Amend Me

Engine.Systems/StateMachine/IState.cs

@@ -4,10 +4,10 @@ namespace Syntriax.Engine.Systems.StateMachine;
 
 public interface IState : IEntity, INameable
 {
-    event StateUpdateEventHandler? OnStateUpdate;
-    event StateTransitionedFromEventHandler? OnStateTransitionedFrom;
-    event StateTransitionedToEventHandler? OnStateTransitionedTo;
-    event StateTransitionReadyEventHandler? OnStateTransitionReady;
+    Event<IState> OnStateUpdate { get; }
+    Event<IState, StateTransitionedFromArguments> OnStateTransitionedFrom { get; }
+    Event<IState, StateTransitionedToArguments> OnStateTransitionedTo { get; }
+    Event<IState, StateTransitionReadyArguments> OnStateTransitionReady { get; }
 
     IState? GetNextState();
 
@@ -15,8 +15,7 @@ public interface IState : IEntity, INameable
     void TransitionTo(IState from);
     void TransitionFrom(IState to);
 
-    delegate void StateUpdateEventHandler(IState sender);
-    delegate void StateTransitionedFromEventHandler(IState sender, IState toState);
-    delegate void StateTransitionedToEventHandler(IState sender, IState fromState);
-    delegate void StateTransitionReadyEventHandler(IState sender, IState toState);
+    readonly record struct StateTransitionedFromArguments(IState ToState);
+    readonly record struct StateTransitionedToArguments(IState FromState);
+    readonly record struct StateTransitionReadyArguments(IState ToState);
 }

Engine.Systems/StateMachine/State.cs

@@ -6,11 +6,11 @@ namespace Syntriax.Engine.Systems.StateMachine;
 
 public class State : BaseEntity, IState
 {
-    public event IState.StateUpdateEventHandler? OnStateUpdate = null;
-    public event IState.StateTransitionedFromEventHandler? OnStateTransitionedFrom = null;
-    public event IState.StateTransitionedToEventHandler? OnStateTransitionedTo = null;
-    public event IState.StateTransitionReadyEventHandler? OnStateTransitionReady = null;
-    public Event<INameable, string> OnNameChanged { get; private set; } = new();
+    public Event<IState> OnStateUpdate { get; init; } = new();
+    public Event<IState, IState.StateTransitionedFromArguments> OnStateTransitionedFrom { get; init; } = new();
+    public Event<IState, IState.StateTransitionedToArguments> OnStateTransitionedTo { get; init; } = new();
+    public Event<IState, IState.StateTransitionReadyArguments> OnStateTransitionReady { get; init; } = new();
+    public Event<INameable, INameable.NameChangedArguments> OnNameChanged { get; init; } = new();
 
     private readonly List<StateTransition> transitions = [];
     private readonly Dictionary<string, StateTransition> possibleTransitions = [];
@@ -28,7 +28,7 @@ public class State : BaseEntity, IState
 
             string previousName = _name;
             _name = value;
-            OnNameChanged?.Invoke(this, previousName);
+            OnNameChanged?.Invoke(this, new(previousName));
         }
     }
 
@@ -53,12 +53,12 @@ public class State : BaseEntity, IState
     public void Update()
     {
         if (GetNextState() is IState transitionState)
-            OnStateTransitionReady?.Invoke(this, transitionState);
+            OnStateTransitionReady?.Invoke(this, new(transitionState));
         OnStateUpdate?.Invoke(this);
     }
 
-    public void TransitionTo(IState from) => OnStateTransitionedTo?.Invoke(this, from);
-    public void TransitionFrom(IState to) => OnStateTransitionedFrom?.Invoke(this, to);
+    public void TransitionTo(IState from) => OnStateTransitionedTo?.Invoke(this, new(from));
+    public void TransitionFrom(IState to) => OnStateTransitionedFrom?.Invoke(this, new(to));
 
     public IState? GetNextState()
     {

Engine.Systems/StateMachine/StateBehaviourBase.cs

@@ -4,13 +4,11 @@ namespace Syntriax.Engine.Systems.StateMachine;
 
