Data commit

Task/Animation/Tcl/animation.tcl

@@ -0,0 +1,20 @@
+package require Tk
+set s "Hello World! "
+set dir 0
+# Periodic animation callback
+proc animate {} {
+    global dir s
+    if {$dir} {
+        set s [string range $s 1 end][string index $s 0]
+    } else {
+        set s [string index $s end][string range $s 0 end-1]
+    }
+    # We will run this code ~8 times a second (== 125ms delay)
+    after 125 animate
+}
+# Make the label (constant width font looks better)
+pack [label .l -textvariable s -font {Courier 14}]
+# Make a mouse click reverse the direction
+bind .l <Button-1> {set dir [expr {!$dir}]}
+# Start the animation
+animate