#region License
/* Copyright (c) 2005 Leslie Sanford
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#endregion
#region Contact
/*
* Leslie Sanford
* Email: jabberdabber@hotmail.com
*/
#endregion
using System;
using System.Collections;
using System.Runtime.InteropServices;
namespace Sanford.Multimedia.Midi
{
/// <summary>
/// Builds a pointer to a MidiHeader structure.
/// </summary>
internal class MidiHeaderBuilder
{
// The length of the system exclusive buffer.
private int bufferLength;
// The system exclusive data.
private byte[] data;
// Indicates whether the pointer to the MidiHeader has been built.
private bool built = false;
// The built pointer to the MidiHeader.
private IntPtr result;
/// <summary>
/// Initializes a new instance of the MidiHeaderBuilder.
/// </summary>
public MidiHeaderBuilder()
{
BufferLength = 1;
}
#region Methods
/// <summary>
/// Builds the pointer to the MidiHeader structure.
/// </summary>
public void Build()
{
MidiHeader header = new MidiHeader();
// Initialize the MidiHeader.
header.bufferLength = BufferLength;
header.bytesRecorded = 0;
header.data = Marshal.AllocHGlobal(BufferLength);
header.flags = 0;
// Write data to the MidiHeader.
for(int i = 0; i < BufferLength; i++)
{
Marshal.WriteByte(header.data, i, data[i]);
}
try
{
result = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(MidiHeader)));
}
catch(Exception)
{
Marshal.FreeHGlobal(header.data);
throw;
}
try
{
Marshal.StructureToPtr(header, result, false);
}
catch(Exception)
{
Marshal.FreeHGlobal(header.data);
Marshal.FreeHGlobal(result);
throw;
}
built = true;
}
/// <summary>
/// Initializes the MidiHeaderBuilder with the specified SysExMessage.
/// </summary>
/// <param name="message">
/// The SysExMessage to use for initializing the MidiHeaderBuilder.
/// </param>
public void InitializeBuffer(SysExMessage message)
{
// If this is a start system exclusive message.
if(message.SysExType == SysExType.Start)
{
BufferLength = message.Length;
// Copy entire message.
for(int i = 0; i < BufferLength; i++)
{
data[i] = message[i];
}
}
// Else this is a continuation message.
else
{
BufferLength = message.Length - 1;
// Copy all but the first byte of message.
for(int i = 0; i < BufferLength; i++)
{
data[i] = message[i + 1];
}
}
}
public void InitializeBuffer(ICollection events)
{
#region Require
if(events == null)
{
throw new ArgumentNullException("events");
}
else if(events.Count % 4 != 0)
{
throw new ArgumentException("Stream events not word aligned.");
}
#endregion
#region Guard
if(events.Count == 0)
{
return;
}
#endregion
BufferLength = events.Count;
events.CopyTo(data, 0);
}
/// <summary>
/// Releases the resources associated with the built MidiHeader pointer.
/// </summary>
public void Destroy()
{
#region Require
if(!built)
{
throw new InvalidOperationException("Cannot destroy MidiHeader");
}
#endregion
Destroy(result);
}
/// <summary>
/// Releases the resources associated with the specified MidiHeader pointer.
/// </summary>
/// <param name="headerPtr">
/// The MidiHeader pointer.
/// </param>
public void Destroy(IntPtr headerPtr)
{
MidiHeader header = (MidiHeader)Marshal.PtrToStructure(headerPtr, typeof(MidiHeader));
Marshal.FreeHGlobal(header.data);
Marshal.FreeHGlobal(headerPtr);
}
#endregion
#region Properties
/// <summary>
/// The length of the system exclusive buffer.
/// </summary>
public int BufferLength
{
get
{
return bufferLength;
}
set
{
#region Require
if(value <= 0)
{
throw new ArgumentOutOfRangeException("BufferLength", value,
"MIDI header buffer length out of range.");
}
#endregion
bufferLength = value;
data = new byte[value];
}
}
/// <summary>
/// Gets the pointer to the MidiHeader.
/// </summary>
public IntPtr Result
{
get
{
return result;
}
}
#endregion
}
}