From: Hidetoshi NAGAI <nagai@...>
Date: 2005-06-24T12:35:50+09:00
Subject: Re: ruby/tk question

From: Joe Van Dyk <joevandyk@gmail.com>
Subject: ruby/tk question
Date: Fri, 24 Jun 2005 09:36:15 +0900
Message-ID: <c715e64050623173662a2efa8@mail.gmail.com>
> I have to draw a colored bar in a Tk application that has differently
> colored segments.
> 
> Like:
> 
> ----------------------------------------
> |  red      |  green   | orange |
> ----------------------------------------

Although I may misunderstand, is the following what you want?
-----------------------------------------------------------
require 'tk'

class ColoredBar < TkWindow
  @@DEFAULT_HEIGHT = 5
  @@DEFAULT_WIDTH  = 100

  def initialize(parent, *cols)
    if parent.kind_of?(Symbol) || parent.kind_of?(String)
      cols.unshift(parent)
      parent = nil
    end

    @frame = TkFrame.new(parent, 
                         :height=>@@DEFAULT_HEIGHT, :width=>@@DEFAULT_WIDTH)
    @path = @frame.path

    @sum = 0.0
    @ratio = []
    @cols = cols.collect{|c|
      @ratio << 1.0
      @sum += 1.0
      TkFrame.new(@frame, :background=>c)
    }

    TkGrid.configure(*(@cols + [:sticky=>:news]))
    @frame.grid_rowconfigure(0, :weight=>1)
    (0...(@cols.size)).each{|i| @frame.grid_columnconfigure(i, :weight=>1) }
    TkGrid.propagate(@frame, false)

    @frame.bind('Configure'){ _config_ratio }
  end

  def _config_ratio
    frame_width = @frame.winfo_width
    @cols.each_with_index{|c, i|
      c.width(frame_width * @ratio[i] / @sum)
    }
  end
  private :_config_ratio

  def ratio(*params)
    if @cols.length != params.length
      raise ArgumentError, "params length doesn't match colors length"
    end

    sum = 0.0
    params.each{|n| 
      raise ArgumentError, "params must be positive values" if n < 0
      sum += n
    }

    @sum = sum
    @ratio = params.dup

    _config_ratio

    self
  end
end

if __FILE__ == $0
  b = ColoredBar.new(:red, :green, :orange).pack(:expand=>true, :fill=>:both)
  b.width 300
  b.height 20

  TkButton.new(:text=>'ratio  1:1:1', :command=>proc{b.ratio(1,1,1)}).pack
  TkButton.new(:text=>'ratio  1:2:3', :command=>proc{b.ratio(1,2,3)}).pack
  TkButton.new(:text=>'ratio  0.25:0.82:0.16', 
               :command=>proc{b.ratio(0.25,0.82,0.16)}).pack

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