import { GeoJSONObject } from "ol/format/GeoJSON";
import Geometry from "ol/geom/Geometry";
import { Feature } from "ol/index";
import Map from "ol/Map";
import { Vector } from "ol/source";
import VectorSource from "ol/source/Vector";
import { ProjectionEnum } from "./projections";
export type AreaUnitEnum = "m2" | "ha";
/**
 * Calculate & format the area of a polygon
 * @param polygon
 * @param unit - defaults to square metres ("m2"), or supports "ha" for hectares
 * @returns - the total area formatted with unit as a string
 */
export declare function formatArea(polygon: Geometry, unit: AreaUnitEnum): string | undefined;
/**
 * Fit map view to extent of data features, overriding default zoom & center
 * @param olMap - an OpenLayers map
 * @param olSource - an OpenLayers vector source
 * @param bufferValue - amount to buffer extent by, refer to https://openlayers.org/en/latest/apidoc/module-ol_extent.html#.buffer
 * @returns - a map view
 */
export declare function fitToData(olMap: Map, olSource: Vector<Feature<Geometry>>, bufferValue: number): void;
/**
 * Translate a hex color to an rgba string with opacity
 * @param hexColor - a hex color string
 * @param alpha - a decimal to represent opacity
 * @returns - a 'rgba(r,g,b,a)' string
 */
export declare function hexToRgba(hexColor: string, alpha: number): string;
/**
 * Generate a geojson object from a vector source or an array of features
 * @param source
 * @param projection
 * @returns
 */
export declare function makeGeoJSON(source: VectorSource<Feature<Geometry>> | Feature<Geometry>[], projection: ProjectionEnum): GeoJSONObject;