package require Tk
proc main {} {
    global xm ym spinning
    set xm 118 ; set ym 135
    set spinning 0
    pack [canvas .c]
 # .c create text 120 10 -text "Hit any key to spin, and assign task"
    .c create text  90 10 -text "Hit any key to  spin,   and assign task"
    button .c.s -text "Spin" -command {spin .c spin}
    button .c.x -text X      -command exit
    .c create window 220 10 -window .c.x
    .c create window  86 10 -window .c.s
    spinarrow .c $xm $ym -tag spin -fill red
    bind . <Key> {spin .c spin}
    cdial .c $xm $ym 85 {A B C D E F G H
        I J K L M N O P R S T U V W Y Z}
    .c create text 120 255 -tag task -font {Tahoma 12 bold}
}

set tasks {
    animal plant city river country profession {girl's name} {boy's name}
    mountain food {famous person}
}

#Draw and place the spinning arrow

proc spinarrow {w x y args} {
    set id [eval $w create poly {\
        30 0 0 50 20 45 20 135 0 155\
        0 200 30 170 60 200 60 155\
        40 135 40 45 60 50} $args]
    $w move $id [expr $x-30] [expr $y-100]
    $w scale $id $x $y .8 .8
}

proc spin {w tag {angle ""}} {
    global xm ym spinning
    if {$angle==""} {
        if $spinning return
        incr spinning
        set angle [expr rand()*0.4+.4]
        $w itemconfig task -text [? $::tasks]?
    }
    rotate $w $tag $angle $xm $ym
    set angle [expr {$angle*.99-0.01}]
    if {$angle>0} {
        after 40 spin $w $tag $angle
    } else {set spinning 0}
}

proc rotate {w tag angle xm ym} {
    set coords {}
    foreach {x y} [$w coords $tag] {
        set r [expr {hypot($x-$xm,$y-$ym)}]
        set a [expr {atan2($y-$ym,$x-$xm)+$angle}]
        lappend coords \
            [expr {$xm+cos($a)*$r}] \
            [expr {$ym+sin($a)*$r}]
    }
    $w coords $tag $coords
 #-- fix drifting during rotation
    foreach {x0 y0 x1 y1} [$w bbox $tag] break
    set dx [expr {$xm-($x0+$x1)/2.}]
    set dy [expr {$ym-($y0+$y1)/2.}]
    $w move $tag $dx $dy
}

#Draw a circular "dial"
proc cdial {w x y r data} {
    set da [expr {2*acos(-1)/[llength $data]}]
    set th 0.0
    set th2 [expr {$da/2.}]
    set r2 [expr {$r+20}]
    set r3 [expr {($r+$r2)/2.}]
    set outside {}
    foreach el $data {
        set x1 [expr {$x+cos($th)*$r}]
        set y1 [expr {$y+sin($th)*$r}]
        set x2 [expr {$x+cos($th)*$r2}]
        set y2 [expr {$y+sin($th)*$r2}]
        $w create line $x1 $y1 $x2 $y2
        lappend outside $x2 $y2
        set x3 [expr {$x+cos($th2)*$r3}]
        set y3 [expr {$y+sin($th2)*$r3}]
        $w create text $x3 $y3 -text $el
        set th [expr {$th + $da}]
        set th2 [expr {$th2 + $da}]
    }
    eval lappend outside [lrange $outside 0 1]
    $w create line $outside -smooth 1
}
 Select random element from a list
proc ? L {
  lindex $L [expr {int(rand()*[llength $L])}]
}
#----------------- Let's go!
main
wm geometry . 240x268+0+0 ;# iPaq