Fixes 'hide-flags' not working in GUI's

MMOCore-API/src/main/java/net/Indyuce/mmocore/api/util/MMOCoreUtils.java

@@ -1,5 +1,6 @@
 package net.Indyuce.mmocore.api.util;
 
+import com.google.common.collect.MultimapBuilder;
 import io.lumine.mythic.lib.MythicLib;
 import io.lumine.mythic.lib.UtilityMethods;
 import io.lumine.mythic.lib.gson.JsonArray;
@@ -16,6 +17,7 @@ import org.bukkit.event.entity.EntityRegainHealthEvent;
 import org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason;
 import org.bukkit.event.player.PlayerItemDamageEvent;
 import org.bukkit.inventory.EquipmentSlot;
+import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.Damageable;
 import org.bukkit.inventory.meta.ItemMeta;
@@ -116,6 +118,18 @@ public class MMOCoreUtils {
         return material == Material.PLAYER_HEAD || material == Material.PLAYER_WALL_HEAD;
     }
 
+    public static void addAllItemFlags(@NotNull ItemMeta meta) {
+        meta.addItemFlags(ItemFlag.values());
+
+        // Fix 1.20.6+ Paper bug that sucks. HIDE_ATTRIBUTES no longer works when item attribute list is empty
+        // TODO refactor with GUI update.
+        try {
+            meta.setAttributeModifiers(MultimapBuilder.hashKeys(0).hashSetValues(0).build());
+        } catch (Exception exception) {
+            // Not needed
+        }
+    }
+
     @NotNull
     public static ItemStack readIcon(String string) {
         final String[] split = string.split(":");

MMOCore-API/src/main/java/net/Indyuce/mmocore/gui/ClassSelect.java

@@ -21,7 +21,6 @@ import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.event.inventory.InventoryCloseEvent;
-import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.persistence.PersistentDataType;
@@ -71,7 +70,7 @@ public class ClassSelect extends EditableInventory {
         public ItemStack display(ProfessSelectionInventory inv, int n) {
             ItemStack item = n == 0 ? playerClass.getIcon() : super.display(inv, n);
             ItemMeta meta = item.getItemMeta();
-            if (hideFlags()) meta.addItemFlags(ItemFlag.values());
+            if (hideFlags()) MMOCoreUtils.addAllItemFlags(meta);
             if (hideTooltip()) meta.setHideTooltip(true);
             meta.setDisplayName(MythicLib.plugin.parseColors(name).replace("{name}", playerClass.getName()));
             List<String> lore = new ArrayList<>(this.lore);

MMOCore-API/src/main/java/net/Indyuce/mmocore/gui/SubclassSelect.java

@@ -8,6 +8,7 @@ import net.Indyuce.mmocore.api.SoundEvent;
 import net.Indyuce.mmocore.api.player.PlayerData;
 import net.Indyuce.mmocore.api.player.profess.ClassOption;
 import net.Indyuce.mmocore.api.player.profess.PlayerClass;
+import net.Indyuce.mmocore.api.util.MMOCoreUtils;
 import net.Indyuce.mmocore.gui.api.EditableInventory;
 import net.Indyuce.mmocore.gui.api.GeneratedInventory;
 import net.Indyuce.mmocore.gui.api.InventoryClickContext;
@@ -62,7 +63,7 @@ public class SubclassSelect extends EditableInventory {
         public ItemStack display(SubclassSelectionInventory inv, int n) {
             ItemStack item = n == 0 ? playerClass.getIcon() : super.display(inv, n);
             ItemMeta meta = item.getItemMeta();
-            if (hideFlags()) meta.addItemFlags(ItemFlag.values());
+            if (hideFlags()) MMOCoreUtils.addAllItemFlags(meta);
             if (hideTooltip()) meta.setHideTooltip(true);
             meta.setDisplayName(MythicLib.plugin.parseColors(name).replace("{name}", playerClass.getName()));
             List<String> lore = new ArrayList<>(this.lore);

MMOCore-API/src/main/java/net/Indyuce/mmocore/gui/WaypointViewer.java

@@ -1,10 +1,10 @@
 package net.Indyuce.mmocore.gui;
 
-import io.lumine.mythic.lib.UtilityMethods;
 import net.Indyuce.mmocore.MMOCore;
 import net.Indyuce.mmocore.api.ConfigMessage;
 import net.Indyuce.mmocore.api.player.PlayerActivity;
 import net.Indyuce.mmocore.api.player.PlayerData;
+import net.Indyuce.mmocore.api.util.MMOCoreUtils;
 import net.Indyuce.mmocore.gui.api.EditableInventory;
 import net.Indyuce.mmocore.gui.api.GeneratedInventory;
 import net.Indyuce.mmocore.gui.api.InventoryClickContext;
@@ -14,12 +14,13 @@ import net.Indyuce.mmocore.gui.api.item.SimplePlaceholderItem;
 import net.Indyuce.mmocore.waypoint.Waypoint;
 import net.Indyuce.mmocore.waypoint.WaypointPath;
 import org.apache.commons.lang.Validate;
-import org.bukkit.*;
+import org.bukkit.ChatColor;
+import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
+import org.bukkit.OfflinePlayer;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
-import org.bukkit.inventory.meta.SkullMeta;
 import org.bukkit.persistence.PersistentDataContainer;
 import org.bukkit.persistence.PersistentDataType;
 import org.jetbrains.annotations.Nullable;
@@ -151,7 +152,7 @@ public class WaypointViewer extends EditableInventory {
 
             if (hasName()) meta.setDisplayName(placeholders.apply(effectivePlayer, getName()));
 
-            if (hideFlags()) meta.addItemFlags(ItemFlag.values());
+            if (hideFlags()) MMOCoreUtils.addAllItemFlags(meta);
             if (hideTooltip()) meta.setHideTooltip(true);
             // If a player can teleport to another waypoint given his location
             Waypoint waypoint = inv.waypoints.get(inv.page * inv.getEditable().getByFunction("waypoint").getSlots().size() + n);

MMOCore-API/src/main/java/net/Indyuce/mmocore/gui/api/item/InventoryItem.java

@@ -2,13 +2,13 @@ package net.Indyuce.mmocore.gui.api.item;
 
 import io.lumine.mythic.lib.MythicLib;
 import io.lumine.mythic.lib.UtilityMethods;
+import net.Indyuce.mmocore.api.util.MMOCoreUtils;
 import net.Indyuce.mmocore.gui.api.GeneratedInventory;
 import org.bukkit.ChatColor;
 import org.bukkit.Material;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.inventory.Inventory;
-import org.bukkit.inventory.ItemFlag;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.inventory.meta.SkullMeta;
@@ -157,8 +157,8 @@ public abstract class InventoryItem<T extends GeneratedInventory> {
 
         if (hasName()) meta.setDisplayName(placeholders.apply(effectivePlayer, getName()));
 
-        if (hideFlags()) meta.addItemFlags(ItemFlag.values());
         if (hideTooltip()) meta.setHideTooltip(true);
+        if (hideFlags()) MMOCoreUtils.addAllItemFlags(meta);
 
         if (hasLore()) {
             List<String> lore = new ArrayList<>();