fix(overlays): correctly re-add root to accessibility tree (#28183)

Issue number: resolves #28180

---------

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issue. -->

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etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

When presenting an overlay, we remove the root (usually
`ion-router-outlet`) from the accessibility tree. This makes it so you
cannot accidentally focus elements behind the overlay. When dismissing
an overlay we re-add the root to the accessibility tree. However, we
fail to consider if there are multiple presented overlays. For example,
if you present a modal, then an alert, then dismiss the alert, then the
root is re-added to the accessibility tree even though the modal is
still presented.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- The root is now re-added to the accessibility tree only if it is the
last presented overlay.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

Dev build: `7.4.1-dev.11694783260.13da477f`

core/src/components/menu/menu.tsx

@@ -6,7 +6,7 @@ import { GESTURE_CONTROLLER } from '@utils/gesture';
 import type { Attributes } from '@utils/helpers';
 import { inheritAriaAttributes, assert, clamp, isEndSide as isEnd } from '@utils/helpers';
 import { menuController } from '@utils/menu-controller';
-import { getOverlay } from '@utils/overlays';
+import { getPresentedOverlay } from '@utils/overlays';
 
 import { config } from '../../global/config';
 import { getIonMode } from '../../global/ionic-global';
@@ -59,7 +59,7 @@ export class Menu implements ComponentInterface, MenuI {
      * open does not contain this ion-menu, then ion-menu's
      * focus trapping should not run.
      */
-    const lastOverlay = getOverlay(document);
+    const lastOverlay = getPresentedOverlay(document);
     if (lastOverlay && !lastOverlay.contains(this.el)) {
       return;
     }

core/src/utils/overlays.ts

@@ -1,3 +1,5 @@
+import { doc } from '@utils/browser';
+
 import { config } from '../global/config';
 import { getIonMode } from '../global/ionic-global';
 import type {
@@ -36,7 +38,7 @@ const createController = <Opts extends object, HTMLElm>(tagName: string) => {
       return dismissOverlay(document, data, role, tagName, id);
     },
     async getTop(): Promise<HTMLElm | undefined> {
-      return getOverlay(document, tagName) as any;
+      return getPresentedOverlay(document, tagName) as any;
     },
   };
 };
@@ -173,7 +175,10 @@ const focusLastDescendant = (ref: Element, overlay: HTMLIonOverlayElement) => {
  * Should NOT include: Toast
  */
 const trapKeyboardFocus = (ev: Event, doc: Document) => {
-  const lastOverlay = getOverlay(doc, 'ion-alert,ion-action-sheet,ion-loading,ion-modal,ion-picker,ion-popover');
+  const lastOverlay = getPresentedOverlay(
+    doc,
+    'ion-alert,ion-action-sheet,ion-loading,ion-modal,ion-picker,ion-popover'
+  );
   const target = ev.target as HTMLElement | null;
 
   /**
@@ -344,7 +349,7 @@ const connectListeners = (doc: Document) => {
 
     // handle back-button click
     doc.addEventListener('ionBackButton', (ev) => {
-      const lastOverlay = getOverlay(doc);
+      const lastOverlay = getPresentedOverlay(doc);
       if (lastOverlay?.backdropDismiss) {
         (ev as BackButtonEvent).detail.register(OVERLAY_BACK_BUTTON_PRIORITY, () => {
           return lastOverlay.dismiss(undefined, BACKDROP);
@@ -355,7 +360,7 @@ const connectListeners = (doc: Document) => {
     // handle ESC to close overlay
     doc.addEventListener('keydown', (ev) => {
       if (ev.key === 'Escape') {
-        const lastOverlay = getOverlay(doc);
+        const lastOverlay = getPresentedOverlay(doc);
         if (lastOverlay?.backdropDismiss) {
           lastOverlay.dismiss(undefined, BACKDROP);
         }
@@ -371,13 +376,16 @@ export const dismissOverlay = (
   overlayTag: string,
   id?: string
 ): Promise<boolean> => {
-  const overlay = getOverlay(doc, overlayTag, id);
+  const overlay = getPresentedOverlay(doc, overlayTag, id);
   if (!overlay) {
     return Promise.reject('overlay does not exist');
   }
   return overlay.dismiss(data, role);
 };
 
