/**
 * Normalizes an `AddEventListener` object to something that can be passed
 * to `addEventListener` on any browser, no matter whether it supports the
 * `options` parameter.
 * @param options Object to be normalized.
 */
export declare function normalizePassiveListenerOptions(options: AddEventListenerOptions): AddEventListenerOptions | boolean;
/**
 * Screen readers will often fire fake mousedown events when a focusable element
 * is activated using the keyboard. We can typically distinguish between these faked
 * mousedown events and real mousedown events using the "buttons" property. While
 * real mousedown will indicate the mouse button that was pressed (e.g. `1` for
 * the left mouse button), faked mousedown will usually set the property value to 0.
 */
export declare function isFakeMousedownFromScreenReader(event: MouseEvent): boolean;
/** Return style property of a DOM element. */
export declare function getStyle(element: HTMLElement, styleProperty?: string): string;
/** Enforces a style recalculation of a DOM element by computing its styles. */
export declare function enforceStyleRecalculation(element: HTMLElement): void;
/**
 * Returns the distance from the point (x, y) to the furthest corner of a rectangle.
 */
export declare function distanceToFurthestCorner(x: number, y: number, rect: ClientRect): number;