[Tile-dev] treeview hidden columns

[Bryan O. <oa...@ba...>]

It seems impossible to create a treeview that has one invisible data 
column. Or am I missing something?

In other words, this gives me three columns, with two visible (the tree 
column and one data column)

   ttk::treeview .tv1 -columns {foo bar} -displaycolumns {foo}

but this gives me two columns with two visible (the tree column and one 
data column)

   ttk::treeview .tv2 -columns {foo} -displaycolumns {}

That is because a -displaycolumn that is the empty string is synonymous 
with "show all rows". It seems to be impossible to have a condition 
where you want none of the data columns visible.

I discovered that I can add an item and give it values for more columns 
than it  has configured, though I'm wondering if that's a feature or a bug:

    ttk::treeview .tv3 -columns {}
    .tv3 insert "" end -values {"hidden value"} -text "visible value"

Is it kosher to be able to supply more values than there are columns? I 
see no other way to get the desired effect.