import { ElementRef } from '@angular/core';
import { NumberInput } from '@angular/cdk/coercion';
import { SapphireOverlay } from '../../theme/public_api';
import * as i0 from "@angular/core";
/**
 * Use `spTooltip` to show extra information, in the form of plain text, which
 * is semantically attached to an element.
 */
export declare class TooltipDirective {
    private _overlay;
    private _elementRef;
    private _overlayRef;
    private _portal;
    private _closeTimeout;
    id: string;
    /**
     * The string to show inside the tooltip or null to disable it.
     */
    tooltipText: string | null;
    /**
     * The amount of time that has to pass before tooltip will show
     * upon user interaction activating it – aka "warm up" period.
     *
     * @default 500
     */
    get delay(): number | undefined;
    set delay(value: NumberInput);
    _delay: number;
    private handleGlobalEscapeKeyEvent;
    private onFocus;
    private onBlur;
    placement: 'start' | 'center' | 'end';
    isOpen: () => boolean | undefined;
    private ensureTooltipEntry;
    private closeOpenTooltips;
    show: () => void;
    hide: (immediate?: boolean) => void;
    warmup: () => void;
    private attachTooltipPortal;
    constructor(_overlay: SapphireOverlay, _elementRef: ElementRef<HTMLElement>);
    static ɵfac: i0.ɵɵFactoryDeclaration<TooltipDirective, never>;
    static ɵdir: i0.ɵɵDirectiveDeclaration<TooltipDirective, "[spTooltip]", ["spTooltip"], { "tooltipText": "spTooltip"; "delay": "spTooltipDelay"; "placement": "spTooltipPlacement"; }, {}, never, never, true, never>;
}