[ruby-list:39985] Re: ruby/tk のイベントハンドラをまとめて設定するには？

山本です。

少し大きいですが、コードを全部載せます。（スケジュール表プログラムを作ろうとしています）

require "tk"
require 'date'

class Calendar < TkFrame

  def initialize
    super
    cal = self
    @prev = TkButton.new(self) {
      text "prev"
      command { cal.date <<= 1 }
      grid("row" => 0, "column" => 0, "sticky" => "news")
    }
    @label = TkLabel.new(self) {
      grid("row" => 0, "column" => 1, "sticky" => "news")
    }
    @next = TkButton.new(self) {
      text "next"
      command { cal.date >>= 1 }
      grid("row" => 0, "column" => 2, "sticky" => "news")
    }
    @canvas = TkCanvas.new(self) {
      grid("row" => 1, "column" => 0, "columnspan" => 3, "sticky" => "news")
    }
    cell(0, 0){|r,t| t.text "Sun"; r.fill "#F7CACA"}
    cell(1, 0){|r,t| t.text "Mon"; r.fill "#E7FFE7"}
    cell(2, 0){|r,t| t.text "Tue"; r.fill "#E7FFE7"}
    cell(3, 0){|r,t| t.text "Wed"; r.fill "#E7FFE7"}
    cell(4, 0){|r,t| t.text "Thu"; r.fill "#E7FFE7"}
    cell(5, 0){|r,t| t.text "Fri"; r.fill "#E7FFE7"}
    cell(6, 0){|r,t| t.text "Sat"; r.fill "#CEFFFF"}
    @cells = []
    for iy in 0...6
      for ix in 0...7
        cell(ix, iy + 1){|r,t|
          c = Struct.new(:rect, :text, :date).new(r, t, nil)  # caution! scope of variable
          r.bind "ButtonPress-1", proc { cal.date = c.date }
          t.bind "ButtonPress-1", proc { cal.date = c.date }
          @cells << c
        }
      end
    end
    self.date = Date.today
  end

  def cell(ix, iy)
    dx = @canvas.width / 7
    dy = @canvas.height / 7
    x = dx * ix
    y = dy * iy
    r = TkcRectangle.new(@canvas, x, y, x + dx, y + dy, "outline" => "gray")
    t = TkcText.new(@canvas, x + dx / 2, y + dy / 2)
    yield r, t
  end
  private :cell

  def date
    @date
  end

  def date=(value)
    unless defined?(@date) && @date.year == value.year && @date.month == value.month
      @label.text = "#{value.year} - #{value.month}"
      @cells.each {|c| c.date = nil }
      temp = value; temp -= 1 while temp.year == value.year && temp.month == value.month; temp += 1
      day = nil
      week = 0
      while temp.year == value.year && temp.month == value.month
        week += 1 if day && day + 1 != temp.day
        day = temp.day
        @cells[temp.wday + week * 7].date = temp
        temp += 1
        week += 1 if temp.wday == 0
      end

      @cells.each{|c|
        if c.date
          c.text.text = c.date.day
          c.rect.fill "white"
          c.rect.state "normal"
          c.text.state "normal"
        else
          c.rect.state "hidden"
          c.text.state "hidden"
        end
      }
    end

    @date = value

    puts @date

  end

end

$cal = Calendar.new {
  pack
}

Tk.mainloop

Java のコードはこんな感じです。final int n = i の final が外れると、
コンパイルエラーになります（バインドできません）

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class Main
{
    public static void main(String args[])
    {
        JFrame frame = new JFrame("Test");
        frame.getContentPane().setLayout(new FlowLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        for (int i = 0; i < 3; ++i) {
            final int n = i;
            JButton button = new JButton(String.valueOf(i));
            button.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    System.out.println(n);
                }
            });
            frame.getContentPane().add(button);
        }

        frame.pack();
        frame.setVisible(true);
    }
}