import { ElementRef, OnInit, Renderer2 } from '@angular/core';
import { FormFieldDirective } from './form-field.directive';
export declare class FieldMaskDirective extends FormFieldDirective implements OnInit {
    protected element: ElementRef;
    protected renderer: Renderer2;
    /**
     * The mask can't contain numbers
     */
    private readonly MASK_SHOULD_NOT_HAVE_NUMBERS;
    private readonly MASK_MUST_FINISH_WITH_A_NUMBER;
    private generatedMaskConfig;
    setFormFieldMask: string;
    constructor(element: ElementRef, renderer: Renderer2);
    private generateMaskConfig;
    private getPartialMask;
    onInput(event: KeyboardEvent): void;
}