Vlákno názorů k článku Programovací jazyk TCL (6) od anonym - Viem ze trochu predbieham ale nevie mi niekto...

Viem ze trochu predbieham ale nevie mi niekto poradit ako vyriesit tento problem:

Mam kod:

package require Itcl
package require Itk

itcl::class CustomListBox {
inherit itk::Widget
constructor {args} {

itk_component add scrollbarh {
scrollbar $itk_interior.scrollbarh -orient\
horizontal -command "$itk_interior.mainlist xview"
}

itk_component add scrollbarv {
scrollbar $itk_interior.scrollbarv\
-orient vertical -command "$itk_interior.mainlist yview"
}

itk_component add label1 {
label $itk_interior.label1 -text "File selected:" -justify left
}

itk_component add entry1 {
entry $itk_interior.entry1 -textvariable fileSelected
}

itk_component add mainlist {
listbox $itk_interior.mainlist -selectmode\
single -width 20 -height 10 -setgrid 1\
-xscroll "$itk_interior.scrollbarh set"\
-yscroll "$itk_interior.scrollbarv set"
}

grid $itk_component(mainlist) -row 0 -column 0\
-columnspan 2 -sticky "news"
grid $itk_component(scrollbarv) -row 0 -column 2 -sticky "ns"
grid $itk_component(scrollbarh) -row 1 -column 0\
-columnspan 2 -sticky "we"
grid $itk_component(label1) -row 2 -column 0
grid $itk_component(entry1) -row 3 -column 0 -columnspan 3 -sticky "we"
grid columnconfigure . 0 -weight 1
grid rowconfigure . 0 -weight 1

foreach file [glob *] {
$itk_component(mainlist) insert end $file
}


bind $itk_component(mainlist) <buttonrelease-1>\
{set fileSelected [%W get [%W curselection]]}

eval itk_initialize $args
}
}


CustomListBox .clb1
pack .clb1
CustomListBox .clb2
pack .clb2

Problem kodu je v tom, ze premenna fileSelected sa vytvori ako globalna a instancie objektu CustomListBox (.clb1, .clb2) odkazuju na tu istu premennu.
Ma to ten dosledok, ze zmena selektnutia itemu v .clb1 sa prejavi aj v .clb2
Nevie mi niekto poratit ako urobit aby sa premenna nevytvarala ako globalna
a ukazovala pre kazdu instanciu do inej pamate tak ako to je to v C++.