/**
 * Type-safe event emitter — engine-neutral.
 *
 * The emitter itself never knew anything about 3D; it only lived in `stage`
 * because that is where the app lived. Anything that wants to announce state
 * changes (an app, a board, a manager) can now use it without pulling in the
 * renderer.
 */
export type Listener<T = unknown> = (data: T) => void;
/**
 * Events every app announces, whatever it renders.
 *
 * Engines extend this with their own map; `history-change` is here because
 * `CommandManager` — also core's — emits it.
 */
export interface AppEventMap {
    "history-change": {
        canUndo: boolean;
        canRedo: boolean;
    };
}
/**
 * Instantiate with an event map and every `on` / `off` / `emit` is checked
 * against it at compile time.
 */
export declare class EventEmitter<TMap = Record<string, unknown>> {
    private listeners;
    /** Subscribe; the returned function unsubscribes. */
    on<K extends string & keyof TMap>(event: K, listener: Listener<TMap[K]>): () => void;
    off<K extends string & keyof TMap>(event: K, listener: Listener<TMap[K]>): void;
    /** Iterates a copy, so a listener may unsubscribe during dispatch. */
    emit<K extends string & keyof TMap>(event: K, data: TMap[K]): void;
    clear(): void;
}