Update the formula evaluator to support XSSF style external named ranges too

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1612133 13f79535-47bb-0310-9956-ffa450edef68

9 files changed, 238 insertions, 75 deletions

diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java b/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
index 199f7ca3c3..748b42a43d 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFEvaluationWorkbook.java
@@ -146,6 +146,10 @@ public final class HSSFEvaluationWorkbook implements FormulaRenderingWorkbook, E
         return _iBook.getExternalName(externSheetIndex, externNameIndex);
     }
 
+    public ExternalName getExternalName(String nameName, String sheetName, int externalWorkbookNumber) {
+        throw new IllegalStateException("XSSF-style external names are not supported for HSSF");
+    }
+
     public String resolveNameXText(NameXPtg n) {
         return _iBook.resolveNameXText(n.getSheetRefIndex(), n.getNameIndex());
     }
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFSheet.java b/src/java/org/apache/poi/hssf/usermodel/HSSFSheet.java
index 170c015ac5..ff33868c57 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFSheet.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFSheet.java
@@ -1504,8 +1504,10 @@ public final class HSSFSheet implements org.apache.poi.ss.usermodel.Sheet {
         // Update any formulas on this sheet that point to
         //  rows which have been moved
         int sheetIndex = _workbook.getSheetIndex(this);
+        String sheetName = _workbook.getSheetName(sheetIndex);
         short externSheetIndex = _book.checkExternSheet(sheetIndex);
-        FormulaShifter shifter = FormulaShifter.createForRowShift(externSheetIndex, startRow, endRow, n);
+        FormulaShifter shifter = FormulaShifter.createForRowShift(
+                         externSheetIndex, sheetName, startRow, endRow, n);
         _sheet.updateFormulasAfterCellShift(shifter, externSheetIndex);
 
         int nSheets = _workbook.getNumberOfSheets();
diff --git a/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java b/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
index f91dacf0de..855ae5929c 100644
--- a/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
+++ b/src/java/org/apache/poi/ss/formula/EvaluationWorkbook.java
@@ -59,7 +59,15 @@ public interface EvaluationWorkbook {
      */
     int convertFromExternSheetIndex(int externSheetIndex);
 
+    /**
+     * HSSF Only - fetch the external-style name details
+     */
     ExternalName getExternalName(int externSheetIndex, int externNameIndex);
+    /**
+     * XSSF Only - fetch the external-style name details
+     */
+    ExternalName getExternalName(String nameName, String sheetName, int externalWorkbookNumber);
+    
     EvaluationName getName(NamePtg namePtg);
     EvaluationName getName(String name, int sheetIndex);
     String resolveNameXText(NameXPtg ptg);
diff --git a/src/java/org/apache/poi/ss/formula/FormulaShifter.java b/src/java/org/apache/poi/ss/formula/FormulaShifter.java
index 74804a8845..9439000d23 100644
--- a/src/java/org/apache/poi/ss/formula/FormulaShifter.java
+++ b/src/java/org/apache/poi/ss/formula/FormulaShifter.java
@@ -17,11 +17,25 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.ss.formula.ptg.*;
+import org.apache.poi.ss.formula.ptg.Area2DPtgBase;
+import org.apache.poi.ss.formula.ptg.Area3DPtg;
+import org.apache.poi.ss.formula.ptg.Area3DPxg;
+import org.apache.poi.ss.formula.ptg.AreaErrPtg;
+import org.apache.poi.ss.formula.ptg.AreaPtg;
+import org.apache.poi.ss.formula.ptg.AreaPtgBase;
+import org.apache.poi.ss.formula.ptg.Deleted3DPxg;
+import org.apache.poi.ss.formula.ptg.DeletedArea3DPtg;
+import org.apache.poi.ss.formula.ptg.DeletedRef3DPtg;
+import org.apache.poi.ss.formula.ptg.Ptg;
+import org.apache.poi.ss.formula.ptg.Ref3DPtg;
+import org.apache.poi.ss.formula.ptg.Ref3DPxg;
+import org.apache.poi.ss.formula.ptg.RefErrorPtg;
+import org.apache.poi.ss.formula.ptg.RefPtg;
+import org.apache.poi.ss.formula.ptg.RefPtgBase;
 
