it is done

core/src/mindustry/ui/fragments/OverlayFragment.java

@@ -0,0 +1,32 @@
+package mindustry.ui.fragments;
+
+import arc.*;
+import arc.scene.event.*;
+import arc.scene.ui.layout.*;
+import mindustry.*;
+
+/** Fragment for displaying overlays such as block inventories. */
+public class OverlayFragment{
+    public final BlockInventoryFragment inv;
+    public final BlockConfigFragment config;
+
+    private WidgetGroup group = new WidgetGroup();
+
+    public OverlayFragment(){
+        group.touchable(Touchable.childrenOnly);
+        inv = new BlockInventoryFragment();
+        config = new BlockConfigFragment();
+    }
+
+    public void add(){
+        group.setFillParent(true);
+        Vars.ui.hudGroup.addChildBefore(Core.scene.find("overlaymarker"), group);
+
+        inv.build(group);
+        config.build(group);
+    }
+
+    public void remove(){
+        group.remove();
+    }
+}