Event System

The Interaction System uses two complementary event layers:

• C# events (event Action<TArgs>) — for code-side subscriptions with full type safety and zero Inspector setup.
• UnityEvents (SerializedField) — for Inspector-wired callbacks, usable by designers without code.

Both layers fire for the same lifecycle points.

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IInteractor C# events

All events are defined on IInteractor and implemented in InteractorBase.

InteractionStarted

Fires when the player first focuses on an interactable target.

interactor.InteractionStarted += (InteractionLifecycleEventArgs args) =>
{
    // args.Target — the IInteractable that was focused
    // args.Context — the current InteractionContext
    highlightOutline.Enable(args.Target.GetGameObject());
};

ActionsDiscovered

Fires after focus is established and the action list has been built. Carries the full (visible) action list.

interactor.ActionsDiscovered += (ActionsDiscoveredEventArgs args) =>
{
    // args.Target — the focused IInteractable
    // args.Actions — List<IInteractableAction> of visible actions
    // args.Context — the current InteractionContext
    hud.ShowActionMenu(args.Actions);
};

ShowActionsDiscovered

Fires specifically when the player enters “show actions” mode (by calling ShowInteractions()). Use this to display the selection UI; ActionsDiscovered fires earlier and is better for background setup.

ActionSelectionChanged

Fires whenever the selected action index changes (cycling with SelectNextAction / SelectPreviousAction).

interactor.ActionSelectionChanged += (ActionSelectionChangedEventArgs args) =>
{
    // args.Target — the focused IInteractable
    // args.Action — the newly selected IInteractableAction
    // args.Index — its index in the visible actions list
    hud.HighlightAction(args.Index);
};

ActionExecuted

Fires after an action has been executed successfully.

interactor.ActionExecuted += (ActionExecutedEventArgs args) =>
{
    // args.Target — the IInteractable
    // args.Action — the IInteractableAction that ran
    // args.Result — InteractionResult (Success, Failed, NotAvailable)
    audioSource.PlayOneShot(executeClip);
};

InteractionEnded

Fires when focus is lost (player looks away, EndInteraction() is called, or the target is destroyed).

interactor.InteractionEnded += (InteractionLifecycleEventArgs args) =>
{
    hud.HideActionMenu();
    highlightOutline.Disable();
};

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IInteractor UnityEvents

The same lifecycle points are exposed as serializable UnityEvent fields in the Inspector on InteractorBase:

Inspector field	Equivalent C# event
onInteractionStarted	InteractionStarted
onActionsDiscovered	ActionsDiscovered
onShowActionsDiscovered	ShowActionsDiscovered
onActionSelectionChanged	ActionSelectionChanged
onActionExecuted	ActionExecuted
onInteractionEnded	InteractionEnded

Drag any component method to these fields in the Inspector without writing any code.

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IInteractableAction.OnExecuted

Every action type (InteractableAction, InteractableActionSO, and wrappers) has a single OnExecuted UnityEvent that fires immediately after Execute() completes.

Use it for per-action feedback that doesn’t need to go through the main interactor pipeline (e.g., a particle burst tied to a specific pickup, audio on a door open).

Caution

OnExecuted fires before ActionExecuted on the interactor. If you need to react to the full result (including InteractionResult), subscribe to ActionExecuted instead.

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Event args reference

InteractionLifecycleEventArgs

Property	Type	Description
Target	IInteractable	The focused interactable
Context	InteractionContext	Current interaction context

ActionsDiscoveredEventArgs

Property	Type	Description
Target	IInteractable	The focused interactable
Actions	List<IInteractableAction>	Visible (filtered) actions
Context	InteractionContext	Current interaction context

ActionSelectionChangedEventArgs

Property	Type	Description
Target	IInteractable	The focused interactable
Action	IInteractableAction	Newly selected action
Index	int	Index in the visible actions list

ActionExecutedEventArgs

Property	Type	Description
Target	IInteractable	The focused interactable
Action	IInteractableAction	Action that was executed
Result	InteractionResult	Outcome of execution

InteractionContext

Property	Type	Description
Interactor	IInteractor	The interactor that initiated the interaction