 
 /**
- * @author Josh Micich
+ * Updates Formulas as rows or sheets are shifted
  */
 public final class FormulaShifter {
 
@@ -31,9 +45,16 @@ public final class FormulaShifter {
     }
 
 	/**
-	 * Extern sheet index of sheet where moving is occurring
+	 * Extern sheet index of sheet where moving is occurring,
+	 *  used for updating HSSF style 3D references
 	 */
 	private final int _externSheetIndex;
+	/**
+	 * Sheet name of the sheet where moving is occurring, 
+	 *  used for updating XSSF style 3D references on row shifts.
+	 */
+	private final String _sheetName;
+	
 	private final int _firstMovedIndex;
 	private final int _lastMovedIndex;
 	private final int _amountToMove;
@@ -48,7 +69,7 @@ public final class FormulaShifter {
      *
      * For example, this will be called on {@link org.apache.poi.hssf.usermodel.HSSFSheet#shiftRows(int, int, int)} }
      */
-	private FormulaShifter(int externSheetIndex, int firstMovedIndex, int lastMovedIndex, int amountToMove) {
+	private FormulaShifter(int externSheetIndex, String sheetName, int firstMovedIndex, int lastMovedIndex, int amountToMove) {
 		if (amountToMove == 0) {
 			throw new IllegalArgumentException("amountToMove must not be zero");
 		}
@@ -56,6 +77,7 @@ public final class FormulaShifter {
 			throw new IllegalArgumentException("firstMovedIndex, lastMovedIndex out of order");
 		}
 		_externSheetIndex = externSheetIndex;
+		_sheetName = sheetName;
 		_firstMovedIndex = firstMovedIndex;
 		_lastMovedIndex = lastMovedIndex;
 		_amountToMove = amountToMove;
@@ -71,14 +93,15 @@ public final class FormulaShifter {
      */
     private FormulaShifter(int srcSheetIndex, int dstSheetIndex) {
         _externSheetIndex = _firstMovedIndex = _lastMovedIndex = _amountToMove = -1;
+        _sheetName = null;
 
         _srcSheetIndex = srcSheetIndex;
         _dstSheetIndex = dstSheetIndex;
         _mode = ShiftMode.Sheet;
     }
 
-	public static FormulaShifter createForRowShift(int externSheetIndex, int firstMovedRowIndex, int lastMovedRowIndex, int numberOfRowsToMove) {
-		return new FormulaShifter(externSheetIndex, firstMovedRowIndex, lastMovedRowIndex, numberOfRowsToMove);
+	public static FormulaShifter createForRowShift(int externSheetIndex, String sheetName, int firstMovedRowIndex, int lastMovedRowIndex, int numberOfRowsToMove) {
+		return new FormulaShifter(externSheetIndex, sheetName, firstMovedRowIndex, lastMovedRowIndex, numberOfRowsToMove);
 	}
 
     public static FormulaShifter createForSheetShift(int srcSheetIndex, int dstSheetIndex) {
@@ -145,6 +168,14 @@ public final class FormulaShifter {
 			}
 			return rowMoveRefPtg(rptg);
 		}
+		if(ptg instanceof Ref3DPxg) {
+		    Ref3DPxg rpxg = (Ref3DPxg)ptg;
+		    if (rpxg.getExternalWorkbookNumber() > 0 ||
+		           ! _sheetName.equals(rpxg.getSheetName())) {
+                // only move 3D refs that refer to the sheet with cells being moved
+		    }
+            return rowMoveRefPtg(rpxg);
+		}
 		if(ptg instanceof Area2DPtgBase) {
 			if (currentExternSheetIx != _externSheetIndex) {
 				// local refs on other sheets are unaffected
@@ -161,6 +192,15 @@ public final class FormulaShifter {
 			}
 			return rowMoveAreaPtg(aptg);
 		}
+        if(ptg instanceof Area3DPxg) {
+            Area3DPxg apxg = (Area3DPxg)ptg;
+            if (apxg.getExternalWorkbookNumber() > 0 ||
+                    ! _sheetName.equals(apxg.getSheetName())) {
+                // only move 3D refs that refer to the sheet with cells being moved
+                return null;
+            }
+            return rowMoveAreaPtg(apxg);
+        }
 		return null;
 	}
 
