import { Observable } from 'rxjs';
import { APIFile, LocalFile } from './drag-drop.models';
/**
 * Helper to extend the base file with {@link APIFile} defaults
 * @param file file base that will be extended with {@link APIFile} defaults
 * @param data extra data to override defaults
 */
export declare const extendFile: (file: File | undefined, ...data: Array<Partial<Omit<LocalFile, "raw"> & APIFile>>) => LocalFile & APIFile;
/**
 * Checks if file matches allowed mime types
 * @param type file mime type
 * @param accept allowed mime types
 */
export declare const verifyAccept: (type: string, accept?: string) => boolean;
/**
 * Determines if browser supports drag and drop
 */
export declare const isDragDropAvailable: () => boolean;
/**
 * Pick only specified keys from a given object
 * @param keys keys to pick from a given object
 * @param object to extract keys from
 */
export declare const pick: <T, K extends keyof T>(object: T, ...keys: K[]) => Pick<T, K>;
/**
 * Will retry running the observable when an error occurs to a maximum limit, increasing delay between executions.
 * @param options specifies number of retries, scaling duration and statuses to exclude
 */
export declare const retryStrategy: ({ maxRetryAttempts, scalingDuration, excludedStatusCodes, }?: {
    maxRetryAttempts?: number;
    scalingDuration?: number;
    excludedStatusCodes?: number[];
}) => (attempts: Observable<any>) => Observable<0>;