From: Hidetoshi NAGAI <nagai@...>
Date: 2005-11-14T00:59:19+09:00
Subject: Re: Scheudle display

From: "csjasnoch@wisc.edu" <csjasnoch@wisc.edu>
Subject: Re: Scheudle display
Date: Fri, 11 Nov 2005 06:22:14 +0900
Message-ID: <1131657574.017316.243080@o13g2000cwo.googlegroups.com>
> Example:
> 
> Someone wants a schedule that is trigger on at 00:00 and off at 6:00
> then on again at 12:00 then off again at 18:00.
> 
> Each time they add these seperate events to the schedule a the canvas
> needs to adjusst its picutre accordingly. With this example in the end
> it would be divided evenly into 4 sections 0degrees to 90degrees would
> be red (or whatever color), as well as 180 to 270 degrees. The
> remaining sections would remain white (or whatever color is
> initialized).

Hmm... How about the following?
-------------------------------------------------------------------------
require 'tk'

class Sched24
  def initialize
    @c = TkCanvas.new(:width=>400, :height=>400, 
                     :scrollregion=>[-200, -200, 200, 200]
                     ).pack(:fill=>:both, :expand=>true)

    @tag = TkcTag.new(@c)

    @circle_coords = [[-180, -180], [180, 180]]
    @oval = TkcOval.new(@c, @circle_coords, :fill=>'white', :tags=>[@tag])

    @center_dot = TkcOval.new(@c, [-5, -5], [5, 5], :fill=>'black')

    @l = TkLabel.new(:text=>'00:00').pack

    cmd = proc{|x, y|
      @l.text = '%02d:%02d' % coords_to_time(@c.canvasx(x), @c.canvasy(y))
    }
    @c.bind('Motion', cmd, '%x %y')
    @tag.bind('Motion', cmd, '%x %y')
  end

  def coords_to_time(x, y)
    return ((y < 0)? [0, 0]: [12, 0])  if x == 0
    h, m = (720.0*Math.atan2(y,x)/Math::PI).divmod(60)
    hh = (x<0 && y<0)? h+30:h+6
    mm = m.round
    if mm >= 60
      hh += 1
      mm -= 60
    end
    [hh, mm]
  end

  def create_pie(hh, mm, span, color='red')
    start  = 90.0 - (hh*60 + mm)/4.0  # 360.0*(hh*60+mm)/(24*60)
    extent = -span/4.0

    pie = TkcArc.new(@c, @circle_coords, :tags=>[@tag], 
                     :outline=>'black', 'fill'=>color, 
                     :start=>start, :extent=>extent)
    @center_dot.raise
    pie
  end
end

sched = Sched24.new
sched.create_pie(0,0, 60)            #  60 minutes from 00:00
sched.create_pie(6,30, 280, 'green') # 280 minutes from 06:30
sched.create_pie(15,20, 90, 'blue')  #  90 minutes from 15:20

Tk.mainloop
-------------------------------------------------------------------------
-- 
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)