import type { Datum } from "../charts/shared/datumTypes";
import * as React from "react";
import type { StreamXYFrameProps, StreamXYFrameHandle } from "./types";
/**
 * Append a 2-char hex alpha to an existing CSS color, returning a valid
 * CSS color string. The naive `${color}${alpha}` concatenation only works
 * when `color` is a 6-char `#rrggbb`; shorthand `#rgb` produces the
 * invalid 5-char `#rgbXX`, which `ctx.strokeStyle`/`fillStyle` silently
 * rejects (falling back to `#000000` — black, invisible on dark themes).
 * The /cookbook/marginal-graphics crosshair invisibility was caused
 * precisely by `--semiotic-text-secondary: "#aaa"` hitting this path.
 *
 * Handles:
 *   • 3-char hex (`#abc`) → expanded to 6-char then concatenated
 *   • 6-char hex (`#aabbcc`) → concatenated directly
 *   • `rgb(...)` → repacked as `rgba(..., a)` with numeric alpha
 * Any other form (named colors, hsl(), oklch(), etc.) falls back to the
 * raw color without alpha — degrades gracefully.
 */
export declare function withAlpha(color: string, alphaHex: string): string;
declare const StreamXYFrame: React.ForwardRefExoticComponent<StreamXYFrameProps<Datum> & React.RefAttributes<StreamXYFrameHandle<Datum>>>;
export default StreamXYFrame;
