Added animation editor's particle list

Data/Scripts/906_New controls container/001 controls container.rb

@@ -11,7 +11,7 @@
 #       this would require manually telling all other controls in this container
 #       that something else is captured and they shouldn't show a hover
 #       highlight when updated (perhaps as a parameter in def update), which I
-#       don't think is ideal. Mark self as "busy" while a control is captured.
+#       don't think is ideal.
 #===============================================================================
 class UIControls::ControlsContainer
   attr_reader :x, :y
@@ -43,6 +43,10 @@ class UIControls::ControlsContainer
     @viewport.dispose
   end
 
+  def busy?
+    return !@captured.nil?
+  end
+
   def changed?
     return !@values.nil?
   end