Re: balance-windows again

[Kim F. Storm]

storm@cua.dk (Kim F. Storm) writes:

> The following patch adds a window-split-tree function which returns a simple
> tree presentation of the window split.  You can use window-edges on the
> elements of the tree to get the dimensions (and build your representation).

I think exposing the "container windows" as my previous patch did was
a really bad idea.  Instead, I prefer to explicitly include the
window-edges of those windows.  Below is a different patch which
implements this.

The new window-split-tree function doesn't return the format Lennart
requested, but it is trivial to convert it to his proposed format:

(defun balance-window-split (&optional frame)
  (balance-window-split-1 (car (window-split-tree frame))))

(defun balance-window-split-1 (split)
  (if (windowp split)
      split
    (let ((dir (car split))
          (edges (car (cdr split)))
          (childs (cdr (cdr split))))
      (list
       (cons 'dir (if dir 'ver 'hor))
       (cons 'b (nth 3 edges))
       (cons 'r (nth 2 edges))
       (cons 't (nth 1 edges))
       (cons 'l (nth 0 edges))
       (cons 'childs (mapcar #'balance-window-split-1 childs))))))


Here's the revised patch:

Index: window.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/window.c,v
retrieving revision 1.516
diff -c -r1.516 window.c
*** window.c    18 Sep 2005 16:28:53 -0000      1.516
--- window.c    29 Sep 2005 12:31:57 -0000
***************
*** 6225,6230 ****
--- 6226,6310 ----
    return unbind_to (count, val);
  }
  
+ 
+ 
+ /***********************************************************************
+                           Window Split Tree
+  ***********************************************************************/
+ 
+ static Lisp_Object
+ window_split_tree (w)
+      struct window *w;
+ {
+   Lisp_Object tail = Qnil;
+   Lisp_Object result = Qnil;
+ 
+   while (w)
+     {
+       Lisp_Object wn;
+ 
+       XSETWINDOW (wn, w);
+       if (!NILP (w->hchild))
+       wn = Fcons (Qnil, Fcons (Fwindow_edges (wn),
+                                window_split_tree (XWINDOW (w->hchild))));
+       else if (!NILP (w->vchild))
+       wn = Fcons (Qt, Fcons (Fwindow_edges (wn),
+                              window_split_tree (XWINDOW (w->vchild))));
+ 
+       if (NILP (result))
+       {
+         result = tail = Fcons (wn, Qnil);
+       }
+       else
+       {
+         XSETCDR (tail, Fcons (wn, Qnil));
+         tail = XCDR (tail);
+       }
+ 
+       w = NILP (w->next) ? 0 : XWINDOW (w->next);
+     }
+ 
+   return result;
+ }
+ 
+ 
+ 
+ DEFUN ("window-split-tree", Fwindow_split_tree, Swindow_split_tree,
+        0, 1, 0,
+        doc: /* Return the window split tree for frame FRAME.
+ 
+ The return value is a list of the form (ROOT MINI), where ROOT
+ represents the window split tree of the frame's root window, and MINI
+ is the frame's minibuffer window.
+ 
+ If the root window is not split, ROOT is the root window itself.
+ Otherwise, ROOT is a list (DIR EDGES W1 W2 ...) where DIR is nil for a
+ horisontal split, and t for a vertical split, EDGES gives the combined
+ size and position of the subwindows in the split, and the rest of the
+ elements are the subwindows in the split.  Each of the subwindows may
+ again be a window or a list representing a window split, and so on.
+ EDGES is a list \(LEFT TOP RIGHT BOTTOM) as returned by `window-edges'.
+ 
+ If FRAME is nil or omitted, return information on the currently
+ selected frame.  */)
+      (frame)
+      Lisp_Object frame;
+ {
+   Lisp_Object alist;
+   FRAME_PTR f;
+ 
+   if (NILP (frame))
+     frame = selected_frame;
+ 
+   CHECK_FRAME (frame);
+   f = XFRAME (frame);
+ 
+   if (!FRAME_LIVE_P (f))
+     return Qnil;
+ 
+   return window_split_tree (XWINDOW (FRAME_ROOT_WINDOW (f)));
+ }
+ 
  
  /***********************************************************************
                            Marginal Areas
***************
*** 7031,7036 ****
--- 7111,7117 ----
    defsubr (&Sset_window_configuration);
    defsubr (&Scurrent_window_configuration);
    defsubr (&Ssave_window_excursion);
+   defsubr (&Swindow_split_tree);
    defsubr (&Sset_window_margins);
    defsubr (&Swindow_margins);
    defsubr (&Sset_window_fringes);

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk