ogrshapelayer.cpp

用于读取TAB、MIF、SHP文件的类

    while( TRUE )
    {
        if( panMatchingFIDs != NULL )
        {
            if( panMatchingFIDs[iMatchingFID] == OGRNullFID )
            {
                return NULL;
            }

            poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn, 
                                           panMatchingFIDs[iMatchingFID++] );
        }
        else
        {
            if( iNextShapeId >= nTotalShapeCount )
            {
                return NULL;
            }
    
            if( hDBF && DBFIsRecordDeleted( hDBF, iNextShapeId ) )
                poFeature = NULL;
            else
                poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn,
                                               iNextShapeId );

            iNextShapeId++;
        }

        if( poFeature != NULL )
        {
            if( poFeature->GetGeometryRef() != NULL )
            {
                poFeature->GetGeometryRef()->assignSpatialReference( poSRS );
            }

            m_nFeaturesRead++;

            if( (m_poFilterGeom == NULL || FilterGeometry( poFeature->GetGeometryRef() ) )
                && (m_poAttrQuery == NULL || m_poAttrQuery->Evaluate( poFeature )) )
            {
                return poFeature;
            }

            delete poFeature;
        }
    }        

    /*
     * NEVER SHOULD GET HERE
     */
    CPLAssert(!"OGRShapeLayer::GetNextFeature(): Execution never should get here!");
}

/************************************************************************/
/*                             GetFeature()                             */
/************************************************************************/

OGRFeature *OGRShapeLayer::GetFeature( long nFeatureId )

{
    OGRFeature *poFeature = NULL;
    poFeature = SHPReadOGRFeature( hSHP, hDBF, poFeatureDefn, nFeatureId );

    if( poFeature != NULL )
    {
        if( poFeature->GetGeometryRef() != NULL )
            poFeature->GetGeometryRef()->assignSpatialReference( poSRS );

        m_nFeaturesRead++;
    
        return poFeature;
    }

    /*
     * Reading shape feature failed.
     */
    return NULL;
}

/************************************************************************/
/*                             SetFeature()                             */
/************************************************************************/

OGRErr OGRShapeLayer::SetFeature( OGRFeature *poFeature )

{
    return SHPWriteOGRFeature( hSHP, hDBF, poFeatureDefn, poFeature );
}

/************************************************************************/
/*                           DeleteFeature()                            */
/************************************************************************/

OGRErr OGRShapeLayer::DeleteFeature( long nFID )

{
    if( nFID < 0 
        || (hSHP != NULL && nFID >= hSHP->nRecords)
        || (hDBF != NULL && nFID >= hDBF->nRecords) )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Attempt to delete shape with feature id (%d) which does "
                  "not exist.", nFID );
        return OGRERR_FAILURE;
    }

    if( !hDBF )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Attempt to delete shape in shapefile with no .dbf file.\n"
                  "Deletion is done by marking record deleted in dbf\n"
                  "and is not supported without a .dbf file." );
        return OGRERR_FAILURE;
    }

    if( DBFIsRecordDeleted( hDBF, nFID ) )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Attempt to delete shape with feature id (%d), but it is marked deleted already.",
                  nFID );
        return OGRERR_FAILURE;
    }

    if( !DBFMarkRecordDeleted( hDBF, nFID, TRUE ) )
        return OGRERR_FAILURE;

    return OGRERR_NONE;
}

/************************************************************************/
/*                           CreateFeature()                            */
/************************************************************************/

OGRErr OGRShapeLayer::CreateFeature( OGRFeature *poFeature )

{
    OGRErr eErr;

    bHeaderDirty = TRUE;

    poFeature->SetFID( OGRNullFID );

    if( nTotalShapeCount == 0 
        && eRequestedGeomType == wkbUnknown 
        && poFeature->GetGeometryRef() != NULL )
    {
        OGRGeometry     *poGeom = poFeature->GetGeometryRef();
        int             nShapeType;
        
        switch( poGeom->getGeometryType() )
        {
          case wkbPoint:
            nShapeType = SHPT_POINT;
            eRequestedGeomType = wkbPoint;
            break;

          case wkbPoint25D:
            nShapeType = SHPT_POINTZ;
            eRequestedGeomType = wkbPoint25D;
            break;

          case wkbMultiPoint:
            nShapeType = SHPT_MULTIPOINT;
            eRequestedGeomType = wkbMultiPoint;
            break;

          case wkbMultiPoint25D:
            nShapeType = SHPT_MULTIPOINTZ;
            eRequestedGeomType = wkbMultiPoint25D;
            break;

          case wkbLineString:
            nShapeType = SHPT_ARC;
            eRequestedGeomType = wkbLineString;
            break;

          case wkbLineString25D:
            nShapeType = SHPT_ARCZ;
            eRequestedGeomType = wkbLineString25D;
            break;

          case wkbPolygon:
          case wkbMultiPolygon:
            nShapeType = SHPT_POLYGON;
            eRequestedGeomType = wkbPolygon;
            break;

          case wkbPolygon25D:
          case wkbMultiPolygon25D:
            nShapeType = SHPT_POLYGONZ;
            eRequestedGeomType = wkbPolygon25D;
            break;

          default:
            nShapeType = -1;
            break;
        }

        if( nShapeType != -1 )
        {
            ResetGeomType( nShapeType );
        }
    }
    
    eErr = SHPWriteOGRFeature( hSHP, hDBF, poFeatureDefn, poFeature );

    if( hSHP != NULL )
        nTotalShapeCount = hSHP->nRecords;
    else 
        nTotalShapeCount = hDBF->nRecords;
    
    return eErr;
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/*                                                                      */
/*      If a spatial filter is in effect, we turn control over to       */
/*      the generic counter.  Otherwise we return the total count.      */
/*      Eventually we should consider implementing a more efficient     */
/*      way of counting features matching a spatial query.              */
/************************************************************************/

int OGRShapeLayer::GetFeatureCount( int bForce )

