fix(popover-container): ensure that tab sequence is not lost when container has radio buttons

src/__internal__/focus-trap/focus-trap.component.tsx

@@ -279,7 +279,7 @@ const FocusTrap = ({
     onFocus: updateCurrentFocusedElement,
   });
 
-  // passes focusProps, sets tabIndex and onBlur if no tabIndex has been expicitly set on child
+  // passes focusProps, sets tabIndex and onBlur if no tabIndex has been explicitly set on child
   const clonedChildren = React.Children.map(children, (child) => {
     const focusableChild = child as React.ReactElement;
     return React.cloneElement(

src/components/popover-container/components.test-pw.tsx

@@ -7,6 +7,7 @@ import Pill from "../pill";
 import Badge from "../badge";
 import Box from "../box";
 import { Select, Option } from "../select";
+import RadioButton, { RadioButtonGroup } from "../radio-button";
 import PopoverContainer, {
   PopoverContainerProps,
 } from "./popover-container.component";
@@ -434,3 +435,31 @@ export const PopoverContainerFocusOrder = (
     </Box>
   );
 };
+
+export const WithRadioButtons = () => {
+  const [open1, setOpen1] = useState(false);
+  return (
+    <Box padding="25px" display="inline-flex">
+      <PopoverContainer
+        position="left"
+        onOpen={() => setOpen1(true)}
+        onClose={() => setOpen1(false)}
+        open={open1}
+        renderOpenComponent={({ ref, onClick }) => (
+          <Button aria-label="open" ref={ref} onClick={onClick}>
+            With Radio children
+          </Button>
+        )}
+        p={0}
+      >
+        <Box display="flex" justifyContent="space-between" p={2}>
+          <RadioButtonGroup name="bar">
+            <RadioButton value="1" label="radio 1" />
+            <RadioButton value="2" label="radio 2" />
+          </RadioButtonGroup>
+        </Box>
+      </PopoverContainer>
+      <Button>foo</Button>
+    </Box>
+  );
+};

src/components/popover-container/popover-container-test.stories.tsx

@@ -11,6 +11,7 @@ import Typography from "../typography";
 import Search from "../search";
 import IconButton from "../icon-button";
 import Icon from "../icon";
+import RadioButton, { RadioButtonGroup } from "../radio-button";
 
 export default {
   title: "Popover Container/Test",
@@ -22,6 +23,7 @@ export default {
     "InsideMenu",
     "InsideMenuWithOpenButton",
     "WithFullWidthButton",
+    "WithRadioButtons",
   ],
   parameters: {
     info: { disable: true },
@@ -246,3 +248,32 @@ export const WithFullWidthButton = () => {
     </PopoverContainer>
   );
 };
+
+export const WithRadioButtons = () => {
+  const [open1, setOpen1] = useState(false);
+
+  return (
+    <Box padding="25px" display="inline-flex">
+      <PopoverContainer
+        position="left"
+        onOpen={() => setOpen1(true)}
+        onClose={() => setOpen1(false)}
+        open={open1}
+        renderOpenComponent={({ ref, onClick }) => (
+          <Button aria-label="Notifications" ref={ref} onClick={onClick}>
+            With Radio children
+          </Button>
+        )}
+        p={0}
+      >
+        <Box display="flex" justifyContent="space-between" p={2}>
+          <RadioButtonGroup name="bar">
+            <RadioButton value="1" label="radio 1" />
+            <RadioButton value="2" label="radio 2" />
+          </RadioButtonGroup>
+        </Box>
+      </PopoverContainer>
+      <Button>foo</Button>
+    </Box>
+  );
+};

src/components/popover-container/popover-container.component.tsx

@@ -30,6 +30,7 @@ import useFocusPortalContent from "../../hooks/__internal__/useFocusPortalConten
 import tagComponent, {
   TagProps,
 } from "../../__internal__/utils/helpers/tags/tags";
+import { defaultFocusableSelectors } from "../../__internal__/focus-trap/focus-trap-utils";
 
 export interface RenderOpenProps {
   tabIndex: number;
@@ -272,6 +273,38 @@ export const PopoverContainer = ({
     closePopover,
   );
 
+  const onFocusNextElement = useCallback((ev) => {
+    const allFocusableElements: HTMLElement[] = Array.from(
+      document.querySelectorAll(defaultFocusableSelectors) ||
+        /* istanbul ignore next */ [],
+    );
+    const filteredElements = allFocusableElements.filter(
+      (el) => el === openButtonRef.current || Number(el.tabIndex) !== -1,
+    );
+
+    const openButtonRefIndex = filteredElements.indexOf(
+      openButtonRef.current as HTMLElement,
+    );
+
+    filteredElements[openButtonRefIndex + 1].focus();
+    closePopover(ev);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const handleFocusGuard = (
+    direction: "prev" | "next",
+    ev: React.FocusEvent<HTMLElement>,
+  ) => {
+    if (direction === "next" && onFocusNextElement) {
+      // Focus the next focusable element outside of the popover
+      onFocusNextElement(ev);
+      return;
+    }
+
+    // istanbul ignore else
+    if (direction === "prev") openButtonRef.current?.focus();
+  };
+
   const renderOpenComponentProps = {
     tabIndex: 0,
     "aria-expanded": isOpen,
@@ -335,7 +368,23 @@ export const PopoverContainer = ({
         </FocusTrap>
       </ModalContext.Provider>
     ) : (
-      popover()
+      <>
+        <div
+          data-element="tab-guard-top"
+          // eslint-disable-next-line jsx-a11y/no-noninteractive-tabindex
+          tabIndex={0}
+          aria-hidden
+          onFocus={(ev) => handleFocusGuard("prev", ev)}
+        />
+        {popover()}
+        <div
+          data-element="tab-guard-bottom"
+          // eslint-disable-next-line jsx-a11y/no-noninteractive-tabindex
+          tabIndex={0}
+          aria-hidden
+          onFocus={(ev) => handleFocusGuard("next", ev)}
+        />
+      </>
     );
 
