qgsdataprovider.h

Go to the documentation of this file.

/***************************************************************************
                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 "qgserror.h"

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
    };

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

    virtual ~QgsDataProvider() {};


    virtual QgsCoordinateReferenceSystem crs() = 0;


    virtual void setDataSourceUri( const QString & 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 );
      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; }

  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;
};


#endif