Indicates that "active-descendant-changed" event is sent when children become 'active' (i.e. are selected or navigated to onscreen).
Used to prevent need to enumerate all children in very large containers, like tables. The presence of STATE_MANAGES_DESCENDANTS is an indication to the client. that the children should not, and need not, be enumerated by the client. Objects implementing this state are expected to provide relevant state notifications to listening clients, for instance notifications of visibility changes and activation of their contained child objects, without the client having previously requested references to those children.