Add PlayerArmorChangeEvent

paper-api/src/main/java/com/destroystokyo/paper/event/player/PlayerArmorChangeEvent.java

@@ -0,0 +1,120 @@
+package com.destroystokyo.paper.event.player;
+
+import java.util.Set;
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+import static org.bukkit.Material.*;
+
+/**
+ * Called when the player themselves change their armor items
+ * <p>
+ * Not currently called for environmental factors though it <strong>MAY BE IN THE FUTURE</strong>
+ */
+@NullMarked
+public class PlayerArmorChangeEvent extends PlayerEvent {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final SlotType slotType;
+    private final ItemStack oldItem;
+    private final ItemStack newItem;
+
+    @ApiStatus.Internal
+    public PlayerArmorChangeEvent(final Player player, final SlotType slotType, final ItemStack oldItem, final ItemStack newItem) {
+        super(player);
+        this.slotType = slotType;
+        this.oldItem = oldItem;
+        this.newItem = newItem;
+    }
+
+    /**
+     * Gets the type of slot being altered.
+     *
+     * @return type of slot being altered
+     */
+    public SlotType getSlotType() {
+        return this.slotType;
+    }
+
+    /**
+     * Gets the existing item that's being replaced
+     *
+     * @return old item
+     */
+    public ItemStack getOldItem() {
+        return this.oldItem;
+    }
+
+    /**
+     * Gets the new item that's replacing the old
+     *
+     * @return new item
+     */
+    public ItemStack getNewItem() {
+        return this.newItem;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+
+    public enum SlotType {
+        HEAD(NETHERITE_HELMET, DIAMOND_HELMET, GOLDEN_HELMET, IRON_HELMET, CHAINMAIL_HELMET, LEATHER_HELMET, CARVED_PUMPKIN, PLAYER_HEAD, SKELETON_SKULL, ZOMBIE_HEAD, CREEPER_HEAD, WITHER_SKELETON_SKULL, TURTLE_HELMET, DRAGON_HEAD, PIGLIN_HEAD),
+        CHEST(NETHERITE_CHESTPLATE, DIAMOND_CHESTPLATE, GOLDEN_CHESTPLATE, IRON_CHESTPLATE, CHAINMAIL_CHESTPLATE, LEATHER_CHESTPLATE, ELYTRA),
+        LEGS(NETHERITE_LEGGINGS, DIAMOND_LEGGINGS, GOLDEN_LEGGINGS, IRON_LEGGINGS, CHAINMAIL_LEGGINGS, LEATHER_LEGGINGS),
+        FEET(NETHERITE_BOOTS, DIAMOND_BOOTS, GOLDEN_BOOTS, IRON_BOOTS, CHAINMAIL_BOOTS, LEATHER_BOOTS);
+
+        private final Set<Material> types;
+
+        SlotType(final Material... types) {
+            this.types = Set.of(types);
+        }
+
+        /**
+         * Gets an immutable set of all allowed material types that can be placed in an
+         * armor slot.
+         *
+         * @return immutable set of material types
+         */
+        public Set<Material> getTypes() {
+            return this.types;
+        }
+
+        /**
+         * Gets the type of slot via the specified material
+         *
+         * @param material material to get slot by
+         * @return slot type the material will go in, or {@code null} if it won't
+         */
+        public static @Nullable SlotType getByMaterial(final Material material) {
+            for (final SlotType slotType : values()) {
+                if (slotType.getTypes().contains(material)) {
+                    return slotType;
+                }
+            }
+            return null;
+        }
+
+        /**
+         * Gets whether this material can be equipped to a slot
+         *
+         * @param material material to check
+         * @return whether this material can be equipped
+         */
+        public static boolean isEquipable(final Material material) {
+            return getByMaterial(material) != null;
+        }
+    }
+}