import { FormGroupDirective, NgControl, NgForm } from '@angular/forms';
import { ErrorStateMatcher } from '@angular/material/core';
import { Subject } from 'rxjs';
/** Base class for error state management */
export declare class FileInputBase {
    _defaultErrorStateMatcher: ErrorStateMatcher;
    _parentForm: NgForm | null;
    _parentFormGroup: FormGroupDirective | null;
    ngControl: NgControl;
    stateChanges: Subject<void>;
    private _errorState;
    constructor(_defaultErrorStateMatcher: ErrorStateMatcher, _parentForm: NgForm | null, _parentFormGroup: FormGroupDirective | null, ngControl: NgControl, stateChanges: Subject<void>);
    /** Determines whether the control is in an error state */
    get errorState(): boolean;
    /** Triggers error state update */
    updateErrorState(): void;
}