export function resolveToPercent(value: number | string | undefined, fallback: number, env: SizeEnvironment): number;
export function resolvePaneConstraints(paneDef: {
    minSize: number | string;
    maxSize: number | string;
} | undefined, env: SizeEnvironment): PaneConstraints;
export function getInitialSizes(resolvedDefaults: number[]): number[];
export function clampResizeDelta(deltaPercent: number, { sizeBefore, sizeAfter, constraintsBefore, constraintsAfter }: {
    sizeBefore: number;
    sizeAfter: number;
    constraintsBefore: PaneConstraints;
    constraintsAfter: PaneConstraints;
}): number;
export function getHandleKeyAction({ key, shiftKey, isHorizontal, rtl }: {
    key: string;
    shiftKey: boolean;
    isHorizontal: boolean;
    rtl: boolean;
}): {
    type: "toggle";
} | {
    type: "resize";
    delta: number;
} | undefined;
export type SizeEnvironment = {
    /**
     * Size of the pane group in pixels along its direction, or `0`
     * if it hasn’t been laid out yet.
     */
    containerSize: number;
    /**
     * Width of the viewport in pixels.
     */
    viewportWidth: number;
    /**
     * Height of the viewport in pixels.
     */
    viewportHeight: number;
};
export type PaneConstraints = {
    /**
     * Minimum size.
     */
    minSize: number;
    /**
     * Maximum size, never below `minSize`.
     */
    maxSize: number;
};