reactos/irc/TechBot/CHMLibrary/CHMDecoding/CHMTopics.cs

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C#
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using System;
using System.IO;
using System.Collections;
using System.Collections.Specialized;
namespace HtmlHelp.ChmDecoding
{
/// <summary>
/// The class <c>CHMTopics</c> implements functionality to decode the #TOPICS internal file
/// </summary>
internal sealed class CHMTopics : IDisposable
{
/// <summary>
/// Internal flag specifying if the object is going to be disposed
/// </summary>
private bool disposed = false;
/// <summary>
/// Internal member storing the binary file data
/// </summary>
private byte[] _binaryFileData = null;
/// <summary>
/// Internal member storing the associated chmfile object
/// </summary>
private CHMFile _associatedFile = null;
/// <summary>
/// Internal member storing the topic list
/// </summary>
private ArrayList _topicTable = new ArrayList();
/// <summary>
/// Constructor of the class
/// </summary>
/// <param name="binaryFileData">binary file data of the #TOPICS file</param>
/// <param name="associatedFile">associated chm file</param>
public CHMTopics(byte[] binaryFileData, CHMFile associatedFile)
{
_binaryFileData = binaryFileData;
_associatedFile = associatedFile;
DecodeData();
// clear internal binary data after extraction
_binaryFileData = null;
}
/// <summary>
/// Standard constructor
/// </summary>
internal CHMTopics()
{
}
#region Data dumping
/// <summary>
/// Dump the class data to a binary writer
/// </summary>
/// <param name="writer">writer to write the data</param>
internal void Dump(ref BinaryWriter writer)
{
writer.Write( _topicTable.Count );
foreach(TopicEntry curItem in _topicTable)
{
curItem.Dump(ref writer);
}
}
/// <summary>
/// Reads the object data from a dump store
/// </summary>
/// <param name="reader">reader to read the data</param>
internal void ReadDump(ref BinaryReader reader)
{
int i=0;
int nCnt = reader.ReadInt32();
for(i=0; i<nCnt;i++)
{
TopicEntry newItem = new TopicEntry();
newItem.SetCHMFile(_associatedFile);
newItem.ReadDump(ref reader);
_topicTable.Add(newItem);
}
}
/// <summary>
/// Sets the associated CHMFile instance
/// </summary>
/// <param name="associatedFile">instance to set</param>
internal void SetCHMFile(CHMFile associatedFile)
{
_associatedFile = associatedFile;
foreach(TopicEntry curEntry in _topicTable)
{
curEntry.SetCHMFile(associatedFile);
}
}
#endregion
/// <summary>
/// Decodes the binary file data and fills the internal properties
/// </summary>
/// <returns>true if succeeded</returns>
private bool DecodeData()
{
bool bRet = true;
MemoryStream memStream = new MemoryStream(_binaryFileData);
BinaryReader binReader = new BinaryReader(memStream);
int nCurOffset = 0;
while( (memStream.Position < memStream.Length) && (bRet) )
{
int entryOffset = nCurOffset;
int tocIdx = binReader.ReadInt32();
int titleOffset = binReader.ReadInt32();
int urltablOffset = binReader.ReadInt32();
int visibilityMode = binReader.ReadInt16();
int unknownMode = binReader.ReadInt16();
TopicEntry newEntry = new TopicEntry(entryOffset, tocIdx, titleOffset, urltablOffset, visibilityMode, unknownMode, _associatedFile);
_topicTable.Add( newEntry );
nCurOffset = (int)memStream.Position;
}
return bRet;
}
/// <summary>
/// Gets the arraylist containing all topic entries.
/// </summary>
public ArrayList TopicTable
{
get
{
return _topicTable;
}
}
/// <summary>
/// Gets the topic entry of a given offset
/// </summary>
public TopicEntry this[int offset]
{
get
{
foreach(TopicEntry curEntry in _topicTable)
if(curEntry.EntryOffset == offset)
return curEntry;
return null;
}
}
/// <summary>
/// Searches a topic by the locale name
/// </summary>
/// <param name="locale">locale name to search</param>
/// <returns>The topicentry instance if found, otherwise null</returns>
public TopicEntry GetByLocale(string locale)
{
foreach(TopicEntry curEntry in TopicTable)
{
if(curEntry.Locale.ToLower() == locale.ToLower())
return curEntry;
}
return null;
}
/// <summary>
/// Searches the topics for all files with a given file extension
/// </summary>
/// <param name="fileExtension">extension to search</param>
/// <returns>An arraylist of TopicEntry instances or null if no topic was found</returns>
public ArrayList GetByExtension(string fileExtension)
{
ArrayList arrRet = new ArrayList();
foreach(TopicEntry curEntry in TopicTable)
{
if(curEntry.Locale.ToLower().EndsWith(fileExtension.ToLower()))
arrRet.Add(curEntry);
}
if(arrRet.Count > 0)
return arrRet;
return null;
}
/// <summary>
/// Implement IDisposable.
/// </summary>
public void Dispose()
{
Dispose(true);
// This object will be cleaned up by the Dispose method.
// Therefore, you should call GC.SupressFinalize to
// take this object off the finalization queue
// and prevent finalization code for this object
// from executing a second time.
GC.SuppressFinalize(this);
}
/// <summary>
/// Dispose(bool disposing) executes in two distinct scenarios.
/// If disposing equals true, the method has been called directly
/// or indirectly by a user's code. Managed and unmanaged resources
/// can be disposed.
/// If disposing equals false, the method has been called by the
/// runtime from inside the finalizer and you should not reference
/// other objects. Only unmanaged resources can be disposed.
/// </summary>
/// <param name="disposing">disposing flag</param>
private void Dispose(bool disposing)
{
// Check to see if Dispose has already been called.
if(!this.disposed)
{
// If disposing equals true, dispose all managed
// and unmanaged resources.
if(disposing)
{
// Dispose managed resources.
_binaryFileData = null;
_topicTable=null;
}
}
disposed = true;
}
}
}