/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.dev/license
 */
export type AriaLivePoliteness = 'off' | 'polite' | 'assertive';
/**
 * Allows to announce messages to screen readers.
 *
 * Adapted from https://github.com/angular/components/blob/main/src/cdk/a11y/live-announcer/live-announcer.ts
 */
export declare class SbbLiveAnnouncer {
    private _liveElement;
    private _previousTimeout;
    private _currentPromise;
    private _currentResolve;
    constructor();
    /**
     * Announces a message to screen readers.
     * @param message Message to be announced to the screen reader.
     * @returns Promise that will be resolved when the message is added to the DOM.
     */
    announce(message: string): Promise<void>;
    /**
     * Announces a message to screen readers.
     * @param message Message to be announced to the screen reader.
     * @param politeness The politeness of the announcer element.
     * @returns Promise that will be resolved when the message is added to the DOM.
     */
    announce(message: string, politeness?: AriaLivePoliteness): Promise<void>;
    /**
     * Announces a message to screen readers.
     * @param message Message to be announced to the screen reader.
     * @param duration Time in milliseconds after which to clear out the announcer element. Note
     *   that this takes effect after the message has been added to the DOM, which can be up to
     *   100ms after `announce` has been called.
     * @returns Promise that will be resolved when the message is added to the DOM.
     */
    announce(message: string, duration?: number): Promise<void>;
    /**
     * Announces a message to screen readers.
     * @param message Message to be announced to the screen reader.
     * @param politeness The politeness of the announcer element.
     * @param duration Time in milliseconds after which to clear out the announcer element. Note
     *   that this takes effect after the message has been added to the DOM, which can be up to
     *   100ms after `announce` has been called.
     * @returns Promise that will be resolved when the message is added to the DOM.
     */
    announce(message: string, politeness?: AriaLivePoliteness, duration?: number): Promise<void>;
    /**
     * Clears the current text from the announcer element. Can be used to prevent
     * screen readers from reading the text out again while the user is going
     * through the page landmarks.
     */
    clear(): void;
    destroy(): void;
    private _createLiveElement;
}
export declare const sbbLiveAnnouncer: SbbLiveAnnouncer;
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