Originally Posted by erwaninho
thank you for your answer, I'm gonna check this...
the real question is : how to set this ALWAYS to true ?
what dedalus said is true. This is done that way because either ICS or JB doesn't allow directly trough SDK to hide navigation bar (or status bar, or whatever) afaik
... That's Amlogic's implementation of how to show app in full screen.
EDIT: you can use /system/bin/set_display_mode.sh script to add line:
setprop "tv.hideStatusBar.enable" "true"