The PseudoClass enum in the Sandbox.UI namespace represents a list of CSS pseudo-classes used by the styling system. These pseudo-classes are utilized for various UI states such as hover, active, and focus. This enum acts as a bit-flag, allowing for the combination of multiple pseudo-classes.
| Member Name | Summary |
|---|---|
| None | No pseudo-class. |
| Unknown | Unused. |
| Hover | :hover - Any element with the mouse cursor hovering over it. |
| Active | :active - A button that is being pressed down. |
| Focus | :focus - An element with input focus. |
| Intro | :intro - Present on all elements for their first frame. Useful to start CSS transitions on creation. |
| Outro | :outro - The element has been marked for deletion, and will be deleted once all CSS transitions on it have stopped. Transitions can be started here to gracefully remove the element visually. |
| Empty | :empty - Any element that has no children. |
| FirstChild | :first-child - The element is the first element among a group of sibling elements. |
| LastChild | :last-child - The element is the last element among a group of sibling elements. |
| OnlyChild | :only-child - The element is the only child of their parent element. |