18.5 Group Helper

This feature of ConstraintLayout allows widgets to be placed into logical groups and the visibility of those widgets controlled as a single entity. A Group is essentially a list of references to other widgets in a layout. Once defined, changing the visibility attribute (visible, invisible or gone) of the group instance will apply the change to all group members. This makes it easy to hide and show multiple widgets with a single attribute change. A single layout may contain multiple groups and a widget can belong to more than one group. If a conflict occurs between groups the last group to be declared in the XML file takes priority.