chore: Updating message classes to make parsing input easier

src/Uno.UWP/Devices/Midi/Internal/MidiHelpers.cs

@@ -15,5 +15,30 @@ internal static byte GetChannel(byte firstMessageByte)
 		{
 			return (byte)(firstMessageByte & 0b0000_1111);
 		}
+
+		/// <summary>
+		/// Returns the MIDI bend value from two bytes in message.
+		/// </summary>
+		/// <param name="firstByte">First byte of the value in MIDI message order.</param>
+		/// <param name="secondByte">Second byte of the value in MIDI message order.</param>
+		/// <returns>Bend.</returns>
+		internal static ushort GetBend(byte firstByte, byte secondByte) => GetUshort(firstByte, secondByte);
+
+		/// <summary>
+		/// Returns the MIDI beats value from two bytes in message.
+		/// </summary>
+		/// <param name="firstByte">First byte of the value in MIDI message order.</param>
+		/// <param name="secondByte">Second byte of the value in MIDI message order.</param>
+		/// <returns>Beats.</returns>
+		internal static ushort GetBeats(byte firstByte, byte secondByte) => GetUshort(firstByte, secondByte);
+
+		/// <summary>
+		/// Reads an ushort value from two bytes (used for beats and bend).
+		/// The parameter value is encoded as using 7 bits of each byte.
+		/// </summary>
+		/// <param name="firstByte">First byte.</param>
+		/// <param name="secondByte">Second byte.</param>
+		/// <returns>Ushort value</returns>
+		private static ushort GetUshort(byte firstByte, byte secondByte) => (ushort)((secondByte << 7) | firstByte);
 	}
 }

src/Uno.UWP/Devices/Midi/Internal/MidiMessageParameter.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Uno.Devices.Midi.Internal
+{
+    internal enum MidiMessageParameter
+    {
+        Channel = 15,
+		Velocity = 127,
+		Pressure = 127,
+		Note = 127,
+		Controller = 127,
+		Control = 127,
+		Bend = 16383
+    }
+}

src/Uno.UWP/Devices/Midi/Internal/MidiMessageValidators.cs

@@ -5,23 +5,36 @@ namespace Uno.Devices.Midi.Internal
 {
 	internal static class MidiMessageValidators
 	{
-		internal static void VerifyMessageType(byte firstMessageByte, MidiMessageType type)
+		internal static void VerifyMessageLength(byte[] messageData, int expectedLength, MidiMessageType type)
+		{
+			if (messageData is null)
+			{
+				throw new ArgumentNullException(nameof(messageData));
+			}
+			if (messageData.Length != expectedLength)
+			{
+				throw new ArgumentException(
+					$"MIDI message of type {type} must have length of {expectedLength} bytes",
+					nameof(messageData));
+			}
+		}
+
+		internal static void VerifyMessageType(byte firstByte, MidiMessageType type)
 		{
 			var typeByte = (byte)type;
-			if ((firstMessageByte & typeByte) != typeByte)
+			if ((firstByte & typeByte) != typeByte)
 			{
 				throw new ArgumentException(
 					$"The message does not match expected type of {type}");
 			}
 		}
 
-		internal static void VerifyRange(int value, int max, string paramName)
+		internal static void VerifyRange(int value, MidiMessageParameter parameter)
 		{
-			if (value > max)
+			if (value > (int)parameter)
 			{
 				throw new ArgumentException(
-					$"{nameof(paramName)} must be a number in the range 0 - {max}",
-					paramName);
+					$"{parameter} must be a number in the range 0 - {(int)parameter}");
 			}
 		}
 	}

src/Uno.UWP/Devices/Midi/MidiActiveSensingMessage.cs

@@ -30,6 +30,6 @@ public MidiActiveSensingMessage()
 		/// Gets the duration from when the MidiInPort was created to the time the message was received.
 		/// For messages being sent to a MidiOutPort, this value has no meaning.
 		/// </summary>
-		public TimeSpan Timestamp { get; } = TimeSpan.Zero;
+		public TimeSpan Timestamp { get; internal set; } = TimeSpan.Zero;
 	}
 }

