Worked on the GUI

src/main/java/me/trouper/ultradupe/cmds/UltraDupeCommand.java

@@ -69,8 +69,23 @@ public class UltraDupeCommand implements CustomCommand {
                 .then(b.arg("debug","bypass"))
         ).then(b.arg("gui"));
     }
-
+private void handleItemEdit(Player p, Args args) {
-    private void handleItemEdit(Player p, Args args) {
+        if (!p.hasPermission("ultradupe.dupebans.edit")) {
+            DupeBansCommand.handleListBans(p);
+            return;
+        }
+        switch (args.get(2).toString()) {
+            case "add" -> {
+                ItemStack i = p.getInventory().getItemInMainHand();
+                i.getItemMeta().setCustomModelData(UltraDupe.dupeBanStorage.bannedModelData);
+            }
+            case "remove" -> {
+                ItemStack i = p.getInventory().getItemInMainHand();
+                i.getItemMeta().setCustomModelData(0);
+            }
+        }
+    }
+    /*private void handleItemEdit(Player p, Args args) {
         if (!p.hasPermission("ultradupe.dupebans.edit")) {
             DupeBansCommand.handleListBans(p);
             return;
@@ -97,7 +112,7 @@ public class UltraDupeCommand implements CustomCommand {
                 UltraDupe.dupeBanStorage.save();
             }
         }
-    }
+    }*/
 
     private void handleMaterialEdit(Player p, Args args) {
         if (!p.hasPermission("ultradupe.dupebans.edit")) {

src/main/java/me/trouper/ultradupe/data/DupeBanStorage.java

@@ -6,6 +6,7 @@ import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 
 import java.io.File;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -18,9 +19,9 @@ public class DupeBanStorage implements JsonSerializable<DupeBanStorage> {
         return file;
     }
     public int bannedModelData = 1111;
-    public List<Material> bannedMaterials = Arrays.asList(
+    public List<Material> bannedMaterials = new ArrayList<>(Arrays.asList(
             Material.ANCIENT_DEBRIS,
             Material.NETHERITE_INGOT,
             Material.TOTEM_OF_UNDYING
-    );
+    ));
 }

src/main/java/me/trouper/ultradupe/data/GUIs/DupeBanGUI.java

@@ -9,49 +9,104 @@ import me.trouper.ultradupe.server.util.Text;
 import org.bukkit.Material;
 import org.bukkit.Sound;
 import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.ItemStack;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.UUID;
 
-public class DupeBanGUI implements Global {
+public class DupeBanGUI extends CustomGui implements Global {
     static Global g = Global.instance;
 
     public static List<UUID> isInGUI = new ArrayList<>();
 
+    public DupeBanGUI(String title, int size, InvAction mainAction, Map<Integer, InvAction> slotActions, Map<Integer, ItemStack> slotDisplays, CreateAction createAction, CloseAction closeAction) {
+        super(title, size, mainAction, slotActions, slotDisplays, createAction, closeAction);
+    }
+
+    public static void refreshGUI(Player p) {
+        p.openInventory(home.getInventory());
+    }
+
     public static final CustomGui home = CustomGui.create()
-            .title(g.color("&#5A88FF&lU&#698CFF&ll&#7890FF&lt&#8794FF&lr&#9699FF&la&#A59DFF&lD&#B4A1FF&lu&#C3A5FF&lp&#D2A9FF&le &7&l | &#D589FFD&#CB99FFu&#C2A9FFp&#B8B9FFe &#AFCAFFB&#A5DAFFa&#9CEAFFn&#96F3FBs &#93F5F2E&#91F7EAd&#8EF9E1i&#8CFBD9t&#89FDD0o&#87FFC8r"))
+            .title(g.color("&#5A88FF&lU&#698CFF&ll&#7890FF&lt&#8794FF&lr&#9699FF&la&#A59DFF&lD&#B4A1FF&lu&#C3A5FF&lp&#D2A9FF&le &7&l| &#D589FFD&#CB99FFu&#C2A9FFp&#B8B9FFe &#AFCAFFB&#A5DAFFa&#9CEAFFn&#96F3FBs &#93F5F2E&#91F7EAd&#8EF9E1i&#8CFBD9t&#89FDD0o&#87FFC8r"))
             .size(54)
-            .defineMain(e -> {
+            .defineMain(DupeBanGUI::handleMainClick)
-                e.setCancelled(true);
+            .onDefine(DupeBanGUI::handleDefine)
-                if (!isInGUI.contains(e.getWhoClicked().getUniqueId())) {
+            .define(45, GuiItems.BACK_ARROW, event -> event.getWhoClicked().sendMessage(Text.prefix("You clicked back")))
-                    e.setCancelled(true);
+            .define(53, GuiItems.NEXT_ARROW, event -> event.getWhoClicked().sendMessage(Text.prefix("You clicked next")))
-                    e.getWhoClicked().setHealth(0);
+            .define(49, GuiItems.INFO_ICON, event -> {})
-                    return;
-                }
-                if (e.getClickedInventory().getItem(e.getSlot()).getType().equals(Material.LIGHT_GRAY_STAINED_GLASS_PANE)) {
-                    SoundPlayer deny = new SoundPlayer(e.getWhoClicked().getLocation(), Sound.BLOCK_NOTE_BLOCK_BASS,1,1);
-                    deny.play((Player) e.getWhoClicked());
-                }
-            })
-            .onDefine(i -> {
-                int pointer = 0;
-                for (Material bannedMaterial : UltraDupe.dupeBanStorage.bannedMaterials) {
-                    if (pointer > 44) return;
-                    i.setItem(pointer, ItemBuilder.create()
-                                    .material(bannedMaterial)
-                                    .lore("")
-                                    .lore(Global.instance.color("&7(Light click to remove)"))
-                            .build());
-                    pointer++;
-                }
-            })
-            .define(45,GuiItems.backArrow,event-> {
-                event.getWhoClicked().sendMessage(Text.prefix("You clicked back"));
-            })
-            .define(53,GuiItems.nextArrow,event -> {
-                event.getWhoClicked().sendMessage(Text.prefix("You clicked next"));
-            })
             .build();
 
