import { ReactiveControllerHost } from 'lit';
import { BaseController } from './base.controller.js';
export type MessageHandler = (payload: unknown) => void;
export type WildcardMessageHandler = (type: string, payload: unknown) => void;
/**
 * Controller for postMessage communication with iframes or other windows.
 *
 * @example
 * ```ts
 * class MyIframeHost extends LitElement {
 *   private messageBus = new MessageBusController(this);
 *
 *   connectedCallback() {
 *     super.connectedCallback();
 *     this.messageBus.onMessage('READY', (payload) => {
 *       console.log('Iframe is ready', payload);
 *     });
 *   }
 *
 *   sendToIframe() {
 *     this.messageBus.send('COMMAND', { action: 'do-something' });
 *   }
 * }
 * ```
 */
export declare class MessageBusController extends BaseController {
    private handlers;
    private wildcardHandlers;
    private targetOrigin;
    /**
     * @param host - The reactive controller host
     * @param targetOrigin - The origin to accept messages from and send messages to.
     *   SECURITY NOTE: Using '*' accepts messages from any origin which can be dangerous.
     *   Always specify an explicit origin in production environments.
     */
    constructor(host: ReactiveControllerHost, targetOrigin?: string);
    send(type: string, payload: unknown, targetWindow?: Window): void;
    sendToFrame(iframe: HTMLIFrameElement, type: string, payload: unknown): void;
    onMessage(type: string, handler: MessageHandler): () => void;
    onMessage(type: '*', handler: WildcardMessageHandler): () => void;
    private handleMessage;
    hostConnected(): void;
    hostDisconnected(): void;
}
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