Finish rough implementation of the new syntax.

samples/RenderTest/Pages/AnimationsPage.xaml

@@ -52,6 +52,8 @@
             </KeyFrame> 
             <KeyFrame Cue="0%">
               <TransformSetter Property="RotateTransform.Angle" Value="360"/>
+              <TransformSetter Property="ScaleTransform.ScaleX" Value="2"/>
+              <TransformSetter Property="ScaleTransform.ScaleY" Value="2"/>
             </KeyFrame> 
             <KeyFrame Cue="100%">
               <DoubleSetter Property="Opacity" Value="1"/>

src/Avalonia.Animation/Animation.cs

@@ -74,9 +74,12 @@ namespace Avalonia.Animation
             this.CollectionChanged += delegate { _isChildrenChanged = true; };
         }
 
+
         private void InterpretKeyframes()
         {
-            var handlerList = new List<Type>();
+            var handlerList = new List<(Type, AvaloniaProperty)>();
+            var kfList = new List<AnimatorKeyFrame>();
+
 
             foreach (var keyframe in this)
             {
@@ -90,12 +93,45 @@ namespace Avalonia.Animation
                     if (!custAttr.Any())
                         throw new InvalidProgramException($"Type {setter.GetType()} doesn't have Animator attribute.");
 
-                    var match = (AnimatorAttribute)custAttr.First();
-                    if (!handlerList.Contains(match.HandlerType))
-                        handlerList.Add(match.HandlerType);
+                    var handler = ((AnimatorAttribute)custAttr.First()).HandlerType;
+                    if (!handlerList.Contains((handler, setter.Property)))
+                        handlerList.Add((handler, setter.Property));
+
+                    var newKF = new AnimatorKeyFrame()
+                    {
+                        Handler = handler,
+                        Property = setter.Property,
+                        Cue = keyframe.Cue,
+                        KeyTime = keyframe.KeyTime,
+                        timeSpanSet = keyframe.timeSpanSet,
+                        cueSet = keyframe.cueSet,
+                        Value = setter.Value
+                    };
+
+                    kfList.Add(newKF);
                 }
             }
 
+            var newAnimatorInstances = new List<(Type handler, AvaloniaProperty prop, IAnimator inst)>();
+
+            foreach (var handler in handlerList)
+            {
+                var newInstance = (IAnimator)Activator.CreateInstance(handler.Item1);
+                newInstance.Property = handler.Item2;
+                newAnimatorInstances.Add((handler.Item1, handler.Item2, newInstance));
+            }
+
+            foreach (var kf in kfList)
+            {
+                var parent = newAnimatorInstances.Where(p=>p.handler == kf.Handler &&
+                                                           p.prop == kf.Property)
+                                                 .First();
+                parent.inst.Add(kf);
+            }
+
+            foreach(var instance in newAnimatorInstances)
+                _animators.Add(instance.inst);
+
         }
 
         /// <summary>

src/Avalonia.Animation/AnimatorKeyFrame.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.ComponentModel;
+using Avalonia.Metadata;
+using Avalonia.Collections;
+
+namespace Avalonia.Animation
+{
+    
+    public class AnimatorKeyFrame
+    {
+        public Type Handler;
+        public Cue Cue;
+        public TimeSpan KeyTime;
+        internal bool timeSpanSet, cueSet;
+        internal AvaloniaProperty Property;
+        public object Value;
+    }
+
+}

src/Avalonia.Animation/Animator`1.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Animation
     /// <summary>
     /// Base class for KeyFrames objects
     /// </summary>
-    public abstract class Animator<T> : AvaloniaList<InternalKeyFrame>, IAnimator
+    public abstract class Animator<T> : AvaloniaList<AnimatorKeyFrame>, IAnimator
     {
         /// <summary>
         /// List of type-converted keyframes.
@@ -117,7 +117,7 @@ namespace Avalonia.Animation
         {
             var typeConv = TypeDescriptor.GetConverter(type);
 
-            foreach (InternalKeyFrame k in this)
+            foreach (AnimatorKeyFrame k in this)
             {
                 if (k.Value == null)
                 {

src/Avalonia.Animation/IAnimator.cs

@@ -5,13 +5,19 @@ using System.Text;
 namespace Avalonia.Animation
 {
     /// <summary>
-    /// Interface for Keyframe group object
+    /// Interface for Animator objects
     /// </summary>
-    public interface IAnimator
+    public interface IAnimator : IList<AnimatorKeyFrame>
     {
+        /// <summary>
+        /// The target property.
+        /// </summary>
+        AvaloniaProperty Property {get; set;}
+
         /// <summary>
         /// Applies the current KeyFrame group to the specified control.
         /// </summary>
         IDisposable Apply(Animation animation, Animatable control, IObservable<bool> obsMatch);
+        
     }
 }

src/Avalonia.Animation/KeyFrame.cs

@@ -75,12 +75,4 @@ namespace Avalonia.Animation
 
     }
 
-    public class InternalKeyFrame
-    {
-        public Cue Cue { get; set; }
-        public TimeSpan KeyTime { get; set; }
-        internal bool timeSpanSet, cueSet;
-        public object Value { get; set; }
-    }
-
 }

src/Avalonia.Visuals/Animation/TransformAnimator.cs

@@ -84,7 +84,7 @@ namespace Avalonia.Animation
         {
             childKeyFrames = new DoubleAnimator();
 
-            foreach (InternalKeyFrame keyframe in this)
+            foreach (AnimatorKeyFrame keyframe in this)
             {
                 childKeyFrames.Add(keyframe);
             }