Widget Instantiation
SetBindings: defines behavior of subwidgets.
proc tixOnOff:SetBindings {w} {
upvar #0 $w data
tixChainMethod $w SetBindings
$data(w:on) config -command “tixOnOff:OnCmd $w”
$data(w:off) config -command “tixOnOff:OffCmd $w”
}
proc tixOnOff:OnCmd {w} {
upvar #0 $w data
$data(w:on) config -relief sunken
$data(w:off) config -relief raised
}