Implemented keyboard as key-group

Devices/Keyboard/Keys/BaseKeyGroup.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Drawing;
 
 namespace CUE.NET.Devices.Keyboard.Keys
@@ -9,7 +10,8 @@ namespace CUE.NET.Devices.Keyboard.Keys
 
         protected CorsairKeyboard Keyboard { get; }
 
-        public IList<CorsairKey> Keys { get; } = new List<CorsairKey>();
+        public IEnumerable<CorsairKey> Keys => new ReadOnlyCollection<CorsairKey>(GroupKeys);
+        protected IList<CorsairKey> GroupKeys { get; } = new List<CorsairKey>();
 
         #endregion
 
@@ -26,15 +28,15 @@ namespace CUE.NET.Devices.Keyboard.Keys
 
         public virtual void SetColor(Color color)
         {
-            foreach (CorsairKey key in Keys)
+            foreach (CorsairKey key in GroupKeys)
                 key.Led.Color = color;
         }
 
         public void MergeKeys(IKeyGroup groupToMerge)
         {
             foreach (CorsairKey key in groupToMerge.Keys)
-                if (!Keys.Contains(key))
-                    Keys.Add(key);
+                if (!GroupKeys.Contains(key))
+                    GroupKeys.Add(key);
         }
 
         #endregion

Devices/Keyboard/Keys/IKeyGroup.cs

@@ -5,11 +5,8 @@ namespace CUE.NET.Devices.Keyboard.Keys
 {
     public interface IKeyGroup
     {
-        //TODO DarthAffe 19.09.2015: This might be not needed/bad
-        IList<CorsairKey> Keys { get; }
+        IEnumerable<CorsairKey> Keys { get; }
 
         void SetColor(Color color);
-
-        void MergeKeys(IKeyGroup groupToMerge);
     }
 }

Devices/Keyboard/Keys/RectangleKeyGroup.cs

@@ -35,7 +35,7 @@ namespace CUE.NET.Devices.Keyboard.Keys
             this.MinOverlayPercentage = minOverlayPercentage;
 
             foreach (CorsairKey key in Keyboard.Where(x => RectangleHelper.CalculateIntersectPercentage(x.KeyRectangle, requestedRectangle) >= minOverlayPercentage))
-                Keys.Add(key);
+                GroupKeys.Add(key);
         }
 
         #endregion

Devices/Keyboard/Keys/SimpleKeyGroup.cs

@@ -31,7 +31,7 @@ namespace CUE.NET.Devices.Keyboard.Keys
             if (keys != null)
                 foreach (CorsairKey key in keys)
                     if (key != null && !ContainsKey(key))
-                        Keys.Add(key);
+                        GroupKeys.Add(key);
 
         }
 
@@ -47,7 +47,7 @@ namespace CUE.NET.Devices.Keyboard.Keys
             if (keys != null)
                 foreach (CorsairKey key in keys)
                     if (key != null)
-                        Keys.Remove(key);
+                        GroupKeys.Remove(key);
         }
 
         public void RemoveKey(params CorsairKeyboardKeyId[] keyIds)
@@ -59,7 +59,7 @@ namespace CUE.NET.Devices.Keyboard.Keys
 
         public bool ContainsKey(CorsairKey key)
         {
-            return key != null && Keys.Contains(key);
+            return key != null && GroupKeys.Contains(key);
         }
 
         public bool ContainsKey(CorsairKeyboardKeyId keyId)