How can I disable the keyguard when a broadcast receiver is activated by screen_on, so that when it occurs the user sees an activity that I have started behind it? (The act
i would recommend using the window flags dismiss_keyguard or show_when_locked if you have a window that needs to come over the top of the lockscreen right at wakeup.
http://developer.android.com/reference/android/view/WindowManager.LayoutParams.html#FLAG_SHOW_WHEN_LOCKED
how you use this is as follows (called in onCreate before setting layout)
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);