如何重绘ncurses菜单

Question

I am working on an ncurses-based tool that has 4 tiled windows with a command bar at the bottom of the screen. The windows form a 2x2 grid like this:

+----+----------------+
| 1  |  2             |
+----+----------------+
| 3  |  4             |
|    |                |
|    |                |
|    |                |
+----+----------------+

The top left is fixed in size, so when the app is resized, 2 changes in width, 3 changes in height, and 4 changes in both directions.

I had the redrawing code working fine until I started putting menus (using menu.h) in window 4. Now, if i resize the window too small, part of the menu will get cut off, but when you make the window bigger again, it does not repaint what was removed. Doing a post_menu() in the redraw code does not repaint it.

What is the proper way to repaint a menu? Do I have to dispose of it and recreate it from scratch every time? I do have logic in my code that only repaints if necessary (data changed, window resized, etc), so it would not be creating a new menu every cycle for no reason, but this still seems a bit heavy handed. There has to be a simple way to just redraw the menu you have already created. What is it?

Answer 1

Recreating the structure is the simplest way.

The form and menu libraries use an abstraction of the keys you type. That abstraction does not include a resize feature.

You could run wresize for each of the windows in the menu, eg, these lines from menu.h

  WINDOW        *win;                   /* Window containing menu          */
  WINDOW        *sub;                   /* Subwindow for menu display      */
  WINDOW        *userwin;               /* User's window                   */
  WINDOW        *usersub;               /* User's subwindow                */

but making that work requires some study of the library. There's an example which resizes a form in ncurses-examples (named cardfile ), but no analogous example for menus .

Further reading:

• wresize - resize a curses window
• is_term_resized , resize_term , resizeterm - change the curses terminal size