[Xotcl] Linking object instance variables to a widget -textvariable?

[Ken Jones]

Hi. I've just starting tinkering around with XOTcl the past few days, trying to add it to my repertoire of Tcl OO extensions. It's definitely quite an interesting contrast to others like [incr Tcl] or Snit. While I won't be abandoning either of those, XOTcl is currently my leading candidate for a project I'm likely to be working on through the rest of the year, in large part because of its mixin support.

But one issue I couldn't figure out from my reading of the documentation or examples is whether it's possible to use an object's instance variable as a widget's -textvariable or -listvariable. For example, [incr Tcl] supports the [itcl::scope] command, so I can do something like this:

package require Itcl

::itcl::class Toggle {
    private variable _state "normal"
    
    constructor {} {
        checkbutton .cb -text Enable \
            -variable [::itcl::scope _state] \
            -onvalue "normal" -offvalue "disabled" \
            -command [::itcl::code $this toggle]
        .cb select  ;# The checkbutton is initially on
        
        # ...
    }
    
    private method toggle {} {
        # ...
    }
}

Is there a similar feature for XOTcl?

Thanks,

- Ken Jones