qgsdataprovider.h

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/***************************************************************************
                qgsdataprovider.h - DataProvider Interface class
                     --------------------------------------
    Date                 : 09-Sep-2003
    Copyright            : (C) 2003 by Gary E.Sherman
    email                : sherman at mrcc.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 QQGSDATAPROVIDER_H
#define QQGSDATAPROVIDER_H

#include <QDateTime>
#include <QObject>
#include <QString>
#include <QStringList>

//#include "qgsdataitem.h"
#include "qgsdatasourceuri.h"
#include "qgserror.h"

typedef int dataCapabilities_t();

class QgsRectangle;
class QgsCoordinateReferenceSystem;


class CORE_EXPORT QgsDataProvider : public QObject
{
    Q_OBJECT

  public:

    Q_ENUMS( DataCapability )

    enum DataCapability
    {
      NoDataCapabilities  = 0,
      File                = 1,
      Dir                 = 1 << 1,
      Database            = 1 << 2,
      Net                 = 1 << 3  // Internet source
    };

    enum ProviderProperty
    {
      EvaluateDefaultValues,       
      CustomData   = 3000          
    };

    QgsDataProvider( QString const & uri = "" )
        : mDataSourceURI( uri )
    {}

    virtual ~QgsDataProvider() {}


    virtual QgsCoordinateReferenceSystem crs() = 0;


    virtual void setDataSourceUri( const QString & uri )
    {
      mDataSourceURI = uri;
    }

    virtual QString dataSourceUri( bool expandAuthConfig = false ) const
    {
      if ( expandAuthConfig && mDataSourceURI.contains( "authcfg" ) )
      {
        QgsDataSourceURI uri( mDataSourceURI );
        return uri.uri( expandAuthConfig );
      }
      else
      {
        return mDataSourceURI;
      }
    }


    virtual QgsRectangle extent() = 0;


    virtual bool isValid() = 0;


    virtual void updateExtents()
    {
      // NOP by default
    }


    virtual bool setSubsetString( const QString& subset, bool updateFeatureCount = true )
    {
      // NOP by default
      Q_UNUSED( subset );
      Q_UNUSED( updateFeatureCount );
      return false;
    }


    virtual bool supportsSubsetString() { return false; }

    virtual QString subsetString()
    {
      return QString::null;
    }


    virtual QStringList subLayers() const
    {
      return QStringList();  // Empty
    }


    virtual QStringList subLayerStyles() const
    {
      return QStringList();  // Empty
    }


    virtual uint subLayerCount() const
    {
      return 0;
    }


    virtual void setLayerOrder( const QStringList &layers )
    {
      //prevent unused var warnings
      if ( layers.count() < 1 )
      {
        return;
      }
      // NOOP
    }


    virtual void setSubLayerVisibility( const QString &name, bool vis )
    {
      //prevent unused var warnings
      if ( name.isEmpty() || !vis )
      {
        return;
      }
      // NOOP
    }


    virtual QString name() const = 0;


    virtual QString description() const = 0;


    virtual QString fileVectorFilters() const
    {
      return "";
    }


    virtual QString fileRasterFilters() const
    {
      return "";
    }

    virtual void reloadData() {}

    virtual QDateTime timestamp() const { return mTimestamp; }

    virtual QDateTime dataTimestamp() const { return QDateTime(); }

    virtual QgsError error() const { return mError; }

    virtual void invalidateConnections( const QString& connection ) { Q_UNUSED( connection ); }

    virtual bool enterUpdateMode() { return true; }

    virtual bool leaveUpdateMode() { return true; }

    void setProviderProperty( ProviderProperty property, const QVariant& value );

    void setProviderProperty( int property, const QVariant& value );

    QVariant providerProperty( ProviderProperty property, const QVariant& defaultValue = QVariant() ) const;

    QVariant providerProperty( int property , const QVariant& defaultValue ) const;

  signals:

    void fullExtentCalculated();

    void dataChanged();

    void dataChanged( int changed );

  protected:
    QDateTime mTimestamp;

    QgsError mError;

    void appendError( const QgsErrorMessage & theMessage ) { mError.append( theMessage );}

    void setError( const QgsError & theError ) { mError = theError;}

  private:

    QString mDataSourceURI;

    QMap< int, QVariant > mProviderProperties;
};


#endif