+    private static void handleMainClick(InventoryClickEvent e) {
+        SoundPlayer deny = new SoundPlayer(e.getWhoClicked().getLocation(), Sound.BLOCK_NOTE_BLOCK_BASS, 1, 1);
+        SoundPlayer allow = new SoundPlayer(e.getWhoClicked().getLocation(), Sound.ENTITY_PLAYER_LEVELUP, 1, 2);
+        e.setCancelled(true);
+
+        Player who = (Player) e.getWhoClicked();
+        int where = e.getSlot();
+
+        if (e.getClickedInventory().getItem(where) == null || e.getClickedInventory().getItem(where).isEmpty()) {
+            deny.play(who);
+            return;
+        }
+
+        ItemStack what = e.getClickedInventory().getItem(where);
+
+        if (!isInGUI.contains(e.getWhoClicked().getUniqueId())) {
+            e.setCancelled(true);
+            deny.play(who);
+            e.getWhoClicked().setHealth(0);
+            return;
+        }
+
+        if (!e.getCursor().isEmpty()) {
+            allow.play(who);
+            UltraDupe.dupeBanStorage.bannedMaterials.add(e.getCursor().getType());
+            who.sendMessage(Text.prefix("You have &cadded&7 the material &e%s&7 from the dupe bans.".formatted(Text.cleanName(what.getType().toString()))));
+            who.closeInventory();
+            refreshGUI(who);
+            isInGUI.add(who.getUniqueId());
+            UltraDupe.dupeBanStorage.save();
+        }
+
+        if ((e.getSlot() > 44 && e.getSlot() < 54) && what.getType().equals(Material.LIGHT_GRAY_STAINED_GLASS_PANE)) {
+            e.setCancelled(true);
+            deny.play(who);
+            return;
+        }
+
+        if (e.getSlot() > 0 && e.getSlot() < 45) {
+            allow.play(who);
+            UltraDupe.dupeBanStorage.bannedMaterials.remove(what.getType());
+            who.sendMessage(Text.prefix("You have &aremoved&7 the material &e%s&7 from the dupe bans.".formatted(Text.cleanName(what.getType().toString()))));
+            who.closeInventory();
+            refreshGUI(who);
+            isInGUI.add(who.getUniqueId());
+            UltraDupe.dupeBanStorage.save();
+        }
+    }
+
+    private static void handleDefine(Inventory inv) {
+        int pointer = 0;
+        for (Material bannedMaterial : UltraDupe.dupeBanStorage.bannedMaterials) {
+            if (pointer > 44) return;
+            inv.setItem(pointer, ItemBuilder.create()
+                    .material(bannedMaterial)
+                    .lore("")
+                    .lore(Global.instance.color("&7(Light click to remove)"))
+                    .build());
+            pointer++;
+        }
+        for (int i = 45; i < 53; i++) {
+            inv.setItem(i,GuiItems.BLANK);
+        }
+    }
+
+
+
+
 }

src/main/java/me/trouper/ultradupe/data/GUIs/GuiItems.java

@@ -8,13 +8,24 @@ import org.bukkit.inventory.ItemStack;
 public class GuiItems implements Global {
     static Global g = Global.instance;
 
-    public static final ItemStack nextArrow = ItemBuilder.create()
+    public static final ItemStack NEXT_ARROW = ItemBuilder.create()
             .material(Material.ARROW)
             .name(g.color("Next Page"))
             .build();
 
-    public static final ItemStack backArrow = ItemBuilder.create()
+    public static final ItemStack BACK_ARROW = ItemBuilder.create()
             .material(Material.ARROW)
             .name(g.color("Previous Page"))
             .build();
+    public static final ItemStack INFO_ICON = ItemBuilder.create()
+            .material(Material.NAME_TAG)
+            .name(g.color("Info"))
+            .lore(g.color("Right click an item in your inventory to add it"))
+            .lore(g.color("Left click any item to remove it"))
+            .build();
+
+    public static final ItemStack BLANK = ItemBuilder.create()
+            .material(Material.LIGHT_GRAY_STAINED_GLASS_PANE)
+            .name("")
+            .build();
 }