feat: Add autoTrigger prop to GeolocateControl (#87)

src/content/examples/geolocate/Geolocate.svelte

@@ -14,6 +14,7 @@
 			position="top-left"
 			positionOptions={{ enableHighAccuracy: true }}
 			trackUserLocation={true}
+			showAccuracyCircle={true}
 			ontrackuserlocationstart={() => log('trackuserlocationstart')}
 			ontrackuserlocationend={() => log('trackuserlocationend')}
 			ongeolocate={(ev) => log(`geolocate ${JSON.stringify(ev.coords, null, 2)}`)}

src/lib/maplibre/controls/GeolocateControl.svelte

@@ -10,7 +10,11 @@
 	type GeolocateEvent = Event<maplibregl.GeolocateControl> & object;
 
 	interface Props extends maplibregl.GeolocateControlOptions {
+		// Position on the map where the control placed
 		position?: maplibregl.ControlPosition;
+		// Automatically call trigger() to start locating the user
+		autoTrigger?: boolean;
+		control?: maplibregl.GeolocateControl;
 		// Events
 		// https://maplibre.org/maplibre-gl-js/docs/API/classes/GeolocateControl/#events
 		ontrackuserlocationend?: Listener<GeolocateEvent>;
@@ -23,6 +27,8 @@
 	}
 	let {
 		position,
+		control = $bindable(),
+		autoTrigger = false,
 		ontrackuserlocationend,
 		ontrackuserlocationstart,
 		onuserlocationlostfocus,
@@ -36,13 +42,22 @@
 	const mapCtx = getMapContext();
 	if (!mapCtx.map) throw new Error('Map instance is not initialized.');
 
-	let control: maplibregl.GeolocateControl | null = null;
 	$effect(() => {
 		control && mapCtx.map?.removeControl(control);
 		control = new maplibregl.GeolocateControl(options);
 		mapCtx.map?.addControl(control, position);
 	});
 
+	$effect(() => {
+		if (mapCtx.map?.loaded()) {
+			control?.trigger();
+		} else {
+			mapCtx.map?.once('load', () => {
+				control?.trigger();
+			});
+		}
+	});
+
 	$effect(() => resetEventListener(control, 'trackuserlocationstart', ontrackuserlocationstart));
 	$effect(() => resetEventListener(control, 'trackuserlocationend', ontrackuserlocationend));
 	$effect(() => resetEventListener(control, 'userlocationlostfocus', onuserlocationlostfocus));