fix(overlays): return focus to presenting element after dismissal (#22167)

resolves #21768

core/src/components/datetime/test/basic/e2e.ts

@@ -7,14 +7,12 @@ const getActiveElementText = async (page) => {
 
 test('datetime/picker: focus trap', async () => {
   const page = await newE2EPage({ url: '/src/components/datetime/test/basic?ionic:_testing=true' });
-
   await page.click('#datetime-part');
   await page.waitForSelector('#datetime-part');
 
   let datetime = await page.find('ion-datetime');
 
   expect(datetime).not.toBe(null);
-  await datetime.waitForVisible();
 
   // TODO fix
   await page.waitFor(100);

core/src/components/modal/test/basic/e2e.ts

@@ -9,17 +9,15 @@ const getActiveElementText = async (page) => {
 
 test('modal: focus trap', async () => {
   const page = await newE2EPage({ url: '/src/components/modal/test/basic?ionic:_testing=true' });
+  const ionModalDidPresent = await page.spyOnEvent('ionModalDidPresent');
 
   await page.click('#basic-modal');
   await page.waitForSelector('#basic-modal');
 
   let modal = await page.find('ion-modal');
-
   expect(modal).not.toBe(null);
-  await modal.waitForVisible();
 
-  // TODO fix
+  await ionModalDidPresent.next();
-  await page.waitFor(50);
 
   await page.keyboard.press('Tab');
 
@@ -39,6 +37,33 @@ test('modal: focus trap', async () => {
   expect(activeElementTextThree).toEqual('Dismiss Modal');
 });
 
+test('modal: return focus', async () => {
+  const page = await newE2EPage({ url: '/src/components/modal/test/basic?ionic:_testing=true' });
+  const ionModalDidDismiss = await page.spyOnEvent('ionModalDidDismiss');
+  const ionModalDidPresent = await page.spyOnEvent('ionModalDidPresent');
+
+  await page.click('#basic-modal');
+  await page.waitForSelector('#basic-modal');
+
+  let modal = await page.find('ion-modal');
+  expect(modal).not.toBe(null);
+
+  await ionModalDidPresent.next()
+
+  await Promise.all([
+    await modal.callMethod('dismiss'),
+    await ionModalDidDismiss.next(),
+    await modal.waitForNotVisible(),
+  ]);
+
+  modal = await page.find('ion-modal');
+  expect(modal).toBeNull();
+
+  const activeElement = await page.evaluateHandle(() => document.activeElement);
+  const id = await activeElement.evaluate((node) => node.id);
+  expect(id).toEqual('basic-modal');
+});
+
 test('modal: basic', async () => {
   await testModal(DIRECTORY, '#basic-modal');
 });

core/src/utils/overlays.ts

@@ -260,11 +260,47 @@ export const present = async (
     overlay.didPresent.emit();
   }
 
+  /**
+   * When an overlay that steals focus
+   * is dismissed, focus should be returned
+   * to the element that was focused
+   * prior to the overlay opening. Toast
+   * does not steal focus and is excluded
+   * from returning focus as a result.
+   */
+  if (overlay.el.tagName !== 'ION-TOAST') {
+    focusPreviousElementOnDismiss(overlay.el);
+  }
+
   if (overlay.keyboardClose) {
     overlay.el.focus();
   }
 };
 
+/**
+ * When an overlay component is dismissed,
+ * focus should be returned to the element
+ * that presented the overlay. Otherwise
+ * focus will be set on the body which
+ * means that people using screen readers
+ * or tabbing will need to re-navigate
+ * to where they were before they
+ * opened the overlay.
+ */
+const focusPreviousElementOnDismiss = async (overlayEl: any) => {
+  let previousElement = document.activeElement as HTMLElement | null;
+  if (!previousElement) { return; }
+
+  const shadowRoot = previousElement && previousElement.shadowRoot;
+  if (shadowRoot) {
+    // If there are no inner focusable elements, just focus the host element.
+    previousElement = shadowRoot.querySelector(innerFocusableQueryString) || previousElement;
+  }
+
+  await overlayEl.onDidDismiss();
+  previousElement.focus();
+}
+
 export const dismiss = async (
   overlay: OverlayInterface,
   data: any | undefined,