import { BooleanInput } from '@angular/cdk/coercion';
import { AfterViewInit, ElementRef, EventEmitter, OnChanges, OnDestroy, SimpleChanges } from '@angular/core';
import { AbstractControl, ControlValueAccessor, ValidationErrors, Validator, ValidatorFn } from '@angular/forms';
import { ThemePalette } from '@angular/material/core';
import { Subject } from 'rxjs';
import { NgxMatDateAdapter } from './core/date-adapter';
import { NgxMatDateFormats } from './core/date-formats';
import { NgxDateSelectionModelChange, NgxExtractDateTypeFromSelection, NgxMatDateSelectionModel } from './date-selection-model';
import * as i0 from "@angular/core";
/**
 * An event used for datepicker input and change events. We don't always have access to a native
 * input or change event because the event may have been triggered by the user clicking on the
 * calendar popup. For consistency, we always use MatDatepickerInputEvent instead.
 */
export declare class NgxMatDatepickerInputEvent<D, S = unknown> {
    /** Reference to the datepicker input component that emitted the event. */
    target: NgxMatDatepickerInputBase<S, D>;
    /** Reference to the native input element associated with the datepicker input. */
    targetElement: HTMLElement;
    /** The new value for the target datepicker input. */
    value: D | null;
    constructor(
    /** Reference to the datepicker input component that emitted the event. */
    target: NgxMatDatepickerInputBase<S, D>, 
    /** Reference to the native input element associated with the datepicker input. */
    targetElement: HTMLElement);
}
/** Function that can be used to filter out dates from a calendar. */
export type NgxDateFilterFn<D> = (date: D | null) => boolean;
/**
 * Partial representation of `MatFormField` that is used for backwards-compatibility
 * between the legacy and non-legacy variants.
 */
export interface _NgxMatFormFieldPartial {
    getConnectedOverlayOrigin(): ElementRef;
    getLabelId(): string | null;
    color: ThemePalette;
    _elementRef: ElementRef;
    _shouldLabelFloat(): boolean;
    _hasFloatingLabel(): boolean;
    _labelId: string;
}
/** Base class for datepicker inputs. */
export declare abstract class NgxMatDatepickerInputBase<S, D = NgxExtractDateTypeFromSelection<S>> implements ControlValueAccessor, AfterViewInit, OnChanges, OnDestroy, Validator {
    protected _elementRef: ElementRef<HTMLInputElement>;
    _dateAdapter: NgxMatDateAdapter<D>;
    private _dateFormats;
    /** Whether the component has been initialized. */
    private _isInitialized;
    /** The value of the input. */
    get value(): D | null;
    set value(value: any);
    protected _model: NgxMatDateSelectionModel<S, D> | undefined;
    /** Whether the datepicker-input is disabled. */
    get disabled(): boolean;
    set disabled(value: BooleanInput);
    private _disabled;
    /** Emits when a `change` event is fired on this `<input>`. */
    readonly dateChange: EventEmitter<NgxMatDatepickerInputEvent<D, S>>;
    /** Emits when an `input` event is fired on this `<input>`. */
    readonly dateInput: EventEmitter<NgxMatDatepickerInputEvent<D, S>>;
    /** Emits when the internal state has changed */
    readonly stateChanges: Subject<void>;
    _onTouched: () => void;
    _validatorOnChange: () => void;
    private _cvaOnChange;
    private _valueChangesSubscription;
    private _localeSubscription;
    /**
     * Since the value is kept on the model which is assigned in an Input,
     * we might get a value before we have a model. This property keeps track
     * of the value until we have somewhere to assign it.
     */
    private _pendingValue;
    /** The form control validator for whether the input parses. */
    private _parseValidator;
    /** The form control validator for the date filter. */
    private _filterValidator;
    /** The form control validator for the min date. */
    private _minValidator;
    /** The form control validator for the max date. */
    private _maxValidator;
    /** Gets the base validator functions. */
    protected _getValidators(): ValidatorFn[];
    /** Gets the minimum date for the input. Used for validation. */
    abstract _getMinDate(): D | null;
    /** Gets the maximum date for the input. Used for validation. */
    abstract _getMaxDate(): D | null;
    /** Gets the date filter function. Used for validation. */
    protected abstract _getDateFilter(): NgxDateFilterFn<D> | undefined;
    /** Registers a date selection model with the input. */
    _registerModel(model: NgxMatDateSelectionModel<S, D>): void;
    /** Opens the popup associated with the input. */
    protected abstract _openPopup(): void;
    /** Assigns a value to the input's model. */
    protected abstract _assignValueToModel(model: D | null): void;
    /** Converts a value from the model into a native value for the input. */
    protected abstract _getValueFromModel(modelValue: S): D | null;
    /** Combined form control validator for this input. */
    protected abstract _validator: ValidatorFn | null;
    /** Predicate that determines whether the input should handle a particular change event. */
    protected abstract _shouldHandleChangeEvent(event: NgxDateSelectionModelChange<S>): boolean;
    /** Whether the last value set on the input was valid. */
    protected _lastValueValid: boolean;
    constructor(_elementRef: ElementRef<HTMLInputElement>, _dateAdapter: NgxMatDateAdapter<D>, _dateFormats: NgxMatDateFormats);
    ngAfterViewInit(): void;
    ngOnChanges(changes: SimpleChanges): void;
    ngOnDestroy(): void;
    /** @docs-private */
    registerOnValidatorChange(fn: () => void): void;
    /** @docs-private */
    validate(c: AbstractControl): ValidationErrors | null;
    writeValue(value: D): void;
    registerOnChange(fn: (value: any) => void): void;
    registerOnTouched(fn: () => void): void;
    setDisabledState(isDisabled: boolean): void;
    _onKeydown(event: KeyboardEvent): void;
    _onInput(value: string): void;
    _onChange(): void;
    /** Handles blur events on the input. */
    _onBlur(): void;
    /** Formats a value and sets it on the input element. */
    protected _formatValue(value: D | null): void;
    /** Assigns a value to the model. */
    private _assignValue;
    /** Whether a value is considered valid. */
    private _isValidValue;
    /**
     * Checks whether a parent control is disabled. This is in place so that it can be overridden
     * by inputs extending this one which can be placed inside of a group that can be disabled.
     */
    protected _parentDisabled(): boolean;
    /** Programmatically assigns a value to the input. */
    protected _assignValueProgrammatically(value: D | null): void;
    /** Gets whether a value matches the current date filter. */
    _matchesFilter(value: D | null): boolean;
    static ɵfac: i0.ɵɵFactoryDeclaration<NgxMatDatepickerInputBase<any, any>, [null, { optional: true; }, { optional: true; }]>;
    static ɵdir: i0.ɵɵDirectiveDeclaration<NgxMatDatepickerInputBase<any, any>, never, never, { "value": { "alias": "value"; "required": false; }; "disabled": { "alias": "disabled"; "required": false; }; }, { "dateChange": "dateChange"; "dateInput": "dateInput"; }, never, never, true, never>;
}
/**
 * Checks whether the `SimpleChanges` object from an `ngOnChanges`
 * callback has any changes, accounting for date objects.
 */
export declare function dateInputsHaveChanged(changes: SimpleChanges, adapter: NgxMatDateAdapter<unknown>): boolean;