diff --git a/README.md b/README.md
index 073d83b..682cbe5 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ class Hello < CyberarmEngine::GuiState
   end
 end
 
-class Window < CyberarmEngine::Engine
+class Window < CyberarmEngine::Window
   def initialize
     super
     self.show_cursor = true
diff --git a/lib/cyberarm_engine.rb b/lib/cyberarm_engine.rb
index bd97a17..41727c5 100644
--- a/lib/cyberarm_engine.rb
+++ b/lib/cyberarm_engine.rb
@@ -11,10 +11,8 @@ require_relative "cyberarm_engine/version"
 
 require_relative "cyberarm_engine/common"
 
-require_relative "cyberarm_engine/gosu_ext/circle"
-
 require_relative "cyberarm_engine/game_object"
-require_relative "cyberarm_engine/engine"
+require_relative "cyberarm_engine/window"
 
 require_relative "cyberarm_engine/bounding_box"
 require_relative "cyberarm_engine/vector"
diff --git a/lib/cyberarm_engine/common.rb b/lib/cyberarm_engine/common.rb
index a578b2c..51b6c32 100644
--- a/lib/cyberarm_engine/common.rb
+++ b/lib/cyberarm_engine/common.rb
@@ -78,15 +78,15 @@ module CyberarmEngine
     end
 
     def get_image(path, retro: false, tileable: false)
-      get_asset(path, Engine::IMAGES, Gosu::Image, retro, tileable)
+      get_asset(path, Window::IMAGES, Gosu::Image, retro, tileable)
     end
 
     def get_sample(path)
-      get_asset(path, Engine::SAMPLES, Gosu::Sample)
+      get_asset(path, Window::SAMPLES, Gosu::Sample)
     end
 
     def get_song(path)
-      get_asset(path, Engine::SONGS, Gosu::Song)
+      get_asset(path, Window::SONGS, Gosu::Song)
     end
 
     def window
diff --git a/lib/cyberarm_engine/gosu_ext/circle.rb b/lib/cyberarm_engine/gosu_ext/circle.rb
deleted file mode 100644
index fd17606..0000000
--- a/lib/cyberarm_engine/gosu_ext/circle.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-module Gosu
-  # Sourced from https://gist.github.com/ippa/662583
-  def self.draw_circle(cx,cy,r, z = 9999,color = Gosu::Color::GREEN, step = 10)
-    0.step(360, step) do |a1|
-      a2 = a1 + step
-      draw_line(cx + Gosu.offset_x(a1, r), cy + Gosu.offset_y(a1, r), color, cx + Gosu.offset_x(a2, r), cy + Gosu.offset_y(a2, r), color, z)
-    end
-  end
-end
\ No newline at end of file
diff --git a/lib/cyberarm_engine/ui/element.rb b/lib/cyberarm_engine/ui/element.rb
index 3729cf1..272aecc 100644
--- a/lib/cyberarm_engine/ui/element.rb
+++ b/lib/cyberarm_engine/ui/element.rb
@@ -111,6 +111,8 @@ module CyberarmEngine
       event(:leave)
 
       event(:blur)
+
+      event(:changed)
     end
 
     def enabled?
diff --git a/lib/cyberarm_engine/ui/elements/check_box.rb b/lib/cyberarm_engine/ui/elements/check_box.rb
index 8b2563f..2fd4870 100644
--- a/lib/cyberarm_engine/ui/elements/check_box.rb
+++ b/lib/cyberarm_engine/ui/elements/check_box.rb
@@ -8,7 +8,25 @@ module CyberarmEngine
         @toggle_button = ToggleButton.new(options)
         @label         = Label.new(text, options)
 
