import { Graph } from "../../graph";
/**
 * KeyboardService
 * This is an internal service that manages keyboard state for the graph.
 *
 * It is used to detect keyboard state changes and to provide a reactive signal with the current keyboard state.
 *
 * @example
 * ```typescript
 * const keyboardService = new KeyboardService(graph);
 * keyboardService.$keyboardState.subscribe((state) => {
 *   console.log("is shift key pressed", state.shiftKey);
 *   console.log("is meta key pressed", state.metaKey);
 *   console.log("is ctrl key pressed", state.ctrlKey);
 *   console.log("is alt key pressed", state.altKey);
 * });
 * ```
 * @internal
 */
export declare class KeyboardService {
    private graph;
    protected $keyboardState: import("@preact/signals-core").Signal<{
        shiftKey: boolean;
        metaKey: boolean;
        ctrlKey: boolean;
        altKey: boolean;
    }>;
    protected lastEvent: KeyboardEvent | null;
    protected unsubscribes: (() => void)[];
    constructor(graph: Graph);
    isShiftPressed(): boolean;
    isMetaPressed(): boolean;
    isCtrlPressed(): boolean;
    isAltPressed(): boolean;
    protected keybordEvents: EventTarget;
    protected startListening(): void;
    onPress(key: string, cb: (event: CustomEvent<KeyboardEvent>) => void, options?: AddEventListenerOptions): () => void;
    onRelease(key: string, cb: (event: CustomEvent<KeyboardEvent>) => void, options?: AddEventListenerOptions): () => void;
    protected stopListening(): void;
    protected hasChanged(event: KeyboardEvent): boolean;
    protected notifyKeyCode(event: KeyboardEvent): void;
    protected handleKeyDown: (event: KeyboardEvent) => void;
    protected cleanup(): void;
}