public GuiScreen(GuiSkin skin)
 {
     Skin     = skin;
     Controls = new GuiControlCollection {
         ItemAdded = c => _isLayoutRequired = true
     };
     Windows = new GuiWindowCollection(this)
     {
         ItemAdded = w => _isLayoutRequired = true
     };
 }
 public GuiControlFactory(GuiSkin skin)
 {
     _skin = skin;
 }