# CaptionsButton

Accessible captions toggle button with availability detection and state reflection

## Import

```tsx
import { CaptionsButton } from '@videojs/react';
```

## Anatomy

```tsx
<CaptionsButton />
```

## Behavior

Toggles captions and subtitles on and off. The button checks the media’s text track list for tracks with `kind="captions"` or `kind="subtitles"`.

When none are present, the component returns `null`.

An explicitly disabled button with caption tracks stays visible and focusable with `aria-disabled="true"` and `data-disabled`, but does not toggle captions.

When `menuTrigger` is enabled and multiple caption or subtitle tracks are available, activation opens the linked captions menu instead of toggling captions directly. `menuTrigger` is enabled automatically when a `CaptionsButton` is rendered inside `Menu.Trigger`.

## Styling

Style the button based on active state:

React renders a `<button>` element. Add a `className` to style it:

```css
.captions-button[data-active] .icon-on { display: inline; }
.captions-button:not([data-active]) .icon-off { display: inline; }
```

Style an explicitly disabled, available button:

```css
.captions-button[data-disabled] {
  cursor: not-allowed;
  opacity: 0.5;
}
```

The button hides automatically when no caption tracks are available. No availability selector or extra hiding CSS is required.

## Accessibility

Renders a `<button>` with an automatic `aria-label`: “Disable captions” when active, “Enable captions” when inactive. Override with the `label` prop. Keyboard activation: Enter / Space.

In menu-trigger mode, the button behaves as a menu trigger and reflects menu state through the trigger attributes.

## Examples

### Basic Usage

**App.tsx**

```tsx
import { CaptionsButton, Container, createPlayer } from '@videojs/react';
import { Video, videoFeatures } from '@videojs/react/video';

const { Player } = createPlayer({ features: videoFeatures });

export default function BasicUsage() {
  return (
    <Player>
      <Container className="media-container">
        <Video src="https://stream.mux.com/BV3YZtogl89mg9VcNBhhnHm02Y34zI1nlMuMQfAbl3dM/highest.mp4" autoPlay muted playsInline loop>
          <track kind="captions" src="/docs/demos/captions-button/captions.vtt" srcLang="en" label="English" />
        </Video>
        <CaptionsButton
          className="media-captions-button"
          render={(props, state) => (
            <button {...props}>{state.subtitlesShowing ? 'Captions Off' : 'Captions On'}</button>
          )}
        />
      </Container>
    </Player>
  );
}
```

**App.css**

```css
.media-container {
  position: relative;
}

.media-container video {
  width: 100%;
}

.media-captions-button {
  position: absolute;
  bottom: 10px;
  left: 10px;
  padding-block: 8px;
  padding-inline: 20px;
  color: black;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 9999px;
  backdrop-filter: blur(10px);
}
```

## API Reference

### Props

| Prop | Type | Default | Description |
| --- | --- | --- | --- |
| `disabled` | `boolean` | `false` | Whether the button is disabled. |
| `label` | `{ key: string; text: string } \| string \| ((state: CaptionsButtonState) => Text \| string)` | `''` | Custom label for the button. |
| `menuTrigger` | `boolean` | `false` | When true with multiple tracks, pointer activation opens a menu instead of toggling. React sets this automatically inside `Menu.Trigger`. |

### State

State is accessible via the `render`, `className`, and `style` props.

| Property | Type | Description |
| --- | --- | --- |
| `subtitlesShowing` | `boolean` | Whether captions/subtitles are currently enabled. |
| `label` | `{ key: string; text: string } \| string` | |
| `availability` | `'available' \| 'unavailable'` | Whether caption/subtitle tracks are present. |
| `disabled` | `boolean` | Non-interactive but still focusable (mirrors `aria-disabled`). |
| `hidden` | `boolean` | Whether the button is hidden because no caption tracks are present. |

### Data attributes

| Attribute | Type | Description |
| --- | --- | --- |
| `data-active` | — | Present when captions are enabled. |
| `data-availability` | `'available' \| 'unavailable'` | Indicates captions availability (`available` or `unavailable`). |
| `data-disabled` | — | Present when the button is non-interactive (mirrors `aria-disabled`). |
| `data-hidden` | — | Present when the button is hidden because no caption tracks are present. |

---

React documentation: https://videojs.org/docs/framework/react/llms.txt
All documentation: https://videojs.org/llms.txt