import { ChangeDetectorRef, ComponentFactoryResolver, ElementRef, EventEmitter, Injector, NgZone, OnDestroy, OnInit, Renderer2, TemplateRef, ViewContainerRef, ApplicationRef, OnChanges, SimpleChanges } from '@angular/core';
import { ControlValueAccessor } from '@angular/forms';
import { OperatorFunction } from 'rxjs';
import { Live } from '../util/accessibility/live';
import { PlacementArray } from '../util/positioning';
import { NgbTypeaheadConfig } from './typeahead-config';
import { ResultTemplateContext } from './typeahead-window';
/**
 * An event emitted right before an item is selected from the result list.
 */
export interface NgbTypeaheadSelectItemEvent<T = any> {
    /**
     * The item from the result list about to be selected.
     */
    item: T;
    /**
     * Calling this function will prevent item selection from happening.
     */
    preventDefault: () => void;
}
/**
 * A directive providing a simple way of creating powerful typeaheads from any text input.
 */
export declare class NgbTypeahead implements ControlValueAccessor, OnInit, OnChanges, OnDestroy {
    private _elementRef;
    private _renderer;
    private _live;
    private _document;
    private _ngZone;
    private _changeDetector;
    private _popupService;
    private _subscription;
    private _closed$;
    private _inputValueBackup;
    private _valueChanges;
    private _resubscribeTypeahead;
    private _windowRef;
    private _zoneSubscription;
    /**
     * The value for the `autocomplete` attribute for the `<input>` element.
     *
     * Defaults to `"off"` to disable the native browser autocomplete, but you can override it if necessary.
     *
     * @since 2.1.0
     */
    autocomplete: string;
    /**
     * A selector specifying the element the typeahead popup will be appended to.
     *
     * Currently only supports `"body"`.
     */
    container: string;
    /**
     * If `true`, model values will not be restricted only to items selected from the popup.
     */
    editable: boolean;
    /**
     * If `true`, the first item in the result list will always stay focused while typing.
     */
    focusFirst: boolean;
    /**
     * The function that converts an item from the result list to a `string` to display in the `<input>` field.
     *
     * It is called when the user selects something in the popup or the model value changes, so the input needs to
     * be updated.
     */
    inputFormatter: (item: any) => string;
    /**
     * The function that converts a stream of text values from the `<input>` element to the stream of the array of items
     * to display in the typeahead popup.
     *
     * If the resulting observable emits a non-empty array - the popup will be shown. If it emits an empty array - the
     * popup will be closed.
     *
     * See the [basic example](#/components/typeahead/examples#basic) for more details.
     *
     * Note that the `this` argument is `undefined` so you need to explicitly bind it to a desired "this" target.
     */
    ngbTypeahead: OperatorFunction<string, readonly any[]> | null | undefined;
    /**
     * The function that converts an item from the result list to a `string` to display in the popup.
     *
     * Must be provided, if your `ngbTypeahead` returns something other than `Observable<string[]>`.
     *
     * Alternatively for more complex markup in the popup you should use `resultTemplate`.
     */
    resultFormatter: (item: any) => string;
    /**
     * The template to override the way resulting items are displayed in the popup.
     *
     * See the [ResultTemplateContext](#/components/typeahead/api#ResultTemplateContext) for the template context.
     *
     * Also see the [template for results demo](#/components/typeahead/examples#template) for more details.
     */
    resultTemplate: TemplateRef<ResultTemplateContext>;
    /**
     * If `true`, will show the hint in the `<input>` when an item in the result list matches.
     */
    showHint: boolean;
    /**
     * The preferred placement of the typeahead.
     *
     * Possible values are `"top"`, `"top-left"`, `"top-right"`, `"bottom"`, `"bottom-left"`,
     * `"bottom-right"`, `"left"`, `"left-top"`, `"left-bottom"`, `"right"`, `"right-top"`,
     * `"right-bottom"`
     *
     * Accepts an array of strings or a string with space separated possible values.
     *
     * The default order of preference is `"bottom-left bottom-right top-left top-right"`
     *
     * Please see the [positioning overview](#/positioning) for more details.
     */
    placement: PlacementArray;
    /**
    * A custom class to append to the typeahead popup window
    *
    * Accepts a string containing CSS class to be applied on the `ngb-typeahead-window`.
    *
    * This can be used to provide instance-specific styling, ex. you can override popup window `z-index`
    *
    * @since 9.1.0
    */
    popupClass: string;
    /**
     * An event emitted right before an item is selected from the result list.
     *
     * Event payload is of type [`NgbTypeaheadSelectItemEvent`](#/components/typeahead/api#NgbTypeaheadSelectItemEvent).
     */
    selectItem: EventEmitter<NgbTypeaheadSelectItemEvent<any>>;
    activeDescendant: string | null;
    popupId: string;
    private _onTouched;
    private _onChange;
    constructor(_elementRef: ElementRef<HTMLInputElement>, viewContainerRef: ViewContainerRef, _renderer: Renderer2, injector: Injector, componentFactoryResolver: ComponentFactoryResolver, config: NgbTypeaheadConfig, ngZone: NgZone, _live: Live, _document: any, _ngZone: NgZone, _changeDetector: ChangeDetectorRef, applicationRef: ApplicationRef);
    ngOnInit(): void;
    ngOnChanges({ ngbTypeahead }: SimpleChanges): void;
    ngOnDestroy(): void;
    registerOnChange(fn: (value: any) => any): void;
    registerOnTouched(fn: () => any): void;
    writeValue(value: any): void;
    setDisabledState(isDisabled: boolean): void;
    /**
     * Dismisses typeahead popup window
     */
    dismissPopup(): void;
    /**
     * Returns true if the typeahead popup window is displayed
     */
    isPopupOpen(): boolean;
    handleBlur(): void;
    handleKeyDown(event: KeyboardEvent): void;
    private _openPopup;
    private _closePopup;
    private _selectResult;
    private _selectResultClosePopup;
    private _showHint;
    private _formatItemForInput;
    private _writeInputValue;
    private _subscribeToUserInput;
    private _unsubscribeFromUserInput;
}