The ATK interface provided by UI components which occupy a physical area on the screen.

This should be implemented by most if not all UI elements with an actual on-screen presence, i.e. components which can be said to have a screen-coordinate bounding box. Virtually all widgets will need to have Atk.Component implementations provided for their corresponding Atk.Object class. In short, only UI elements which are* not* GUI elements will omit this ATK interface.

A possible exception might be textual information with a transparent background, in which case text glyph bounding box information is provided by Atk.Text.