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

From: Ken Jones <ken_at_redsummit.net>
Date: Fri, 14 Nov 2003 15:04:34 -0800

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