Nice !!

I just found my need we can check if the permission is granted by :

checkSelfPermission(Manifest.permission.READ_CONTACTS)

Request permissions if necessary

if (checkSelfPermission(Manifest.permission.READ_CONTACTS)
            != PackageManager.PERMISSION_GRANTED) {
        requestPermissions(new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant

        return;
    }

Handle the permissions request response

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! do the
                // calendar task you need to do.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'switch' lines to check for other
        // permissions this app might request
    }
}