RE: How to force the visibility of a GTK2 treeview row expander

["Rastatter, Ken (OH32)" <Ken Rastatter Honeywell com>]

Sam wrote on 29 May 2003 18:18:13 +0200
> I have a GTK2 treeview (tree store) row that has no children and I'd
> like to have it's expander visible anyway.
> Is there a way to do this or will I have to add a dummy node?

Nope, you have to add a dummy child node.

For a parent node to have a expand/collapse handle, I create a child 
node using gtk_tree_store_append() and then don't follow with a call to gtk_tree_store_set().  This creates a 
child
node, albeit an empty one. 

This empty child node is easy to detect in a "row_expand" signal
callback.  This is how I do it:


void
on_treeview1_row_expanded       (GtkTreeView     *treeview,
                                 GtkTreeIter     *arg1,
                                 GtkTreePath     *arg2,
                                 gpointer         user_data)
{
    extern GtkTreeStore *treestore;
    GtkTreeIter child_iter;

    gchar *name;   // "name" is the file/directory name of G_TYPE_STRING

    // See if this row has ever had a name gtk_tree_store_set()'ed to it.
    // If not, read the directory contents
    gtk_tree_model_get(GTK_TREE_MODEL(treestore), arg1,
                       NAME_COLUMN, &name, -1);
    if (!name)
    {
        g_print("Read this directory's contents here.");

        // Replace the blank child with the first directory entry
        // You may be tempted to remove the blank child node and then 
        // append a new one.  Don't.  If you remove the blank child 
        // node GTK gets confused and won't expand the parent row. 
        gtk_tree_model_iter_children(GTK_TREE_MODEL(treestore), 
                                     &child_iter, arg1);
        gtk_tree_store_set (treestore, &child_iter, 
                            NAME_COLUMN, first_entry_name, -1);

        // Append all of the other directory entries
        gtk_tree_store_append(treestore, &child_iter, arg1);
        gtk_tree_store_set (treestore, &child_iter, 
                            NAME_COLUMN, second_entry_name, -1);
     }
     return;
}

I hope this helps.

--
Ken Rastatter, Design Engineer
Honeywell Sensotec
2080 Arlingate Lane, Columbus, Ohio, 43228-4112 USA
Home Page:  http://www.sensotec.com
"These opinions are mine and not necessarily those of Honeywell."