import { OnInit } from '@angular/core';
import { Nullable } from '@fundamental-ngx/cdk/utils';
import { NotificationGroupBaseDirective } from '../notification-utils/notification-group-base';
import * as i0 from "@angular/core";
export declare class NotificationGroupHeaderComponent extends NotificationGroupBaseDirective implements OnInit {
    /**
     * Title for the group header
     * default value: "Expand/Collapse"
     */
    title: import("@angular/core").WritableSignal<Nullable<string>>;
    /**
     * id of the list element that the group header controls
     * string value
     */
    ariaControls: import("@angular/core").WritableSignal<Nullable<string>>;
    /** @hidden */
    expanded: import("@angular/core").WritableSignal<boolean>;
    /** @hidden */
    readonly _buttonIcon$: import("@angular/core").Signal<"slim-arrow-down" | "slim-arrow-left" | "slim-arrow-right">;
    /** @hidden */
    private readonly _rtlService;
    /** @hidden */
    private readonly _lang$;
    /** @hidden */
    private _translationResolver;
    /** @hidden */
    keydownHandler(event: KeyboardEvent): void;
    /** Method that toggles the Notification list content */
    toggleExpand(): void;
    /** @hidden */
    ngOnInit(): void;
    static ɵfac: i0.ɵɵFactoryDeclaration<NotificationGroupHeaderComponent, never>;
    static ɵcmp: i0.ɵɵComponentDeclaration<NotificationGroupHeaderComponent, "fd-notification-group-header", never, {}, {}, never, ["fd-notification-group-header-title", "*"], true, never>;
}
