The DropDownButton is a single tab stop component.

## Keyboard Shortcuts

**Button element**

| Key         | Behavior                                                    |
|-------------|-------------------------------------------------------------|
| `Alt+Down Arrow` | Opens the DropDownButton Popup and moves the focus to its first menuitem. |
| `Enter` | Opens the DropDownButton Popup and moves the focus to its first menuitem. |
| `Space` | Opens the DropDownButton Popup and moves the focus to its first menuitem. |

**Popup element**

| Key         | Behavior                                                    |
|-------------|-------------------------------------------------------------|
| `Alt+Up Arrow` | Closes the Popup and moves focus back to the main Button. |
| `Esc` | Closes the Popup and moves focus back to the main Button. |
| `Down Arrow`  | Moves focus to the next menuitem. If focus is on the last menu item, moves focus to the first menuitem. |
| `Up Arrow`  | Moves focus to the previous menuitem. If focus is on the first menu item, moves focus to the last menu item. |
| `Home`  | Moves focus to the first menuitem. |
| `End`  | Moves focus to the last menuitem. |
| `Enter` | Clicks (activates) the currently active menuitem and closes the Popup. |
| `Space` | Clicks (activates) the currently active menuitem and closes the Popup. |

## Resources

https://www.w3.org/TR/wai-aria-practices/examples/menu-button/menu-button-links.html