2 files changed, 21 insertions, 15 deletions
diff --git a/core/src/ch/asynk/gdx/boardgame/ui/Assembly.java b/core/src/ch/asynk/gdx/boardgame/ui/Assembly.java
index 866c3dd..28a7597 100644
--- a/core/src/ch/asynk/gdx/boardgame/ui/Assembly.java
+++ b/core/src/ch/asynk/gdx/boardgame/ui/Assembly.java
@@ -7,7 +7,6 @@ import ch.asynk.gdx.boardgame.utils.IterableSet;
 
 public abstract class Assembly extends Element
 {
-    protected IterableSet<Element> children;
     private Element touched;
 
     public Assembly(int c)
@@ -15,20 +14,6 @@ public abstract class Assembly extends Element
         this.children = new IterableSet<Element>(c);
     }
 
-    public void add(Element e)
-    {
-        if (children.add(e)) {
-            e.setParent(this);
-        }
-    }
-
-    public void remove(Element e)
-    {
-        if (children.remove(e)) {
-            e.setParent(null);
-        }
-    }
-
     public void taintChildren()
     {
         children.forEach( c -> c.taint() );
diff --git a/core/src/ch/asynk/gdx/boardgame/ui/Element.java b/core/src/ch/asynk/gdx/boardgame/ui/Element.java
index 9885b59..73d068f 100644
--- a/core/src/ch/asynk/gdx/boardgame/ui/Element.java
+++ b/core/src/ch/asynk/gdx/boardgame/ui/Element.java
@@ -7,10 +7,12 @@ import ch.asynk.gdx.boardgame.Drawable;
 import ch.asynk.gdx.boardgame.Paddable;
 import ch.asynk.gdx.boardgame.Positionable;
 import ch.asynk.gdx.boardgame.Touchable;
+import ch.asynk.gdx.boardgame.utils.IterableSet;
 
 public abstract class Element implements Drawable, Paddable, Positionable, Touchable
 {
     public static boolean DEBUG_GEOMETRY = false;
+    public static int DEFAULT_CHILD_COUNT = 2;
 
     public boolean blocked;
     public boolean visible;
@@ -23,6 +25,8 @@ public abstract class Element implements Drawable, Paddable, Positionable, Touch
     protected boolean tainted;          // geometry must be computed
     public boolean taintParent;         // propagate tainted state up the tree
 
+    protected IterableSet<Element> children;
+
     protected Element()
     {
         this(false);
@@ -40,6 +44,7 @@ public abstract class Element implements Drawable, Paddable, Positionable, Touch
         this.x = this.y = 0;
         this.tainted = true;
         this.taintParent = taintParent;
+        this.children = null;
     }
 
     @Override public final float getX()         { return rect.x; }
@@ -78,6 +83,22 @@ public abstract class Element implements Drawable, Paddable, Positionable, Touch
         return r;
     }
 
+    public void add(Element e)
+    {
+        if (children == null)
+            children = new IterableSet<Element>(DEFAULT_CHILD_COUNT);
+        if (children.add(e)) {
+            e.setParent(this);
+        }
+    }
+
+    public void remove(Element e)
+    {
+        if (children.remove(e)) {
+            e.setParent(null);
+        }
+    }
+
     @Override public void drawDebug(ShapeRenderer shapeRenderer)
     {
         shapeRenderer.rect(getX(), getY(), getWidth(), getHeight());