Add readonly modifier for suitable fields

main/DDF/DefaultEscherRecordFactory.cs

@@ -30,15 +30,15 @@ namespace NPOI.DDF
     /// </summary>
     public class DefaultEscherRecordFactory : IEscherRecordFactory
     {
-        private static Type[] escherRecordClasses = {
+        private static readonly Type[] escherRecordClasses = {
 
             typeof(EscherBSERecord), typeof(EscherOptRecord), typeof(EscherTertiaryOptRecord),
             typeof(EscherClientAnchorRecord), 
             typeof(EscherDgRecord), typeof(EscherSpgrRecord), typeof(EscherSpRecord), 
             typeof(EscherClientDataRecord), typeof(EscherDggRecord),
             typeof(EscherSplitMenuColorsRecord), typeof(EscherChildAnchorRecord), typeof(EscherTextboxRecord)
         };
-        private static Dictionary<short,ConstructorInfo> recordsMap = RecordsToMap(escherRecordClasses);
+        private static readonly Dictionary<short,ConstructorInfo> recordsMap = RecordsToMap(escherRecordClasses);
 
         /// <summary>
         /// Initializes a new instance of the <see cref="DefaultEscherRecordFactory"/> class.

main/DDF/EscherContainerRecord.cs

@@ -40,7 +40,7 @@ public class EscherContainerRecord : EscherRecord
         public const short SPGR_CONTAINER = unchecked((short)0xF003);
         public const short SP_CONTAINER = unchecked((short)0xF004);
         public const short SOLVER_CONTAINER = unchecked((short)0xF005);
-        private static POILogger log = POILogFactory.GetLogger(typeof(EscherContainerRecord));
+        private static readonly POILogger log = POILogFactory.GetLogger(typeof(EscherContainerRecord));
 
         /**
          * in case if document contains any charts we have such document structure:
@@ -65,7 +65,7 @@ public class EscherContainerRecord : EscherRecord
          * and add it to container size when we serialize it
          */
         private int _remainingLength;
-        private List<EscherRecord> _childRecords = new List<EscherRecord>();
+        private readonly List<EscherRecord> _childRecords = new List<EscherRecord>();
 
         /// <summary>
         /// The contract of this method is to deSerialize an escher record including

main/HPSF/Array.cs

@@ -39,7 +39,7 @@ public ArrayDimension( byte[] data, int offset )
 
     internal class ArrayHeader
     {
-        private ArrayDimension[] _dimensions;
+        private readonly ArrayDimension[] _dimensions;
         internal int _type;
 
         public ArrayHeader( byte[] data, int startOffset )

main/HPSF/Blob.cs

@@ -4,7 +4,7 @@ namespace NPOI.HPSF
 {
     internal class Blob
     {
-        private byte[] _value;
+        private readonly byte[] _value;
 
         public Blob(byte[] data, int offset)
         {

main/HPSF/ClipboardData.cs

@@ -8,8 +8,8 @@ public class ClipboardData
         //private static final POILogger logger = POILogFactory
         //    .getLogger( ClipboardData.class );
 
-        private int _format;
-        private byte[] _value;
+        private readonly int _format;
+        private readonly byte[] _value;
 
         public ClipboardData(byte[] data, int offset)
         {

main/HPSF/Filetime.cs

@@ -7,8 +7,8 @@ public class Filetime
     {
         public const int SIZE = LittleEndian.INT_SIZE * 2;
 
-        private int _dwHighDateTime;
-        private int _dwLowDateTime;
+        private readonly int _dwHighDateTime;
+        private readonly int _dwLowDateTime;
 
         public Filetime(byte[] data, int offset)
         {

main/HPSF/IndirectPropertyName.cs

@@ -2,7 +2,7 @@
 {
     public class IndirectPropertyName
     {
-        private CodePageString _value;
+        private readonly CodePageString _value;
 
         public IndirectPropertyName(byte[] data, int offset)
         {

main/HPSF/UnicodeString.cs

@@ -25,7 +25,7 @@ public class UnicodeString
         //private final static POILogger logger = POILogFactory
         //   .getLogger( UnicodeString.class );
 