   return (

src/components/popover-container/popover-container.pw.tsx

@@ -34,6 +34,7 @@ import {
   WithRenderCloseButtonComponent,
   PopoverContainerComponentCoverButton,
   PopoverContainerFocusOrder,
+  WithRadioButtons,
 } from "../popover-container/components.test-pw";
 import Portrait from "../portrait";
 
@@ -624,6 +625,25 @@ test.describe("Check props of Popover Container component", () => {
     await expect(third).toBeFocused();
   });
 
+  test("should focus the next focusable element outside of the container once finished keyboard navigating through the container's content", async ({
+    mount,
+    page,
+  }) => {
+    await mount(<WithRadioButtons />);
+
+    const openButton = page.getByRole("button", { name: "open" });
+    const container = popoverContainerContent(page);
+    const additionalButton = page.getByRole("button", { name: "foo" });
+
+    await openButton.click();
+    await page.keyboard.press("Tab"); // focus on first radio button
+    await page.keyboard.press("Tab"); // focus on close icon
+    await page.keyboard.press("Tab"); // focus outside of container and on to additional button
+
+    await expect(container).not.toBeVisible();
+    await expect(additionalButton).toBeFocused();
+  });
+
   test.describe("Accessibility tests", () => {
     test("should check accessibility for Default example", async ({
       mount,

src/components/popover-container/popover-container.test.tsx

@@ -12,6 +12,8 @@ import { testStyledSystemPadding } from "../../__spec_helper__/__internal__/test
 import PopoverContainer from "./popover-container.component";
 import { Select, Option } from "../select";
 import useMediaQuery from "../../hooks/useMediaQuery";
+import Button from "../button";
+import RadioButton, { RadioButtonGroup } from "../radio-button";
 
 jest.mock("../../hooks/useMediaQuery");
 
@@ -531,6 +533,89 @@ describe("closing the popup", () => {
   });
 });
 
+test("when content is navigated via keyboard, the next focusable item should be focused and popup closed", async () => {
+  const user = userEvent.setup({ advanceTimers: jest.advanceTimersByTime });
+  render(
+    <>
+      <PopoverContainer
+        position="left"
+        renderOpenComponent={({ ref, onClick }) => (
+          <Button aria-label="open button" ref={ref} onClick={onClick}>
+            Open
+          </Button>
+        )}
+      >
+        <RadioButtonGroup name="bar">
+          <RadioButton value="1" label="radio 1" />
+          <RadioButton value="2" label="radio 2" />
+        </RadioButtonGroup>
+      </PopoverContainer>
+      <Button>Example Button</Button>
+    </>,
+  );
+
+  const openButton = screen.getByRole("button", { name: "open button" });
+  await user.click(openButton);
+  await user.tab(); // tab to close icon
+  await user.tab(); // tab to RadioButtonGroup
+  await user.tab(); // tab to Example Button (outside of popup)
+
+  const popup = await screen.findByRole("dialog");
+  await waitFor(() => expect(popup).not.toBeVisible());
+
+  const exampleButton = screen.getByRole("button", { name: "Example Button" });
+  expect(exampleButton).toHaveFocus();
+});
+
+test("when the popover is opened and shift tab key is pressed, the open button should be focused and popup closed", async () => {
+  const user = userEvent.setup({ advanceTimers: jest.advanceTimersByTime });
+  render(
+    <>
+      <PopoverContainer
+        position="left"
+        renderOpenComponent={({ ref, onClick }) => (
+          <Button aria-label="open button" ref={ref} onClick={onClick}>
+            Open
+          </Button>
+        )}
+      >
+        <RadioButtonGroup name="bar">
+          <RadioButton value="1" label="radio 1" />
+          <RadioButton value="2" label="radio 2" />
+        </RadioButtonGroup>
+      </PopoverContainer>
+      <Button>Example Button</Button>
+    </>,
+  );
+
+  const openButton = screen.getByRole("button", { name: "open button" });
+  await user.click(openButton);
+  await user.tab(); // tab to close icon
+  await user.tab(); // tab to content
+  await user.tab({ shift: true }); // shift tab back to close icon
+  await user.tab({ shift: true }); // shift tab back to the opening trigger element
+
+  const popup = await screen.findByRole("dialog");
+  await waitFor(() => expect(popup).not.toBeVisible());
+  expect(openButton).toHaveFocus();
+});
+
+test("if only the open trigger is the only focusable element on screen, when the popover is opened and tab key is used to navigate content, it should navigate back to the opening trigger", async () => {
+  const user = userEvent.setup({ advanceTimers: jest.advanceTimersByTime });
+  render(
+    <>
+      <PopoverContainer title="My popup" open />
+    </>,
+  );
+
+  const openButton = screen.getByRole("button", { name: "My popup" });
+  await user.click(openButton);
+  await user.tab(); // tab to close icon
+  await user.tab(); // tab back out of content to the opening trigger element
+
+  expect(openButton).toHaveFocus();
+});
+
 testStyledSystemPadding(
   (props) => (
     <PopoverContainer open title="My popup" {...props}>