/**
* @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
*/
/**
* @module upload/filereader
*/
import { type ObservableMixinConstructor } from "@ckeditor/ckeditor5-utils";
declare const FileReaderBase: ObservableMixinConstructor;
/**
* Wrapper over the native `FileReader`.
*/
export declare class FileReader extends FileReaderBase {
	total: number;
	/**
	* Instance of native FileReader.
	*/
	private readonly _reader;
	/**
	* Holds the data of an already loaded file. The file must be first loaded
	* by using {@link module:upload/filereader~FileReader#read `read()`}.
	*/
	private _data?;
	/**
	* Number of bytes loaded.
	*
	* @readonly
	* @observable
	*/
	loaded: number;
	/**
	* Creates an instance of the FileReader.
	*/
	constructor();
	/**
	* Returns error that occurred during file reading.
	*/
	get error(): DOMException | null;
	/**
	* Holds the data of an already loaded file. The file must be first loaded
	* by using {@link module:upload/filereader~FileReader#read `read()`}.
	*/
	get data(): string | undefined;
	/**
	* Reads the provided file.
	*
	* @param file Native File object.
	* @returns Returns a promise that will be resolved with file's content.
	* The promise will be rejected in case of an error or when the reading process is aborted.
	*/
	read(file: File): Promise<string>;
	/**
	* Aborts file reader.
	*/
	abort(): void;
}
export {};