+/**
+ * Returns a list of all overlays in the DOM even if they are not presented.
+ */
 export const getOverlays = (doc: Document, selector?: string): HTMLIonOverlayElement[] => {
   if (selector === undefined) {
     selector = 'ion-alert,ion-action-sheet,ion-loading,ion-modal,ion-picker,ion-popover,ion-toast';
@@ -386,14 +394,29 @@ export const getOverlays = (doc: Document, selector?: string): HTMLIonOverlayEle
 };
 
 /**
- * Returns an overlay element
+ * Returns a list of all presented overlays.
+ * Inline overlays can exist in the DOM but not be presented,
+ * so there are times when we want to exclude those.
+ * @param doc The document to find the element within.
+ * @param overlayTag The selector for the overlay, defaults to Ionic overlay components.
+ */
+const getPresentedOverlays = (doc: Document, overlayTag?: string): HTMLIonOverlayElement[] => {
+  return getOverlays(doc, overlayTag).filter((o) => !isOverlayHidden(o));
+};
+
+/**
+ * Returns a presented overlay element.
  * @param doc The document to find the element within.
  * @param overlayTag The selector for the overlay, defaults to Ionic overlay components.
  * @param id The unique identifier for the overlay instance.
  * @returns The overlay element or `undefined` if no overlay element is found.
  */
-export const getOverlay = (doc: Document, overlayTag?: string, id?: string): HTMLIonOverlayElement | undefined => {
-  const overlays = getOverlays(doc, overlayTag).filter((o) => !isOverlayHidden(o));
+export const getPresentedOverlay = (
+  doc: Document,
+  overlayTag?: string,
+  id?: string
+): HTMLIonOverlayElement | undefined => {
+  const overlays = getPresentedOverlays(doc, overlayTag);
   return id === undefined ? overlays[overlays.length - 1] : overlays.find((o) => o.id === id);
 };
 
@@ -525,7 +548,13 @@ export const dismiss = async <OverlayDismissOptions>(
     return false;
   }
 
-  setRootAriaHidden(false);
+  /**
+   * If this is the last visible overlay then
+   * we want to re-add the root to the accessibility tree.
+   */
+  if (doc !== undefined && getPresentedOverlays(doc).length === 1) {
+    setRootAriaHidden(false);
+  }
 
   overlay.presented = false;
 

core/src/utils/test/overlays/overlays.spec.ts

@@ -2,6 +2,8 @@ import { newSpecPage } from '@stencil/core/testing';
 
 import { Nav } from '../../../components/nav/nav';
 import { RouterOutlet } from '../../../components/router-outlet/router-outlet';
+import { Modal } from '../../../components/modal/modal';
+
 import { setRootAriaHidden } from '../../overlays';
 
 describe('setRootAriaHidden()', () => {
@@ -77,4 +79,54 @@ describe('setRootAriaHidden()', () => {
 
     setRootAriaHidden(true);
   });
+
+  it('should remove router-outlet from accessibility tree when overlay is presented', async () => {
+    const page = await newSpecPage({
+      components: [RouterOutlet, Modal],
+      html: `
+        <ion-router-outlet>
+          <ion-modal></ion-modal>
+        </ion-router-outlet>
+      `,
+    });
+
+    const routerOutlet = page.body.querySelector('ion-router-outlet');
+    const modal = page.body.querySelector('ion-modal');
+
+    await modal.present();
+
+    expect(routerOutlet.hasAttribute('aria-hidden')).toEqual(true);
+  });
+
+  it('should add router-outlet from accessibility tree when then final overlay is dismissed', async () => {
+    const page = await newSpecPage({
+      components: [RouterOutlet, Modal],
+      html: `
+        <ion-router-outlet>
+          <ion-modal id="one"></ion-modal>
+          <ion-modal id="two"></ion-modal>
+        </ion-router-outlet>
+      `,
+    });
+
+    const routerOutlet = page.body.querySelector('ion-router-outlet');
+    const modalOne = page.body.querySelector('ion-modal#one');
+    const modalTwo = page.body.querySelector('ion-modal#two');
+
+    await modalOne.present();
+
+    expect(routerOutlet.hasAttribute('aria-hidden')).toEqual(true);
+
+    await modalTwo.present();
+
+    expect(routerOutlet.hasAttribute('aria-hidden')).toEqual(true);
+
+    await modalOne.dismiss();
+
+    expect(routerOutlet.hasAttribute('aria-hidden')).toEqual(true);
+
+    await modalTwo.dismiss();
+
+    expect(routerOutlet.hasAttribute('aria-hidden')).toEqual(false);
+  });
 });