MotionLayout constraintSet types

New for 2.2.0 ConstraintSet's now have a concept called constraintSetTypes Types are a series of string that can be used to identify / lookup a constraintSet.

Added are two methods:

class MotionLayout {...
   public int[] getMatchingConstraintSetIds(String ... types){...}
}

class ConstraintSet {...
 String[]   getConstraintSetTypes();

In xml constraintSet's now have one more attribute:

<ConstraintSet android:id="@+id/foo" constraintSetTypes="a,b,c" > ..

so now you can query a motionLayout for constraintSets that match a series of strings

MotionLayout m = findMotionLayout()
String[]types =  m.getConstraintSet(m.getCurrentState()).getConstraintSetTypes();
int[]matched = m.getMatchingConstraintSetIds("a","b")
m.transitionTo(matched[0])

Typically you would use this when you have a Matrix of States For example

• Open, Closed
• list, detail
• friend, unknown This would result in 8 permutations you would then need id r.id.open_list_friend, r.id.open_list_unknown This allows you to tag a Constraintset with constraintSetTypes="open,list,friend" This allows you then to know an query this list.