ugkfeature.cpp

linux下一款GIS程序源码

// ugkfeature.cpp: implementation of the UGKFeature class.
//
//////////////////////////////////////////////////////////////////////

#include "ugkfeature.h"

#include "ugk_memopr.h"
#include "ugk_string.h"


/************************************************************************/
/*                             UGKFeature()                             */
/************************************************************************/
/**
 * Constructor
 *
 * Note that the UGKFeature will increment the reference count of it's
 * defining UGKFeatureDefn.  Destruction of the UGKFeatureDefn before
 * destruction of all UGKFeatures that depend on it is likely to result in
 * a crash. 
 *
 * @param poDefnIn feature class (layer) definition to which the feature will
 * adhere.
 */

UGKFeature::UGKFeature( UGKFeatureDefn * poDefnIn )
{
	m_pszStyleString = NULL;
	m_poStyleTable = NULL;
	poDefnIn->Reference();
	poDefn = poDefnIn;

	nFID = UGKNullFID;

	poGeometry = NULL;

    pauFields = (UGKField *) UGK_Calloc( poDefn->GetFieldCount(),
                                        sizeof(UGKField) );
	for( int i = 0; i < poDefn->GetFieldCount(); i++ )
    {
        pauFields[i].Set.nMarker1 = UGKUnsetMarker;//设置为默认值
        pauFields[i].Set.nMarker2 = UGKUnsetMarker;//这样标志未赋值
    }

}

/************************************************************************/
/*                            ~UGKFeature()                             */
/************************************************************************/

UGKFeature::~UGKFeature()
{
	poDefn->Dereference();
	if( poGeometry != NULL )
		delete poGeometry;
	for( int i = 0; i < poDefn->GetFieldCount(); i++ )
	{
		UGKFieldDefn    *poFDefn = poDefn->GetFieldDefn(i);

		if( !IsFieldSet(i) )//判断此字段是否已经设置
			continue;
		switch( poFDefn->GetType() )//根据不同字段类型来释放内存
		{
			case OFTString:
				if( pauFields[i].String != NULL )
					UGK_Free( pauFields[i].String );
				break;
			case OFTStringList:
				FreeStrList( pauFields[i].StringList.paList );
				break;
			
			case OFTIntegerList:
			case OFTRealList:
				UGK_Free( pauFields[i].IntegerList.paList );
				break;

			default:
				break;

		}
	}
	UGK_Free( pauFields );
	UGK_Free(m_pszStyleString);

}


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

/**
 * Feature factory.
 *                         
 * 
 * @param poDefn Feature definition defining schema.
 * 
 * @return new feature object with null fields and no geometry.  May be
 * deleted with delete. 
 */

UGKFeature *UGKFeature::CreateFeature( UGKFeatureDefn *poDefn )

{
    return new UGKFeature( poDefn );
}



/************************************************************************/
/*                           DestroyFeature()                           */
/************************************************************************/

/**
 * Destroy feature
 *
 * 
 * @param poFeature the feature to delete.
 */

void UGKFeature::DestroyFeature( UGKFeature *poFeature )

{
    delete poFeature;
}


/************************************************************************/
/*                        SetGeometryDirectly()                         */
/************************************************************************/

/**
 * Set feature geometry.
 *
 * This method updates the features geometry, and operate exactly as
 * SetGeometry(), except that this method assumes ownership of the
 * passed geometry.
 *
 * @param poGeomIn new geometry to apply to feature.
 *
 * @return UGKERR_NONE if successful, or UGK_UNSUPPORTED_GEOMETRY_TYPE if
 * the geometry type is illegal for the UGKFeatureDefn (checking not yet
 * implemented). 
 */ 

UGKErr UGKFeature::SetGeometryDirectly( UGKGeometry * poGeomIn )

{
    if( poGeometry != NULL )
        delete poGeometry;

    poGeometry = poGeomIn;

    // I should be verifying that the geometry matches the defn's type.
    
    return UGKERR_NONE;
}



/************************************************************************/
/*                            SetGeometry()                             */
/************************************************************************/

/**
 * Set feature geometry.
 *
 * This method updates the features geometry, and operate exactly as
 * SetGeometryDirectly(), except that this method does not assume ownership
 * of the passed geometry, but instead makes a copy of it. 
 *
 * @param poGeomIn new geometry to apply to feature.
 *
 * @return UGKERR_NONE if successful, or UGK_UNSUPPORTED_GEOMETRY_TYPE if
 * the geometry type is illegal for the UGKFeatureDefn (checking not yet
 * implemented). 
 */ 

UGKErr UGKFeature::SetGeometry( UGKGeometry * poGeomIn )

{
    if( poGeometry != NULL )
        delete poGeometry;

    if( poGeomIn != NULL )
        poGeometry = poGeomIn->clone();
    else
        poGeometry = NULL;

    // I should be verifying that the geometry matches the defn's type.
    
    return UGKERR_NONE;
}


/************************************************************************/
/*                           StealGeometry()                            */
/************************************************************************/

/**
 * Take away ownership of geometry.
 *
 * Fetch the geometry from this feature, and clear the reference to the
 * geometry on the feature.  This is a mechanism for the application to
 * take over ownship of the geometry from the feature without copying. 
 * Sort of an inverse to SetGeometryDirectly().
 *
 * After this call the UGKFeature will have a NULL geometry.
 *
 * @return the pointer to the geometry.
 */

UGKGeometry *UGKFeature::StealGeometry()

{
    UGKGeometry *poReturn = poGeometry;
    poGeometry = NULL;
    return poReturn;
}


/************************************************************************/
/*                               Clone()                                */
/************************************************************************/

