Reached a basic consensus in Shoes/shoes4 issue shoes#6.

shoes#6

lib/shoes/app.rb

@@ -7,7 +7,7 @@ class App
     include Shoes::ElementMethods
 
     def initialize &blk
-      @gui = Shoes.backend::App.new(Swt.display)
+      @gui = Shoes.backend::App.new
       instance_eval &blk
       @gui.open
     end

lib/shoes/swing.rb

@@ -2,16 +2,7 @@
 #require 'swing'
 
 module Shoes
-  #include Swing
-end
-
-module Shoes
-  module Swing
-    module App; end
-    module Check; end
-  end
-  class App; include Swing::App end
-  class Check; include Swing::Check end
+  module Swing; end
 end
 
 require 'shoes/swing/app'

lib/shoes/swing/app.rb

@@ -1,11 +1,11 @@
-module Shoes::Swing::App
-  def gui_init
+class Shoes::Swing::App
+  def initialize
     @shell = 'create Swing object'
   end
 
   attr_reader :shell
 
-  def gui_open
+  def open
     # bla bla bla
   end
 end

lib/shoes/swing/check.rb

@@ -1,5 +1,5 @@
-module Shoes::Swing::Check
-  def gui_init_open app
+class Shoes::Swing::Check
+  def initialize app
     @real = 'create Swing object'
   end
   attr_accessor :real

lib/shoes/swt.rb

@@ -2,7 +2,9 @@
 require 'swt'
 
 module Shoes
-  module Swt
+  module Swt; end
+  def self.display
+    @display ||= ::Swt::Widgets::Display.new
   end
 end
 

lib/shoes/swt/app.rb

@@ -1,6 +1,6 @@
 class Shoes::Swt::App
-  def initialize(display)
-    @shell = Swt::Widgets::Shell.new display
+  def initialize
+    @shell = Swt::Widgets::Shell.new Shoes.display
   end
 
   attr_reader :shell