Re: MY window tree!

[martin rudalics <rudalics@gmx.at>]

 > I have actually changed that to just change the 'window property of the
 > overlays. No overlays are normally copied any more. If the window object
 > that the 'window properties points to is not a valid window any more
 > then I just replace that value with a pointer to the new window that
 > have replaced the old one.

I'm using this concept for two years now and it never failed (I suppose
because a window can't be collected as long as an overlay references
it).

 > I guess that for most cases this will be sufficient. But there can still
 > be cases where a mode (or some other code) have a persisting pointer to
 > a window object. I can not replace this pointers.

Never mind.  `window-configuration-change-hook' must handle this.  Any
mode referencing a window object must be aware of the fact that the user
may delete the window and recreate another one showing the same buffer
whenever she wants to.  When one window replaces another the
configuration changes and the mode should be able to handle this.

In some cases it might be, however, reasonable to advert the mode that
the window has been resurrected.  Hence, what's needed are two hooks: A
`before-winsav' or so hook (which tells the mode designer to not run any
configuration change hooks) and an `after-winsav' hook.  The latter
would have to be called with a list of old-window/new-window
correspondences (again I suppose that windows are not collected as long
as they are referenced from that list).