import { Fragment } from 'prosemirror-model';
/**
 * 从 dataTransferItemList 获取文件集合
 */
export declare function getFiles(itemList: DataTransferItemList | DataTransferItem[] | undefined): never[];
/**
 * 将字节数格式化为 kb/M 显示格式
 */
export declare function byteSizeFormat(byteSize: number): string;
/**
 * 根据 pattern 导入所有组件
 */
export declare function importComponents(modules: {
    [propName: string]: any;
}): any;
/**
 * 下载文件
 */
export declare function downloadByUrl(url: string, filename: string): void;
/**
 * 获取首个符合选取规则的父级元素
 */
export declare function getMatchParentElement(el: HTMLElement, selectorStr: string): HTMLElement | null;
/**
 * 从 proseMirror 的 Fragment 中获取 textContent
 */
export declare function getTextContentByProseMirrorFragment(fragment: Fragment | undefined): string;
/**
 * 将 hex 格式转化 arrayBuffer, 可以用于转化 rtf 中的图片
 */
export declare function hexToBlob(str: string): ArrayBuffer | null;
/**
 * Uses canvas.measureText to compute and return the width of the given text of given font in pixels.
 *
 * @param {String} text The text to be rendered.
 * @param {String} font The css font descriptor that text is to be rendered with (e.g. "bold 14px verdana").
 *
 * @see https://stackoverflow.com/questions/118241/calculate-text-width-with-javascript/21015393#21015393
 */
export declare function getTextWidth(text: string, font: string): number;