How are things now
This has been discussed in many questions but neither one offers a good solution. Things look simple, after having a BroadcastReceiver is really easy to intercept and block a call. The main issue that appears is the default Android incoming call screen. You know, the one with sliders for answer/end call. Because i have some rules to block the call, there is a small delay before the call gets hangup. In all this time, the Incoming call screen is active.
How I want things to be
I want the user to not get notified by this call blocking, as in my application I have a clear Log of all blocks done. So, the main thing remains: how do I prevent the Incoming call screen from starting?