DynamicByteProvider.cs :  » Development » Be.HexEditor » Be » Windows » Forms » C# / CSharp Open Source

using System;

namespace Be.Windows.Forms{
  /// <summary>
  /// Byte provider for a small amount of data.
  /// </summary>
  public class DynamicByteProvider : IByteProvider
  {
    /// <summary>
    /// Contains information about changes.
    /// </summary>
    bool _hasChanges;
    /// <summary>
    /// Contains a byte collection.
    /// </summary>
    ByteCollection _bytes;

    /// <summary>
    /// Initializes a new instance of the DynamicByteProvider class.
    /// </summary>
    /// <param name="data"></param>
    public DynamicByteProvider(byte[] data) : this(new ByteCollection(data)) 
    {
    }

    /// <summary>
    /// Initializes a new instance of the DynamicByteProvider class.
    /// </summary>
    /// <param name="bytes"></param>
    public DynamicByteProvider(ByteCollection bytes)
    {
      _bytes = bytes;
    }

    /// <summary>
    /// Raises the Changed event.
    /// </summary>
    void OnChanged(EventArgs e)
    {
      _hasChanges = true;

      if(Changed != null)
        Changed(this, e);
    }

    /// <summary>
    /// Raises the LengthChanged event.
    /// </summary>
    void OnLengthChanged(EventArgs e)
    {
      if(LengthChanged != null)
        LengthChanged(this, e);
    }

    /// <summary>
    /// Gets the byte collection.
    /// </summary>
    public ByteCollection Bytes
    {
      get { return _bytes; }
    }

    #region IByteProvider Members
    /// <summary>
    /// True, when changes are done.
    /// </summary>
    public bool HasChanges()
    {
      return _hasChanges;
    }

    /// <summary>
    /// Applies changes.
    /// </summary>
    public void ApplyChanges()
    {
      _hasChanges = false;
    }

    /// <summary>
    /// Occurs, when the write buffer contains new changes.
    /// </summary>
    public event EventHandler Changed;

    /// <summary>
    /// Occurs, when InsertBytes or DeleteBytes method is called.
    /// </summary>
    public event EventHandler LengthChanged;


    /// <summary>
    /// Reads a byte from the byte collection.
    /// </summary>
    /// <param name="index">the index of the byte to read</param>
    /// <returns>the byte</returns>
    public byte ReadByte(long index)
    { return _bytes[(int)index]; }

    /// <summary>
    /// Write a byte into the byte collection.
    /// </summary>
    /// <param name="index">the index of the byte to write.</param>
    /// <param name="value">the byte</param>
    public void WriteByte(long index, byte value)
    {
      _bytes[(int)index] = value;
      OnChanged(EventArgs.Empty);
    }

    /// <summary>
    /// Deletes bytes from the byte collection.
    /// </summary>
    /// <param name="index">the start index of the bytes to delete.</param>
    /// <param name="length">the length of bytes to delete.</param>
    public void DeleteBytes(long index, long length)
    { 
      int internal_index = (int)Math.Max(0, index);
      int internal_length = (int)Math.Min((int)Length, length);
      _bytes.RemoveRange(internal_index, internal_length); 

      OnLengthChanged(EventArgs.Empty);
      OnChanged(EventArgs.Empty);
    }

    /// <summary>
    /// Inserts byte into the byte collection.
    /// </summary>
    /// <param name="index">the start index of the bytes in the byte collection</param>
    /// <param name="bs">the byte array to insert</param>
    public void InsertBytes(long index, byte[] bs)
    { 
      _bytes.InsertRange((int)index, bs); 

      OnLengthChanged(EventArgs.Empty);
      OnChanged(EventArgs.Empty);
    }

    /// <summary>
    /// Gets the length of the bytes in the byte collection.
    /// </summary>
    public long Length
    {
      get
      {
        return _bytes.Count;
      }
    }

    /// <summary>
    /// Returns true
    /// </summary>
    public bool SupportsWriteByte()
    {
      return true;
    }

    /// <summary>
    /// Returns true
    /// </summary>
    public bool SupportsInsertBytes()
    {
      return true;
    }

    /// <summary>
    /// Returns true
    /// </summary>
    public bool SupportsDeleteBytes()
    {
      return true;
    }
    #endregion
  }
}