Refactoring

core/src/mindustry/game/Objectives.java

@@ -1,6 +1,7 @@
 package mindustry.game;
 
 import arc.*;
+import arc.scene.ui.layout.*;
 import arc.util.ArcAnnotate.*;
 import mindustry.type.*;
 import mindustry.world.*;
@@ -93,4 +94,25 @@ public class Objectives{
     public abstract static class ZoneObjective implements Objective{
         public @NonNull SectorPreset zone;
     }
+
+    /** Defines a specific objective for a game. */
+    public static interface Objective{
+
+        /** @return whether this objective is met. */
+        boolean complete();
+
+        /** @return the string displayed when this objective is completed, in imperative form.
+         * e.g. when the objective is 'complete 10 waves', this would display "complete 10 waves".
+         * If this objective should not be displayed, should return null.*/
+        @Nullable String display();
+
+        /** Build a display for this zone requirement.*/
+        default void build(Table table){
+
+        }
+
+        default SectorPreset zone(){
+            return this instanceof ZoneObjective ? ((ZoneObjective)this).zone : null;
+        }
+    }
 }