recharts/types/theme/graphicalItemIdentity.d.ts

React charts

/**
 * @fileOverview
 * This file provides helper methods for assigning theme identity to a
 * graphical item. Graphical items are individual drawable data representations,
 * such as Line or Bar. In previous Recharts versions these can be styled
 * individually. In next version, Recharts will allow the user to provide an
 * array of themes, and then have the graphical items pick one. There is a gap
 * however; graphical items are not sorted and not indexed. We can't use DOM
 * order because that order changes. So instead we need an identifier that:
 * - we can calculate from props, without requiring the user to provide an
 *   explicit id
 * - is stable across renders, so that the same item will always get the same
 *   theme
 * - is (within possibilities) unique across all items, so that no two items
 *   will get the same theme The uniqueness is impossible to guarantee 100% so
 * we will only provide a best-effort. This file provides a helper method to
 * calculate such an identifier.
 */
import { DataKey } from '..';
export type ThemableItem = {
    dataKey: DataKey<unknown>;
};
/**
 * Calculates theme index from a given item. The identity is computed
 * deterministically from the dataKey string, ensuring stability across renders
 * and module reloads.
 * @param item - The themable item to calculate identity for
 * @param themeCount - Optional number of available themes; if provided, clamps
 *  the hash to [0, themeCount).
 */
export declare function graphicalItemIdentity(item: ThemableItem, themeCount?: number): number;