question: public void onHigherLevel ( View view ) { IndoorBuilding building = mMap . getFocusedBuilding ( ) ; if ( building != null ) { List < IndoorLevel > levels = building . getLevels ( ) ; if ( ! levels . isEmpty ( ) ) { int currentLevel = building . getActiveLevelIndex ( ) ; int newLevel = currentLevel - 1 ; if ( newLevel == - 1 ) { newLevel = levels . size ( ) - 1 ; } IndoorLevel level = levels . get ( newLevel ) ; setText ( "Activiating level " + level . getName ( ) ) ; level . activate ( ) ; } else { setText ( "No levels in building" ) ; } } else { setText ( "No visible building" ) ; } }
target:  Called when the activate higher level is clicked.