Using atomWithHash to enable back/forward actions.

src/App.tsx

@@ -22,23 +22,36 @@ import '@ionic/react/css/display.css';
 import './theme/variables.css';
 import LiveMap from './components/map/LiveMap';
 
+import { useAtom } from 'jotai';
+import { atomWithHash } from 'jotai/utils';
+import { MapScope } from './components/map/types';
+import { debounce } from 'lodash';
+
 setupIonicReact();
 
+const initialScope: MapScope = {
+  center: { lat: -37.8403508, lon: 77.5539501 },
+  zoom: 13,
+  tileProvider: 'osm',
+};
+const scopeAtom = atomWithHash('scope', initialScope);
+
 /**
  *
  * @returns The root app component
  */
-const App: React.FC = () => (
+const App: React.FC = () => {
+  const [scope, setScope] = useAtom(scopeAtom);
+
+  console.log(`App, scope: ${JSON.stringify(scope)}`);
+  return (
     <IonApp>
       <IonReactRouter>
         <IonRouterOutlet>
           <Route exact path='/home'>
             <LiveMap
-            scope={{
+              scope={scope}
-              center: { lat: -37.8403508, lon: 77.5539501 },
+              setScope={debounce(setScope, 1000)}
-              zoom: 13,
-              tileProvider: 'osm',
-            }}
               numberOfTiledLayers={5}
             />
           </Route>
@@ -48,6 +61,7 @@ const App: React.FC = () => (
         </IonRouterOutlet>
       </IonReactRouter>
     </IonApp>
-);
+  );
+};
 
 export default App;

src/components/map/LiveMap.tsx

@@ -1,4 +1,4 @@
-import react, { useState } from 'react';
+import react, { useEffect, useState } from 'react';
 import { MapScope, Point } from './types';
 import Map from './Map';
 import Handlers from './Handlers';
@@ -31,8 +31,12 @@ export interface Transformation {
 }
 
 export interface LiveMapProperties {
+  /** The initial map's scope */
   scope: MapScope;
+  /** The number of tiled layers (default to 1) */
   numberOfTiledLayers?: number;
+  /** If provided, a function to call when the scope is updated. */
+  setScope?: (scope: MapScope) => void;
 }
 
 /**
@@ -50,7 +54,10 @@ export const LiveMap: react.FC<LiveMapProperties> = (
   props: LiveMapProperties
 ) => {
   const [scope, setScope] = useState(props.scope);
-  // console.log(`LiveMap rendering: ${JSON.stringify(scope)}`);
+  useEffect(() => {
+    setScope(props.scope);
+  }, [props.scope]);
+  console.log(`LiveMap rendering: ${JSON.stringify(scope)}`);
   const transform = (t: Transformation) => {
     const deltaZoom = t.deltaZoom === null ? 1 : t.deltaZoom;
     const deltaZoomLevel = Math.log2(deltaZoom);
@@ -114,6 +121,9 @@ export const LiveMap: react.FC<LiveMapProperties> = (
     //   }, delta lon: ${newScope.center.lon - scope.center.lon}`
     // );
     setScope(newScope);
+    if (props.setScope !== undefined) {
+      props.setScope(newScope);
+    }
   };
 
   return (