1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 * 

    14 * Description:

    15 *

    16 */

    17 using System;

    18 using System.IO;

    19 using System.Text;

    20 using System.Threading;

    21 using System.Collections;

    22 using SymbianUtils.Tracer;

    23 

    24 namespace SymbianUtils

    25 {

    26 	public abstract class AsyncTextDataReader : AsyncTextReader

    27 	{

    28 		#region Enumerations

    29 		public enum TReadDirection

    30 		{

    31 			EReadDirectionForwards = 0,

    32 			EReadDirectionBackwards

    33 		}

    34 		#endregion

    35 

    36 		#region Construct & destruct

    37 		protected AsyncTextDataReader( string[] aLines )

    38 			: this( aLines, new AsyncTextReaderPrefix() )

    39 		{

    40 		}

    41 

    42         protected AsyncTextDataReader( string[] aLines, ITracer aTracer )

    43             : this( aLines, new AsyncTextReaderPrefix(), aTracer )

    44         {

    45         }

    46 

    47         protected AsyncTextDataReader( string[] aLines, AsyncTextReaderPrefix aPrefixes )

    48 			: this( aLines, TReadDirection.EReadDirectionForwards, aPrefixes )

    49 		{

    50 		}

    51 

    52         protected AsyncTextDataReader( string[] aLines, AsyncTextReaderPrefix aPrefixes, ITracer aTracer )

    53             : this( aLines, TReadDirection.EReadDirectionForwards, aPrefixes, aTracer )

    54         {

    55         }

    56 

    57         protected AsyncTextDataReader( string[] aLines, TReadDirection aReadDirection )

    58 			: this( aLines, TReadDirection.EReadDirectionForwards, new AsyncTextReaderPrefix(), null )

    59 		{

    60 		}

    61 

    62         protected AsyncTextDataReader( string[] aLines, TReadDirection aReadDirection, ITracer aTracer )

    63             : this( aLines, TReadDirection.EReadDirectionForwards, new AsyncTextReaderPrefix(), aTracer )

    64 		{

    65 		}

    66 

    67         protected AsyncTextDataReader( string[] aLines, TReadDirection aReadDirection, AsyncTextReaderPrefix aPrefixes )

    68             : this( aLines, aReadDirection, aPrefixes, null )

    69         {

    70 		}

    71 

    72         protected AsyncTextDataReader( string[] aLines, TReadDirection aReadDirection, AsyncTextReaderPrefix aPrefixes, ITracer aTracer )

    73 			: base( aPrefixes, aTracer )

    74 		{

    75 			iLines = aLines;

    76 			iReadDirection = aReadDirection;

    77 			//

    78 			switch( iReadDirection )

    79 			{

    80 			default:

    81 			case TReadDirection.EReadDirectionForwards:

    82 				iLineIndex = 0;

    83 				break;

    84 			case TReadDirection.EReadDirectionBackwards:

    85 				iLineIndex = iLines.Length - 1;

    86 				break;

    87 			}

    88 		}

    89 		#endregion

    90 

    91         #region Properties

    92         public int LineNumber

    93 		{

    94 			get { return iLineIndex; }

    95 		}

    96 		#endregion

    97 

    98 		#region Abstract reading framework

    99 		protected override int CalculateProgress()

   100 		{

   101 			int prog = 0;

   102 			//

   103 			switch( iReadDirection )

   104 			{

   105 			default:

   106 			case TReadDirection.EReadDirectionForwards:

   107 				{

   108 				prog = base.CalculateProgress();

   109 				break;

   110 				}

   111 			case TReadDirection.EReadDirectionBackwards:

   112 				{

   113 				float positionAsFloat = (float)Position;

   114 				float sizeAsFloat = (float)Size;

   115 				prog = (int)((positionAsFloat / sizeAsFloat) * 100.0);

   116 				prog = System.Math.Max(1, System.Math.Min(100, prog));

   117 				break;

   118 				}

   119 			}

   120 			//

   121 			return prog;

   122 		}

   123 

   124 		protected override string ProvideReadLine()

   125 		{

   126 			string ret = null;

   127 			//

   128 			switch( iReadDirection )

   129 			{

   130 			default:

   131 			case TReadDirection.EReadDirectionForwards:

   132 				if	( iLineIndex < iLines.Length )

   133 				{

   134 					ret = iLines[ iLineIndex++ ];

   135 				}

   136 				break;

   137 			case TReadDirection.EReadDirectionBackwards:

   138 				if	( iLineIndex >= 0 )

   139 				{

   140 					ret = iLines[ iLineIndex-- ];

   141 				}

   142 				break;

   143 			}

   144 			//

   145 			return ret;

   146 		}

   147 

   148 		protected override long Size

   149 		{

   150 			get

   151 			{

   152 				long size = iLines.LongLength;

   153 				return size;

   154 			}

   155 		}

   156 

   157 		protected override long Position

   158 		{

   159 			get

   160 			{

   161 				long position = (long) iLineIndex;

   162 				return position;

   163 			}

   164 		}

   165 		#endregion

   166 

   167 		#region Data members

   168 		private readonly string[] iLines;

   169 		private readonly TReadDirection iReadDirection;

   170 		private int iLineIndex = 0;

   171 		#endregion

   172 	}

   173 }