Merge pull request #10194 from workgroupengineering/perf/core/Animatable

perf: Animatable small adjust

src/Avalonia.Base/Animation/Animatable.cs

@@ -29,6 +29,9 @@ namespace Avalonia.Animation
         private bool _transitionsEnabled = true;
         private bool _isSubscribedToTransitionsCollection = false;
         private Dictionary<ITransition, TransitionState>? _transitionState;
+        private NotifyCollectionChangedEventHandler? _collectionChanged;
+        private NotifyCollectionChangedEventHandler TransitionsCollectionChangedHandler => 
+            _collectionChanged ??= TransitionsCollectionChanged;
 
         /// <summary>
         /// Gets or sets the clock which controls the animations on the control.
@@ -61,14 +64,14 @@ namespace Avalonia.Animation
             {
                 _transitionsEnabled = true;
 
-                if (Transitions is object)
+                if (Transitions is Transitions transitions)
                 {
                     if (!_isSubscribedToTransitionsCollection)
                     {
                         _isSubscribedToTransitionsCollection = true;
-                        Transitions.CollectionChanged += TransitionsCollectionChanged;
+                        transitions.CollectionChanged += TransitionsCollectionChangedHandler;
                     }
-                    AddTransitions(Transitions);
+                    AddTransitions(transitions);
                 }
             }
         }
@@ -86,14 +89,14 @@ namespace Avalonia.Animation
             {
                 _transitionsEnabled = false;
 
-                if (Transitions is object)
+                if (Transitions is Transitions transitions)
                 {
                     if (_isSubscribedToTransitionsCollection)
                     {
                         _isSubscribedToTransitionsCollection = false;
-                        Transitions.CollectionChanged -= TransitionsCollectionChanged;
+                        transitions.CollectionChanged -= TransitionsCollectionChangedHandler;
                     }
-                    RemoveTransitions(Transitions);
+                    RemoveTransitions(transitions);
                 }
             }
         }
@@ -120,7 +123,7 @@ namespace Avalonia.Animation
                         toAdd = newTransitions.Except(oldTransitions).ToList();
                     }
 
-                    newTransitions.CollectionChanged += TransitionsCollectionChanged;
+                    newTransitions.CollectionChanged += TransitionsCollectionChangedHandler;
                     _isSubscribedToTransitionsCollection = true;
                     AddTransitions(toAdd);
                 }
@@ -134,19 +137,19 @@ namespace Avalonia.Animation
                         toRemove = oldTransitions.Except(newTransitions).ToList();
                     }
 
-                    oldTransitions.CollectionChanged -= TransitionsCollectionChanged;
+                    oldTransitions.CollectionChanged -= TransitionsCollectionChangedHandler;
                     RemoveTransitions(toRemove);
                 }
             }
             else if (_transitionsEnabled &&
-                     Transitions is object &&
+                     Transitions is Transitions transitions &&
                      _transitionState is object &&
                      !change.Property.IsDirect &&
                      change.Priority > BindingPriority.Animation)
             {
-                for (var i = Transitions.Count -1; i >= 0; --i)
+                for (var i = transitions.Count - 1; i >= 0; --i)
                 {
-                    var transition = Transitions[i];
+                    var transition = transitions[i];
 
                     if (transition.Property == change.Property &&
                         _transitionState.TryGetValue(transition, out var state))
@@ -166,11 +169,11 @@ namespace Avalonia.Animation
                             {
                                 oldValue = animatedValue;
                             }
-
+                            var clock = Clock ?? AvaloniaLocator.Current.GetRequiredService<IGlobalClock>();
                             state.Instance?.Dispose();
                             state.Instance = transition.Apply(
                                 this,
-                                Clock ?? AvaloniaLocator.Current.GetRequiredService<IGlobalClock>(),
+                                clock,
                                 oldValue,
                                 newValue);
                             return;