Re: Gtk2::TreeModel::foreach callback not getting any arguments?

[muppet <scott asofyet org>]

On Saturday, September 20, 2003, at 05:00 PM, Dan Lyke wrote:

> First: I'm browsing a rather large tree which could have a lot of
> images, so I want to be able to load and unload images as the tree
> gets browsed. I'm doing a:
>
>     $treestore->foreach($iterator, forEach, ['populate',  
> $self->{-nodemapping}]);
>
> on the expand message, but although my "forEach" callback is getting
> called, it isn't getting any arguments. Any hints?

um...  yeah, how is that working at all?  i can't find any foreach  
method that takes an iterator.

there's these two:
   $treemodel->foreach (\&func, $data);
	http://developer.gnome.org/doc/API/2.0/gtk/GtkTreeModel.html#gtk-tree- 
model-foreach
   $treeselection->selected_foreach (\&func, $data);
	http://developer.gnome.org/doc/API/2.0/gtk/GtkTreeSelection.html#gtk- 
tree-selection-selected-foreach

remember also that you have to give a code *reference* either via  
anonymous subs or taking references to named subs:

   $coderef = sub { };      # an anonymous subroutine.

   $coderef = \&named_sub;  # note the all-important backslash!
                            # if you use & only then you're just
                            # calling it.


> Which leads me to: Is there a better way to store metadata in a
> TreeStore than just put it in an unused column?

if it's per-row metadata, no.  and it's not so much unused as unshown.   
;)

if it's per-model data, then you can just put it in a key within the  
$model itself, like

    $model->{foo} = $bar;


> I'm using a string
> right now, which means that when I get it back out it's unblessed, and
> I have to run it back through a hash to figure out which object it was
> originally associated with.

you can put any perl scalar, including blessed or unblessed references,  
in a column of type Glib::Scalar.

--
muppet <scott at asofyet dot org>