- only send acknowledge message for veloctiy.on

Lib.Audio/Channel.cs

@@ -4,6 +4,7 @@
 
 using System.Collections.Generic;
 using System.Linq;
+using Lib.Audio.Controls;
 using Lib.Audio.Controls.Buttons.Factories;
 using Lib.Audio.Controls.Buttons.Interfaces;
 using Lib.Audio.Controls.Factories;
@@ -60,7 +61,7 @@ namespace Lib.Audio
                 else 
                 {
                     IButton? button = Buttons?.FirstOrDefault(b => b.NoteNumber == noteOnMessage.NoteNumber);
-                    _acknowledgeMessage = button?.HandleOn(Controllable, noteOnMessage.Velocity);
+                    _acknowledgeMessage = button?.Handle(Controllable, (Velocity) noteOnMessage.Velocity);
                 }
             }
             else if (message is NoteMessage noteMessage)
@@ -73,7 +74,7 @@ namespace Lib.Audio
                 else 
                 {
                     IButton? button = Buttons?.FirstOrDefault(b => b.NoteNumber == noteMessage.NoteNumber);
-                    _acknowledgeMessage = button?.HandleOff(Controllable, noteMessage.Velocity);
+                    _acknowledgeMessage = button?.Handle(Controllable, (Velocity) noteMessage.Velocity);
                 }
             }
             else if (message is PitchWheelChangeMessage pitchWheelChangeMessage)

Lib.Audio/Controls/Buttons/Button.cs

@@ -20,11 +20,23 @@ namespace Lib.Audio.Controls.Buttons
         }
 
         public int NoteNumber { get; }
+        protected bool IsActive { get; private set; }
         
-        public virtual IMidiMessage HandleOn(IControllable? controllable, int velocity) =>
-            new NoteOnMessage(0, _channelNumber, NoteNumber, velocity, 0);
+        public virtual IMidiMessage? Handle(IControllable? controllable, Velocity velocity)
+        {
+            if (velocity != Velocity.On)
+                return null;
+            
+            IsActive = !IsActive;
+            Handle(controllable);
+            
+            return IsActive ? new NoteOnMessage(0, _channelNumber, NoteNumber, (int) Velocity.On, 0)
+                : new NoteMessage(0, _channelNumber, NoteNumber, (int) Velocity.Off);
+        }
 
-        public virtual IMidiMessage HandleOff(IControllable? controllable, int velocity) => 
-            new NoteMessage(0, _channelNumber, NoteNumber, velocity);
+        protected virtual void Handle(IControllable? controllable)
+        {
+            
+        }
     }
 }

Lib.Audio/Controls/Buttons/Interfaces/IButton.cs

@@ -11,7 +11,6 @@ namespace Lib.Audio.Controls.Buttons.Interfaces
     {
         int NoteNumber { get; }
 
-        IMidiMessage HandleOn(IControllable? controllable, int velocity);
-        IMidiMessage HandleOff(IControllable? controllable, int velocity);
+        IMidiMessage? Handle(IControllable? controllable, Velocity velocity);
     }
 }

Lib.Audio/Controls/Buttons/MuteButton.cs

@@ -4,7 +4,6 @@
 
 using Lib.Audio.Controls.Buttons.Interfaces;
 using Lib.Audio.Interfaces;
-using Lib.Midi.Messages.Interfaces;
 
 namespace Lib.Audio.Controls.Buttons
 {
@@ -16,16 +15,12 @@ namespace Lib.Audio.Controls.Buttons
             
         }
 
-        public override IMidiMessage HandleOn(IControllable? controllable, int velocity)
+        protected override void Handle(IControllable? controllable)
         {
+            if (IsActive)
                 controllable?.Mute();
-            return base.HandleOn(controllable, velocity);
-        }
-
-        public override IMidiMessage HandleOff(IControllable? controllable, int velocity)
-        {
+            else
                 controllable?.UnMute();
-            return base.HandleOff(controllable, velocity);
         }
     }
 }