android content observer - onChange method check i

问题:

I am working on an android app and I need to increment the incoming missed calls.

I registered a ContentObserver. How can I check in the onChange method if the call is a missed call or not?

I have a contentobserver with the following code:

public class IncomingCall extend BroadcastReceiver
{
public void onReceive( final Context context, Intent intent)
{
String state= extras.getString(TelephonyManager.EXTRA_STATE);
    if (TelephonyManager.EXTRA_STATE_IDLE.equals(state))
        {
            context.getApplicationContext().getContentResolver().registerContentObserver(android.provider.CallLog.Calls.CONTENT_URI, true, new CallContentObserver(new Handler(), context));
        }

}

 class CallContentObserver extends ContentObserver {

    Context context;

    public CallContentObserver(Handler handler, Context context) {
        super(handler);
        this.context = context;
    }

    @Override
    public boolean deliverSelfNotifications() {
        return true;
    }

    @Override
    public void onChange(boolean selfChange) {
        super.onChange(selfChange);

        //flag for missed calls
        how to check if last call is missed call?

Cursor c = context.getContentResolver().query(CallLog.Calls.CONTENT_URI,null,null, null, null);
        int type = c.getColumnIndex(CallLog.Calls.TYPE);
        while (c.moveToNext()) {
            String callType = c.getString(type);

            int dircode = Integer.parseInt(callType);
            switch (dircode) {

            case CallLog.Calls.MISSED_TYPE:
                flag++;

            }
            break;
        }

}

Isn't there another way to do this? (better than I did when checking the last call from CallLog database?

回答1:

I would suggest to try the following code in order to determine 'if last call is missed call or not':

@Override
public void onChange(boolean selfChange, Uri uri) {

    if (null == uri) {
        onChange(selfChange);
        return;
    }

    super.onChange(selfChange, uri);

    final Cursor c = context.getContentResolver().query(uri,null,null, null, null);
    final int type = c.getColumnIndex(CallLog.Calls.TYPE);
    final int dircode = c.getInt(type);

    switch (dircode) {
        case CallLog.Calls.MISSED_TYPE:
            flag++;
            break;
    }
}

It would be faster than checking all calls in case if You need to check only latest call. However, if where will be no uri, then provided way looks fine.

Another suggestion is to implement Service to do checking of missed calls count, so You will not have long processing in ContentObserver.