-        private byte[] _value;
+        private readonly byte[] _value;
 
         public UnicodeString(byte[] data, int offset)
         {

main/HPSF/Vector.cs

@@ -22,7 +22,7 @@ namespace NPOI.HPSF
 {
     public class Vector
     {
-        private short _type;
+        private readonly short _type;
 
         private TypedPropertyValue[] _values;
 

main/HPSF/VersionedStream.cs

@@ -19,7 +19,7 @@ namespace NPOI.HPSF
     public class VersionedStream
     {
         private GUID _versionGuid;
-        private IndirectPropertyName _streamName;
+        private readonly IndirectPropertyName _streamName;
 
         public VersionedStream(byte[] data, int offset)
         {

main/HSSF/EventModel/EventRecordFactory.cs

@@ -36,8 +36,8 @@ namespace NPOI.HSSF.EventModel
     public class EventRecordFactory
     {
 
-        private IERFListener _listener;
-        private ArrayList _sids;
+        private readonly IERFListener _listener;
+        private readonly ArrayList _sids;
 
         /**
          * Create an EventRecordFactory

main/HSSF/Extractor/ExcelExtractor.cs

@@ -35,8 +35,8 @@ namespace NPOI.HSSF.Extractor
     /// </summary>
     public class ExcelExtractor : POIOLE2TextExtractor, IExcelExtractor
     {
-        private HSSFWorkbook wb;
-        private HSSFDataFormatter _formatter;
+        private readonly HSSFWorkbook wb;
+        private readonly HSSFDataFormatter _formatter;
         private bool includeSheetNames = true;
         private bool formulasNotResults = false;
         private bool includeCellComments = false;

main/HSSF/Model/InternalSheet.cs

@@ -179,7 +179,7 @@ public static InternalSheet CreateSheet(RecordStream rs)
 
         private class RecordCloner : RecordVisitor
         {
-            private IList<Record> _destList;
+            private readonly IList<Record> _destList;
 
             public RecordCloner(IList<Record> destList)
             {
@@ -452,7 +452,7 @@ private InternalSheet(RecordStream rs)
         }
         private class RecordVisitor1:RecordVisitor
         {
-            List<RecordBase> _records;
+            readonly List<RecordBase> _records;
             public RecordVisitor1(List<RecordBase> recs)
             {
                 _records=recs;
@@ -2339,7 +2339,7 @@ public int GetColumnOutlineLevel(int columnIndex)
 
     public class UnsupportedBOFType : RecordFormatException
     {
-        private BOFRecordType type;
+        private readonly BOFRecordType type;
         public UnsupportedBOFType(BOFRecordType type)
             : base("BOF not of a supported type, found " + type)
         {

main/HSSF/Model/LinkTable.cs

@@ -91,8 +91,8 @@ private static ExternSheetRecord ReadExtSheetRecord(RecordStream rs)
         private class CRNBlock
         {
 
-            private CRNCountRecord _countRecord;
-            private CRNRecord[] _crns;
+            private readonly CRNCountRecord _countRecord;
+            private readonly CRNRecord[] _crns;
 
             public CRNBlock(RecordStream rs)
             {
@@ -113,7 +113,7 @@ public CRNRecord[] GetCrns()
 
         private class ExternalBookBlock
         {
-            private SupBookRecord _externalBookRecord;
+            private readonly SupBookRecord _externalBookRecord;
             internal ExternalNameRecord[] _externalNameRecords;
             private CRNBlock[] _crnBlocks;
             /**
@@ -217,10 +217,10 @@ public int GetNameIx(int definedNameIndex)
         }
 
         private ExternalBookBlock[] _externalBookBlocks;
-        private ExternSheetRecord _externSheetRecord;
-        private List<NameRecord> _definedNames;
-        private int _recordCount;
-        private WorkbookRecordList _workbookRecordList; // TODO - would be nice to Remove this
+        private readonly ExternSheetRecord _externSheetRecord;
+        private readonly List<NameRecord> _definedNames;
+        private readonly int _recordCount;
+        private readonly WorkbookRecordList _workbookRecordList; // TODO - would be nice to Remove this
 
         public LinkTable(List<Record> inputList, int startIndex, WorkbookRecordList workbookRecordList, Dictionary<String, NameCommentRecord> commentRecords)
         {

main/HSSF/Model/ParseNode.cs

@@ -32,10 +32,10 @@ class ParseNode
     {
 
         public static ParseNode[] EMPTY_ARRAY = { };
-        private Ptg _token;
-        private ParseNode[] _children;
-        private bool _isIf;
-        private int _tokenCount;
+        private readonly Ptg _token;
+        private readonly ParseNode[] _children;
+        private readonly bool _isIf;
+        private readonly int _tokenCount;
 
         public ParseNode(Ptg token, ParseNode[] children)
         {
@@ -178,7 +178,7 @@ public ParseNode[] Children
         private class TokenCollector
         {
 