 public abstract class StateBehaviourBase : Behaviour, IState
 {
-    public event IState.StateUpdateEventHandler? OnStateUpdate = null;
-    public event IState.StateTransitionedFromEventHandler? OnStateTransitionedFrom = null;
-    public event IState.StateTransitionedToEventHandler? OnStateTransitionedTo = null;
-
-    public Event<INameable, string> OnNameChanged { get; private set; } = new();
-
-    public abstract event IState.StateTransitionReadyEventHandler? OnStateTransitionReady;
+    public Event<IState> OnStateUpdate { get; init; } = new();
+    public Event<IState, IState.StateTransitionedFromArguments> OnStateTransitionedFrom { get; init; } = new();
+    public Event<IState, IState.StateTransitionedToArguments> OnStateTransitionedTo { get; init; } = new();
+    public Event<IState, IState.StateTransitionReadyArguments> OnStateTransitionReady { get; init; } = new();
+    public Event<INameable, INameable.NameChangedArguments> OnNameChanged { get; init; } = new();
 
     private string _name = string.Empty;
     public string Name
@@ -23,7 +21,7 @@ public abstract class StateBehaviourBase : Behaviour, IState
 
             string previousName = _name;
             _name = value;
-            OnNameChanged?.Invoke(this, previousName);
+            OnNameChanged?.Invoke(this, new(previousName));
         }
     }
 
@@ -38,14 +36,14 @@ public abstract class StateBehaviourBase : Behaviour, IState
     public void TransitionTo(IState from)
     {
         OnTransitionedToState(from);
-        OnStateTransitionedTo?.Invoke(this, from);
+        OnStateTransitionedTo?.Invoke(this, new(from));
     }
 
     protected virtual void OnTransitionedFromState(IState to) { }
     public void TransitionFrom(IState to)
     {
         OnTransitionedFromState(to);
-        OnStateTransitionedFrom?.Invoke(this, to);
+        OnStateTransitionedFrom?.Invoke(this, new(to));
     }
 
     public abstract IState? GetNextState();

Engine.Systems/StateMachine/StateMachine.cs

@@ -5,9 +5,17 @@ namespace Syntriax.Engine.Systems.StateMachine;
 
 public class StateMachine : Behaviour
 {
-    public event StateChangedEventHandler? OnStateChanged = null;
+    public Event<StateMachine, StateChangedArguments> OnStateChanged { get; init; } = new();
+
+    private readonly Event<IState, IState.StateTransitionReadyArguments>.EventHandler cachedOnStateTransitionReady = null!;
 
     private IState _state = new State();
+
+    public StateMachine()
+    {
+        cachedOnStateTransitionReady = OnStateTransitionReady;
+    }
+
     [Serialize]
     public IState State
     {
@@ -18,20 +26,20 @@ public class StateMachine : Behaviour
                 return;
 
             IState previousState = _state;
-            previousState.OnStateTransitionReady -= OnStateTransitionReady;
+            previousState.OnStateTransitionReady.RemoveListener(cachedOnStateTransitionReady);
 
             _state = value;
             previousState.TransitionFrom(value);
             value.TransitionTo(_state);
-            OnStateChanged?.Invoke(this, previousState, value);
+            OnStateChanged?.Invoke(this, new(value, previousState));
 
-            value.OnStateTransitionReady += OnStateTransitionReady;
+            value.OnStateTransitionReady.AddListener(cachedOnStateTransitionReady);
         }
     }
 
-    private void OnStateTransitionReady(IState sender, IState toState)
+    private void OnStateTransitionReady(IState sender, IState.StateTransitionReadyArguments arguments)
     {
-        State = toState;
+        State = arguments.ToState;
         while (State.GetNextState() is IState nextState)
             State = nextState;
     }
@@ -47,5 +55,5 @@ public class StateMachine : Behaviour
         State.Update();
     }
 
-    public delegate void StateChangedEventHandler(StateMachine sender, IState previousState, IState newState);
+    public readonly record struct StateChangedArguments(IState CurrentState, IState PreviousState);
 }