table_calculator.cpp

这是一个GPS相关的程序

/*******************************************************************************
    TableCalculator.cpp
    Copyright (C) Victor Olaya

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*******************************************************************************/
#include "Table_Calculator.h"

CTableCalculator::CTableCalculator(void){

	CSG_Parameter	*pNode_0;

	Parameters.Set_Name(_TL("Table calculator"));

	Parameters.Set_Description(_TW("Calculation of new values in tables."));

	pNode_0	= Parameters.Add_Table(	NULL,
									"TABLE",
									_TL("Table"),
									_TL(""),
									PARAMETER_INPUT);

	Parameters.Add_String(NULL, "FORMULA", _TL("Formula"), _TL(""), SG_T("a+b"));
	
	Parameters.Add_String(NULL, "NAME", _TL("Field Name"), _TL(""), SG_T("a+b"));

}//constructor


CTableCalculator::~CTableCalculator(void){}

bool CTableCalculator::On_Execute(void){

	int iFields;
	int i,j;	
	double dValue;
	double *pFieldValues;
	CSG_Table *pTable;
	CSG_Table_Record *pRecord;
	const SG_Char *pFormula;
	CSG_Formula Formula;

	pTable	= Parameters("TABLE")->asTable();
	iFields = pTable->Get_Field_Count();

	pTable->Add_Field(Parameters("NAME")->asString(), TABLE_FIELDTYPE_Double);

	pFormula = Parameters("FORMULA")->asString();

	Formula.Set_Formula(pFormula);
		
	int Pos;
	const SG_Char * Msg;
	if (Formula.Get_Error(&Pos, &Msg)){
		CSG_String msg;
		msg.Printf(_TL("Syntax error at position #%d: \n%s\n"), Pos, pFormula);
		
		Message_Add(msg);
		
		msg.Printf(SG_T("\n%s\n"), Msg);
		
		Message_Add(msg);
		
		return false;
	}//if
		
	pFieldValues= new double[iFields];

	for (i = 0; i < pTable->Get_Record_Count(); i++){
				
		pRecord = pTable->Get_Record(i);

		for (j = 0; j < iFields; j++){
			pFieldValues[j] = pRecord->asDouble(j);
		}//for
		
		dValue = Formula.Val(pFieldValues, iFields);	

		pRecord->Set_Value(iFields, dValue);
		
	}//for

	delete[] pFieldValues;	
	return (true);

	DataObject_Update(pTable, true);

}//method