[wxruby-users] chart extension for wxRuby?

Alex Fenton
Thu, 31 Jan 2008 19:41:58 -0000

Ellis, Peter wrote:
> Thanks, Alex.
>
> I was hoping that we wouldn''t have to create our own, but we might
do it
> if that turns out to be the best solution.  I''ll keep the list
posted.
>

Following your earlier message I had a closer look at Scruffy and Gruff.
Scruffy has the drawing code very nicely separated from the logic that
organises the chart elements. So in about 20 mins I was able to replace
enough of the svg-based drawing code with dc-based code to get it to
draw the chart background, title, frame, axis and labels in a Wx::Window
(see below for the app code)

It''s a fairly mechanical job of replacing calls to svg.text with
dc.draw_text, svg.line with dc.draw_line etc in scruffy/components and
scruffy/layers. I''m sure the individual chart types would need a little
more work, but each is still only a couple of calls to the same basic
methods. I would recommend looking into it.

hth
alex

__
require ''scruffy''
require ''wx''

class Chart < Wx::Window
  attr_reader :graph
  def initialize(*args)
    super
    evt_paint :on_paint
    @graph = Scruffy::Graph.new(:title => "Monthly Profits")
    graph.add(:line, ''John'', [100, -20, 30, 60])
    graph.add(:line, ''Sara'', [120, 50, -80, 20])
  end

  def on_paint
    paint do | dc |
      graph.render(dc, :width => size.width, :height => size.height)
    end
  end
end


Wx::App.run do
  frame = Wx::Frame.new(nil, :title => ''chart demo'')
  chart = Chart.new(frame)
  frame.show
end