mitab_miffile.cpp

mitab,读取MapInfo的地图文件

   
    m_bBoundsSet = FALSE;

    return 0;
}

/**********************************************************************
 *                   MIFFile::GetNextFeatureId()
 *
 * Returns feature id that follows nPrevId, or -1 if it is the
 * last feature id.  Pass nPrevId=-1 to fetch the first valid feature id.
 **********************************************************************/
int MIFFile::GetNextFeatureId(int nPrevId)
{
    if (m_eAccessMode != TABRead)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "GetNextFeatureId() can be used only with Read access.");
        return -1;
    }

    if (nPrevId <= 0 && m_poMIFFile->GetLastLine() != NULL)
        return 1;       // Feature Ids start at 1
    else if (nPrevId > 0 && m_poMIFFile->GetLastLine() != NULL)
        return nPrevId + 1;
    else
        return -1;

    return 0;
}

/**********************************************************************
 *                   MIFFile::GotoFeature()
 *
 * Private method to move MIF and MID pointers ready to read specified 
 * feature.  Note that Feature Ids start at 1.
 *
 * Returns 0 on success, -1 on error (likely request for invalid feature id)
 **********************************************************************/
int MIFFile::GotoFeature(int nFeatureId)
{

    if (nFeatureId < 1)
      return -1;

    if (nFeatureId == m_nPreloadedId) // CorrectPosition
    {
        return 0;
    }
    else
    {
        if (nFeatureId < m_nCurFeatureId || m_nCurFeatureId == 0)
            ResetReading();

        while(m_nPreloadedId < nFeatureId)
        {
            if (NextFeature() == FALSE)
              return -1;
        }

        CPLAssert(m_nPreloadedId == nFeatureId);

        return 0;
    }
}

/**********************************************************************
 *                   MIFFile::NextFeature()
 **********************************************************************/

GBool MIFFile::NextFeature()
{
    const char *pszLine;
    while ((pszLine = m_poMIFFile->GetLine()) != NULL)
    {
        if (m_poMIFFile->IsValidFeature(pszLine))
        {
            m_poMIDFile->GetLine();
            m_nPreloadedId++;
            return TRUE;
        }
    }
    return FALSE;
}

/**********************************************************************
 *                   MIFFile::GetFeatureRef()
 *
 * Fill and return a TABFeature object for the specified feature id.
 *
 * The retruned pointer is a reference to an object owned and maintained
 * by this MIFFile object.  It should not be altered or freed by the 
 * caller and its contents is guaranteed to be valid only until the next
 * call to GetFeatureRef() or Close().
 *
 * Returns NULL if the specified feature id does not exist of if an
 * error happened.  In any case, CPLError() will have been called to
 * report the reason of the failure.
 **********************************************************************/
TABFeature *MIFFile::GetFeatureRef(int nFeatureId)
{
    const char *pszLine;

    if (m_eAccessMode != TABRead)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "GetFeatureRef() can be used only with Read access.");
        return NULL;
    }
    
    /*-----------------------------------------------------------------
     * Make sure file is opened and Validate feature id by positioning
     * the read pointers for the .MAP and .DAT files to this feature id.
     *----------------------------------------------------------------*/
    if (m_poMIDFile == NULL)
    {
        CPLError(CE_Failure, CPLE_IllegalArg,
                 "GetFeatureRef() failed: file is not opened!");
        return NULL;
    }

    if (GotoFeature(nFeatureId)!= 0 )
    {
        CPLError(CE_Failure, CPLE_IllegalArg,
                 "GetFeatureRef() failed: invalid feature id %d", 
                 nFeatureId);
        return NULL;
    }


    /*-----------------------------------------------------------------
     * Create new feature object of the right type
     *----------------------------------------------------------------*/
    if ((pszLine = m_poMIFFile->GetLastLine()) != NULL)
    {
        // Delete previous feature... we'll start we a clean one.
        if (m_poCurFeature)
            delete m_poCurFeature;
        m_poCurFeature = NULL;

        m_nCurFeatureId = m_nPreloadedId;

        if (EQUALN(pszLine,"NONE",4))
        {
            m_poCurFeature = new TABFeature(m_poDefn);
        }
        else if (EQUALN(pszLine,"POINT",5))
        {
            // Special case, we need to know two lines to decide the type
            char **papszToken;
            papszToken = CSLTokenizeString(pszLine);
            
            if (CSLCount(papszToken) !=3)
            {
                CSLDestroy(papszToken);
                CPLError(CE_Failure, CPLE_NotSupported,
                         "GetFeatureRef() failed: invalid point line: '%s'",
                         pszLine);
                return NULL;
            }
            
            m_poMIFFile->SaveLine(pszLine);

            if ((pszLine = m_poMIFFile->GetLine()) != NULL)
            {
                CSLDestroy(papszToken);
                papszToken = CSLTokenizeStringComplex(pszLine," ,()\t",
                                                      TRUE,FALSE);
                if (CSLCount(papszToken)> 0 &&EQUALN(papszToken[0],"SYMBOL",6))
                {
                    switch (CSLCount(papszToken))
                    {
                      case 4:
                        m_poCurFeature = new TABPoint(m_poDefn);
                        break;
                      case 7:
                        m_poCurFeature = new TABFontPoint(m_poDefn);
                        break;
                      case 5:
                        m_poCurFeature = new TABCustomPoint(m_poDefn);
                        break;
                      default:
                        CSLDestroy(papszToken);
                        CPLError(CE_Failure, CPLE_NotSupported,
                                 "GetFeatureRef() failed: invalid symbol "
                                 "line: '%s'", pszLine);
                        return NULL;
                        break;
                    }