-        define_label_singletons
+        @label.subscribe(:holding_left_mouse_button) do |sender, x, y|
+          @toggle_button.left_mouse_button(sender, x, y)
+        end
+
+        @label.subscribe(:released_left_mouse_button) do |sender, x, y|
+          @toggle_button.released_left_mouse_button(sender, x, y)
+        end
+
+        @label.subscribe(:clicked_left_mouse_button) do |sender, x, y|
+          @toggle_button.clicked_left_mouse_button(sender, x, y)
+        end
+
+        @label.subscribe(:enter) do |sender|
+          @toggle_button.enter(sender)
+        end
+
+        @label.subscribe(:leave) do |sender|
+          @toggle_button.leave(sender)
+        end
 
         add(@toggle_button)
         add(@label)
@@ -26,34 +44,6 @@ module CyberarmEngine
       def value=(bool)
         @toggle_button.vlaue = bool
       end
-
-      def define_label_singletons
-        @label.define_singleton_method(:_toggle_button) do |button|
-          @_toggle_button = button
-        end
-
-        @label._toggle_button(@toggle_button)
-
-        @label.define_singleton_method(:holding_left_mouse_button) do |sender, x, y|
-          @_toggle_button.left_mouse_button(sender, x, y)
-        end
-
-        @label.define_singleton_method(:released_left_mouse_button) do |sender, x, y|
-          @_toggle_button.released_left_mouse_button(sender, x, y)
-        end
-
-        @label.define_singleton_method(:clicked_left_mouse_button) do |sender, x, y|
-          @_toggle_button.clicked_left_mouse_button(sender, x, y)
-        end
-
-        @label.define_singleton_method(:enter) do |sender|
-          @_toggle_button.enter(sender)
-        end
-
-        @label.define_singleton_method(:leave) do |sender|
-          @_toggle_button.leave(sender)
-        end
-      end
     end
   end
 end
\ No newline at end of file
diff --git a/lib/cyberarm_engine/ui/elements/label.rb b/lib/cyberarm_engine/ui/elements/label.rb
index 2ffadb1..f8b5b50 100644
--- a/lib/cyberarm_engine/ui/elements/label.rb
+++ b/lib/cyberarm_engine/ui/elements/label.rb
@@ -44,6 +44,8 @@ module CyberarmEngine
         recalculate
 
         root.gui_state.request_recalculate if old_width != width || old_height != height
+
+        publish(:changed, self.value)
       end
     end
   end
diff --git a/lib/cyberarm_engine/ui/elements/progress.rb b/lib/cyberarm_engine/ui/elements/progress.rb
index 4827ce6..d54a24d 100644
--- a/lib/cyberarm_engine/ui/elements/progress.rb
+++ b/lib/cyberarm_engine/ui/elements/progress.rb
@@ -43,6 +43,7 @@ module CyberarmEngine
         @fraction = decimal.clamp(0.0, 1.0)
         update_background
 
+        publish(:changed, @fraction)
         return @fraction
       end
     end
diff --git a/lib/cyberarm_engine/ui/elements/slider.rb b/lib/cyberarm_engine/ui/elements/slider.rb
index 599fa42..1ba9c63 100644
--- a/lib/cyberarm_engine/ui/elements/slider.rb
+++ b/lib/cyberarm_engine/ui/elements/slider.rb
@@ -8,31 +8,29 @@ module CyberarmEngine
           event(:begin_drag)
           event(:drag_update)
           event(:end_drag)
+
+          subscribe :begin_drag do |sender, x, y, button|
+            @drag_start_pos = Vector.new(x, y)
+
+            :handled
+          end
+
+          subscribe :drag_update do |sender, x, y, button|
+            @parent.handle_dragged_to(x, y)
+
+            :handled
+          end
+
+          subscribe :end_drag do
+            @drag_start_pos = nil
+
+            :handled
+          end
         end
 
         def draggable?(button)
           button == :left
         end
-
-        def begin_drag(sender, x, y, button)
-          @drag_start_pos = Vector.new(x, y)
-
-          :handled
-        end
-
-        def drag_update(sender, x, y, button)
-          # ratio = (@parent.x - (x - @drag_start_pos.x) / (@parent.width - width) * -1).clamp(0.0, 1.0)
-          # @x = @parent.x + width + ((@parent.width * ratio) - width * 2)
-          @parent.handle_dragged_to(x, y)
-
-          :handled
-        end
-
-        def end_drag(sender, x, y, button)
-          @drag_start_pos = nil
-
-          :handled
-        end
       end
 
       attr_reader :range, :step_size
@@ -43,7 +41,7 @@ module CyberarmEngine
         @step_size = @options[:step] ? @options[:step] : 0.1
         @value     = @options[:value] ? @options[:value] : 0.5
 