{
    if( m_poFilterGeom != NULL || m_poAttrQuery != NULL )
        return OGRLayer::GetFeatureCount( bForce );
    else
        return nTotalShapeCount;
}

/************************************************************************/
/*                             GetExtent()                              */
/*                                                                      */
/*      Fetch extent of the data currently stored in the dataset.       */
/*      The bForce flag has no effect on SHO files since that value     */
/*      is always in the header.                                        */
/*                                                                      */
/*      Returns OGRERR_NONE/OGRRERR_FAILURE.                            */
/************************************************************************/

OGRErr OGRShapeLayer::GetExtent (OGREnvelope *psExtent, int bForce)

{
    double adMin[4], adMax[4];

    if( hSHP == NULL )
        return OGRERR_FAILURE;

    SHPGetInfo(hSHP, NULL, NULL, adMin, adMax);

    psExtent->MinX = adMin[0];
    psExtent->MinY = adMin[1];
    psExtent->MaxX = adMax[0];
    psExtent->MaxY = adMax[1];

    return OGRERR_NONE;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRShapeLayer::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,OLCRandomRead) )
        return TRUE;

    else if( EQUAL(pszCap,OLCSequentialWrite) 
             || EQUAL(pszCap,OLCRandomWrite) )
        return bUpdateAccess;

    else if( EQUAL(pszCap,OLCFastFeatureCount) )
        return m_poFilterGeom == NULL;

    else if( EQUAL(pszCap,OLCDeleteFeature) )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastSpatialFilter) )
        return FALSE;

    else if( EQUAL(pszCap,OLCFastGetExtent) )
        return TRUE;

    else if( EQUAL(pszCap,OLCFastSetNextByIndex) )
        return m_poFilterGeom == NULL && m_poAttrQuery == NULL;

    else if( EQUAL(pszCap,OLCCreateField) )
        return TRUE;

    else 
        return FALSE;
}

/************************************************************************/
/*                            CreateField()                             */
/************************************************************************/

OGRErr OGRShapeLayer::CreateField( OGRFieldDefn *poField, int bApproxOK )

{
    CPLAssert( NULL != poField );

    int         iNewField;
    if( GetFeatureCount(TRUE) != 0 )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Can't create fields on a Shapefile layer with features.\n");
        return OGRERR_FAILURE;
    }

    if( !bUpdateAccess )
    {
        CPLError( CE_Failure, CPLE_NotSupported,
                  "Can't create fields on a read-only shapefile layer.\n");
        return OGRERR_FAILURE;

    }

/* -------------------------------------------------------------------- */
/*      Normalize field name                                            */
/* -------------------------------------------------------------------- */
        
    char * pszNewFieldName = NULL;

    size_t nNameSize = strlen( poField->GetNameRef() );
    pszNewFieldName = CPLScanString( poField->GetNameRef(),
                                     nNameSize, TRUE, TRUE);

    if( !EQUAL(poField->GetNameRef(),pszNewFieldName) )
        CPLDebug( "Shape", "Normalized field name: '%s' to '%s'", 
                  poField->GetNameRef(),
                  pszNewFieldName );

    // Set field name with normalized value
    poField->SetName( pszNewFieldName );

    CPLFree( pszNewFieldName );

/* -------------------------------------------------------------------- */
/*      Add field to layer                                              */
/* -------------------------------------------------------------------- */

    if( poField->GetType() == OFTInteger )
    {
        if( poField->GetWidth() == 0 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTInteger, 11, 0 );
        else
            iNewField = DBFAddField( hDBF, poField->GetNameRef(), FTInteger,
                                     poField->GetWidth(), 0 );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTReal )
    {
        if( poField->GetWidth() == 0 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTDouble, 24, 15 );
        else
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTDouble,
                             poField->GetWidth(), poField->GetPrecision() );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTString )
    {
        if( poField->GetWidth() < 1 )
            iNewField =
                DBFAddField( hDBF, poField->GetNameRef(), FTString, 80, 0 );
        else
            iNewField = DBFAddField( hDBF, poField->GetNameRef(), FTString, 
                                     poField->GetWidth(), 0 );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTDate )
    {
        iNewField =
            DBFAddNativeFieldType( hDBF, poField->GetNameRef(), 'D', 8, 0 );

        if( iNewField != -1 )
            poFeatureDefn->AddFieldDefn( poField );
    }
    else if( poField->GetType() == OFTDateTime )
    {
        CPLError( CE_Warning, CPLE_NotSupported,
                  "Field %s create as date field, though DateTime requested.\n",
                  poField->GetNameRef() );