import { ElementRef, NgZone, OnDestroy, ViewContainerRef } from '@angular/core';
import { Overlay, OverlayRef } from '@angular/cdk/overlay';
import { Directionality } from '@angular/cdk/bidi';
import { Subject } from 'rxjs';
import { HcPopComponent } from './popover.component';
import { HcPopoverOpenOptions } from './types';
import { HcPopoverAnchorDirective } from './directives/popover-anchor.directive';
export declare class HcPopoverAnchoringService implements OnDestroy {
    private _overlay;
    private _ngZone;
    private _dir;
    /** Emits when the popover is opened. */
    popoverOpened: Subject<void>;
    /** Emits when the popover is closed. */
    popoverClosed: Subject<void>;
    /** Reference to the overlay containing the popover component. */
    _overlayRef: OverlayRef | null;
    /** Reference to the target popover. */
    private _popover;
    /** Stores the context assigned to the popover */
    _context: any;
    /** Reference to the view container for the popover template. */
    private _viewContainerRef;
    /** Reference to the anchor */
    private _anchor;
    /** Reference to a template portal where the overlay will be attached. */
    private _portal;
    /** Communications channel with the popover. */
    private _notifications;
    /** Single subscription to notifications service events. */
    private _notificationsSubscription;
    /** Single subscription to position changes. */
    private _positionChangeSubscription;
    /** Whether the popover is presently open. */
    private _popoverOpen;
    /** Emits when the service is destroyed. */
    private _onDestroy;
    constructor(_overlay: Overlay, _ngZone: NgZone, _dir: Directionality);
    ngOnDestroy(): void;
    /** Anchor a popover instance to a view and connection element. */
    anchor(popover: HcPopComponent, viewContainerRef: ViewContainerRef, anchor: HcPopoverAnchorDirective): void;
    /** Gets whether the popover is presently open. */
    isPopoverOpen(): boolean;
    /** Toggles the popover between the open and closed states. */
    togglePopover(): void;
    /** Opens the popover. */
    openPopover(options?: HcPopoverOpenOptions): void;
    /** Closes the popover. */
    closePopover(value?: any): void;
    /** Realign the popover to the anchor. */
    realignPopoverToAnchor(): void;
    /** Get a reference to the anchor element. */
    getAnchorElement(): ElementRef;
    /** Apply behavior properties on the popover based on the open options. */
    private _applyOpenOptions;
    /** Create an overlay to be attached to the portal. */
    private _createOverlay;
    /** Removes the popover from the DOM. Does NOT update open state. */
    private _destroyPopover;
    /**
     * Destroys the popover immediately if it is closed, or waits until it
     * has been closed to destroy it.
     */
    private _destroyPopoverOnceClosed;
    /**
     * Call appropriate anchor method when an event is dispatched through
     * the notification service.
     */
    private _subscribeToNotifications;
    /** Close popover when backdrop is clicked. */
    private _subscribeToBackdrop;
    /** Close popover when escape keydown event occurs. */
    private _subscribeToEscape;
    /** Set state back to closed when detached. */
    private _subscribeToDetachments;
    /** Save the opened state of the popover and emit. */
    private _saveOpenedState;
    /** Save the closed state of the popover and emit. */
    private _saveClosedState;
    /** Gets the text direction of the containing app. */
    private _getDirection;
    /** Create and return a config for creating the overlay. */
    private _getOverlayConfig;
    /**
     * Listen to changes in the position of the overlay and set the correct alignment classes,
     * ensuring that the animation origin is correct, even with a fallback position.
     */
    private _subscribeToPositionChanges;
    /** Map a scroll strategy string type to an instance of a scroll strategy. */
    private _getScrollStrategyInstance;
    /** Create and return a position strategy based on config provided to the component instance. */
    private _getPositionStrategy;
    /** Get fallback positions based around target alignments. */
    private _getFallbacks;
}