-        @handle = Handle.new("", parent: self, width: 8) { close }
+        @handle = Handle.new("", parent: self, width: 8, height: 1.0) { close }
         self.add(@handle)
       end
 
@@ -55,8 +53,11 @@ module CyberarmEngine
         @height = _height
 
         @handle.x = @x + @style.border_thickness_left + @style.padding_left
-        @handle.y = @y + @style.border_thickness_top + @style.padding_left
+        @handle.y = @y + @style.border_thickness_top + @style.padding_top
         @handle.recalculate
+        @handle.update_background
+
+        pp @handle.height
 
         update_background
       end
@@ -76,9 +77,13 @@ module CyberarmEngine
 
       def holding_left_mouse_button(sender, x, y)
         handle_dragged_to(x, y)
+
+        :handled
       end
 
       def handle_dragged_to(x, y)
+        puts
+        pp x, y, @handle.width, content_width
         @ratio = ((x - @handle.width) - @x) / content_width
 
         # p [@ratio, @value]
@@ -94,7 +99,10 @@ module CyberarmEngine
         @value = n
         @handle.x = @x + @style.padding_left + @style.border_thickness_left +
                     (content_width * (@value - @range.min) / (@range.max - @range.min).to_f)
+
         @handle.recalculate
+
+        publish(:changed, @value)
       end
     end
   end
diff --git a/lib/cyberarm_engine/ui/elements/toggle_button.rb b/lib/cyberarm_engine/ui/elements/toggle_button.rb
index 9139e80..8b66b0b 100644
--- a/lib/cyberarm_engine/ui/elements/toggle_button.rb
+++ b/lib/cyberarm_engine/ui/elements/toggle_button.rb
@@ -5,8 +5,8 @@ module CyberarmEngine
 
       def initialize(options, block = nil)
         super(options[:checkmark], options, block)
-        @toggled = options[:toggled] || false
-        if @toggled
+        @value = options[:checked] || false
+        if @value
           @text.text = @options[:checkmark]
         else
           @text.text = ""
@@ -15,29 +15,14 @@ module CyberarmEngine
         return self
       end
 
-      def toggled=(boolean)
-        @toggled = !boolean
-        toggle
-      end
-
       def clicked_left_mouse_button(sender, x, y)
-        toggle
+        self.value = !@value
 
         @block.call(self) if @block
 
         return :handled
       end
 
-      def toggle
-        if @toggled
-          @toggled = false
-          @text.text = ""
-        else
-          @toggled = true
-          @text.text = @options[:checkmark]
-        end
-      end
-
       def recalculate
         super
 
@@ -51,7 +36,21 @@ module CyberarmEngine
       end
 
       def value
-        @toggled
+        @value
+      end
+
+      def value=(boolean)
+        @value = boolean
+
+        if boolean
+          @text.text = @options[:checkmark]
+        else
+          @text.text = ""
+        end
+
+        recalculate
+
+        publish(:changed, @value)
       end
     end
   end
diff --git a/lib/cyberarm_engine/engine.rb b/lib/cyberarm_engine/window.rb
similarity index 98%
rename from lib/cyberarm_engine/engine.rb
rename to lib/cyberarm_engine/window.rb
index a3e5a1c..c166903 100644
--- a/lib/cyberarm_engine/engine.rb
+++ b/lib/cyberarm_engine/window.rb
@@ -1,5 +1,5 @@
 module CyberarmEngine
-  class Engine < Gosu::Window
+  class Window < Gosu::Window
     IMAGES = {}
     SAMPLES= {}
     SONGS  = {}