src/core/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.                                   *
 *                                                                         *
 ***************************************************************************/
/* $Id$ */

#ifndef QQGSDATAPROVIDER_H
#define QQGSDATAPROVIDER_H

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

class QgsRectangle;
class QgsCoordinateReferenceSystem;


class CORE_EXPORT QgsDataProvider : public QObject
{
    Q_OBJECT

  public:

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

    virtual ~QgsDataProvider() {};


    virtual QgsCoordinateReferenceSystem crs() = 0;


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

    virtual QString dataSourceUri() const
    {
      return mDataSourceURI;
    }


    virtual QgsRectangle extent() = 0;


    virtual bool isValid() = 0;


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


    virtual bool setSubsetString( QString subset, bool updateFeatureCount = true )
    {
      // NOP by default
      Q_UNUSED( subset );
      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( QStringList layers )
    {
      //prevent unused var warnings
      if ( layers.count() < 1 )
      {
        return;
      }
      // NOOP
    }


    virtual void setSubLayerVisibility( 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(); }

  signals:

    void fullExtentCalculated();

    void dataChanged();

    void dataChanged( int changed );

  protected:
    QDateTime mTimestamp;
  private:

    QString mDataSourceURI;
};


#endif