Method: Bio::Graphics::Ruler#draw

Defined in:
lib/bio/graphics/ruler.rb

#draw(panel_drawing) ⇒ Object 



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# File 'lib/bio/graphics/ruler.rb', line 64

def draw(panel_drawing)
  ruler_drawing = Cairo::Context.new(panel_drawing)

  # Draw line
  ruler_drawing.move_to(0,10)
  ruler_drawing.line_to(panel.width, 10)
  ruler_drawing.stroke

  # Draw ticks
  #  * And start drawing the rest.
  first_tick_position.step(@panel.display_stop, @minor_tick_distance) do |tick|
    tick_pixel_position = (tick - panel.display_start) / @panel.rescale_factor
    ruler_drawing.move_to(tick_pixel_position.floor, @min_pixels_per_tick)
    if tick.modulo(@major_tick_distance) == 0
      ruler_drawing.rel_line_to(0, 3*@tick_height)
      
      # Draw tick number
      ruler_drawing.select_font_face(*Bio::Graphics::FONT)
      ruler_drawing.set_font_size(@tick_text_height)
      ruler_drawing.move_to(tick_pixel_position.floor, 4*@tick_height + @tick_text_height)
      ruler_drawing.show_text(tick.to_i.to_s)
    else
      ruler_drawing.rel_line_to(0, @tick_height)
      
    end
    ruler_drawing.stroke
  end

  @height = 5*@tick_height + @tick_text_height          
end