Richard Suchenwirth 2003-02-18 - Reading a Java tutorial in a bored moment, I came upon the ClickMe example at http://java.sun.com/docs/books/tutorial/java/concepts/practical.html , where with only two Java class files, in less than 40 LOC, you can implement a rectangle where a red spot appears when you click on it. After compilation, you have 5 files (one HTML) that perform this feat.
Hm, thought I, how would that look in Tcl?
package require Tk
proc drawSpot {w x y} {
$w delete spot
set r 7
$w create oval [expr {$x-$r}] [expr {$y-$r}] [expr {$x+$r}] [expr {$y+$r}]\
-fill red -outline red -tag spot
}
pack [canvas .c]
.c create rect 5 5 205 205 -fill white -outline black -tag box
.c bind box <1> {drawSpot %W %x %y}