intersectLine

$canvaseditor intersectLine: intersects selected line into two

obj method canvaseditor intersectLine {} {
  lassign [my selection] line
  set before [$line restoreCode]
  $self select
  #
  set newLine [$line intersect]
  append before \n "$newLine draw no"\
    \n "$newLine remove [$newLine firstDot] [$newLine lastDot]"
  #
  $line draw
  $newLine draw
  $self canvas raise line$newLine line$line
  set after [$newLine restoreCode]
  append after \n "$newLine draw"
  append after \n [$line restoreCode] \n "$line draw"
  append after \n "$self canvas raise line$newLine line$line"
  #
  $self initUndoRedo $before $after
  $self select $newLine
}