import { ElementRef, Renderer2, AfterViewInit } from '@angular/core';
export declare class YangFuriganaDirective implements AfterViewInit {
    private el;
    private renderer;
    yangFurigana: string;
    yangFuriganaClass: string;
    yangFuriganaStyle: string;
    constructor(el: ElementRef, renderer: Renderer2);
    ngAfterViewInit(): void;
    /**
     * Check if the element passed as argument is a <span> element and has no child tags
     * @param el the Element to evaluate
     */
    private isValidElement;
    /**
     * Generate the template to be added to the HTML as result
     */
    private generateRubyTag;
}