Changing the way your mobile displays incoming calls - Where to begin?

Question

Here's a situation: I own a nokia mobile device. Quite often, I receive calls from unknown local/national numbers. Now, I would like to take those calls that are from unknown national numbers coz they could be important and I would not like to take calls from local numbers. I would like to write an application which displays " calling" instead of the regular " calling". For instance, " AT&T, CA". I have a database of codes with carriers and their reserved numbers for each state.

Now, I know this not simple coz I am talking about changing something that is native to the mobile phone. Sure, I could write a java app or a symbian app or something like that, but obviously, that would be kind of an aftermath app, which you would run after you've missed the call. I need something that is real-time.

So, to do what I want, where do I start? Is it even possible? Does some sort of SDK exist for this kind of stuff?

Answer 1

Without known the specific type of the phone I can only give you a general answer.

You have to find out if the APIs that your phone supports (J2ME or symbian) support an event to watch for incomming calls.

Then it should be simple.