Dynamic spacer class

arc-core/src/arc/scene/ui/layout/Spacer.java

@@ -0,0 +1,38 @@
+package arc.scene.ui.layout;
+
+import arc.func.*;
+import arc.scene.*;
+
+public class Spacer extends Element{
+    Floatp widthFunc, heightFunc;
+
+    public Spacer(Floatp widthFunc, Floatp heightFunc){
+        this.widthFunc = widthFunc;
+        this.heightFunc = heightFunc;
+
+        width = Scl.scl(widthFunc.get());
+        height = Scl.scl(heightFunc.get());
+    }
+
+    @Override
+    public void act(float delta){
+        super.act(delta);
+
+        float w = Scl.scl(widthFunc.get()), h = Scl.scl(heightFunc.get());
+        if(w != width || h != height){
+            width = w;
+            height = h;
+            invalidateHierarchy();
+        }
+    }
+
+    @Override
+    public float getPrefHeight(){
+        return heightFunc.get();
+    }
+
+    @Override
+    public float getPrefWidth(){
+        return widthFunc.get();
+    }
+}

arc-core/src/arc/scene/ui/layout/Table.java

@@ -366,6 +366,18 @@ public Cell<Stack> stack(Element... elements){
         return add(stack);
     }
 
+    public Cell<Spacer> spacer(Floatp width, Floatp height){
+        return add(new Spacer(width, height));
+    }
+
+    public Cell<Spacer> spacerX(Floatp width){
+        return add(new Spacer(width, () -> 0f));
+    }
+
+    public Cell<Spacer> spacerY(Floatp height){
+        return add(new Spacer(() -> 0f, height));
+    }
+
     public Cell<Image> image(Prov<TextureRegion> reg){
         return add(new Image(reg.get())).update(i -> {
             ((TextureRegionDrawable)i.getDrawable()).setRegion(reg.get());