Caps Lock

Kevin Kenny wrote in comp.lang.tcl on 2002-12-12:

If you own the keyboard focus, you get <Key> and <KeyRelease> events for caps lock as with any other key. When you get other keyboard and mouse events, the 'state' field in the event indicates the state of caps lock. It's a trifle platform- dependent (different platforms appear to use different state bits), but on Windows, I tried

bind all <Motion> [list updateState %s]
bind all <KeyRelease-Caps_Lock> [list updateState %s]
bind all <KeyRelease-Num_Lock> [list updateState %s]
focus .

grid [label .capslock -width 10 -textvariable capslock]
grid [label .numlock -width 10 -textvariable numlock]

proc updateState { s } {
    if { $s & 2 } {
        set ::capslock {CAPS LOCK}
    } else {
        set ::capslock {}
    }
    if { $s & 8 || $s & 16 } {
        set ::numlock {NUM LOCK}
    } else {
        set ::numlock {}
    }
}

and it seems to give the right answers, at least when the app is on top.

Category Example