import { IRawStyle } from '@uifabric/merge-styles';
import { ITheme, ISemanticColors, IPalette } from '../interfaces/index';
/**
 * - Generates a style used to fade out an overflowing content by defining a style for an :after pseudo element.
 * - Apply it to the :after selector for all combination of states the parent of content might have (normal, hover,
 * selected, focus).
 * - Requires the target to have position set to relative and overflow set to hidden.
 *
 * @example
 * ```tsx
 * // Assuming the following DOM structure and the different background colors coming from
 * // the parent holding the content.
 * <div className={classNames.parent}>
 *   <span className={classNames.content}>Overflown Content</span>
 * </div>
 * ```
 * ```ts
 * // This is how the style set would look in Component.styles.ts
 * const { bodyBackground } = theme.semanticColors;
 * const { neutralLighter } = theme.palette;
 *
 * // The second argument of getFadedOverflowStyle function is a string representing a key of
 * // ISemanticColors or IPalette.
 *
 * const styles = {
 *   parent: [
 *     backgroundColor: bodyBackground,
 *     selectors: {
 *       '&:hover: {
 *         backgroundColor: neutralLighter
 *       },
 *       '$content:after': {
 *         ...getFadedOverflowStyle(theme, 'bodyBackground')
 *       },
 *       '&:hover $content:after': {
 *         ...getFadedOverflowStyle(theme, 'neutralLighter')
 *       }
 *     }
 *   ],
 *   content: [
 *     width: '100%',
 *     display: 'inline-block',
 *     position: 'relative',
 *     overflow: 'hidden'
 *   ]
 * }
 * ```
 * @param theme - The theme object to use.
 * @param color - The background color to fade out to. Accepts only keys of ISemanticColors or IPalette.
 * Defaults to 'bodyBackground'.
 * @param direction - The direction of the overflow. Defaults to horizontal.
 * @param width - The width of the fading overflow. Vertical direction defaults it to 100% vs 20px when horizontal.
 * @param height - The Height of the fading overflow. Vertical direction defaults it to 50% vs 100% when horizontal.
 * @returns The style object.
 */
export declare function getFadedOverflowStyle(theme: ITheme, color?: keyof ISemanticColors | keyof IPalette, direction?: 'horizontal' | 'vertical', width?: string | number, height?: string | number): IRawStyle;