How do I put a subwindow within a subwindow? - c++

Question

I am using NCurses to try and get the desired output:
However with the following code:
int main(void)
{
WINDOW *white_space,*red_space,*blue_box;
int maxx,maxy;
initscr();
start_color();
init_pair(1,COLOR_WHITE,COLOR_BLUE);
init_pair(2,COLOR_RED,COLOR_WHITE);
init_pair(3,COLOR_BLACK,COLOR_GREEN);
init_pair(4,COLOR_RED,COLOR_RED);
white_space = subwin(stdscr,10,76,6,2);
red_space = subwin(stdscr,1,80,23,0);
getmaxyx(white_space,maxy,maxx);
blue_box = subwin(white_space,maxy-1,maxx-1,8,20);
if(white_space == NULL)
{
addstr("Unable to create subwindow\n");
endwin();
return 1;
}
bkgd(COLOR_PAIR(1));
addstr("Master window");
wbkgd(white_space,COLOR_PAIR(2));
mvwprintw(white_space, 0, 0, "%46s", "White space");
wbkgd(blue_box,COLOR_PAIR(4));
wbkgd(red_space,COLOR_PAIR(3));
waddstr(red_space,"Alert area");
wrefresh(white_space);
wrefresh(stdscr);
refresh();
getch();
endwin();
return 0;
}
I get the following output:
Is it possible to create a subwindow within a subwindow?
Thanks

Answer 1

ncurses (any non-buggy version of curses) supports subwindows, as noted in the manual.
In the given example, there are a few problems noticed:
white_space = subwin(stdscr,10,76,6,2);
red_space = subwin(stdscr,1,80,23,0);
getmaxyx(white_space,maxy,maxx);
blue_box = subwin(white_space,maxy-1,maxx-1,8,20);
For instance:
the initial size given to white_space does not take into account the actual screen-size (which could be narrower than 80 columns)
the size asked for blue_box is only slightly smaller than white_space, but starts far enough to the right that the window could not (in 80 columns) be shown. If so, no window is created.
There are several programs in ncurses-examples using subwin and the related derwin, which may be useful for comparison.