qgsogrprovider.cpp

一个非常好的GIS开源新版本

{
  return "[OGR] " + 
    longName + " (" + glob.lower() + " " + glob.upper() + ");;";
} // createFileFilter_



QGISEXTERN QString fileVectorFilters()
{
  static QString myFileFilters;

  // if we've already built the supported vector string, just return what
  // we've already built
  if ( ! ( myFileFilters.isEmpty() || myFileFilters.isNull() ) )
  {
    return myFileFilters;
  }

  // register ogr plugins
  OGRRegisterAll();

  // first get the GDAL driver manager

  OGRSFDriverH driver;          // current driver

  QString driverName;           // current driver name

  // Grind through all the drivers and their respective metadata.
  // We'll add a file filter for those drivers that have a file
  // extension defined for them; the others, welll, even though
  // theoreticaly we can open those files because there exists a
  // driver for them, the user will have to use the "All Files" to
  // open datasets with no explicitly defined file name extension.
  QgsDebugMsg( QString("Driver count: %1").arg( OGRGetDriverCount() ) );

  for (int i = 0; i < OGRGetDriverCount(); ++i)
  {
    driver = OGRGetDriver(i);

    Q_CHECK_PTR(driver);

    if (!driver)
    {
      QgsLogger::warning("unable to get driver " + QString::number(i));
      continue;
    }

    driverName = OGR_Dr_GetName(driver);


    if (driverName.startsWith("ESRI"))
    {
      myFileFilters += createFileFilter_("ESRI Shapefiles", "*.shp");
    }
    else if (driverName.startsWith("UK"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("SDTS"))
    {
      myFileFilters += createFileFilter_( "Spatial Data Transfer Standard",
        "*catd.ddf" );
    }
    else if (driverName.startsWith("TIGER"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("S57"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("MapInfo"))
    {
      myFileFilters += createFileFilter_("MapInfo", "*.mif *.tab");
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("DGN"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("VRT"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("AVCBin"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("REC"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("Memory"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("Jis"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("GML"))
    {
      // XXX not yet supported; post 0.1 release task
      myFileFilters += createFileFilter_( "Geography Markup Language",
        "*.gml" );
    }
    else if (driverName.startsWith("CSV"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("PostgreSQL"))
    {
      // XXX needs file filter extension
    }
    else if (driverName.startsWith("GRASS")) 
    { 
      // XXX needs file filter extension 
    } 
    else if (driverName.startsWith("KML")) 
    { 
      // XXX needs file filter extension 
    } 
    else if (driverName.startsWith("Interlis 1")) 
    { 
      // XXX needs file filter extension 
    } 
    else if (driverName.startsWith("Interlis 2")) 
    { 
      // XXX needs file filter extension 
    } 
    else if (driverName.startsWith("SQLite")) 
    { 
      // XXX needs file filter extension 
    } 
    else if (driverName.startsWith("MySQL")) 
    { 
      // XXX needs file filter extension 
    } 
    else
    {
      // NOP, we don't know anything about the current driver
      // with regards to a proper file filter string
      QgsLogger::debug("fileVectorFilters, unknown driver: " + driverName);
    }

  }                           // each loaded GDAL driver

  // can't forget the default case

  myFileFilters += "All files (*.*)";

  return myFileFilters;

} // fileVectorFilters() const


QString QgsOgrProvider::fileVectorFilters() const
{
  return fileVectorFilters();
} // QgsOgrProvider::fileVectorFilters() const


/**
 * Class factory to return a pointer to a newly created 
 * QgsOgrProvider object
 */
QGISEXTERN QgsOgrProvider * classFactory(const QString *uri)
{
  return new QgsOgrProvider(*uri);
}



/** Required key function (used to map the plugin to a data store type)
*/
QGISEXTERN QString providerKey()
{
  return TEXT_PROVIDER_KEY;
}


/**
 * Required description function 
 */
QGISEXTERN QString description()
{
  return TEXT_PROVIDER_DESCRIPTION;
} 

/**
 * Required isProvider function. Used to determine if this shared library
 * is a data provider plugin
 */

