Function focusElementInContext

core/src/utils/focus-trap.ts:68–92

(
  hostToFocus: HTMLElement | null | undefined,
  fallbackElement: T
)

 * the host element itself.
 */
const focusElementInContext = <T extends HTMLElement>(
  hostToFocus: HTMLElement | null | undefined,
  fallbackElement: T
) => {
  let elementToFocus = hostToFocus;

  const shadowRoot = hostToFocus?.shadowRoot;
  if (shadowRoot) {
    // If there are no inner focusable elements, just focus the host element.
    elementToFocus = shadowRoot.querySelector<HTMLElement>(focusableQueryString) || hostToFocus;
  }

  if (elementToFocus) {
    const radioGroup = elementToFocus.closest('ion-radio-group');

    if (radioGroup) {
      radioGroup.setFocus();
    } else {
      focusVisibleElement(elementToFocus);
    }
  } else {
    // Focus fallback element instead of letting focus escape
    fallbackElement.focus();
  }
};