MVH/NAudio-2.2.1/NAudio.Midi/Midi/KeySignatureEvent.cs
2024-06-07 00:47:07 +02:00

75 lines
2.4 KiB
C#

using System;
using System.IO;
namespace NAudio.Midi
{
/// <summary>
/// Represents a MIDI key signature event event
/// </summary>
public class KeySignatureEvent : MetaEvent
{
private readonly byte sharpsFlats;
private readonly byte majorMinor;
/// <summary>
/// Reads a new track sequence number event from a MIDI stream
/// </summary>
/// <param name="br">The MIDI stream</param>
/// <param name="length">the data length</param>
public KeySignatureEvent(BinaryReader br, int length)
{
if (length != 2)
{
throw new FormatException("Invalid key signature length");
}
sharpsFlats = br.ReadByte(); // sf=sharps/flats (-7=7 flats, 0=key of C,7=7 sharps)
majorMinor = br.ReadByte(); // mi=major/minor (0=major, 1=minor)
}
/// <summary>
/// Creates a new Key signature event with the specified data
/// </summary>
public KeySignatureEvent(int sharpsFlats, int majorMinor, long absoluteTime)
: base(MetaEventType.KeySignature, 2, absoluteTime)
{
this.sharpsFlats = (byte) sharpsFlats;
this.majorMinor = (byte) majorMinor;
}
/// <summary>
/// Creates a deep clone of this MIDI event.
/// </summary>
public override MidiEvent Clone() => (KeySignatureEvent)MemberwiseClone();
/// <summary>
/// Number of sharps or flats
/// </summary>
public int SharpsFlats => (sbyte)sharpsFlats;
/// <summary>
/// Major or Minor key
/// </summary>
public int MajorMinor => majorMinor;
/// <summary>
/// Describes this event
/// </summary>
/// <returns>String describing the event</returns>
public override string ToString()
{
return String.Format("{0} {1} {2}", base.ToString(), SharpsFlats, majorMinor);
}
/// <summary>
/// Calls base class export first, then exports the data
/// specific to this event
/// <seealso cref="MidiEvent.Export">MidiEvent.Export</seealso>
/// </summary>
public override void Export(ref long absoluteTime, BinaryWriter writer)
{
base.Export(ref absoluteTime, writer);
writer.Write(sharpsFlats);
writer.Write(majorMinor);
}
}
}