Initial work for releasing colors on fill/stroke

lib/shoes/swt/color.rb

@@ -13,6 +13,10 @@ def initialize(color)
         @real = ::Swt::Graphics::Color.new(Shoes.display, @dsl.red, @dsl.green, @dsl.blue)
       end
 
+      def dispose
+        @real.dispose unless @real.disposed?
+      end
+
       attr_reader :dsl
 
       # @return [Integer] the alpha value, from 0 (transparent) to 255 (opaque)

lib/shoes/swt/common/clear.rb

@@ -6,9 +6,22 @@ def clear
           app.remove_paint_listener @painter
           remove_click_listeners
           @real.dispose unless @real.nil? || @real.disposed?
+          dispose_held_resources
           dispose
         end
 
+        def mark_to_dispose(resource)
+          @to_dispose ||= []
+          @to_dispose << resource
+        end
+
+        def dispose_held_resources
+          return unless @to_dispose
+
+          @to_dispose.each(&:dispose)
+          @to_dispose.clear
+        end
+
         # Classes should override to dispose of any Swt resources they create
         def dispose
         end

lib/shoes/swt/common/fill.rb

@@ -9,7 +9,9 @@ module Fill
         #
         # @return [Swt::Graphics::Color] The Swt representation of this object's fill color
         def fill
-          dsl.fill ? ::Shoes.configuration.backend_for(dsl.fill) : nil
+          fill_color = dsl.fill ? ::Shoes.configuration.backend_for(dsl.fill) : nil
+          mark_to_dispose(fill_color)
+          fill_color
         end
 
         # This object's fill alpha value

lib/shoes/swt/common/stroke.rb

@@ -9,7 +9,9 @@ module Stroke
         #
         # @return [Swt::Graphics::Color] The Swt representation of this object's stroke color
         def stroke
-          dsl.stroke ? ::Shoes.configuration.backend_for(dsl.stroke) : nil
+          stroke_color = dsl.stroke ? ::Shoes.configuration.backend_for(dsl.stroke) : nil
+          mark_to_dispose(stroke_color)
+          stroke_color
         end
 
         # This object's stroke alpha value