How to show NCursesPanel on screen by c++ bindings of NCurses - c++

Question

DemoI am trying out the c++ bindings shipped with ncurses-5.9. It seems that it is not easy to show a panel with window inside on screen easily. Here is my code
class SpiderApplication : NCursesApplication
{
protected:
int titlesize() const { return 2; };
void title();
public:
SpiderApplication() : NCursesApplication(TRUE) {}
int run();
};
void SpiderApplication::title()
{
const char * const titleText = "Demo";
const int len = ::strlen(titleText);
titleWindow->bkgd(screen_titles());
titleWindow->addstr(0, (titleWindow->cols() - len) / 2, titleText);
titleWindow->noutrefresh();
}
int SpiderApplication::run()
{
NCursesPanel mystd;
NCursesPanel P(mystd.lines() - titlesize(), mystd.cols(), titlesize() - 1, 0);
P.label("Demo", NULL);
P.show();
::getch();
P.clear();
return 0;
}
I suppose that the there should be a panel shown under titleline of this application. However, it doesn't. Do I miss something important here. Is there any example for how to use the c++ binding of ncurses?
Thanks.

Answer 1

I find the answer for my own question.
To make panel shown on screen, refresh() call cannot be omitted. Here is the working code:
NCursesPanel mystd;
NCursesPanel P(mystd.lines() - titlesize(), mystd.cols(), titlesize() - 1, 0);
P.label("Demo", NULL);
P.show();
mystd.refresh();
::getch();
P.clear();