ogrfeaturestyle.cpp

用于读取TAB、MIF、SHP文件的类

            CSLDestroy( papszToken );
            CSLDestroy( papszToken2 );
            return FALSE;
        }
        break;
      case OGRSTCSymbol:
        if (!EQUAL(papszToken[0],"SYMBOL"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, 
                     "Error in the Type of StyleTool %s should be a SYMBOL Type\n",
                     papszToken[0]);
            CSLDestroy( papszToken );
            CSLDestroy( papszToken2 );
            return FALSE;
        }
        break;
      case OGRSTCLabel:
        if (!EQUAL(papszToken[0],"LABEL"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, 
                     "Error in the Type of StyleTool %s should be a LABEL Type\n",
                     papszToken[0]);
            CSLDestroy( papszToken );
            CSLDestroy( papszToken2 );
            return FALSE;
        }
        break;
      case OGRSTCVector:
        if (!EQUAL(papszToken[0],"VECTOR"))
        {
            CPLError(CE_Failure, CPLE_AppDefined, 
                     "Error in the Type of StyleTool %s should be a VECTOR Type\n",
                     papszToken[0]);
            CSLDestroy( papszToken );
            CSLDestroy( papszToken2 );
            return FALSE;
        }
        break;
      default:
        CPLError(CE_Failure, CPLE_AppDefined, 
                 "Error in the Type of StyleTool, Type undetermined\n");
        CSLDestroy( papszToken );
        CSLDestroy( papszToken2 );
        return FALSE;
        break;
    }
    
    ////////////////////////////////////////////////////////////////////////
    // Here we will loop on each element in the StyleString. If it's 
    // a valid element, we will add it in the StyleTool with 
    // SetParamStr().
    //
    // It's important to note that the SetInternalUnit...() is use to update 
    // the unit of the StyleTool param (m_eUnit). 
    // See OGRStyleTool::SetParamStr().
    // There's a StyleTool unit (m_eUnit), which is the output unit, and each 
    // parameter of the style have its own unit value (the input unit). Here we
    // set m_eUnit to the input unit and in SetParamStr(), we will use this
    // value to set the input unit. Then after the loop we will reset m_eUnit 
    // to it's original value. (Yes it's a side effect / black magic)
    //
    // The pasStyle variable is a global variable passed in argument to the
    // function. See at the top of this file the four OGRStyleParamId 
    // variable. They are used to register the valid parameter of each 
    // StyleTool.
    ////////////////////////////////////////////////////////////////////////

    // Save Scale and output Units because the parsing code will alter 
    // the values
    eLastUnit = m_eUnit;
    double  dSavedScale = m_dfScale;
    int     i, nElements = CSLCount(papszToken2);

    for ( i = 0; i < nElements; i++ )
    {
        char    **papszStylePair =
            CSLTokenizeString2( papszToken2[i], ":", CSLT_HONOURSTRINGS );
        int     j, nTokens = CSLCount(papszStylePair);

        if ( nTokens < 1 || nTokens > 2 )
        {
            CPLError( CE_Warning, CPLE_AppDefined,
                      "Error in the StyleTool String %s", m_pszStyleString );
            CPLError( CE_Warning, CPLE_AppDefined,
                      "Malformed element #%d (\"%s\") skipped",
                      i, papszToken2[i] );
            CSLDestroy(papszStylePair);
            continue;
        }
        
        for ( j = 0; j < nCount; j++ )
        {
            if ( EQUAL(pasStyle[j].pszToken, papszStylePair[0]) )
            {
                if (nTokens == 2 && pasStyle[j].bGeoref == TRUE)
                    SetInternalInputUnitFromParam(papszStylePair[1]);

                // Set either the actual value of style parameter or "1"
                // for boolean parameters which do not have values.
                // "1" means that boolean parameter is present in the style
                // string.
                OGRStyleTool::SetParamStr( pasStyle[j], pasValue[j],
                                    (nTokens == 2) ? papszStylePair[1] : "1" );

                break;
            }
        }

        CSLDestroy( papszStylePair );
    }

    m_eUnit = eLastUnit;
    m_dfScale = dSavedScale;

    CSLDestroy(papszToken2);
    CSLDestroy(papszToken);

    return TRUE;
}

/************************************************************************/
/*                   SetInternalInputUnitFromParam()                    */
/************************************************************************/

void OGRStyleTool::SetInternalInputUnitFromParam(char *pszString)
{

    char *pszUnit;

    if (pszString == NULL)
      return;
    pszUnit = strstr(pszString,"g");
    if (pszUnit)
    {
        SetUnit(OGRSTUGround);
        pszUnit[0]= '\0';
        return;
    }
    pszUnit = strstr(pszString,"px");
    if (pszUnit)
    {
        SetUnit(OGRSTUPixel);
        pszUnit[0]= '\0';
        return;
    }
    pszUnit = strstr(pszString,"pt");
    if (pszUnit)
    {
        SetUnit(OGRSTUPoints);
        pszUnit[0]= '\0';
        return;
    }
    pszUnit = strstr(pszString,"mm");
    if (pszUnit)
    {
        SetUnit(OGRSTUMM);
        pszUnit[0]= '\0';
        return;
    }
    pszUnit = strstr(pszString,"cm");
    if (pszUnit)
    {
        SetUnit(OGRSTUCM);
        pszUnit[0]= '\0';
        return;
    }
    pszUnit = strstr(pszString,"in");
    if (pszUnit)
    {
        SetUnit(OGRSTUInches);
        pszUnit[0]= '\0';
        return;
    }
    
