Re: moving nested subwins

[Thomas Dickey]

On Thu, 7 Jun 2007, Clive Nicolson wrote:

> Oops I forgot to attach the code.
>
> Hi,
>
> here is some code which demonstrates how to fix the "menu subwin moving"
> problem for mvwin. This code is nonrecursive and I think will not break user 
> code which traverses the window parent tree and recalculates _begy
> and _begx. It also fixes the "form subwin moving" problem!
>
> mvderwin needs a somewhat slightly different fix.
>
> Anyone want a patch?

not exactly.  Let's go back to the top of the discussion.  What's needed 
is a concise proposal for

(a) an identifiable mismatch between ncurses behavior that leads to a fix 
or

(b) an example of how to provide the functionality without modifying 
ncurses or

(c) a new feature which could be used to provide the functionality, e.g., 
an extension

(extensions can't make it harder to port applications between flavors of 
curses...)

> #include <stdlib.h>
> #include <stdio.h>
>
> typedef struct _win_st WINDOW;
> struct _win_st {
>  int _begy;
>  int _begx;
>  WINDOW *_parent;
>  /* New fields */
>  WINDOW *_nc_lastchild;
>  WINDOW *_nc_lastsibling;
>  /* Test fields */
>  char name[16+1];
>  int moved;
> };
>
> static int i;
>
> /* Move all descendants of root */
> static void
> moveall(WINDOW *root, int dy, int dx) {
>  WINDOW *window;
>
>  window = root;
> loop:
>  while (window->_nc_lastchild)
>    window = window->_nc_lastchild;
>  while (window != root) {
>    {
>      i--;
>      printf("%s 1: %p %p %p",
>              window->name,
>              (void *)window->_parent,
>              (void *)window->_nc_lastchild, (void *)window->_nc_lastsibling);
>      if (window->moved)
>         printf(" ****");
>      else
>         window->moved = 1;
>      printf("\n");
>    }
>    window->_begy += dy;
>    window->_begx += dx;
>
>    if (window->_nc_lastsibling) {
>      window = window->_nc_lastsibling;
>      goto loop;
>    } else
>      window = window->_parent;
>  }
> }
>
> static void
> addsubwindow(WINDOW *parent, WINDOW *window) {
>  window->_parent = parent;
>  window->_nc_lastchild = NULL;
>  window->_nc_lastsibling = parent->_nc_lastchild;
>
>  parent->_nc_lastchild = window;
> }
>
> static void
> delwindow(WINDOW *window) {
>  WINDOW *child;
>
>  child = window->_nc_lastchild;
>  while (child) {
>    WINDOW *temp;
>
>    temp = child->_nc_lastsibling;
>
>    child->_parent = NULL;
>    child->_nc_lastsibling = NULL;
>
>    child = temp;
>  }
>
>  if (window->_parent) {
>    WINDOW *parent;
>
>    parent = window->_parent;
>    if (parent->_nc_lastchild) {
>      if (parent->_nc_lastchild == window)
>         parent->_nc_lastchild = window->_nc_lastsibling;
>      else {
>         WINDOW *sibling;
>
>         sibling = parent->_nc_lastchild;
>         while (sibling && sibling->_nc_lastsibling != window)
>           sibling = sibling->_nc_lastsibling;
>
>         if (sibling)
>           sibling->_nc_lastsibling = window->_nc_lastsibling;
>      }
>    }
>  }
>
>  free(window);
> }
>
> static WINDOW *
> build(WINDOW *parent) {
>  WINDOW *win;
>
>  win = malloc(sizeof(*win));
>  win->_begy = 0;
>  win->_begx = 0;
>  win->_parent = parent;
>  win->_nc_lastchild = (random() <= (RAND_MAX-1)/2) ? NULL : build(win);
>  win->_nc_lastsibling = (random() <= (RAND_MAX-1)/2) ? NULL : build(parent);
>  sprintf(win->name, "%p", (void *)win);
>  win->moved = 0;
>  printf("%s 0\n", win->name);
>
>  i++;
>
>  return win;
> }
>
> int
> main(int argc, char **argv) {
>  WINDOW *root;
>
>  i = 0;
>  root = build(NULL);
>  moveall(root, 2, 4);
>  printf("i=%i\n", i);
>
>  if (0) {
>    addsubwindow(root, NULL);
>    delwindow(root);
>  }
>
>  return (EXIT_SUCCESS);
> }
>
>
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--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net