                }
            }
            CSLDestroy(papszToken);

            if (m_poCurFeature == NULL)
            {
                // No symbol clause... default to TABPoint
                m_poCurFeature = new TABPoint(m_poDefn);
            }
        }
        else if (EQUALN(pszLine,"LINE",4) ||
                 EQUALN(pszLine,"PLINE",5))
        {
            m_poCurFeature = new TABPolyline(m_poDefn);
        }
        else if (EQUALN(pszLine,"REGION",6))
        {
            m_poCurFeature = new TABRegion(m_poDefn);
        }  
        else if (EQUALN(pszLine,"ARC",3))
        { 
            m_poCurFeature = new TABArc(m_poDefn);
        }
        else if (EQUALN(pszLine,"TEXT",4))
        {
            m_poCurFeature = new TABText(m_poDefn);
        }
        else if (EQUALN(pszLine,"RECT",4) ||
                 EQUALN(pszLine,"ROUNDRECT",9))
        {
            m_poCurFeature = new TABRectangle(m_poDefn);
        }
        else if (EQUALN(pszLine,"ELLIPSE",7))
        {
            m_poCurFeature = new TABEllipse(m_poDefn);       
        }
        else if (EQUALN(pszLine,"MULTIPOINT",10))
        {
            m_poCurFeature = new TABMultiPoint(m_poDefn);       
        }
        else if (EQUALN(pszLine,"COLLECTION",10))
        {
            m_poCurFeature = new TABCollection(m_poDefn);       
        }
        else
        {
            if (!EQUAL(pszLine,""))
               CPLError(CE_Failure, CPLE_NotSupported,
                   "Error during reading, unknown type %s.",
                     pszLine);
        
            //m_poCurFeature = new TABDebugFeature(m_poDefn);
            return NULL;
        }
    }

    CPLAssert(m_poCurFeature);
    if (m_poCurFeature == NULL)
        return NULL;

   /*-----------------------------------------------------------------
     * Read fields from the .DAT file
     * GetRecordBlock() has already been called above...
     *----------------------------------------------------------------*/
    if (m_poCurFeature->ReadRecordFromMIDFile(m_poMIDFile) != 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Error during reading Record.");
        
        delete m_poCurFeature;
        m_poCurFeature = NULL;
        return NULL;
    }
    
    /*-----------------------------------------------------------------
     * Read geometry from the .MAP file
     * MoveToObjId() has already been called above...
     *----------------------------------------------------------------*/
    if (m_poCurFeature->ReadGeometryFromMIFFile(m_poMIFFile) != 0)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "Error during reading Geometry.");
        
        delete m_poCurFeature;
        m_poCurFeature = NULL;
        return NULL;
    }

    /*---------------------------------------------------------------------
     * The act of reading the geometry causes the first line of the    
     * next object to be preloaded.  Set the preloaded id appropriately.
     *--------------------------------------------------------------------- */
    if( m_poMIFFile->GetLastLine() != NULL )
        m_nPreloadedId++;
    else
        m_nPreloadedId = 0;
   
    /* Update the Current Feature ID */
    m_poCurFeature->SetFID(m_nCurFeatureId);

    return m_poCurFeature;
}

/**********************************************************************
 *                   MIFFile::SetFeature()
 *
 * Write a feature to this dataset.  
 *
 * For now only sequential writes are supported (i.e. with nFeatureId=-1)
 * but eventually we should be able to do random access by specifying
 * a value through nFeatureId.
 *
 * Returns the new featureId (> 0) on success, or -1 if an
 * error happened in which case, CPLError() will have been called to
 * report the reason of the failure.
 **********************************************************************/
int MIFFile::SetFeature(TABFeature *poFeature, int nFeatureId /*=-1*/)
{
    
    if (m_eAccessMode != TABWrite)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetFeature() can be used only with Write access.");
        return -1;
    }

    if (nFeatureId != -1)
    {
        CPLError(CE_Failure, CPLE_NotSupported,
                 "SetFeature(): random access not implemented yet.");
        return -1;
    }

    /*-----------------------------------------------------------------
     * Make sure file is opened and establish new feature id.
     *----------------------------------------------------------------*/
    if (m_poMIDFile == NULL)
    {
        CPLError(CE_Failure, CPLE_IllegalArg,
                 "SetFeature() failed: file is not opened!");
        return -1;
    }

    if (m_bHeaderWrote == FALSE)
    {
        /*-------------------------------------------------------------
         * OK, this is the first feature in the dataset... make sure the
         * .MID schema has been initialized.
         *------------------------------------------------------------*/
        if (m_poDefn == NULL)
            SetFeatureDefn(poFeature->GetDefnRef(), NULL);

         WriteMIFHeader();     
         nFeatureId = 1;
    }
    else
    {
        nFeatureId = ++ m_nWriteFeatureId;
    }


    /*-----------------------------------------------------------------
     * Write geometry to the .Mif file
     *----------------------------------------------------------------*/
    if (m_poMIFFile == NULL ||
        poFeature->WriteGeometryToMIFFile(m_poMIFFile) != 0)
    {
        CPLError(CE_Failure, CPLE_FileIO,
                 "Failed writing geometry for feature id %d in %s",
                 nFeatureId, m_pszFname);
        return -1;
    }

    if (m_poMIDFile == NULL ||
        poFeature->WriteRecordToMIDFile(m_poMIDFile) != 0 )
    {
        CPLError(CE_Failure, CPLE_FileIO,
                 "Failed writing attributes for feature id %d in %s",
                 nFeatureId, m_pszFname);
        return -1;
    }

   
    return nFeatureId; 
}



/**********************************************************************