code: @Override
      public void onBusEvent(Event event) {
          if (event instanceof AppVisibleChanged) {
              AppVisibleChanged visibleChanged = (AppVisibleChanged) event;
              if (visibleChanged.isVisible()) {
                  onAppVisible();
              } else {
                  onAppHidden();
              }
          } else if (event instanceof PeerChatOpened) {
              onConversationVisible(((PeerChatOpened) event).getPeer());
          } else if (event instanceof PeerChatClosed) {
              onConversationHidden(((PeerChatClosed) event).getPeer());
          }
      }
docs: Receiving bus events
  
  @param event event