-            private Ptg[] _ptgs;
+            private readonly Ptg[] _ptgs;
             private int _offset;
 
             public TokenCollector(int tokenCount)

main/HSSF/Model/RecordStream.cs

@@ -29,9 +29,9 @@ namespace NPOI.HSSF.Model
     public class RecordStream
     {
 
-        private IList _list;
+        private readonly IList _list;
         private int _nextIndex;
-        private int _endIx;
+        private readonly int _endIx;
         private int _countRead;
 
         public RecordStream(IList inputList, int startIndex, int endIx)

main/HSSF/Model/RowBlocksReader.cs

@@ -34,9 +34,9 @@ namespace NPOI.HSSF.Model
     public class RowBlocksReader
     {
 
-        private ArrayList _plainRecords;
-        private SharedValueManager _sfm;
-        private MergeCellsRecord[] _mergedCellsRecords;
+        private readonly ArrayList _plainRecords;
+        private readonly SharedValueManager _sfm;
+        private readonly MergeCellsRecord[] _mergedCellsRecords;
 
         /**
          * Also collects any loose MergeCellRecords and puts them in the supplied

main/HSSF/Record/Aggregates/Chart/ChartSheetAggregate.cs

@@ -31,15 +31,15 @@ namespace NPOI.HSSF.Record.Aggregates.Chart
     /// </summary>
     public class ChartSheetAggregate : ChartRecordAggregate
     {
-        private BOFRecord _bofRec;
+        private readonly BOFRecord _bofRec;
         /**
          * All the records between BOF and EOF
          */
-        private List<RecordBase> _recs;
-        private PageSettingsBlock _psBlock;
+        private readonly List<RecordBase> _recs;
+        private readonly PageSettingsBlock _psBlock;
 
-        private ChartFormatsAggregate chartFormats;
-        private SeriesDataAggregate seriesData;
+        private readonly ChartFormatsAggregate chartFormats;
+        private readonly SeriesDataAggregate seriesData;
 
         public ChartSheetAggregate(RecordStream rs, ChartRecordAggregate container)
             : base(RuleName_CHARTSHEET, container)

main/HSSF/Record/Aggregates/ChartSubstreamRecordAggregate.cs

@@ -33,12 +33,12 @@ namespace NPOI.HSSF.Record.Aggregates
     public class ChartSubstreamRecordAggregate : RecordAggregate
     {
 
-        private BOFRecord _bofRec;
+        private readonly BOFRecord _bofRec;
         /**
          * All the records between BOF and EOF
          */
-        private List<RecordBase> _recs;
-        private PageSettingsBlock _psBlock;
+        private readonly List<RecordBase> _recs;
+        private readonly PageSettingsBlock _psBlock;
 
         public ChartSubstreamRecordAggregate(RecordStream rs)
         {

main/HSSF/Record/Aggregates/ConditionalFormattingTable.cs

@@ -36,7 +36,7 @@ namespace NPOI.HSSF.Record.Aggregates
     public class ConditionalFormattingTable : RecordAggregate
     {
 
-        private IList<CFRecordsAggregate> _cfHeaders;
+        private readonly IList<CFRecordsAggregate> _cfHeaders;
 
         /**
          * Creates an empty ConditionalFormattingTable

main/HSSF/Record/Aggregates/CustomViewSettingsRecordAggregate.cs

@@ -31,13 +31,13 @@ namespace NPOI.HSSF.Record.Aggregates
     public class CustomViewSettingsRecordAggregate : RecordAggregate
     {
 
-        private Record _begin;
-        private Record _end;
+        private readonly Record _begin;
+        private readonly Record _end;
         /**
          * All the records between BOF and EOF
          */
-        private List<RecordBase> _recs;
-        private PageSettingsBlock _psBlock;
+        private readonly List<RecordBase> _recs;
+        private readonly PageSettingsBlock _psBlock;
 
         public CustomViewSettingsRecordAggregate(RecordStream rs)
         {

main/HSSF/Record/Aggregates/DataValidityTable.cs

@@ -30,12 +30,12 @@ namespace NPOI.HSSF.Record.Aggregates
     public class DataValidityTable : RecordAggregate
     {
 
