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/***************************************************************************
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qgsdataprovider.h - DataProvider Interface class
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--------------------------------------
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Copyright : (C) 2003 by Gary E.Sherman
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email : sherman at mrcc.com
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***************************************************************************
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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***************************************************************************/
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/* $Id: qgsdataprovider.h,v 1.14.2.3 2004/12/10 03:54:23 gsherman Exp $ */
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#ifndef QQGSDATAPROVIDER_H
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#define QQGSDATAPROVIDER_H
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class QgsDataSourceURI;
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/** \class QgsDataProvider
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* \brief Abstract base class for spatial data provider implementations
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*@author Gary E.Sherman
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class QgsDataProvider {
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* We need this so the subclass destructors get called
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virtual ~QgsDataProvider() {};
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* Select features based on a bounding rectangle. Features can be retrieved
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* with calls to getFirstFeature and getNextFeature. Request for features
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* for use in drawing the map canvas should set useIntersect to false.
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* @param mbr QgsRect containing the extent to use in selecting features
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* @param useIntersect If true, use the intersects function to select features
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* rather than the PostGIS && operator that selects based on bounding box
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virtual void select(QgsRect *mbr, bool useIntersect=false)=0;
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* Set the data source specification. This may be a path or database
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* @param data source specification
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virtual void setDataSourceUri(QString uri) = 0;
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* Get the data source specification. This may be a path or database
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* @return data source specification
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virtual QString getDataSourceUri() = 0;
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virtual QgsDataSourceURI * getURI()=0;
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* Get the extent of the layer
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* @return QgsRect containing the extent of the layer
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virtual QgsRect * extent() = 0;
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* Identify features within the search radius specified by rect
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* @param rect Bounding rectangle of search radius
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* @return std::vector containing QgsFeature objects that intersect rect
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//virtual std::vector<QgsFeature>& QgsDataProvider::identify(QgsRect *rect)=0;
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* Return the endian of this layer.
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* @return 0 for NDR (little endian), 1 for XDR (big endian
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virtual int endian()=0;
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* Returns true if this is a valid layer. It is up to individual providers
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* to determine what constitutes a valid layer
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virtual bool isValid()=0;
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/* Reset the layer - for an OGRLayer, this means clearing the
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* spatial filter and calling ResetReading
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* Update the feature count based on current spatial filter. If not
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* overridden in the data provider this function returns -1
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virtual long updateFeatureCount()
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* Update the extents of the layer. Not implemented by default
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virtual void updateExtents()
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* Set the subset string used to create a subset of features in
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* the layer. This may be a sql where clause or any other string
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* that can be used by the data provider to create a subset.
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* Must be implemented in the dataprovider.
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virtual void setSubsetString(QString subset)
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* Returns the subset definition string (typically sql) currently in
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* use by the layer and used by the provider to limit the feature set.
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* Must be overridden in the dataprovider, otherwise returns a null
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virtual QString subsetString()
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return QString::null;
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src/qgsdataprovider.h
