From 0b1d800dc5e4b9bf0b1ddb42b9fed392b23b8dae Mon Sep 17 00:00:00 2001
From: Martin Schuhfuss <m.schuhfuss@gmail.com>
Date: Tue, 7 Nov 2023 23:20:23 +0100
Subject: [PATCH] feat: update map viewport when props are changed

Improves handling of view props (center, zoom, heading, tilt) and introduces a new `useCallbackRef` hook
---
 src/components/map.tsx             | 87 ++++++++++++++++++------------
 src/libraries/use-callback-ref.tsx |  8 +++
 2 files changed, 62 insertions(+), 33 deletions(-)
 create mode 100644 src/libraries/use-callback-ref.tsx

diff --git a/src/components/map.tsx b/src/components/map.tsx
index ba4539b7..22d2d694 100644
--- a/src/components/map.tsx
+++ b/src/components/map.tsx
@@ -2,6 +2,8 @@
 import React, {
   CSSProperties,
   PropsWithChildren,
+  Ref,
+  RefCallback,
   useCallback,
   useContext,
   useEffect,
@@ -14,6 +16,7 @@ import {APIProviderContext, APIProviderContextValue} from './api-provider';
 
 import {useApiIsLoaded} from '../hooks/use-api-is-loaded';
 import {logErrorOnce} from '../libraries/errors';
+import {useCallbackRef} from '../libraries/use-callback-ref';
 
 // Google Maps context
 export interface GoogleMapsContextValue {
@@ -75,6 +78,7 @@ export const Map = (props: PropsWithChildren<MapProps>) => {
   }
 
   const [map, mapRef] = useMapInstanceHandlerEffects(props, context);
+  useMapOptionsEffects(map, props);
   useDeckGLCameraUpdateEffect(map, viewState);
 
   const isViewportSet = useMemo(() => Boolean(viewport), [viewport]);
@@ -117,13 +121,10 @@ Map.deckGLViewProps = true;
 function useMapInstanceHandlerEffects(
   props: MapProps,
   context: APIProviderContextValue
-): readonly [
-  map: google.maps.Map | null,
-  mapRef: (instance: HTMLDivElement | null) => void
-] {
+): readonly [map: google.maps.Map | null, containerRef: Ref<HTMLDivElement>] {
   const apiIsLoaded = useApiIsLoaded();
   const [map, setMap] = useState<google.maps.Map | null>(null);
-  const [container, setContainer] = useState<HTMLDivElement | null>(null);
+  const [container, containerRef] = useCallbackRef<HTMLDivElement>();
 
   const {
     id,
@@ -134,10 +135,6 @@ function useMapInstanceHandlerEffects(
     ...mapOptions
   } = props;
 
-  const mapRef = useCallback((node: HTMLDivElement | null) => {
-    setContainer(node || null);
-  }, []);
-
   // create the map instance and register it in the context
   useEffect(
     () => {
@@ -175,7 +172,7 @@ function useMapInstanceHandlerEffects(
     },
 
     // Dependencies need to be inaccurately limited here. The cleanup function
-    // will remove  the map-instance with all it's internal state, and we can't
+    // will remove the map-instance with all its internal state, and we can't
     // have that happening. This is only ok when the id or mapId is changed,
     // since this requires a new map to be created anyway.
 
@@ -190,28 +187,6 @@ function useMapInstanceHandlerEffects(
     [id, container, apiIsLoaded, props.mapId]
   );
 
-  // update the map options when mapOptions is changed
-  useEffect(
-    () => {
-      if (!map) {
-        return;
-      }
-
-      // FIXME: for now, we have to filter all options describing the viewport
-      //   here, since those are updated in google maps internally or using the
-      //   viewState parameter externally.
-      // eslint-disable-next-line @typescript-eslint/no-unused-vars
-      const {center, zoom, heading, tilt, mapId, ...otherOptions} = mapOptions;
-
-      map.setOptions(otherOptions);
-    },
-    // Not triggered when the map is changed, since in that case the
-    // options have already been passed to the map constructor.
-
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-    [mapOptions]
-  );
-
   // report an error if the same map-id is used multiple times
   useEffect(() => {
     if (!id) {
@@ -229,7 +204,53 @@ function useMapInstanceHandlerEffects(
     }
   }, [id, context, map]);
 
-  return [map, mapRef] as const;
+  return [map, containerRef] as const;
+}
+
+/**
+ * Internal hook to update the map-options and view-parameters when
+ * props are changed.
+ */
+function useMapOptionsEffects(map: google.maps.Map | null, mapProps: MapProps) {
+  const {center, zoom, heading, tilt, ...mapOptions} = mapProps;
+
+  // All of these effects aren't triggered when the map is changed.
+  // In that case, the values have already been passed to the map constructor.
+
+  // update the map options when mapOptions is changed
+  useEffect(() => {
+    if (!map) return;
+
+    // NOTE: passing a mapId to setOptions triggers an error-message we don't need to see here
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const {mapId, ...opts} = mapOptions;
+
+    map.setOptions(opts);
+  }, [mapProps]);
+
+  useEffect(() => {
+    if (!map || !center) return;
+
+    map.setCenter(center);
+  }, [center]);
+
+  useEffect(() => {
+    if (!map || !Number.isFinite(zoom)) return;
+
+    map.setZoom(zoom as number);
+  }, [zoom]);
+
+  useEffect(() => {
+    if (!map || !Number.isFinite(heading)) return;
+
+    map.setHeading(heading as number);
+  }, [heading]);
+
+  useEffect(() => {
+    if (!map || !Number.isFinite(tilt)) return;
+
+    map.setTilt(tilt as number);
+  }, [tilt]);
 }
 
 /**
diff --git a/src/libraries/use-callback-ref.tsx b/src/libraries/use-callback-ref.tsx
new file mode 100644
index 00000000..2bfe46a7
--- /dev/null
+++ b/src/libraries/use-callback-ref.tsx
@@ -0,0 +1,8 @@
+import {Ref, useCallback, useState} from 'react';
+
+export function useCallbackRef<T>() {
+  const [el, setEl] = useState<T | null>(null);
+  const ref = useCallback((value: T) => setEl(value), [setEl]);
+
+  return [el, ref as Ref<T>] as const;
+}