[pygtk] Ok. A new try...

[Tim Evans]

John Ehresman wrote:
> Gonzalo Aguilar Delgado wrote:
>> How do I find a widget (say a GtkEntry) inside it with the name
>> "txtbox"?
> 
> You need to go through all the children and find the one with the name. 
>   Try the following:
> 
> def all_descendants(w, flags=None):
>   """ Generator to traverse all descendants of a widget in depth-first 
>   order.  Assumes that the widget hierarchy doesn't change during the 
>   traversal.  Use flags to only return widgets where widget & flags is
>   true.  If a widget is filtered out, all of its descendants are also
>   filtered out. """
> 
>   if not isinstance(w, gtk.Container):
>     return
> 
>   for child in w.get_children():
>     if flags is None or child.flags() & flags:
>       yield child
> 
>       for g_kid in all_descendants(child):
>         yield g_kid
> 
> def find_named(parent, name):
>   for w in all_descendants(parent):
>     if w.get_name() = name:
>       return w
>   return None
> 
> entry = find_named(frame, 'txtbox')
> 
> You probably do want to make sure that only one widget with the name 
> 'txtbox' is a descendant of frame.  gtk does not enforce this for you.

I generally prefer to avoid the recursion and use something like this:

     def all_descendants(root):
         stack = [root]
         while stack:
             w = stack.pop()
             yield w
             if isinstance(w, gtk.Container):
                 stack.extend(reversed(w.get_children()))
             if isinstance(w, gtk.MenuItem):
                 submenu = w.get_submenu()
                 if submenu:
                     stack.append(submenu)

Submenus don't count as children but for most things it's useful to have
them listed in the same way.  I would also recommend putting all the
widgets into a dictionary if you'll be doing these lookups often:

     def named_widgets(root):
          r = {}
          for w in all_descendants(root):
              name = w.get_name()
              if name:
                  r[name] = w
          return r

-- 
Tim Evans
Applied Research Associates NZ
http://www.aranz.co.nz/