SheetRefEvaluator CreateExternSheetRefEvaluator(int externSheetIndex)
        {
            ExternalSheet     externalSheet = _workbook.GetExternalSheet(externSheetIndex);
            WorkbookEvaluator targetEvaluator;
            int otherSheetIndex;

            if (externalSheet == null)
            {
                // sheet is in same workbook
                otherSheetIndex = _workbook.ConvertFromExternSheetIndex(externSheetIndex);
                targetEvaluator = _bookEvaluator;
            }
            else
            {
                // look up sheet by name from external workbook
                String workbookName = externalSheet.GetWorkbookName();
                try
                {
                    targetEvaluator = _bookEvaluator.GetOtherWorkbookEvaluator(workbookName);
                }
                catch (WorkbookNotFoundException)
                {
                    throw;
                }
                otherSheetIndex = targetEvaluator.GetSheetIndex(externalSheet.GetSheetName());
                if (otherSheetIndex < 0)
                {
                    throw new Exception("Invalid sheet name '" + externalSheet.GetSheetName()
                                        + "' in bool '" + workbookName + "'.");
                }
            }
            return(new SheetRefEvaluator(targetEvaluator, _tracker, otherSheetIndex));
        }
        public ValueEval GetNameXEval(NameXPtg nameXPtg)
        {
            ExternalSheet externSheet = _workbook.GetExternalSheet(nameXPtg.SheetRefIndex);

            if (externSheet == null)
            {
                return(new NameXEval(nameXPtg));
            }
            String       workbookName = externSheet.GetWorkbookName();
            ExternalName externName   = _workbook.GetExternalName(
                nameXPtg.SheetRefIndex,
                nameXPtg.NameIndex
                );

            try
            {
                WorkbookEvaluator refWorkbookEvaluator = _bookEvaluator.GetOtherWorkbookEvaluator(workbookName);
                IEvaluationName   evaluationName       = refWorkbookEvaluator.GetName(externName.Name, externName.Ix - 1);
                if (evaluationName != null && evaluationName.HasFormula)
                {
                    if (evaluationName.NameDefinition.Length > 1)
                    {
                        throw new Exception("Complex name formulas not supported yet");
                    }
                    Ptg ptg = evaluationName.NameDefinition[0];
                    if (ptg is Ref3DPtg)
                    {
                        Ref3DPtg          ref3D      = (Ref3DPtg)ptg;
                        int               sheetIndex = refWorkbookEvaluator.GetSheetIndexByExternIndex(ref3D.ExternSheetIndex);
                        String            sheetName  = refWorkbookEvaluator.GetSheetName(sheetIndex);
                        SheetRefEvaluator sre        = CreateExternSheetRefEvaluator(workbookName, sheetName);
                        return(new LazyRefEval(ref3D.Row, ref3D.Column, sre));
                    }
                    else if (ptg is Area3DPtg)
                    {
                        Area3DPtg         area3D     = (Area3DPtg)ptg;
                        int               sheetIndex = refWorkbookEvaluator.GetSheetIndexByExternIndex(area3D.ExternSheetIndex);
                        String            sheetName  = refWorkbookEvaluator.GetSheetName(sheetIndex);
                        SheetRefEvaluator sre        = CreateExternSheetRefEvaluator(workbookName, sheetName);
                        return(new LazyAreaEval(area3D.FirstRow, area3D.FirstColumn, area3D.LastRow, area3D.LastColumn, sre));
                    }
                }
                return(ErrorEval.REF_INVALID);
            }
            catch (WorkbookNotFoundException)
            {
                return(ErrorEval.REF_INVALID);
            }
        }