implements NSResponder scrolling methods
implements NSResponder scrolling methods
jwilling/JNWCollectionView,Spark-Xl/JNWCollectionView,kettch/JNWCollectionView,danielmartinprieto/JNWCollectionView,hachidorii/JNWCollectionView,regexident/JNWCollectionView,Deadpikle/JNWCollectionView,konstantinpavlikhin/JNWCollectionView