-        private DVALRecord _headerRec;
+        private readonly DVALRecord _headerRec;
         /**
          * The list of data validations for the current sheet.
          * Note - this may be empty (contrary to OOO documentation)
          */
-        private IList _validationList;
+        private readonly IList _validationList;
 
         public DataValidityTable(RecordStream rs)
         {

main/HSSF/Record/Aggregates/MergedCellsTable.cs

@@ -32,7 +32,7 @@ public class MergedCellsTable : RecordAggregate
     {
         private const int MAX_MERGED_REGIONS = 1027; // enforced by the 8224 byte limit
 
-        private List<CellRangeAddress> _mergedRegions;
+        private readonly List<CellRangeAddress> _mergedRegions;
 
         /// <summary>
         /// Creates an empty aggregate

main/HSSF/Record/Aggregates/PLSAggregate.cs

@@ -5,15 +5,15 @@ namespace NPOI.HSSF.Record.Aggregates
 {
     internal class PLSAggregate : RecordAggregate
     {
-        private static ContinueRecord[] EMPTY_CONTINUE_RECORD_ARRAY = { };
-        private Record _pls;
+        private static readonly ContinueRecord[] EMPTY_CONTINUE_RECORD_ARRAY = { };
+        private readonly Record _pls;
         /**
          * holds any continue records found after the PLS record.<br/>
          * This would not be required if PLS was properly interpreted.
          * Currently, PLS is an {@link UnknownRecord} and does not automatically
          * include any trailing {@link ContinueRecord}s.
          */
-        private ContinueRecord[] _plsContinues;
+        private readonly ContinueRecord[] _plsContinues;
 
         public PLSAggregate(RecordStream rs)
         {

main/HSSF/Record/Aggregates/PageSettingsBlock.cs

@@ -51,8 +51,8 @@ public class PageSettingsBlock : RecordAggregate
         private Record _bitmap;
         private HeaderFooterRecord _headerFooter;
 
-        private List<HeaderFooterRecord> _sviewHeaderFooters = new List<HeaderFooterRecord>();
-        private List<PLSAggregate> _plsRecords;
+        private readonly List<HeaderFooterRecord> _sviewHeaderFooters = new List<HeaderFooterRecord>();
+        private readonly List<PLSAggregate> _plsRecords;
 
         private Record _printSize;
 
@@ -671,10 +671,10 @@ public void PositionRecords(List<RecordBase> sheetRecords)
         }
         private class CustomRecordVisitor1 : RecordVisitor
         {
-            CustomViewSettingsRecordAggregate _cv;
-            HeaderFooterRecord _hf;
-            List<HeaderFooterRecord> _sviewHeaderFooters;
-            Dictionary<String, HeaderFooterRecord> _hfGuidMap;
+            readonly CustomViewSettingsRecordAggregate _cv;
+            readonly HeaderFooterRecord _hf;
+            readonly List<HeaderFooterRecord> _sviewHeaderFooters;
+            readonly Dictionary<String, HeaderFooterRecord> _hfGuidMap;
             public CustomRecordVisitor1(CustomViewSettingsRecordAggregate cv, HeaderFooterRecord hf, 
                 List<HeaderFooterRecord> sviewHeaderFooter, Dictionary<String, HeaderFooterRecord> hfGuidMap)
             {

main/HSSF/Record/Aggregates/RecordAggregate.cs

@@ -77,8 +77,8 @@ public override int RecordSize
         private class SerializingRecordVisitor : RecordVisitor
         {
 
-            private byte[] _data;
-            private int _startOffset;
+            private readonly byte[] _data;
+            private readonly int _startOffset;
             private int _countBytesWritten;
 
             public SerializingRecordVisitor(byte[] data, int startOffset)
@@ -129,7 +129,7 @@ public virtual Record CloneViaReserialise()
      */
     public class PositionTrackingVisitor : RecordVisitor
     {
-        private RecordVisitor _rv;
+        private readonly RecordVisitor _rv;
         private int _position;
 
         public PositionTrackingVisitor(RecordVisitor rv, int initialPosition)