src/Uno.UWP/Devices/Midi/MidiChannelPressureMessage.cs

@@ -9,23 +9,30 @@ namespace Windows.Devices.Midi
 	/// </summary>
 	public partial class MidiChannelPressureMessage : IMidiMessage
 	{
+		private readonly InMemoryBuffer _buffer;
+
 		/// <summary>
 		/// Creates a new MidiChannelPressureMessage object.
 		/// </summary>
 		/// <param name="channel">The channel from 0-15 that this message applies to.</param>
 		/// <param name="pressure">The pressure from 0-127.</param>
 		public MidiChannelPressureMessage(byte channel, byte pressure)
+			: this(new byte[]
+			{
+				(byte)((byte)MidiMessageType.ChannelPressure | channel),
+				pressure
+			})
+		{			
+		}
+
+		internal MidiChannelPressureMessage(byte[] rawData)
 		{
-			MidiMessageValidators.VerifyRange(channel, 15, nameof(channel));
-			MidiMessageValidators.VerifyRange(pressure, 127, nameof(pressure));
+			MidiMessageValidators.VerifyMessageLength(rawData, 2, MidiMessageType.ChannelPressure);
+			MidiMessageValidators.VerifyMessageType(rawData[0], MidiMessageType.ChannelPressure);
+			MidiMessageValidators.VerifyRange(MidiHelpers.GetChannel(rawData[0]), MidiMessageParameter.Channel);
+			MidiMessageValidators.VerifyRange(rawData[1], MidiMessageParameter.Pressure);
 
-			Channel = channel;
-			Pressure = pressure;
-			RawData = new InMemoryBuffer(new byte[]
-			{
-				(byte)((byte)Type | Channel),
-				Pressure
-			});
+			_buffer = new InMemoryBuffer(rawData);
 		}
 
 		/// <summary>
@@ -36,22 +43,22 @@ public MidiChannelPressureMessage(byte channel, byte pressure)
 		/// <summary>
 		/// Gets the channel from 0-15 that this message applies to.
 		/// </summary>
-		public byte Channel { get; }
+		public byte Channel => MidiHelpers.GetChannel(_buffer.Data[0]);
 
 		/// <summary>
 		/// Gets the pressure from 0-127.
 		/// </summary>
-		public byte Pressure { get; }
+		public byte Pressure => _buffer.Data[1];
 
 		/// <summary>
 		/// Gets the array of bytes associated with the MIDI message, including status byte.
 		/// </summary>
-		public IBuffer RawData { get; }
+		public IBuffer RawData => _buffer;
 
 		/// <summary>
 		/// Gets the duration from when the MidiInPort was created to the time the message was received.
 		/// For messages being sent to a MidiOutPort, this value has no meaning.
 		/// </summary>
-		public TimeSpan Timestamp { get; } = TimeSpan.Zero;
+		public TimeSpan Timestamp { get; internal set; } = TimeSpan.Zero;
 	}
 }

src/Uno.UWP/Devices/Midi/MidiControlChangeMessage.cs

@@ -9,27 +9,33 @@ namespace Windows.Devices.Midi
 	/// </summary>
 	public partial class MidiControlChangeMessage : IMidiMessage
 	{
+		private readonly InMemoryBuffer _buffer;
+
 		/// <summary>
 		/// Creates a new MidiControlChangeMessage object.
 		/// </summary>
 		/// <param name="channel">The channel from 0-15 that this message applies to.</param>
 		/// <param name="controller">The controller from 0-127 to receive this message.</param>
 		/// <param name="controlValue">The value from 0-127 to apply to the controller.</param>
 		public MidiControlChangeMessage(byte channel, byte controller, byte controlValue)
+			: this(new byte[]
+			{
+				(byte)((byte)MidiMessageType.ControlChange | channel),
+				controller,
+				controlValue
+			})
+		{
+		}
+
+		internal MidiControlChangeMessage(byte[] rawData)
 		{
-			MidiMessageValidators.VerifyRange(channel, 15, nameof(channel));
-			MidiMessageValidators.VerifyRange(controller, 127, nameof(controller));
-			MidiMessageValidators.VerifyRange(controlValue, 127, nameof(controlValue));
+			MidiMessageValidators.VerifyMessageLength(rawData, 3, MidiMessageType.ControlChange);
+			MidiMessageValidators.VerifyMessageType(rawData[0], MidiMessageType.ControlChange);
+			MidiMessageValidators.VerifyRange(MidiHelpers.GetChannel(rawData[0]), MidiMessageParameter.Channel);
+			MidiMessageValidators.VerifyRange(rawData[1], MidiMessageParameter.Controller);
+			MidiMessageValidators.VerifyRange(rawData[2], MidiMessageParameter.Control);
 
-			Channel = channel;
-			Controller = controller;
-			ControlValue = controlValue;
-			RawData = new InMemoryBuffer(new byte[]
-			{
-				(byte)((byte)Type | Channel),
-				Controller,
-				ControlValue
-			});
+			_buffer = new InMemoryBuffer(rawData);
 		}
 
 		/// <summary>
@@ -40,27 +46,27 @@ public MidiControlChangeMessage(byte channel, byte controller, byte controlValue
 		/// <summary>
 		/// Gets the channel from 0-15 that this message applies to.
 		/// </summary>
-		public byte Channel { get; }
+		public byte Channel => MidiHelpers.GetChannel(_buffer.Data[0]);
 
