def next_column
      # TODO take care of multipliers
      _calculate_column_offsets unless @coffsets
      c = @column_pointer.next
      cp = @coffsets[c]
      #$log.debug " next_column #{c} , #{cp} "
      @curpos = cp if cp
      down() if c < @column_pointer.last_index
      fire_column_event :ENTER_COLUMN
    end
def next_column
      # TODO take care of multipliers
      _calculate_column_offsets unless @coffsets
      c = @column_pointer.next
      cp = @coffsets[c]
      #$log.debug " next_column #{c} , #{cp} "
      @curpos = cp if cp
      down() if c < @column_pointer.last_index
      fire_column_event :ENTER_COLUMN
    end
jump cursor to next column
 TODO : if cursor goes out of view, then pad should scroll right or left and down