How to disable Notification and Navigation bar for Pattern Lock Screen

Question

I am working on a Pattern Lock Screen Application and for its completion I need to disable Notification and Navigation bar. So far till now I am successful in hiding them but not disabling them. I have read many posts here which says that its not possible. But then how is it possible that there are number of Pattern Lock applications available on play store that disables them :(. If for a minute we think that its not possible then is there a way to disable navigation bar buttons like back, home ,recent and notifications bar drop down panel. In buttons, I have only got successful in overriding back button. There must be some way to do it. Thanks in advance:).