import { ElementRef } from '@angular/core';
import { Platform } from '@bravobit/bb-foundation';
export declare class BbFocusTrap {
    private _platform;
    private _elementRef;
    private readonly _focusableElements;
    constructor(_platform: Platform, _elementRef: ElementRef);
    onKeydown(event: KeyboardEvent): void;
    trapFocus(event: KeyboardEvent): void;
    private readonly element;
    private getFocusableNodes;
    private focus;
    private isTabEvent;
}
