CallScreeningService class on Android, used to handle phone calls (incoming and outgoing), as the default caller-id.
Docs: https://developer.android.com/reference/android/telecom/CallScreeningService
This service can be implemented by the default dialer (see TelecomManager#getDefaultDialerPackage()) or a third party app to allow or disallow incoming calls before they are shown to a user. A CallScreeningService can also see outgoing calls for the purpose of providing caller ID services for those calls.
A CallScreeningService performs two functions:
- Call blocking/screening - the service can choose which calls will ring on the user's device, and which will be silently sent to voicemail.
- Call identification - services which provide call identification functionality can display a user-interface of their choosing which contains identifying information for a call.