feat: use CloseWatcher API for overlay dismiss in supported browsers

packages/react-aria/src/overlays/useOverlay.ts

@@ -14,6 +14,7 @@ import {DOMAttributes, RefObject} from '@react-types/shared';
 import {getEventTarget} from '../utils/shadowdom/DOMFunctions';
 import {isElementInChildOfActiveScope} from '../focus/FocusScope';
 import {useEffect, useRef} from 'react';
+import {useEffectEvent} from '../utils/useEffectEvent';
 import {useFocusWithin} from '../interactions/useFocusWithin';
 import {useInteractOutside} from '../interactions/useInteractOutside';
 
@@ -57,6 +58,10 @@ export interface OverlayAria {
 
 const visibleOverlays: RefObject<Element | null>[] = [];
 
+function supportsCloseWatcher(): boolean {
+  return typeof globalThis.CloseWatcher !== 'undefined';
+}
+
 /**
  * Provides the behavior for overlays such as dialogs, popovers, and menus.
  * Hides the overlay when the user interacts outside it, when the Escape key is pressed,
@@ -74,25 +79,44 @@ export function useOverlay(props: AriaOverlayProps, ref: RefObject<Element | nul
 
   let lastVisibleOverlay = useRef<RefObject<Element | null>>(undefined);
 
+  // Only hide the overlay when it is the topmost visible overlay in the stack
+  let onHide = () => {
+    if (visibleOverlays[visibleOverlays.length - 1] === ref && onClose) {
+      onClose();
+    }
+  };
+
+  // Stable callback for CloseWatcher that always calls the latest onHide.
+  // useEffectEvent returns a stable reference, so the watcher doesn't need
+  // to be recreated when onClose changes.
+  let onHideEvent = useEffectEvent(onHide);
+
   // Add the overlay ref to the stack of visible overlays on mount, and remove on unmount.
+  // When CloseWatcher is supported, each overlay gets its own instance. The browser
+  // internally stacks watchers so Escape dismisses the most recently created one first,
+  // which also handles the Android back button. The onKeyDown handler below is kept as
+  // a fallback and is a no-op if the CloseWatcher already dismissed the overlay.
   useEffect(() => {
     if (isOpen && !visibleOverlays.includes(ref)) {
       visibleOverlays.push(ref);
+
+      let watcher: {onclose: (() => void) | null, destroy: () => void} | null = null;
+      if (!isKeyboardDismissDisabled && supportsCloseWatcher()) {
+        watcher = new (globalThis as any).CloseWatcher();
+        watcher!.onclose = () => {
+          onHideEvent();
+        };
+      }
+
       return () => {
         let index = visibleOverlays.indexOf(ref);
         if (index >= 0) {
           visibleOverlays.splice(index, 1);
         }
+        watcher?.destroy();
       };
     }
-  }, [isOpen, ref]);
-
-  // Only hide the overlay when it is the topmost visible overlay in the stack
-  let onHide = () => {
-    if (visibleOverlays[visibleOverlays.length - 1] === ref && onClose) {
-      onClose();
-    }
-  };
+  }, [isOpen, isKeyboardDismissDisabled, ref]);
 
   let onInteractOutsideStart = (e: PointerEvent) => {
     const topMostOverlay = visibleOverlays[visibleOverlays.length - 1];

packages/react-aria/test/overlays/useOverlay.test.js

@@ -128,4 +128,94 @@ describe('useOverlay', function () {
     fireEvent.keyDown(el, {key: 'Escape'});
     expect(onClose).toHaveBeenCalledTimes(1);
   });
+
+  describe('CloseWatcher', function () {
+    let closeWatcherInstances;
+    let MockCloseWatcher;
+
+    beforeEach(function () {
+      closeWatcherInstances = [];
+      MockCloseWatcher = class {
+        constructor() {
+          this.onclose = null;
+          closeWatcherInstances.push(this);
+        }
+        destroy() {
+          let index = closeWatcherInstances.indexOf(this);
+          if (index >= 0) {
+            closeWatcherInstances.splice(index, 1);
+          }
+        }
+      };
+      globalThis.CloseWatcher = MockCloseWatcher;
+    });
+
+    afterEach(function () {
+      delete globalThis.CloseWatcher;
+    });
+
+    it('should use CloseWatcher to dismiss overlay when available', function () {
+      let onClose = jest.fn();
+      render(<Example isOpen onClose={onClose} />);
+      expect(closeWatcherInstances.length).toBe(1);
+      closeWatcherInstances[0].onclose();
+      expect(onClose).toHaveBeenCalledTimes(1);
+    });
+
+    it('should not create CloseWatcher when isKeyboardDismissDisabled is true', function () {
+      let onClose = jest.fn();
+      render(<Example isOpen onClose={onClose} isKeyboardDismissDisabled />);
+      expect(closeWatcherInstances.length).toBe(0);
+    });
+
+    it('should not create CloseWatcher when overlay is not open', function () {
+      let onClose = jest.fn();
+      render(<Example isOpen={false} onClose={onClose} />);
+      expect(closeWatcherInstances.length).toBe(0);
+    });
+
+    it('should destroy CloseWatcher when overlay unmounts', function () {
+      let onClose = jest.fn();
+      let res = render(<Example isOpen onClose={onClose} />);
+      expect(closeWatcherInstances.length).toBe(1);
+      res.unmount();
+      expect(closeWatcherInstances.length).toBe(0);
+    });
+
+    it('should dismiss only the top-most overlay with nested overlays', function () {
+      let onCloseOuter = jest.fn();
+      let onCloseInner = jest.fn();
+      render(<Example isOpen onClose={onCloseOuter} data-testid="outer" />);
+      render(<Example isOpen onClose={onCloseInner} data-testid="inner" />);
+
+      // Each overlay gets its own CloseWatcher
+      expect(closeWatcherInstances.length).toBe(2);
+
+      // Browser fires close on the most recently created watcher (inner overlay)
+      closeWatcherInstances[1].onclose();
+      expect(onCloseInner).toHaveBeenCalledTimes(1);
+      expect(onCloseOuter).not.toHaveBeenCalled();
+    });
+
+    it('should dismiss inner then outer with per-overlay watchers', function () {
+      let onCloseOuter = jest.fn();
+      let onCloseInner = jest.fn();
+      render(<Example isOpen onClose={onCloseOuter} data-testid="outer" />);
+      let inner = render(<Example isOpen onClose={onCloseInner} data-testid="inner" />);
+
+      expect(closeWatcherInstances.length).toBe(2);
+
+      // Dismiss inner overlay via its watcher
+      closeWatcherInstances[1].onclose();
+      expect(onCloseInner).toHaveBeenCalledTimes(1);
+
+      // Unmount inner - its watcher is destroyed
+      inner.unmount();
+      expect(closeWatcherInstances.length).toBe(1);
+
+      // Dismiss outer via its watcher
+      closeWatcherInstances[0].onclose();
+      expect(onCloseOuter).toHaveBeenCalledTimes(1);
+    });
+  });
 });