fix(header): use aria attributes to hide small title when collapsed (#30027)

Issue number: resolves #29347 

---------

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

Focusable elements like buttons cannot be accessed within the
`ion-header` when it's collapsed. They're only accessible once the small
title is displayed.

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

- Moved the `aria-hidden` from the header to `ion-title`, this aligns
with native.
- Updated existing test.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

Dev build: `8.4.1-dev.11732064156.12837790`

core/src/components/header/header.utils.ts

@@ -167,13 +167,34 @@ export const handleToolbarIntersection = (
 
 export const setHeaderActive = (headerIndex: HeaderIndex, active = true) => {
   const headerEl = headerIndex.el;
+  const toolbars = headerIndex.toolbars;
+  const ionTitles = toolbars.map((toolbar) => toolbar.ionTitleEl);
 
   if (active) {
     headerEl.classList.remove('header-collapse-condense-inactive');
-    headerEl.removeAttribute('aria-hidden');
+
+    ionTitles.forEach((ionTitle) => {
+      if (ionTitle) {
+        ionTitle.removeAttribute('aria-hidden');
+      }
+    });
   } else {
     headerEl.classList.add('header-collapse-condense-inactive');
-    headerEl.setAttribute('aria-hidden', 'true');
+
+    /**
+     * The small title should only be accessed by screen readers
+     * when the large title collapses into the small title due
+     * to scrolling.
+     *
+     * Originally, the header was given `aria-hidden="true"`
+     * but this caused issues with screen readers not being
+     * able to access any focusable elements within the header.
+     */
+    ionTitles.forEach((ionTitle) => {
+      if (ionTitle) {
+        ionTitle.setAttribute('aria-hidden', 'true');
+      }
+    });
   }
 };
 

core/src/components/header/test/condense/header.e2e.ts

@@ -3,13 +3,19 @@ import { configs, test } from '@utils/test/playwright';
 
 configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, screenshot, config }) => {
   test.describe(title('header: condense'), () => {
-    test('should be hidden from screen readers when collapsed', async ({ page }) => {
+    test('should hide small title from screen readers when collapsed', async ({ page }) => {
+      test.info().annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/29347',
+      });
+
       await page.goto('/src/components/header/test/condense', config);
       const largeTitleHeader = page.locator('#largeTitleHeader');
       const smallTitleHeader = page.locator('#smallTitleHeader');
+      const smallTitle = smallTitleHeader.locator('ion-title');
       const content = page.locator('ion-content');
 
-      await expect(smallTitleHeader).toHaveAttribute('aria-hidden', 'true');
+      await expect(smallTitle).toHaveAttribute('aria-hidden', 'true');
 
       await expect(largeTitleHeader).toHaveScreenshot(screenshot(`header-condense-large-title-initial-diff`));
 
@@ -24,7 +30,7 @@ configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, screenshot, c
        * Playwright can't do .not.toHaveAttribute() because a value is expected,
        * and toHaveAttribute can't accept a value of type null.
        */
-      const ariaHidden = await smallTitleHeader.getAttribute('aria-hidden');
+      const ariaHidden = await smallTitle.getAttribute('aria-hidden');
       expect(ariaHidden).toBeNull();
 
       await content.evaluate(async (el: HTMLIonContentElement) => {
@@ -32,7 +38,7 @@ configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, screenshot, c
       });
       await page.locator('#smallTitleHeader.header-collapse-condense-inactive').waitFor();
 
-      await expect(smallTitleHeader).toHaveAttribute('aria-hidden', 'true');
+      await expect(smallTitle).toHaveAttribute('aria-hidden', 'true');
     });
   });
 });