/**
 * State of visual viewport.
 */
export interface VisualViewportState {
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/height). */
    readonly height: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/offsetLeft). */
    readonly offsetLeft: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/offsetTop). */
    readonly offsetTop: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/pageLeft). */
    readonly pageLeft: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/pageTop). */
    readonly pageTop: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/scale). */
    readonly scale: number;
    /** [MDN Reference](https://developer.mozilla.org/en-US/docs/Web/API/VisualViewport/width). */
    readonly width: number;
    /** False by default (before mount), true when initialized (after mount). */
    readonly ready: boolean;
}
export interface UseVisualViewportOptions {
    /**
     * Mode of how hook will be work.
     *
     * Possible values:
     * - `stateful` (default) - hook will update returned state and cause rerender.
     * - `stateless` - hook will not update returned state.
     *
     * If you can observe `visualViewport` without re-renders
     * you can set `mode: 'stateless'` and also `onChange` to listen changes.
     */
    mode?: 'stateful' | 'stateless';
    /**
     * Will be called each time `visualViewport` changes.
     * Also will be called once during listening initialization.
     */
    onChange?: (state: VisualViewportState) => void;
    /** Initial returned state. Used before subscription effect applied. */
    defaultState?: VisualViewportState | (() => VisualViewportState);
}
/**
 * Hook of window.visualViewport state.
 * @param options Options.
 * @returns State of visualViewport (width, height, etc).
 */
export declare function useVisualViewport({ mode, onChange, defaultState, }?: UseVisualViewportOptions): VisualViewportState;