@@ -348,6 +388,14 @@ public final class FormulaShifter {
 			Area3DPtg area3DPtg = (Area3DPtg) ptg;
 			return new DeletedArea3DPtg(area3DPtg.getExternSheetIndex());
 		}
+        if (ptg instanceof Ref3DPxg) {
+            Ref3DPxg pxg = (Ref3DPxg)ptg;
+            return new Deleted3DPxg(pxg.getExternalWorkbookNumber(), pxg.getSheetName());
+        }
+        if (ptg instanceof Area3DPxg) {
+            Area3DPxg pxg = (Area3DPxg)ptg;
+            return new Deleted3DPxg(pxg.getExternalWorkbookNumber(), pxg.getSheetName());
+        }
 
 		throw new IllegalArgumentException("Unexpected ref ptg class (" + ptg.getClass().getName() + ")");
 	}
diff --git a/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java b/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
index 4a7ac7a8ef..ab87208227 100644
--- a/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
+++ b/src/java/org/apache/poi/ss/formula/OperationEvaluationContext.java
@@ -23,7 +23,8 @@ import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalName;
 import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalSheet;
 import org.apache.poi.ss.formula.eval.AreaEval;
 import org.apache.poi.ss.formula.eval.ErrorEval;
-import org.apache.poi.ss.formula.eval.NameXEval;
+import org.apache.poi.ss.formula.eval.ExternalNameEval;
+import org.apache.poi.ss.formula.eval.FunctionNameEval;
 import org.apache.poi.ss.formula.eval.RefEval;
 import org.apache.poi.ss.formula.eval.ValueEval;
 import org.apache.poi.ss.formula.functions.FreeRefFunction;
@@ -299,32 +300,82 @@ public final class OperationEvaluationContext {
     }
     
     public ValueEval getNameXEval(NameXPtg nameXPtg) {
+        // Is the name actually on our workbook?
         ExternalSheet externSheet = _workbook.getExternalSheet(nameXPtg.getSheetRefIndex());
         if(externSheet == null || externSheet.getWorkbookName() == null) {
             // External reference to our own workbook's name
-            return new NameXEval(nameXPtg);
+            return getLocalNameXEval(nameXPtg);
         }
         
+        // Look it up for the external workbook
         String workbookName = externSheet.getWorkbookName();
         ExternalName externName = _workbook.getExternalName(
               nameXPtg.getSheetRefIndex(), 
               nameXPtg.getNameIndex()
         );
-        return getNameXEval(externName, workbookName);
+        return getExternalNameXEval(externName, workbookName);
     }
 	public ValueEval getNameXEval(NameXPxg nameXPxg) {
 	    ExternalSheet externSheet = _workbook.getExternalSheet(nameXPxg.getSheetName(), nameXPxg.getExternalWorkbookNumber());
         if(externSheet == null || externSheet.getWorkbookName() == null) {
             // External reference to our own workbook's name
-            // TODO How to do this?
-            return new NameXEval(null);
+            return getLocalNameXEval(nameXPxg);
         }
   
