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/*
* Created by: Leslie Sanford
*
* Contact: jabberdabber@hotmail.com
*
* Last modified: 05/07/2004
*/
using System;
using System.Text;
namespace Multimedia.Midi
{
/// <summary>
/// Represents the method that will handle the event that occurs when a
/// system exclusive message is received.
/// </summary>
public delegate void SysExEventHandler(object sender, SysExEventArgs e);
/// <summary>
/// Represents various system exclusive message types.
/// </summary>
public enum SysExType
{
/// <summary>
/// Represents the start of system exclusive message type.
/// </summary>
Start = 0xF0,
/// <summary>
/// Represents either the continuation or the escape system
/// exclusive message type.
/// </summary>
Special = 0xF7
}
/// <summary>
/// Represents Midi system exclusive messages.
/// </summary>
public class SysExMessage : IMidiMessage
{
#region SysExMessage Members
#region Fields
// The system exclusive type.
private SysExType type;
// The system exclusive message data.
private StringBuilder message;
#endregion
#region Construction
/// <summary>
/// Initializes a new instance of the SysExMessage class with the
/// specified system exclusive type and data.
/// </summary>
/// <param name="type">
/// The type of system exclusive message.
/// </param>
/// <param name="data">
/// The system exclusive data.
/// </param>
public SysExMessage(SysExType type, byte[] data)
{
this.type = type;
// If this is a regular system exclusive message.
if(this.type == SysExType.Start)
{
// Create storage for message data which includes an extra byte
// for the status value.
message = new StringBuilder(data.Length + 1);
message.Length = message.Capacity;
// Store status value.
message[0] = (char)this.type;
}
// Else this is a continuation message or an escaped message.
else
{
message = new StringBuilder(data.Length);
}
// Copy data into message.
for(int i = 0; i < data.Length; i++)
{
this[i] = data[i];
}
}
/// <summary>
/// Initializes a new instance of the SysExMessage class with
/// another instance of the SysExMessage class.
/// </summary>
/// <param name="message">
/// The SysExMessage instance to use for initialization.
/// </param>
public SysExMessage(SysExMessage message)
{
type = message.type;
this.message = new StringBuilder(message.Message);
}
#endregion
#region Methods
/// <summary>
/// Tests to see if a status value belongs to a system exclusive
/// message.
/// </summary>
/// <param name="status">
/// The status value to test.
/// </param>
/// <returns>
/// <b>true</b> if the status value belongs to a system exclusive
/// message; otherwise, <b>false</b>.
/// </returns>
public static bool IsSysExMessage(int status)
{
bool result = false;
if(status == (int)SysExType.Start ||
status == (int)SysExType.Special)
{
result = true;
}
return result;
}
#endregion
#region Properties
/// <summary>
/// Gets or sets the element at the specified index.
/// </summary>
/// <remarks>
/// Indexing this class allows access to the system exclusive data.
/// This is any element other than the status value, which cannot
/// be changed.
/// </remarks>
public byte this[int index]
{
get
{
// Enforce preconditions.
if(index < 0 || index >= Length)
throw new ArgumentOutOfRangeException("index", index,
"Index into system exclusive message out of range.");
byte value;
// If this is a regular system exclusive message.
if(Type == SysExType.Start)
{
// Offset by one so that the status byte isn't
// included.
value = (byte)message[index + 1];
}
// Else this is a continuation or escaped system exclusive
// message.
else
{
// No offset necessary.
value = (byte)message[index];
}
return value;
}
set
{
// Enforce preconditions.
if(index < 0 || index >= Length)
throw new ArgumentOutOfRangeException("index", index,
"Index into system exclusive message out of range.");
// If this is a regular system exclusive message.
if(Type == SysExType.Start)
{
// Offset by one so that the status byte isn't
// overwritten.
message[index + 1] = (char)value;
}
// Else this is a continuation or escaped system exclusive
// message.
else
{
// Assign value at the specified index.
message[index] = (char)value;
}
}
}
/// <summary>
/// Gets the length of the system exclusive data.
/// </summary>
public int Length
{
get
{
int length;
// If this is a regular system exclusive message
if(Type == SysExType.Start)
{
// Do not include status value in data length.
length = message.Length - 1;
}
// Else this is a continuation or escaped system exclusive
// message.
else
{
// Data length is the length of the message.
length = message.Length;
}
return length;
}
}
/// <summary>
/// Gets the system exclusive data.
/// </summary>
public string Message
{
get
{
return message.ToString();
}
}
/// <summary>
/// Gets the system exclusive type.
/// </summary>
public SysExType Type
{
get
{
return type;
}
}
#endregion
#endregion
#region ICloneable Members
/// <summary>
/// Creates a clone of this instance of the SysExMessage class.
/// </summary>
/// <returns>
/// A clone of this instance of the SysExMessage class.
/// </returns>
public object Clone()
{
return new SysExMessage(this);
}
#endregion
#region IMidiMessage Members
/// <summary>
/// Accepts an IMidiMessageVisitor.
/// </summary>
/// <param name="visitor">
/// The IMidiMessageVisitor to accept.
/// </param>
public void Accept(IMidiMessageVisitor visitor)
{
visitor.Visit(this);
}
/// <summary>
/// Gets the status value.
/// </summary>
public int Status
{
get
{
return (int)Type;
}
}
#endregion
}
/// <summary>
/// Provides data for the <b>SysExReceived</b> event.
/// </summary>
public class SysExEventArgs : EventArgs
{
#region SysExEventArgs Memebers
#region Fields
// The system exclusive message for this event.
private SysExMessage message;
// The time in milliseconds since the input device began recording.
private int timeStamp;
#endregion
#region Construction
/// <summary>
/// Initializes a new instance of the SysExEventArgs class with the
/// specified system exclusive message and the time stamp.
/// </summary>
/// <param name="message">
/// The system exclusive message for this event.
/// </param>
/// <param name="timeStamp">
/// The time in milliseconds since the input device began recording.
/// </param>
public SysExEventArgs(SysExMessage message, int timeStamp)
{
this.message = message;
this.timeStamp = timeStamp;
}
#endregion
#region Properties
/// <summary>
/// Gets the system exclusive message for this event.
/// </summary>
public SysExMessage Message
{
get
{
return message;
}
}
/// <summary>
/// Gets the time in milliseconds since the input device began
/// recording.
/// </summary>
public int TimeStamp
{
get
{
return timeStamp;
}
}
#endregion
#endregion
}
}
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Aside from dabbling in BASIC on his old Atari 1040ST years ago, Leslie's programming experience didn't really begin until he discovered the Internet in the late 90s. There he found a treasure trove of information about two of his favorite interests: MIDI and sound synthesis.
After spending a good deal of time calculating formulas he found on the Internet for creating new sounds by hand, he decided that an easier way would be to program the computer to do the work for him. This led him to learn C. He discovered that beyond using programming as a tool for synthesizing sound, he loved programming in and of itself.
Eventually he taught himself C++ and C#, and along the way he immersed himself in the ideas of object oriented programming. Like many of us, he gotten bitten by the design patterns bug and a copy of GOF is never far from his hands.
Now his primary interest is in creating a complete MIDI toolkit using the C# language. He hopes to create something that will become an indispensable tool for those wanting to write MIDI applications for the .NET framework.
Besides programming, his other interests are photography and playing his Les Paul guitars.
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