QueryLayer.h

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/*  Copyright (C) 2008 National Institute For Space Research (INPE) - Brazil.
 
    This file is part of the TerraLib - a Framework for building GIS enabled applications.
 
    TerraLib is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License,
    or (at your option) any later version.
 
    TerraLib is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public License
    along with TerraLib. See COPYING. If not, write to
    TerraLib Team at <terralib-team@terralib.org>.
 */
 
/*!
  \file terralib/maptools/QueryLayer.h
 
  \brief A layer resulting from a query.
*/
 
#ifndef __TERRALIB_MAPTOOLS_INTERNAL_QUERYLAYER_H
#define __TERRALIB_MAPTOOLS_INTERNAL_QUERYLAYER_H
 
// TerraLib
#include "AbstractLayer.h"
 
namespace te
{
// Forward declaration
  namespace da { 
    class Select; 
    class Join;
  }
 
  namespace map
  {
    /*!
      \class QueryLayer
 
      \brief A layer resulting from a query.
 
      A QueryLayer is a reference to a dataset that will result from a query to a data source.
 
      \ingroup map
 
      \sa AbstractLayer, DataSetLayer, RasterLayer, FolderLayer
    */
    class TEMAPEXPORT QueryLayer : public AbstractLayer
    {
      public:
 
        /*!
          \brief It initializes a new layer.
 
          \param parent The parent layer (NULL if it has no parent).
        */
        QueryLayer(AbstractLayer* parent = 0);
 
        /*!
          \brief It initializes a new layer.
 
          \param id     The layer id.
          \param parent The parent layer (NULL if it has no parent).
        */
        QueryLayer(const std::string& id, AbstractLayer* parent = 0);
 
        /*!
          \brief It initializes a new layer.
 
          \param id     The layer id.
          \param title  The title is a brief description about the layer.
          \param parent The parent layer (NULL if it has no parent).
        */
        QueryLayer(const std::string& id, const std::string& title, AbstractLayer* parent = 0);
 
        /*! \brief Destructor. */
        ~QueryLayer();
 
        AbstractLayer* clone();
 
        std::unique_ptr<LayerSchema> getSchema() const;
 
        /* Fills internal the cached schema for the dataset */
        void loadSchema() const;
 
        std::unique_ptr<te::da::DataSet> getData(te::common::TraverseType travType = te::common::FORWARDONLY,
                                               const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
        std::unique_ptr<te::da::DataSet> getData(const std::string& propertyName,
                                               const te::gm::Envelope* e,
                                               te::gm::SpatialRelation r = te::gm::INTERSECTS,
                                               te::common::TraverseType travType = te::common::FORWARDONLY,
                                               const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
        std::unique_ptr<te::da::DataSet> getData(const std::string& propertyName,
                                               const te::gm::Geometry* g,
                                               te::gm::SpatialRelation r,
                                               te::common::TraverseType travType = te::common::FORWARDONLY,
                                               const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
        std::unique_ptr<te::da::DataSet> getData(te::da::Expression* restriction,
                                               te::common::TraverseType travType = te::common::FORWARDONLY,
                                               const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
        std::unique_ptr<te::da::DataSet> getData(const te::da::ObjectIdSet* oids,
                                               te::common::TraverseType travType = te::common::FORWARDONLY,
                                               const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
        bool isValid() const;
 
        void draw(Canvas* canvas, const te::gm::Envelope& bbox, int srid, const double& scale, bool* cancel);
 
        /*!
          \brief It returns the layer type: QUERY_LAYER.
 
          \return The layer type: QUERY_LAYER.
        */
        const std::string& getType() const;
 
        /*!
          \brief
 
          \return
        */
        te::da::Select* getQuery() const;
 
        /*!
        \brief
 
        \return
        */
      std::string getQueryAsString() const;
 
        /*!
          \brief
 
          \param name
        */
        void setQuery(te::da::Select* s);
 
        /*!
          \brief
 
          \return
        */
        const std::string& getRendererType() const;
 
        /*!
          \brief
 
          \param t
        */
        void setRendererType(const std::string& t);
 
        void computeExtent();
 
      private:
 
         std::unique_ptr<te::da::DataSet> getData(te::da::Select* query,
                                                te::common::TraverseType travType = te::common::FORWARDONLY,
                                                const te::common::AccessPolicy accessPolicy = te::common::RAccess) const;
 
         /*!
           \brief Its indicate that the layer schema is out of date.
         */
         virtual void setOutOfDate();
 
         std::string searchJoin(const te::da::Join* dsJoin, 
           const std::string & token, bool & allowKeysWithNullValues) const;
 
      private:
 
        std::string m_rendererType;        //!< A pointer to the internal renderer used to paint this layer.
        te::da::Select* m_query;           //!< The dataset name where we will retrieve the layer objects.
 
        mutable LayerSchema* m_schema;     //!< The dataset schema.
 
        static const std::string sm_type;  //!< A static data member used in the implementation of getType method.
    };
 
    typedef boost::intrusive_ptr<QueryLayer> QueryLayerPtr;
 
  } // end namespace map
}   // end namespace te
 
#endif  // __TERRALIB_MAPTOOLS_INTERNAL_QUERYLAYER_H