refactor!: redesign Geolocation as static utility with watcher handle

DESIGN_GUIDELINES.md

@@ -31,10 +31,9 @@ holds `private final UI ui`, and all `executeJs` calls go through
 `ui.getElement()` or `ui.getPage()`. Follow the `Page` / `History`
 pattern. Enforce single-instance creation in the constructor if needed.
 
-If the facade hands out a stateful handle (e.g.
-`Geolocation.watchPosition()` returning a `GeolocationWatcher`), make the
-handle's constructor **package-private** so application code cannot bypass
-the facade.
+If a feature hands out a stateful handle (e.g. `Geolocation.watchPosition()`
+returning a `GeolocationWatcher`), make the handle's constructor
+**package-private** so application code cannot bypass the entry point.
 
 ### Keep internal mutators off user-facing classes
 

flow-server/src/main/java/com/vaadin/flow/component/UI.java

@@ -32,7 +32,6 @@
 import tools.jackson.databind.node.BaseJsonNode;
 
 import com.vaadin.flow.component.dependency.JsModule;
-import com.vaadin.flow.component.geolocation.Geolocation;
 import com.vaadin.flow.component.internal.JavaScriptNavigationStateRenderer;
 import com.vaadin.flow.component.internal.UIInternalUpdater;
 import com.vaadin.flow.component.internal.UIInternals;
@@ -136,8 +135,6 @@ public class UI extends Component
 
     private final Page page;
 
-    private final Geolocation geolocation;
-
     /*
      * Despite section 6 of RFC 4122, this particular use of UUID *is* adequate
      * for security capabilities. Type 4 UUIDs contain 122 bits of random data,
@@ -168,7 +165,6 @@ protected UI(UIInternalUpdater internalsHandler) {
         Component.setElement(this, Element.get(getNode()));
         pushConfiguration = new PushConfigurationImpl(this);
         page = new Page(this);
-        geolocation = new Geolocation(this);
     }
 
     /**
@@ -951,16 +947,6 @@ public Page getPage() {
         return page;
     }
 
-    /**
-     * Returns the {@link Geolocation} facade for this UI, used to read the end
-     * user's physical location from the browser.
-     *
-     * @return the Geolocation facade
-     */
-    public Geolocation getGeolocation() {
-        return geolocation;
-    }
-
     /**
      * Updates this UI to show the view corresponding to the given navigation
      * target.

flow-server/src/main/java/com/vaadin/flow/component/geolocation/BrowserGeolocationClient.java

@@ -77,7 +77,7 @@ private record AvailabilityDetail(
 
     @Override
     public CompletableFuture<GeolocationOutcome> get(
-            @Nullable GeolocationOptions options) {
+            GeolocationOptions options) {
         CompletableFuture<GeolocationOutcome> future = new CompletableFuture<>();
         ui.getElement()
                 .executeJs("return window.Vaadin.Flow.geolocation.get($0)",
@@ -98,8 +98,7 @@ public CompletableFuture<GeolocationOutcome> get(
     }
 
     @Override
-    public WatchHandle startWatch(Component owner,
-            @Nullable GeolocationOptions options,
+    public WatchHandle startWatch(Component owner, GeolocationOptions options,
             SerializableConsumer<GeolocationResult> onUpdate) {
         return new BrowserWatchHandle(owner, options, onUpdate);
     }
@@ -154,8 +153,7 @@ private final class BrowserWatchHandle implements WatchHandle {
         private @Nullable DomListenerRegistration errorListener;
         private boolean active = true;
 
-        BrowserWatchHandle(Component owner,
-                @Nullable GeolocationOptions options,
+        BrowserWatchHandle(Component owner, GeolocationOptions options,
                 SerializableConsumer<GeolocationResult> onUpdate) {
             this.owner = owner;
             Element el = owner.getElement();