Indicates this object is visible, e.
g. has been explicitly marked for exposure to the user. **note**: atk_state_visible is no guarantee that the object is actually unobscured on the screen, only that it is 'potentially' visible, barring obstruction, being scrolled or clipped out of the field of view, or having an ancestor container that has not yet made visible. A widget is potentially onscreen if it has both atk_state_visible and atk_state_showing. The absence of atk_state_visible and atk_state_showing is semantically equivalent to saying that an object is 'hidden'. See also atk_state_truncated, which applies if an object with atk_state_visible and atk_state_showing set lies within a viewport which means that its contents are clipped, e.g. a truncated spreadsheet cell or an image within a scrolling viewport. Mostly useful for screen-review and magnification algorithms.