-        // TODO
-        return null;
-//        return getNameXEval(nameXPxg.getNameName(), externSheet.getWorkbookName());
+        // Look it up for the external workbook
+        String workbookName = externSheet.getWorkbookName();
+        ExternalName externName = _workbook.getExternalName(
+              nameXPxg.getNameName(),
+              nameXPxg.getSheetName(),
+              nameXPxg.getExternalWorkbookNumber()
+        );
+        return getExternalNameXEval(externName, workbookName);
+	}
+	
+    private ValueEval getLocalNameXEval(NameXPxg nameXPxg) {
+        // Look up the sheet, if present
+        int sIdx = -1;
+        if (nameXPxg.getSheetName() != null) {
+            sIdx = _workbook.getSheetIndex(nameXPxg.getSheetName());
+        }
+        
+        // Is it a name or a function?
+        String name = nameXPxg.getNameName();
+        EvaluationName evalName = _workbook.getName(name, sIdx);
+        if (evalName != null) {
+            // Process it as a name
+            return new ExternalNameEval(evalName);
+        } else {
+            // Must be an external function
+            return new FunctionNameEval(name);
+        }
+    }
+	private ValueEval getLocalNameXEval(NameXPtg nameXPtg) {
+        String name = _workbook.resolveNameXText(nameXPtg);
+        
+        // Try to parse it as a name
+        int sheetNameAt = name.indexOf('!'); 
+        EvaluationName evalName = null;
+        if (sheetNameAt > -1) {
+            // Sheet based name
+            String sheetName = name.substring(0, sheetNameAt);
+            String nameName = name.substring(sheetNameAt+1);
+            evalName = _workbook.getName(nameName, _workbook.getSheetIndex(sheetName));
+        } else {
+            // Workbook based name
+            evalName = _workbook.getName(name, -1);
+        }
+        
+        if (evalName != null) {
+            // Process it as a name
+            return new ExternalNameEval(evalName);
+        } else {
+            // Must be an external function
+            return new FunctionNameEval(name);
+        }
 	}
-    private ValueEval getNameXEval(ExternalName externName, String workbookName) {
+	
+    private ValueEval getExternalNameXEval(ExternalName externName, String workbookName) {
         try {
             WorkbookEvaluator refWorkbookEvaluator = _bookEvaluator.getOtherWorkbookEvaluator(workbookName);
             EvaluationName evaluationName = refWorkbookEvaluator.getName(externName.getName(),externName.getIx()-1);
diff --git a/src/java/org/apache/poi/ss/formula/UserDefinedFunction.java b/src/java/org/apache/poi/ss/formula/UserDefinedFunction.java
index 47df90a00d..c526137554 100644
--- a/src/java/org/apache/poi/ss/formula/UserDefinedFunction.java
+++ b/src/java/org/apache/poi/ss/formula/UserDefinedFunction.java
@@ -17,7 +17,7 @@
 
 package org.apache.poi.ss.formula;
 
-import org.apache.poi.ss.formula.eval.NameEval;
+import org.apache.poi.ss.formula.eval.FunctionNameEval;
 import org.apache.poi.ss.formula.eval.NotImplementedFunctionException;
 import org.apache.poi.ss.formula.eval.ValueEval;
 import org.apache.poi.ss.formula.functions.FreeRefFunction;
@@ -45,8 +45,8 @@ final class UserDefinedFunction implements FreeRefFunction {
 