/**
 * Duplicate feature.
 *
 * The newly created feature is owned by the caller, and will have it's own
 * reference to the UGKFeatureDefn.
 *
 * @return new feature, exactly matching this feature.
 */

UGKFeature *UGKFeature::Clone()

{
    UGKFeature  *poNew = new UGKFeature( poDefn );

    poNew->SetGeometry( poGeometry );//设置几何体

    for( int i = 0; i < poDefn->GetFieldCount(); i++ )//设置字段
    {
        poNew->SetField( i, pauFields + i );
    }

    if( GetStyleString() != NULL )   //设置Style名
        poNew->SetStyleString(GetStyleString());

    poNew->SetFID( GetFID() );       //设置ID

    return poNew;
}


/************************************************************************/
/*                             UnsetField()                             */
/************************************************************************/

/**                   清除一个字段    将其标志为未设置
 * Clear a field, marking it as unset.
 *
 * @param iField the field to unset.
 */

void UGKFeature::UnsetField( int iField )

{
    UGKFieldDefn        *poFDefn = poDefn->GetFieldDefn( iField ); //获取指定的字段的定义
                                                                   
    assert( poFDefn != NULL || iField == -1 );
    if( poFDefn == NULL || !IsFieldSet(iField) )
        return;
    
    switch( poFDefn->GetType() )
    {
      case OFTRealList:
      case OFTIntegerList:
        UGK_Free( pauFields[iField].IntegerList.paList );
        break;

      case OFTStringList:
		 FreeStrList( pauFields[iField].StringList.paList );
         break;

      case OFTString:
        UGK_Free( pauFields[iField].String );
        break;

      default:
        break;
    }

    pauFields[iField].Set.nMarker1 = UGKUnsetMarker;
    pauFields[iField].Set.nMarker2 = UGKUnsetMarker;
}



/************************************************************************/
/*                         GetFieldAsInteger()                          */
/*                          获取字段的整数值                            */
/************************************************************************/

/**
 * Fetch field value as integer.
 *
 * OFTString features will be translated using atoi().  OFTReal fields
 * will be cast to integer.   Other field types, or errors will result in
 * a return value of zero.
 *
 * @param iField the field to fetch, from 0 to GetFieldCount()-1.
 *
 * @return the field value.
 */

int UGKFeature::GetFieldAsInteger( int iField )

{
    UGKFieldDefn        *poFDefn = poDefn->GetFieldDefn( iField );
    
    assert( poFDefn != NULL || iField == -1 );
    if( poFDefn == NULL )
        return 0;
    
    if( !IsFieldSet(iField) )
        return 0;
    
    if( poFDefn->GetType() == OFTInteger )
        return pauFields[iField].Integer;
    else if( poFDefn->GetType() == OFTReal )
        return (int) pauFields[iField].Real;
    else if( poFDefn->GetType() == OFTString )
    {
        if( pauFields[iField].String == NULL )
            return 0;
        else
            return atoi(pauFields[iField].String);
    }
    else
        return 0;
}


/************************************************************************/
/*                          GetFieldAsDouble()                          */
/*                           获取字段的双精度值                         */
/************************************************************************/

/**
 * Fetch field value as a double.
 *
 * OFTString features will be translated using atof().  OFTInteger fields
 * will be cast to double.   Other field types, or errors will result in
 * a return value of zero.
 *
 * @param iField the field to fetch, from 0 to GetFieldCount()-1.
 *
 * @return the field value.
 */

double UGKFeature::GetFieldAsDouble( int iField )

{
    UGKFieldDefn        *poFDefn = poDefn->GetFieldDefn( iField );
    
    assert( poFDefn != NULL || iField == -1 );
    if( poFDefn == NULL )
        return 0.0;

    if( !IsFieldSet(iField) )
        return 0.0;
    
    if( poFDefn->GetType() == OFTReal )
        return pauFields[iField].Real;
    else if( poFDefn->GetType() == OFTInteger )
        return pauFields[iField].Integer;
    else if( poFDefn->GetType() == OFTString )
    {
        if( pauFields[iField].String == NULL )
            return 0;
        else
            return atof(pauFields[iField].String);
    }
    else
        return 0.0;
}



/************************************************************************/
/*                          GetFieldAsString()                          */
/************************************************************************/

/**
 * Fetch field value as a string.
 *
 * OFTReal and OFTInteger fields will be translated to string using
 * sprintf(), but not necessarily using the established formatting rules.
 * Other field types, or errors will result in a return value of zero.
 *
 * @param iField the field to fetch, from 0 to GetFieldCount()-1.
 *
 * @return the field value.  This string is internal, and should not be
 * modified, or freed.  It's lifetime may be very brief. 
 */

const char *UGKFeature::GetFieldAsString( int iField )

{
    UGKFieldDefn        *poFDefn = poDefn->GetFieldDefn( iField );
    static char         szTempBuffer[80];

    assert( poFDefn != NULL || iField == -1 );
    if( poFDefn == NULL )
        return "";
    
    if( !IsFieldSet(iField) )
        return "";
    
    if( poFDefn->GetType() == OFTString )
    {
        if( pauFields[iField].String == NULL )
            return "";
        else
            return pauFields[iField].String;
    }
    else if( poFDefn->GetType() == OFTInteger )
    {
        sprintf( szTempBuffer, "%d", pauFields[iField].Integer );
        return szTempBuffer;
    }
    else if( poFDefn->GetType() == OFTReal )
    {
        char    szFormat[64];

        if( poFDefn->GetWidth() != 0 )
        {
            sprintf( szFormat, "%%%d.%df",
                     poFDefn->GetWidth(), poFDefn->GetPrecision() );
        }
        else
            strcpy( szFormat, "%.16g" );
        
        sprintf( szTempBuffer, szFormat, pauFields[iField].Real );