QGISEXTERN bool isProvider()
{
  return true;
}

/**Creates an empty data source
@param uri location to store the file(s)
@param format data format (e.g. "ESRI Shapefile"
@param vectortype point/line/polygon or multitypes
@param attributes a list of name/type pairs for the initial attributes
@return true in case of success*/
QGISEXTERN bool createEmptyDataSource(const QString& uri,
                                      const QString& format,
                                      const QString& encoding,
                                      QGis::WKBTYPE vectortype,
                                      const std::list<std::pair<QString, QString> >& attributes)
{
  OGRSFDriverH driver;
  OGRRegisterAll();
  driver = OGRGetDriverByName(format);
  if(driver == NULL)
  {
    return false;
  }

  OGRDataSourceH dataSource;
  dataSource = OGR_Dr_CreateDataSource(driver,QFile::encodeName(uri).constData(), NULL);
  if(dataSource == NULL)
  {
    return false;
  }

  //consider spatial reference system
  OGRSpatialReferenceH reference = NULL;
  QgsSpatialRefSys mySpatialRefSys;
  mySpatialRefSys.validate();
  QString myWKT = mySpatialRefSys.toWkt();

  if( !myWKT.isNull()  &&  myWKT.length() != 0 )
  {
    reference = OSRNewSpatialReference(myWKT.toLocal8Bit().data());
  }

  // Map the qgis geometry type to the OGR geometry type
  OGRwkbGeometryType OGRvectortype = wkbUnknown;
  switch (vectortype)
  {
  case QGis::WKBPoint:
    OGRvectortype = wkbPoint;
    break;
  case QGis::WKBLineString:
    OGRvectortype = wkbLineString;
    break;
  case QGis::WKBPolygon:
    OGRvectortype = wkbPolygon;
    break;
  case QGis::WKBMultiPoint:
    OGRvectortype = wkbMultiPoint;
    break;
  case QGis::WKBMultiLineString:
    OGRvectortype = wkbMultiLineString;
    break;
  case QGis::WKBMultiPolygon:
    OGRvectortype = wkbMultiPolygon;
    break;
  default:
    {
      QgsLogger::debug("Unknown vector type of: ", (int)(vectortype), 1, 
        __FILE__, __FUNCTION__, __LINE__);
      return false;
      break;
    }
  }

  OGRLayerH layer;	
  layer = OGR_DS_CreateLayer(dataSource,QFile::encodeName(QFileInfo(uri).baseName()).constData(), reference, OGRvectortype, NULL);
  if(layer == NULL)
  {
    return false;
  }

  //create the attribute fields

  QTextCodec* codec=QTextCodec::codecForName(encoding.toLocal8Bit().data());

  for(std::list<std::pair<QString, QString> >::const_iterator it= attributes.begin(); it != attributes.end(); ++it)
  {
    if(it->second == "Real")
    {
      OGRFieldDefnH field = OGR_Fld_Create(codec->fromUnicode(it->first).data(), OFTReal);
      OGR_Fld_SetPrecision(field,3);
      OGR_Fld_SetWidth(field,32);
      if( OGR_L_CreateField(layer,field,TRUE) != OGRERR_NONE)
      {
        QgsLogger::warning("creation of OFTReal field failed");
      }
    }
    else if(it->second == "Integer")
    {
      OGRFieldDefnH field = OGR_Fld_Create(codec->fromUnicode(it->first).data(), OFTInteger);
      OGR_Fld_SetWidth(field,10); // limit to 10.  otherwise OGR sets it to 11 and recognizes as OFTDouble later
      if(OGR_L_CreateField(layer,field,TRUE) != OGRERR_NONE)
      {
        QgsLogger::warning("creation of OFTInteger field failed");
      }
    }
    else if(it->second == "String")
    {
      OGRFieldDefnH field = OGR_Fld_Create(codec->fromUnicode(it->first).data(), OFTString);
      if(OGR_L_CreateField(layer,field,TRUE) != OGRERR_NONE)
      {
        QgsLogger::warning("creation of OFTString field failed");
      }
    }
  }

  OGR_DS_Destroy(dataSource);

  QgsDebugMsg( QString("GDAL Version number %1").arg( GDAL_VERSION_NUM ) );
#if GDAL_VERSION_NUM >= 1310
  if(reference)
  {
    OSRRelease( reference );
  }
#endif //GDAL_VERSION_NUM
  return true;
}

QgsSpatialRefSys QgsOgrProvider::getSRS()
{
  QgsDebugMsg("QgsOgrProvider::getSRS()");

