class Canvas

# File lib/rtl/canvas.rb, line 4
def initialize
  super()

  @running=false
  set_size_request(800,100)
  signal_connect('draw') do
    redraw @graph
  end
end

# File lib/rtl/canvas.rb, line 14
def clear cr
  cr.set_source_rgb(0.1, 0.1, 0.1)
  cr.paint
end

# File lib/rtl/canvas.rb, line 19
def redraw graph=nil,zoom_factor=1,shift=Vector.new(0,0)
  @graph=graph
  cr = window.create_cairo_context
  cr.set_line_width(0.8)

  w = allocation.width
  h = allocation.height

  cr.translate(w/2, h/2)

  clear cr

  if graph
    cr.set_source_rgb(0.4, 0.4, 0.4)
    @graph.edges.each do |edge|
      n1,n2=edge.source,edge.sink
      cr.move_to(shift.x + n1.x*zoom_factor,shift.y + n1.y*zoom_factor)
      cr.line_to(shift.x + n2.x*zoom_factor,shift.y + n2.y*zoom_factor)
      cr.stroke
    end

    cr.set_source_rgb(0.9, 0.5, 0.2)
    @graph.nodes.each do |node|
      cr.arc(shift.x+node.x*zoom_factor, shift.y+node.y*zoom_factor, 10*zoom_factor, 0, 2.0 * Math::PI)
      cr.fill_preserve()
      cr.stroke
    end
  end

end