试用GtkSimpleLayout制作UI

rubynroll的《300行代码你能做什么》中，介绍了GtkSimpleLayout，实现了类似Shose的代码风格。

从http://github.com/rickyzheng/GtkSimpleLayout/tree/master下载了最新的代码，编译的时候却无法通过，显示SyntaxError。

引用

c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': ./simple_layout.rb:105: syntax error, unexpected ',', expecting '|' (SyntaxError)
        define_method(k) do |*args, &block|
                                   ^
./simple_layout.rb:487: syntax error, unexpected kEND, expecting $end   from c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from test1.rb:2

调查了之后发现，原来Ruby 1.8中，define_method中不能使用block，Ruby 1.9中没有问题。因此对simple_layout.rb的代码进行了如下修改。

105行：
        define_method(k) do |*args, &block|
          create_component(v, args, block)
        end
         ↓
eval <<-EOM
        def #{k}(*args, &block)
          create_component("#{v}", args, block)
        end
EOM

432行：
    def create_component(component_class, args, block)
      @common_attribute ||= []
      options = {}
      options = args.pop if args.last.is_a?(Hash)
      options.merge! @common_attribute.last if @common_attribute.last
      
      
+      w = eval("#{component_class}.new(*args)")
      layout_component(w, options, &block)
    end

终于编译通过了。

简单的实验
竖排三个按钮

require 'gtk2'
require 'simple_layout'

class MyWin < Gtk::Window
  include SimpleLayout::Base
  def initialize
    super
    add my_layout
    signal_connect('destroy') do
      Gtk.main_quit
    end
  end

  def my_layout
    vbox do
      button 'Mice'
      button 'Eagles'
      button 'Quail'
    end
  end
end

MyWin.new.show_all
Gtk.main

计算器布局

require 'gtk2'  
require 'simple_layout'  
  
class MyWin < Gtk::Window  
  include SimpleLayout::Base  
  def initialize  
    super  
    add my_layout  
    signal_connect('destroy') do  
      Gtk.main_quit  
    end  
  end  
  
  def my_layout  
    vbox do  
      with_attr :border_width => 3 do  
        hbox do  
          entry :id => :ent_input, :layout => [true, true, 5]  
        end  
        hbox do  
          frame do  
            label 'M', :set_size_request => [20, 20]  
          end  
          hbutton_box do  
            button 'Backspace'  
            button 'CE'  
            button 'C'  
          end  
        end  
        hbox do  
          vbutton_box do  
            button 'MC'  
            button 'MR'  
            button 'MS'  
            button 'M+'  
          end  
          with_attr :layout => [true, true] do  
            number_and_operators_layout  
          end  
        end  
      end  
    end  
  end  
  
  def number_and_operators_layout  
    vbox do  
      [ ['7', '8', '9', '/', 'sqt'],  
        ['4', '5', '6', '*', '%'],  
        ['1', '2', '3', '-', '1/x'],  
        ['0', '+/=', '.', '+', '=']].each do |cols|  
        hbox :layout => [true, true] do  
          cols.each do |txt|  
            button txt, :set_size_request => [20, 20], :layout => [true, true]  
          end  
        end  
      end  
    end  
  end  
  
end  
  
MyWin.new.show_all  
Gtk.main

模仿http://the-shoebox.org/apps/126写的小程序

require 'gtk2'
require 'simple_layout'

class MyWin < Gtk::Window
  include SimpleLayout::Base
  def initialize
    super('Little Helper v0.4')
    add my_layout
    signal_connect('destroy') do
      Gtk.main_quit
    end
    register_auto_events()
  end
  
  def my_layout
    entry1 = nil
    vpaned do
      area_first do
        frame 'Awful numbers', :border_width => 5 do
          vbox do
            label 'Hours/week', :set_size_request => [200, -1]
            @entry1 = entry :layout => [false, false], :max_length => 20, :id => :entry1
            label 'Money/hour', :set_size_request => [200, -1]
            @entry2 = entry :layout => [false, false], :max_length => 20, :text => '16', :id => :entry2
            label 'Tax (in %)', :set_size_request => [200, -1]
            @entry3 = entry :layout => [false, false], :max_length => 20, :text => '20', :id => :entry3
          end
        end
      end
      area_second do
        frame 'Rags or riches', :border_width => 5 do
          vbox do
            @lab1 = label '0.0'
          end
        end
      end
    end
  end
  
  def entry1_on_key_release_event(*_)
    @lab1.text = calculate.to_s
  end
  
  def entry2_on_key_release_event(*_)
    @lab1.text = calculate.to_s
  end
  
  def entry3_on_key_release_event(*_)
    @lab1.text = calculate.to_s
  end 

  def calculate
     @entry1.text.to_f * @entry2.text.to_f * (([e-mail]_f)/100.0) * 4.3
  end
end

MyWin.new.show_all
Gtk.main

参考：
http://coderrr.wordpress.com/2008/10/29/using-define_method-with-blocks-in-ruby-18/