvalidGeometryCheck = other.mInvalidGeometryCheck;
      mTransformErrorCallback = other.mTransformErrorCallback;
      mDefaultEncoding = other.mDefaultEncoding;
      mFeedback = other.mFeedback;
    }

    QgsProcessingContext::Flags flags() const { return mFlags; }

    void setFlags( QgsProcessingContext::Flags flags ) { mFlags = flags; }

    QgsProject *project() const { return mProject; }

    void setProject( QgsProject *project )
    {
      mProject = project;
      if ( mProject )
        mTransformContext = mProject->transformContext();
    }

    QgsExpressionContext &expressionContext() { return mExpressionContext; }

    SIP_SKIP const QgsExpressionContext &expressionContext() const { return mExpressionContext; }

    void setExpressionContext( const QgsExpressionContext &context ) { mExpressionContext = context; }

    QgsCoordinateTransformContext transformContext() const { return mTransformContext; }

    void setTransformContext( const QgsCoordinateTransformContext &context ) { mTransformContext = context; }

    QgsMapLayerStore *temporaryLayerStore() { return &tempLayerStore; }

    class CORE_EXPORT LayerDetails
    {
      public:

        LayerDetails( const QString &name, QgsProject *project, const QString &outputName = QString() )
          : name( name )
          , outputName( outputName )
          , project( project )
        {}

        LayerDetails() = default;

        QString name;

        QString outputName;

        QgsProcessingLayerPostProcessorInterface *postProcessor() const;

        void setPostProcessor( QgsProcessingLayerPostProcessorInterface *processor SIP_TRANSFER );

        QgsProject *project = nullptr;

      private:

        // Ideally a unique_ptr, but cannot be due to use within QMap. Is cleaned up by QgsProcessingContext.
        QgsProcessingLayerPostProcessorInterface *mPostProcessor = nullptr;

    };

    QMap< QString, QgsProcessingContext::LayerDetails > layersToLoadOnCompletion() const
    {
      return mLayersToLoadOnCompletion;
    }

    bool willLoadLayerOnCompletion( const QString &layer ) const
    {
      return mLayersToLoadOnCompletion.contains( layer );
    }

    void setLayersToLoadOnCompletion( const QMap< QString, QgsProcessingContext::LayerDetails > &layers );

    void addLayerToLoadOnCompletion( const QString &layer, const QgsProcessingContext::LayerDetails &details );

    QgsProcessingContext::LayerDetails &layerToLoadOnCompletionDetails( const QString &layer )
    {
      return mLayersToLoadOnCompletion[ layer ];
    }

    QgsFeatureRequest::InvalidGeometryCheck invalidGeometryCheck() const { return mInvalidGeometryCheck; }

    void setInvalidGeometryCheck( QgsFeatureRequest::InvalidGeometryCheck check );

#ifndef SIP_RUN
    void setInvalidGeometryCallback( const std::function< void( const QgsFeature & ) > &callback ) { mInvalidGeometryCallback = callback; }
#else
    void setInvalidGeometryCallback( SIP_PYCALLABLE / AllowNone / );
    % MethodCode
    Py_BEGIN_ALLOW_THREADS

    sipCpp->setInvalidGeometryCallback( [a0]( const QgsFeature &arg )
    {
      SIP_BLOCK_THREADS
      Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
      SIP_UNBLOCK_THREADS
    } );

    Py_END_ALLOW_THREADS
    % End
#endif

    SIP_SKIP std::function< void( const QgsFeature & ) > invalidGeometryCallback() const { return mInvalidGeometryCallback; }

#ifndef SIP_RUN
    void setTransformErrorCallback( const std::function< void( const QgsFeature & ) > &callback ) { mTransformErrorCallback = callback; }
#else
    void setTransformErrorCallback( SIP_PYCALLABLE / AllowNone / );
    % MethodCode
    Py_BEGIN_ALLOW_THREADS

    sipCpp->setTransformErrorCallback( [a0]( const QgsFeature &arg )
    {
      SIP_BLOCK_THREADS
      Py_XDECREF( sipCallMethod( NULL, a0, "D", &arg, sipType_QgsFeature, NULL ) );
      SIP_UNBLOCK_THREADS
    } );

    Py_END_ALLOW_THREADS
    % End
#endif

    std::function< void( const QgsFeature & ) > transformErrorCallback() const { return mTransformErrorCallback; } SIP_SKIP

    QString defaultEncoding() const { return mDefaultEncoding; }

    void setDefaultEncoding( const QString &encoding ) { mDefaultEncoding = encoding; }

    QgsProcessingFeedback *feedback() { return mFeedback; }

    void setFeedback( QgsProcessingFeedback *feedback ) { mFeedback = feedback; }

    QThread *thread() { return tempLayerStore.thread(); }

    void pushToThread( QThread *thread )
    {
      Q_ASSERT_X( QThread::currentThread() == QgsProcessingContext::thread(), "QgsProcessingContext::pushToThread", "Cannot push context to another thread unless the current thread matches the existing context thread affinity" );
      tempLayerStore.moveToThread( thread );
    }

    void takeResultsFrom( QgsProcessingContext &context );

    QgsMapLayer *getMapLayer( const QString &identifier );

    QgsMapLayer *takeResultLayer( const QString &id ) SIP_TRANSFERBACK;

  private:

    QgsProcessingContext::Flags mFlags = nullptr;
    QPointer< QgsProject > mProject;
    QgsCoordinateTransformContext mTransformContext;
    QgsMapLayerStore tempLayerStore;
    QgsExpressionContext mExpressionContext;
    QgsFeatureRequest::InvalidGeometryCheck mInvalidGeometryCheck = QgsFeatureRequest::GeometryNoCheck;
    std::function< void( const QgsFeature & ) > mInvalidGeometryCallback;
    std::function< void( const QgsFeature & ) > mTransformErrorCallback;
    QString mDefaultEncoding;
    QMap< QString, LayerDetails > mLayersToLoadOnCompletion;

    QPointer< QgsProcessingFeedback > mFeedback;

#ifdef SIP_RUN
    QgsProcessingContext( const QgsProcessingContext &other );
#endif
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsProcessingContext::Flags )



class CORE_EXPORT QgsProcessingLayerPostProcessorInterface
{
  public:

    virtual ~QgsProcessingLayerPostProcessorInterface() = default;

    virtual void postProcessLayer( QgsMapLayer *layer, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) = 0;

};


#endif // QGSPROCESSINGPARAMETERS_H