 		ValueEval nameArg = args[0];
 		String functionName;
-		if (nameArg instanceof NameEval) {
-			functionName = ((NameEval) nameArg).getFunctionName();
+		if (nameArg instanceof FunctionNameEval) {
+			functionName = ((FunctionNameEval) nameArg).getFunctionName();
 		} else {
 			throw new RuntimeException("First argument should be a NameEval, but got ("
 					+ nameArg.getClass().getName() + ")");
diff --git a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
index 6dd5dd2068..4cbcee40cf 100644
--- a/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
+++ b/src/java/org/apache/poi/ss/formula/WorkbookEvaluator.java
@@ -30,10 +30,10 @@ import org.apache.poi.ss.formula.eval.BlankEval;
 import org.apache.poi.ss.formula.eval.BoolEval;
 import org.apache.poi.ss.formula.eval.ErrorEval;
 import org.apache.poi.ss.formula.eval.EvaluationException;
+import org.apache.poi.ss.formula.eval.ExternalNameEval;
 import org.apache.poi.ss.formula.eval.FunctionEval;
+import org.apache.poi.ss.formula.eval.FunctionNameEval;
 import org.apache.poi.ss.formula.eval.MissingArgEval;
-import org.apache.poi.ss.formula.eval.NameEval;
-import org.apache.poi.ss.formula.eval.NameXEval;
 import org.apache.poi.ss.formula.eval.NotImplementedException;
 import org.apache.poi.ss.formula.eval.NumberEval;
 import org.apache.poi.ss.formula.eval.OperandResolver;
@@ -638,37 +638,13 @@ public final class WorkbookEvaluator {
            EvaluationName nameRecord = _workbook.getName(namePtg);
            return getEvalForNameRecord(nameRecord, ec);
        }
-       if (ptg instanceof NameXPtg) { // TODO Generalise for NameXPxg
+       if (ptg instanceof NameXPtg) {
            // Externally defined named ranges or macro functions
-           NameXPtg nameXPtg = (NameXPtg)ptg;
-           ValueEval eval = ec.getNameXEval(nameXPtg);
-
-           if (eval instanceof NameXEval) {
-               // Could not be directly evaluated, so process as a name
-               return getEvalForNameX(nameXPtg, ec);
-           } else {
-               // Use the evaluated version
-               return eval;
-           }
+           return processNameEval(ec.getNameXEval((NameXPtg)ptg), ec);
        }
        if (ptg instanceof NameXPxg) {
-           // TODO This is a temporary hack....
-           NameXPxg pxg = (NameXPxg)ptg;
-           int sIdx = -1;
-           if (pxg.getSheetName() != null) {
-               sIdx = _workbook.getSheetIndex(pxg.getSheetName());
-           }
-           EvaluationName evalName = _workbook.getName(pxg.getNameName(), sIdx);
-           if (evalName == null) {
-               // We don't know about that name, sorry
-               // TODO What about UDFs?
-               logInfo("Unknown Name referenced: " + pxg.getNameName());
-               return ErrorEval.NAME_INVALID;
-           }
-           
-           int nIdx = evalName.createPtg().getIndex();
-           NameXPtg nptg = new NameXPtg(sIdx, nIdx);
-           return getEvalForPtg(nptg, ec);
+           // Externally defined named ranges or macro functions
+           return processNameEval(ec.getNameXEval((NameXPxg)ptg), ec);
        }
 
        if (ptg instanceof IntPtg) {
@@ -728,10 +704,18 @@ public final class WorkbookEvaluator {
 
        throw new RuntimeException("Unexpected ptg class (" + ptg.getClass().getName() + ")");
     }
+   
+   private ValueEval processNameEval(ValueEval eval, OperationEvaluationContext ec) {
+       if (eval instanceof ExternalNameEval) {
+           EvaluationName name = ((ExternalNameEval)eval).getName();
+           return getEvalForNameRecord(name, ec);
+       }
+       return eval;
+   }
 	
     private ValueEval getEvalForNameRecord(EvaluationName nameRecord, OperationEvaluationContext ec) {
         if (nameRecord.isFunctionName()) {
-            return new NameEval(nameRecord.getNameText());
+            return new FunctionNameEval(nameRecord.getNameText());
         }
         if (nameRecord.hasFormula()) {
             return evaluateNameFormula(nameRecord.getNameDefinition(), ec);
@@ -739,30 +723,6 @@ public final class WorkbookEvaluator {
 
         throw new RuntimeException("Don't now how to evalate name '" + nameRecord.getNameText() + "'");
     }
-    private ValueEval getEvalForNameX(NameXPtg nameXPtg, OperationEvaluationContext ec) {
-        String name = _workbook.resolveNameXText(nameXPtg);
-        
-        // Try to parse it as a name
-        int sheetNameAt = name.indexOf('!'); 
-        EvaluationName nameRecord = null;
-        if (sheetNameAt > -1) {
-            // Sheet based name
-            String sheetName = name.substring(0, sheetNameAt);
-            String nameName = name.substring(sheetNameAt+1);
-            nameRecord = _workbook.getName(nameName, _workbook.getSheetIndex(sheetName));
-        } else {
-            // Workbook based name
-            nameRecord = _workbook.getName(name, -1);
-        }
-        
-        if (nameRecord != null) {
-            // Process it as a name
-            return getEvalForNameRecord(nameRecord, ec);
-        } else {
-            // Must be an external function
-            return new NameEval(name);
-        }
-    }
     
