private void updateCallState(CallInfo ci) {
    TextView tvPeer = (TextView) findViewById(R.id.textViewPeer);
    TextView tvState = (TextView) findViewById(R.id.textViewCallState);
    Button buttonHangup = (Button) findViewById(R.id.buttonHangup);
    Button buttonAccept = (Button) findViewById(R.id.buttonAccept);
    String call_state = "";

    if (ci.getRole() == pjsip_role_e.PJSIP_ROLE_UAC) {
      buttonAccept.setVisibility(View.GONE);
    }

    if (ci.getState().swigValue() < pjsip_inv_state.PJSIP_INV_STATE_CONFIRMED.swigValue()) {
      if (ci.getRole() == pjsip_role_e.PJSIP_ROLE_UAS) {
        call_state = "Incoming call..";
        /* Default button texts are already 'Accept' & 'Reject' */
      } else {
        buttonHangup.setText("Cancel");
        call_state = ci.getStateText();
      }
    } else if (ci.getState().swigValue() >= pjsip_inv_state.PJSIP_INV_STATE_CONFIRMED.swigValue()) {
      buttonAccept.setVisibility(View.GONE);
      call_state = ci.getStateText();
      if (ci.getState() == pjsip_inv_state.PJSIP_INV_STATE_CONFIRMED) {
        buttonHangup.setText("Hangup");
      } else if (ci.getState() == pjsip_inv_state.PJSIP_INV_STATE_DISCONNECTED) {
        buttonHangup.setText("OK");
        call_state = "Call disconnected: " + ci.getLastReason();
        MainActivity.currentCall = null;
      }
    }

    tvPeer.setText(ci.getRemoteUri());
    tvState.setText(call_state);
  }