Layers and measures

// apps/docs/examples/geo/points.tsx'use client';
import {useEffect, useState} from 'react';
import {  englishGeoTranslator,  GeoMap,  type GeoAreaFeature,  type GeoContextGeometry,} from '@workspace/active-geo';import {  loadWorld50m,  world50m,} from '@workspace/active-geo/collections/world-50m';
const BENELUX = new Set(['NLD', 'BEL', 'LUX']);
// Invented sites, sized by their staff.const SITES = [  {key: 'ams', name: 'Amsterdam', latitude: 52.37, longitude: 4.9, staff: 120},  {key: 'rtm', name: 'Rotterdam', latitude: 51.92, longitude: 4.48, staff: 64},  {key: 'utr', name: 'Utrecht', latitude: 52.09, longitude: 5.12, staff: 38},  {key: 'ein', name: 'Eindhoven', latitude: 51.44, longitude: 5.47, staff: 45},  {key: 'bru', name: 'Brussels', latitude: 50.85, longitude: 4.35, staff: 72},  {key: 'ant', name: 'Antwerp', latitude: 51.22, longitude: 4.4, staff: 51},  {key: 'lux', name: 'Luxembourg', latitude: 49.61, longitude: 6.13, staff: 19},];
/** * Point symbols over context geometry, sized by a count, with a legend, a * tooltip and selection (click, or Enter on a focused point). */export default function SitesMap() {  const [outline, setOutline] = useState<GeoAreaFeature[] | null>(null);  useEffect(() => {    let current = true;    void loadWorld50m().then((loaded) => {      if (current) setOutline(loaded.filter((f) => BENELUX.has(String(f.key))));    });    return () => {      current = false;    };  }, []);  if (!outline) {    return <p className="text-muted-foreground text-sm">Loading the map…</p>;  }  return (    // The map takes the width of its container (a ResizeObserver);    // in a centring layout the host gives it one.    <div className="w-full">      <GeoMap        title="Sites in the Benelux"        projection="conic-equal-area"        locale="en-GB"        t={englishGeoTranslator}        attribution={world50m.attribution}        layers={[          {            type: 'context',            id: 'benelux',            title: 'Benelux',            // Context, not the frame: the Netherlands of Natural Earth            // include the Caribbean islands, so the sites frame the map.            fit: false,            geometries: outline.flatMap((feature): GeoContextGeometry[] =>              feature.geometry ? [feature.geometry] : [],            ),          },          {            type: 'point',            id: 'sites',            title: 'Sites',            measures: [              {id: 'staff', label: 'Staff', semantics: {kind: 'count'}},            ],            marker: {size: {measure: 'staff'}},            points: SITES.map(({staff, ...site}) => ({              ...site,              values: {staff},            })),          },        ]}      />    </div>  );}