How to detect incoming calls, in an Android device?

Question

I\'m trying to make an app like, when a call comes to the phone I want to detect the number. Below is what I tried, but it\'s not detecting incoming calls.

I want t

Answer 1

@Gabe Sechan, thanks for your code. It works fine except the onOutgoingCallEnded(). It is never executed. Testing phones are Samsung S5 & Trendy. There are 2 bugs I think.

1: a pair of brackets is missing.

case TelephonyManager.CALL_STATE_IDLE: 
    // Went to idle-  this is the end of a call.  What type depends on previous state(s)
    if (lastState == TelephonyManager.CALL_STATE_RINGING) {
        // Ring but no pickup-  a miss
        onMissedCall(context, savedNumber, callStartTime);
    } else {
        // this one is missing
        if(isIncoming){
            onIncomingCallEnded(context, savedNumber, callStartTime, new Date());                       
        } else {
            onOutgoingCallEnded(context, savedNumber, callStartTime, new Date());                                               
        }
    }
    // this one is missing
    break;

2: lastState is not updated by the state if it is at the end of the function. It should be replaced to the first line of this function by

public void onCallStateChanged(Context context, int state, String number) {
    int lastStateTemp = lastState;
    lastState = state;
    // todo replace all the "lastState" by lastStateTemp from here.
    if (lastStateTemp  == state) {
        //No change, debounce extras
        return;
    }
    //....
}

Additional I've put lastState and savedNumber into shared preference as you suggested.

Just tested it with above changes. Bug fixed at least on my phones.