 		/// <summary>
 		/// Gets the value from 0-127 to apply to the controller.
 		/// </summary>
-		public byte ControlValue { get; }
+		public byte ControlValue => _buffer.Data[2];
 
 		/// <summary>
 		/// Gets controller from 0-127 to receive this message.
 		/// </summary>
-		public byte Controller { get; }
+		public byte Controller => _buffer.Data[1];
 
 		/// <summary>
 		/// Gets the array of bytes associated with the MIDI message, including status byte.
 		/// </summary>
-		public IBuffer RawData { get; }
+		public IBuffer RawData => _buffer;
 
 		/// <summary>
 		/// Gets the duration from when the MidiInPort was created to the time the message was received.
 		/// For messages being sent to a MidiOutPort, this value has no meaning.
 		/// </summary>
-		public TimeSpan Timestamp { get; } = TimeSpan.Zero;
+		public TimeSpan Timestamp { get; internal set; } = TimeSpan.Zero;
 	}
 }

src/Uno.UWP/Devices/Midi/MidiNoteOffMessage.cs

@@ -28,20 +28,13 @@ public MidiNoteOffMessage(byte channel, byte note, byte velocity)
 
 		internal MidiNoteOffMessage(byte[] rawData)
 		{
-			if ((rawData[0] & (byte)MidiMessageType.NoteOff) == (byte)MidiMessageType.NoteOff)
-			{
+			MidiMessageValidators.VerifyMessageLength(rawData, 3, Type);
+			MidiMessageValidators.VerifyMessageType(rawData[0], Type);
+			MidiMessageValidators.VerifyRange(MidiHelpers.GetChannel(rawData[0]), MidiMessageParameter.Channel);
+			MidiMessageValidators.VerifyRange(rawData[1], MidiMessageParameter.Note);
+			MidiMessageValidators.VerifyRange(rawData[2], MidiMessageParameter.Velocity);
 
-			}
-				MidiMessageValidators.VerifyRange(channel, 15, nameof(channel));
-			MidiMessageValidators.VerifyRange(note, 127, nameof(note));
-			MidiMessageValidators.VerifyRange(velocity, 127, nameof(velocity));
-
-			_buffer = new InMemoryBuffer(new byte[]
-			{
-				(byte)((byte)Type | Channel),
-				Note,
-				Velocity
-			};
+			_buffer = new InMemoryBuffer(rawData);
 		}
 
 		/// <summary>
@@ -62,7 +55,7 @@ internal MidiNoteOffMessage(byte[] rawData)
 		/// <summary>
 		/// Gets the value of the velocity from 0-127.
 		/// </summary>
-		public byte Velocity { get; }
+		public byte Velocity => _buffer.Data[2];
 
 		/// <summary>
 		/// Gets the array of bytes associated with the MIDI message, including status byte.

src/Uno.UWP/Devices/Midi/MidiNoteOnMessage.cs

@@ -9,27 +9,33 @@ namespace Windows.Devices.Midi
 	/// </summary>
 	public partial class MidiNoteOnMessage : IMidiMessage
 	{
+		private readonly InMemoryBuffer _buffer;
+
 		/// <summary>
 		/// Creates a new MidiNoteOnMessage object.
 		/// </summary>
 		/// <param name="channel">The channel from 0-15 that this message applies to.</param>
 		/// <param name="note">The note which is specified as a value from 0-127.</param>
 		/// <param name="velocity">The velocity which is specified as a value from 0-127.</param>
 		public MidiNoteOnMessage(byte channel, byte note, byte velocity)
-		{
-			MidiMessageValidators.VerifyRange(channel, 15, nameof(channel));
-			MidiMessageValidators.VerifyRange(note, 127, nameof(note));
-			MidiMessageValidators.VerifyRange(velocity, 127, nameof(velocity));
-
-			Channel = channel;
-			Note = note;
-			Velocity = velocity;
-			RawData = new InMemoryBuffer(new byte[]
+			: this(new byte[]
 			{
 				(byte)((byte)Type | Channel),
 				Note,
 				Velocity
-			});
+			})
+		{			
+		}
+
+		internal MidiNoteOnMessage(byte[] rawData)
+		{
+			MidiMessageValidators.VerifyMessageLength(rawData, 3, Type);
+			MidiMessageValidators.VerifyMessageType(rawData[0], Type);
+			MidiMessageValidators.VerifyRange(MidiHelpers.GetChannel(rawData[0]), MidiMessageParameter.Channel);
+			MidiMessageValidators.VerifyRange(rawData[1], MidiMessageParameter.Note);
+			MidiMessageValidators.VerifyRange(rawData[2], MidiMessageParameter.Velocity);
+
+			_buffer = new InMemoryBuffer(rawData);
 		}
 
 		/// <summary>