  QgsSpatialRefSys srs;

  OGRSpatialReferenceH mySpatialRefSys = OGR_L_GetSpatialRef(ogrLayer);
  if (mySpatialRefSys == NULL)
  {
    QgsDebugMsg("no spatial reference found"); 
  }
  else
  {
    // get the proj4 text
    char * ppszProj4;
    OSRExportToProj4(mySpatialRefSys, &ppszProj4 );
    QgsDebugMsg(ppszProj4); 
    char    *pszWKT = NULL;
    OSRExportToWkt(mySpatialRefSys, &pszWKT );
    QString myWKTString = QString(pszWKT);
    OGRFree(pszWKT);  

    // create SRS from WKT
    srs.createFromWkt( myWKTString );
  }

  return srs;
}

void QgsOgrProvider::getUniqueValues(int index, QStringList &uniqueValues)
{
  QgsField fld = mAttributeFields[index];
  QFileInfo fi( dataSourceUri() );
  if( !fi.exists() )
    return;
  
  QString sql = QString("SELECT DISTINCT %1 FROM %2 ORDER BY %1").arg( fld.name() ).arg( fi.baseName() );

  uniqueValues.clear();

  OGRLayerH l = OGR_DS_ExecuteSQL(ogrDataSource, sql.ascii(), NULL, "SQL");
  if(l==0)
    return;

  OGRFeatureH f;
  while( f=OGR_L_GetNextFeature(l) )
  {
    uniqueValues.append( mEncoding->toUnicode(OGR_F_GetFieldAsString(f, 0)) );
    OGR_F_Destroy(f);
  }

  OGR_DS_ReleaseResultSet(l, ogrDataSource);
}



QVariant QgsOgrProvider::minValue(int index)
{
  QgsField fld = mAttributeFields[index];
  QFileInfo fi( dataSourceUri() );
  if( !fi.exists() )
    return QVariant();
  
  QString sql = QString("SELECT MIN(%1) FROM %2").arg( fld.name() ).arg( fi.baseName() );

  OGRLayerH l = OGR_DS_ExecuteSQL(ogrDataSource, sql.ascii(), NULL, "SQL");

  if(l==0)
    return QVariant();

  OGRFeatureH f = OGR_L_GetNextFeature(l);
  if(f==0)
  {
    OGR_DS_ReleaseResultSet(l, ogrDataSource);
    return QVariant();
  }

  QString str = mEncoding->toUnicode( OGR_F_GetFieldAsString(f,0) );
  OGR_F_Destroy(f);

  QVariant value;
 
  switch (fld.type())
  {
    case QVariant::String: value = QVariant(str); break;
    case QVariant::Int: value = QVariant(str.toInt()); break;
    case QVariant::Double: value = QVariant(str.toDouble()); break;
    //case QVariant::DateTime: value = QVariant(QDateTime::fromString(str)); break;
    default: assert(NULL && "unsupported field type");
  }
  
  OGR_DS_ReleaseResultSet(l, ogrDataSource);

  return value;
}

QVariant QgsOgrProvider::maxValue(int index)
{
  QgsField fld = mAttributeFields[index];
  QFileInfo fi( dataSourceUri() );
  if( !fi.exists() )
    return QVariant();
  
  QString sql = QString("SELECT MAX(%1) FROM %2").arg( fld.name() ).arg( fi.baseName() );

  OGRLayerH l = OGR_DS_ExecuteSQL(ogrDataSource, sql.ascii(), NULL, "SQL");
  if(l==0)
    return QVariant();

  OGRFeatureH f = OGR_L_GetNextFeature(l);
  if(f==0)
  {
    OGR_DS_ReleaseResultSet(l, ogrDataSource);
    return QVariant();
  }

  QString str = mEncoding->toUnicode( OGR_F_GetFieldAsString(f,0) );
  OGR_F_Destroy(f);

  QVariant value;
 
  switch (fld.type())
  {
    case QVariant::String: value = QVariant(str); break;
    case QVariant::Int: value = QVariant(str.toInt()); break;
    case QVariant::Double: value = QVariant(str.toDouble()); break;
    //case QVariant::DateTime: value = QVariant(QDateTime::fromString(str)); break;
    default: assert(NULL && "unsupported field type");
  }
  
  OGR_DS_ReleaseResultSet(l, ogrDataSource);

  return value;
}