---
:wxScrolled.DoPrepareDC:
  :detail:
    :pre:
      :programlisting:
        - :pattern: !ruby/regexp /.*/
          :replace: |
            
            ```ruby
              class MyWindow < Wx::ScrolledCanvas
            
                def on_event(event)
                  Wx::ClientDC.draw_on(self) do |dc|
                    do_prepare_dc(dc)
                  
                    dc.set_pen(Wx::BLACK_PEN)
                    pos = event.position
                    if xpos > -1 && ypos > -1 && event.dragging
                      dc.draw_line(xpos, ypos, pos.x, pos.y)
                    end
                    xpos = pos.x
                    ypos = pos.y
                  end
                end
            
              end
            ```
:wxScrolled.SetScrollbars:
  :detail:
    :pre:
      :programlisting:
        - :pattern: !ruby/regexp /.*/
          :replace: |
            
            ```ruby
              window.set_scrollbars(20, 20, 50, 50)
            ```