     /**
      * YK: Used by OperationEvaluationContext to resolve indirect names.
diff --git a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
index 442b748593..93d3ec5565 100644
--- a/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
+++ b/src/java/org/apache/poi/ss/formula/eval/forked/ForkedEvaluationWorkbook.java
@@ -117,8 +117,11 @@ final class ForkedEvaluationWorkbook implements EvaluationWorkbook {
 	public ExternalName getExternalName(int externSheetIndex, int externNameIndex) {
 	   return _masterBook.getExternalName(externSheetIndex, externNameIndex);
 	}
+	public ExternalName getExternalName(String nameName, String sheetName, int externalWorkbookNumber) {
+	       return _masterBook.getExternalName(nameName, sheetName, externalWorkbookNumber);
+    }
 
-	public int getSheetIndex(EvaluationSheet sheet) {
+    public int getSheetIndex(EvaluationSheet sheet) {
 		if (sheet instanceof ForkedEvaluationSheet) {
 			ForkedEvaluationSheet mes = (ForkedEvaluationSheet) sheet;
 			return mes.getSheetIndex(_masterBook);
diff --git a/src/java/org/apache/poi/ss/formula/ptg/Deleted3DPxg.java b/src/java/org/apache/poi/ss/formula/ptg/Deleted3DPxg.java
new file mode 100644
index 0000000000..772e10b2f1
--- /dev/null
+++ b/src/java/org/apache/poi/ss/formula/ptg/Deleted3DPxg.java
@@ -0,0 +1,87 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss.formula.ptg;
+
+import org.apache.poi.ss.usermodel.ErrorConstants;
+import org.apache.poi.util.LittleEndianOutput;
+
+
+/**
+ * An XSSF only representation of a reference to a deleted area
+ */
+public final class Deleted3DPxg extends OperandPtg {
+    private int externalWorkbookNumber = -1;
+    private String sheetName;
+
+    public Deleted3DPxg(int externalWorkbookNumber, String sheetName) {
+        this.externalWorkbookNumber = externalWorkbookNumber;
+        this.sheetName = sheetName;
+    }
+    public Deleted3DPxg(String sheetName) {
+        this(-1, sheetName);
+    }
+
+    public String toString() {
+        StringBuffer sb = new StringBuffer();
+        sb.append(getClass().getName());
+        sb.append(" [");
+        if (externalWorkbookNumber >= 0) {
+            sb.append(" [");
+            sb.append("workbook=").append(getExternalWorkbookNumber());
+            sb.append("] ");
+        }
+        sb.append("sheet=").append(getSheetName());
+        sb.append(" ! ");
+        sb.append(ErrorConstants.getText(ErrorConstants.ERROR_REF));
+        sb.append("]");
+        return sb.toString();
+    }
+
+    public int getExternalWorkbookNumber() {
+        return externalWorkbookNumber;
+    }
+    public String getSheetName() {
+        return sheetName;
+    }
+
+    public String toFormulaString() {
+        StringBuffer sb = new StringBuffer();
+        if (externalWorkbookNumber >= 0) {
+            sb.append('[');
+            sb.append(externalWorkbookNumber);
+            sb.append(']');
+        }
+        if (sheetName != null) {
+            sb.append(sheetName);
+        }
+        sb.append('!');
+        sb.append(ErrorConstants.getText(ErrorConstants.ERROR_REF));
+        return sb.toString();
+    }
+    
+    public byte getDefaultOperandClass() {
+        return Ptg.CLASS_VALUE;
+    }
+
+    public int getSize() {
+        return 1;
+    }
+    public void write(LittleEndianOutput out) {
+        throw new IllegalStateException("XSSF-only Ptg, should not be serialised");
+    }
+}