Problems with overlapping windows

[Jiri Fogl]

Hi, I'd like to ask if there are some circumstances I should be aware of when 
creating overlapping windows.

I'm building an application on top of ncurses and I still have problems with 
overlapping windows - sometimes it works as one would expect (I'll call it "A 
scenario"), sometimes it does not ("B scenario").

I create windows by newwin() along with new_panel(). Generally I have one huge 
window filling all the screen and a popup window.

In "B scenario": If fullscreen window is created, popup window doesn't show up 
then. newwin() as well as new_panel() for popup window return a pointer (not 
NULL), but attempt for i.e panel_top() ends up in segmentation fault.
After commenting out creation of the fullscreen window, the popup window 
appears 
and behaves as expected.

In "A scenario" popup window works on top of the fullscreen window.

I said "sometimes" above. That means my application alternates between A and B 
scenarios "by its own decision". At first I had B situation, after some 
structure wiping I got it working, and now after some other minor adjustments 
in code I'm back in B. That means I affected something important without 
knowing it is important, and I would like to learn what it is. Can you help me 
to find the catch please?



Here is a snippet of my C++ code:

TnmWindow wStatus(2, 0, LINES - 2, 0, true),
          wMain(LINES - 2, 0, 0, 0, true), // fullscreen window
          wAbout(20, 60, 5, 5, true);    // popup window

where TnmWindow is my own class to represent individual window. This class is 
defined like this:

class TnmWindow {

  WINDOW *wnd;
  PANEL  *pan;
  bool initialized;

  public:
    TnmWindow(int lines, int cols, int begin_y, int begin_x, bool drawFrame = 
false, bool visible = true);
    TnmWindow(int lines, int cols, bool drawFrame = false, bool visible = true);

    void show();
    void hide();
};

TnmWindow::TnmWindow(int lines, int cols, int begin_y, int begin_x, bool 
drawFrame, bool visible) {
  if (!initialized) {
    if ((wnd = newwin(lines, cols, begin_y, begin_x)) == NULL)
      return;

    if (drawFrame)
      box(wnd, 0, 0);

    pan = new_panel(wnd);
    set_panel_userptr(pan, this);

    if (!visible)
      hide_panel(pan);
    else {
      update_panels();
      doupdate();
    }

    initialized = true;
  }
}

void TnmWindow::show() {
  if (!initialized || (pan == NULL))
    return;

  if (panel_hidden(pan))
    show_panel(pan);
  else
    top_panel(pan);

  update_panels();
  doupdate();
}

void TnmWindow::hide() {
  if (!initialized || (pan == NULL))
    return;

  if (!panel_hidden(pan))
    hide_panel(pan);
}