    SetUnit(OGRSTUMM);
}

/************************************************************************/
/*                          ComputeWithUnit()                           */
/************************************************************************/
double OGRStyleTool::ComputeWithUnit(double dfValue, OGRSTUnitId eInputUnit)
{
    OGRSTUnitId eOutputUnit = GetUnit();

    double dfNewValue = dfValue;        // dfValue in  Meter;


    if (eOutputUnit == eInputUnit)
      return dfValue;

    switch (eInputUnit)
    {
      case OGRSTUGround:
        dfNewValue = dfValue / m_dfScale;
        break;
      case OGRSTUPixel:
        dfNewValue = dfValue / (72.0 * 39.37);
        break;
      case OGRSTUPoints:
        dfNewValue =dfValue / (72.0 * 39.37);
        break;
      case OGRSTUMM:
        dfNewValue = 0.001 * dfValue;
        break;
      case OGRSTUCM:
        dfNewValue = 0.01 * dfValue;
        break;
      case OGRSTUInches:
        dfNewValue = dfValue / 39.37;
        break;
      default:
        break;    //imp
    }

    switch (eOutputUnit)
    {
      case OGRSTUGround:
        dfNewValue *= m_dfScale;
        break;
      case OGRSTUPixel:
        dfNewValue *= (72.0 * 39.37);
        break;
      case OGRSTUPoints:
        dfNewValue *= (72.0 * 39.37);
        break;
      case OGRSTUMM:
        dfNewValue *= 1000.0;
        break;
      case OGRSTUCM:
        dfNewValue *= 100.0;
        break;
      case OGRSTUInches:
        dfNewValue *= 39.37;
        break;
      default:
        break;  // imp
    }
    return dfNewValue;
}

/************************************************************************/
/*                          ComputeWithUnit()                           */
/************************************************************************/
int   OGRStyleTool::ComputeWithUnit(int nValue, OGRSTUnitId eUnit)
{
    return (int) ComputeWithUnit((double )nValue, eUnit);
}

/************************************************************************/
/*                            GetParamStr()                             */
/************************************************************************/
const char *OGRStyleTool::GetParamStr(OGRStyleParamId &sStyleParam ,
                                      OGRStyleValue &sStyleValue,
                                      GBool &bValueIsNull)
{

    if (!Parse())
    {
        bValueIsNull = TRUE;
        return NULL;
    }

    bValueIsNull = !sStyleValue.bValid;
    
    if (bValueIsNull == TRUE)
      return NULL;

    switch (sStyleParam.eType)
    {
      
        // if sStyleParam.bGeoref == TRUE , need to convert to output value;
      case OGRSTypeString:
        return sStyleValue.pszValue;
      case OGRSTypeDouble:
        if (sStyleParam.bGeoref)
          return CPLSPrintf("%f",ComputeWithUnit(sStyleValue.dfValue,
                                                 sStyleValue.eUnit));
        else
          return CPLSPrintf("%f",sStyleValue.dfValue);
                            
      case OGRSTypeInteger:
        if (sStyleParam.bGeoref)
          return CPLSPrintf("%d",ComputeWithUnit(sStyleValue.nValue,
                                                 sStyleValue.eUnit));
        else
          return CPLSPrintf("%d",sStyleValue.nValue);
      case OGRSTypeBoolean:
        return CPLSPrintf("%d",sStyleValue.nValue);
      default:
        bValueIsNull = TRUE;
        return NULL;
    }
}

/****************************************************************************/
/*    int OGRStyleTool::GetParamNum(OGRStyleParamId sStyleParam ,           */
/*                               OGRStyleValue sStyleValue,                 */
/*                               GBool &bValueIsNull)                       */
/*                                                                          */
/****************************************************************************/
int OGRStyleTool::GetParamNum(OGRStyleParamId &sStyleParam ,
                                 OGRStyleValue &sStyleValue,
                                 GBool &bValueIsNull)
{
    return (int)GetParamDbl(sStyleParam,sStyleValue,bValueIsNull);
}

/****************************************************************************/
/*       double OGRStyleTool::GetParamDbl(OGRStyleParamId sStyleParam ,     */
/*                               OGRStyleValue sStyleValue,                 */
/*                               GBool &bValueIsNull)                       */
/*                                                                          */
/****************************************************************************/
double OGRStyleTool::GetParamDbl(OGRStyleParamId &sStyleParam ,
                                 OGRStyleValue &sStyleValue,
                                 GBool &bValueIsNull)
{
    if (!Parse())
    {
        bValueIsNull = TRUE;
        return 0;
    }

    bValueIsNull = !sStyleValue.bValid;
    
    if (bValueIsNull == TRUE)
      return 0;

    switch (sStyleParam.eType)
    {
      
        // if sStyleParam.bGeoref == TRUE , need to convert to output value;
      case OGRSTypeString:
        if (sStyleParam.bGeoref)
          return ComputeWithUnit(atof(sStyleValue.pszValue),
                                 sStyleValue.eUnit);
        else
          return atof(sStyleValue.pszValue);
      case OGRSTypeDouble:
        if (sStyleParam.bGeoref)
          return ComputeWithUnit(sStyleValue.dfValue,
                                      sStyleValue.eUnit);
        else
          return sStyleValue.dfValue;
      case OGRSTypeInteger:
        if (sStyleParam.bGeoref)
          return (double)ComputeWithUnit(sStyleValue.nValue,
                                         sStyleValue.eUnit);
        else    
          return (double)sStyleValue.nValue;
      case OGRSTypeBoolean: