fix C++ type error for playground

projects/nat-flixel-playground/source/PlayState.kiss

@@ -38,11 +38,10 @@
 
     // TODO allow configuring the tags at runtime and erasing/re-creating sprites later
     // TODO allow using other position keys and erasing/re-creating sprites later
-    (let [entrySpriteSystem (new EntrySpriteSystem "!done" "Playground-MAIN" this)]
-        (archive.addSystem entrySpriteSystem)
-        (entrySpriteSystem.process archive))
-    
-    )
+    (prop &mut :EntrySpriteSystem spriteSystem)
+    (set spriteSystem (new EntrySpriteSystem "!done" "Playground-MAIN" this))
+    (archive.addSystem spriteSystem)
+    (spriteSystem.process archive))
 
 (method &override :Void update [:Float elapsed]
     (super.update elapsed)
@@ -153,9 +152,13 @@
 
         
 (method handleChanges [:Archive archive :ChangeSet changeSet]
-    // TODO refresh the sprites/other UI elements for entries that changed data
     (doFor e changeSet
-        (print (archive.fullString e))))
+        // refresh the sprites for entries that changed data.
+        // Entries whose data changed to remove them from the sprite pool will already have been removed
+        // by refreshEntry()
+        (when (spriteSystem.entries.exists e.id)
+            (spriteSystem.onRemoveEntry e)
+            (spriteSystem.processEntry e))))
 
 (prop &mut :Int uiY 0)