redo

$canvaseditor redo: repeats last undone user-action

obj method canvaseditor redo {} {
  # Letztes Rückgängig zurück nehmen
  if {[my undonePtr] > 0} then {
    my undonePtr [- [my undonePtr] 1]
    set code [lindex [my redoStack] end-[my undonePtr]]
    set before [$self elements]
    # den Code als Lambda-Körper ausführen
    apply [list "" $code]
    $self statusLine Redo
  } else {
    $self statusLine No more redo.
  }
}