import { Ean13 } from './Ean13';
/**
 * Constructor.
 *
 * @param int gs1
 */
declare class Isbn extends Ean13 {
    private gs1;
    constructor(gs1?: Isbn.GS1 | null);
    /**
     * Adds the default label.
     */
    protected addDefaultLabel(): void;
    /**
     * Sets the first numbers of the barcode.
     *  - GS1_AUTO: Adds 978 before the code
     *  - GS1_PREFIX978: Adds 978 before the code
     *  - GS1_PREFIX979: Adds 979 before the code
     *
     * @param gs1 The GS1 code.
     */
    setGS1(gs1: Isbn.GS1): void;
    /**
     * Check chars allowed.
     */
    protected checkCharsAllowed(): void;
    /**
     * Check correct length.
     */
    protected checkCorrectLength(): void;
    /**
     * Creates the ISBN text.
     *
     * @return The ISBN text.
     */
    private createISBNText;
}
declare namespace Isbn {
    /**
     * GS1 Prefix.
     */
    enum GS1 {
        /**
         * Auto Prefix.
         */
        Auto = 0,
        /**
         * Prefix 978.
         */
        PREFIX978 = 1,
        /**
         * Prefix 979.
         */
        PREFIX979 = 2
    }
}
export { Isbn };