import { ICanvasViewport, IFrame, IFrameSequence } from "./intefaces";
/**
 * RegExp expression to find last digits in a string
 */
export declare const RegExpLastDigitsMatch: RegExp;
/**
* Available events
**/
export declare const AppEvent: {
    viewport: {
        resize: string;
        scroll: string;
    };
    images: {
        progress: string;
        loaded: string;
    };
};
/**
* List of events
**/
export declare const EventList: unknown[];
/**
 * Debounce ot throttle function
 *
 * @param {func}
 * @param {threshold}
 * @returns
 */
export declare const debounce: <F extends (...args: any) => any>(func: F, threshold?: number) => any;
/**
 * Preload images
 *
 * @param {imagesList} Array of strings
 * @param {callback} CallbackFunction
 */
export declare function getImage(imageLink: string): Promise<HTMLImageElement>;
/**
 * Preloading image list
 *
 * @returns Promise<HTMLImageElement>[]
 */
export declare function preloadImages(frameOptions: IFrame): Promise<HTMLImageElement>[];
/**
 * Get scroll top position
 *
 * @returns number
 */
export declare function getScrollTop(): number;
/**
 * Get scroll top position
 *
 * @param {scrollTop}
 * @param {ICanvasViewport}
 * @returns number
 */
export declare function getScrollFraction(cViewport: ICanvasViewport, scrollTop?: number): number;
/**
 * Get frame URL by frame number
 *
 * @param {IFrame} frameOptions
 * @param {number} frameNumber
 * @returns {string}
 */
export declare function getFramePathByIndex(frameOptions: IFrame, frameNumber?: number): string;
/**
   * Get image base path
   *
   * @param firstFramePath
   * @returns
   */
export declare function getImageBasePath(firstFramePath: string): string;
/**
   * Get frame image structure
   *
   * @param {string} firstFramePath
   * @param {number} frameCount
   * @returns
   * @throws {AppError}
   */
export declare function getImageStructure(firstFramePath: string, frameCount: number): IFrameSequence;
/**
 * Get image sequence with leading zeros
 *
 * @param {string} imageName
 * @returns {string}
 * @throws {AppError} image sequence format not supported
 */
export declare function getImageSequence(imageName: string): string;
/**
 * Get file extension/suffix
 * Test whether is within supported extension/suffixes list
 *
 * @param fileName
 * @returns {string}
 * @throws {AppError} Unsupported image
 */
export declare function getFileSuffix(fileName: string): string;
/**
 * Get ending of a url
 *
 * @param path
 * @returns
 */
export declare function getPathEnding(path: string): string;