[base] Removes invisible tabbable elements from TrapFocus component

docs/data/base/components/trap-focus/ContainedToggleTrappedFocus.js

@@ -0,0 +1,33 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import TrapFocus from '@mui/base/TrapFocus';
+
+export default function BasicTrapFocus() {
+  const [open, setOpen] = React.useState(false);
+
+  return (
+    <Box
+      sx={{
+        display: 'flex',
+        alignItems: 'center',
+        flexDirection: 'column',
+      }}
+    >
+      <TrapFocus open={open} disableRestoreFocus disableAutoFocus>
+        <Stack>
+          <Stack alignItems="center">
+            <button type="button" onClick={() => setOpen(!open)}>
+              {open ? 'Close' : 'Open'}
+            </button>
+          </Stack>
+          {open && (
+            <label>
+              First name: <input type="text" />
+            </label>
+          )}
+        </Stack>
+      </TrapFocus>
+    </Box>
+  );
+}

docs/data/base/components/trap-focus/ContainedToggleTrappedFocus.tsx

@@ -0,0 +1,33 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Stack from '@mui/material/Stack';
+import TrapFocus from '@mui/base/TrapFocus';
+
+export default function BasicTrapFocus() {
+  const [open, setOpen] = React.useState(false);
+
+  return (
+    <Box
+      sx={{
+        display: 'flex',
+        alignItems: 'center',
+        flexDirection: 'column',
+      }}
+    >
+      <TrapFocus open={open} disableRestoreFocus disableAutoFocus>
+        <Stack>
+          <Stack alignItems="center">
+            <button type="button" onClick={() => setOpen(!open)}>
+              {open ? 'Close' : 'Open'}
+            </button>
+          </Stack>
+          {open && (
+            <label>
+              First name: <input type="text" />
+            </label>
+          )}
+        </Stack>
+      </TrapFocus>
+    </Box>
+  );
+}

docs/data/base/components/trap-focus/ContainedToggleTrappedFocus.tsx.preview

@@ -0,0 +1,14 @@
+<TrapFocus open={open} disableRestoreFocus disableAutoFocus>
+  <Stack>
+    <Stack alignItems="center">
+      <button type="button" onClick={() => setOpen(!open)}>
+        {open ? 'Close' : 'Open'}
+      </button>
+    </Stack>
+    {open && (
+      <label>
+        First name: <input type="text" />
+      </label>
+    )}
+  </Stack>
+</TrapFocus>

docs/data/base/components/trap-focus/trap-focus.md

@@ -84,3 +84,10 @@ When auto focus is disabled—as in the demo below—the component only traps th
 The following demo uses the [`Portal`](/base/react-portal/) component to render a subset of the `TrapFocus` children into a new "subtree" outside of the current DOM hierarchy, so they are no longer part of the focus loop:
 
 {{"demo": "PortalTrapFocus.js"}}
+
+### Using a toggle inside the trap
+
+The most common use case for the `TrapFocus` component is to maintain focus within a [modal](/base/react-modal/) component that is entirely separate from the element that opens the modal.
+But you can also create a toggle button for the `open` prop of the `TrapFocus` component that is stored inside of the component itself, as shown in the following demo:
+
+{{"demo": "ContainedToggleTrappedFocus.js"}}

package.json

@@ -88,6 +88,7 @@
     "@rollup/plugin-replace": "^4.0.0",
     "@testing-library/dom": "^8.16.0",
     "@testing-library/react": "^13.3.0",
+    "@testing-library/user-event": "^14.3.0",
     "@types/chai": "^4.3.1",
     "@types/chai-dom": "^0.0.13",
     "@types/enzyme": "^3.10.12",

packages/mui-base/src/TrapFocus/TrapFocus.js

@@ -325,13 +325,18 @@ function TrapFocus(props) {
   return (
     <React.Fragment>
       <div
-        tabIndex={0}
+        tabIndex={open ? 0 : -1}
         onFocus={handleFocusSentinel}
         ref={sentinelStart}
-        data-test="sentinelStart"
+        data-testid="sentinelStart"
       />
       {React.cloneElement(children, { ref: handleRef, onFocus })}
-      <div tabIndex={0} onFocus={handleFocusSentinel} ref={sentinelEnd} data-test="sentinelEnd" />
+      <div
+        tabIndex={open ? 0 : -1}
+        onFocus={handleFocusSentinel}
+        ref={sentinelEnd}
+        data-testid="sentinelEnd"
+      />
     </React.Fragment>
   );
 }

packages/mui-base/src/TrapFocus/TrapFocus.test.js

@@ -4,6 +4,7 @@ import { expect } from 'chai';
 import { act, createRenderer, screen } from 'test/utils';
 import TrapFocus from '@mui/base/TrapFocus';
 import Portal from '@mui/base/Portal';
+import userEvent from '@testing-library/user-event';
 
 describe('<TrapFocus />', () => {
   const { clock, render } = createRenderer();
@@ -283,6 +284,36 @@ describe('<TrapFocus />', () => {
     expect(screen.getByTestId('root')).toHaveFocus();
   });
 
+  it('does not create any tabbable elements when open={false}', () => {
+    function Test(props) {
+      return (
+        <div>
+          <button autoFocus data-testid="initial-focus">
+            Test
+          </button>
+          <TrapFocus open={false} {...props}>
+            <div tabIndex={-1}>
+              <button data-testid="inside-focus">Test</button>
+            </div>
+          </TrapFocus>
+          <button data-testid="end-focus">Test</button>
+        </div>
+      );
+    }
+
+    render(<Test />);
+
+    expect(screen.getByTestId('initial-focus')).toHaveFocus();
+    act(() => {
+      userEvent.tab();
+    });
+    expect(screen.getByTestId('inside-focus')).toHaveFocus();
+    act(() => {
+      userEvent.tab();
+    });
+    expect(screen.getByTestId('end-focus')).toHaveFocus();
+  });
+
   describe('interval', () => {
     clock.withFakeTimers();
 

yarn.lock

@@ -3163,6 +3163,11 @@
     "@testing-library/dom" "^8.5.0"
     "@types/react-dom" "^18.0.0"
 
+"@testing-library/user-event@^14.3.0":
+  version "14.3.0"
+  resolved "https://registry.yarnpkg.com/@testing-library/user-event/-/user-event-14.3.0.tgz#0a6750b94b40e4739706d41e8efc2ccf64d2aad9"
+  integrity sha512-P02xtBBa8yMaLhK8CzJCIns8rqwnF6FxhR9zs810flHOBXUYCFjLd8Io1rQrAkQRWEmW2PGdZIEdMxf/KLsqFA==
+
 "@theme-ui/color-modes@0.14.7":
   version "0.14.7"
   resolved "https://registry.yarnpkg.com/@theme-ui/color-modes/-/color-modes-0.14.7.tgz#6f93bf4d0890ffe3386df311663eaee9bea40796"