SPIGOT-7209: Accessors and events for player's exp cooldown

By: FreeSoccerHDX <freesoccerhdx@gmail.com>

paper-api/src/main/java/org/bukkit/event/player/PlayerExpCooldownChangeEvent.java

@@ -0,0 +1,78 @@
+package org.bukkit.event.player;
+
+import org.bukkit.entity.Player;
+import org.bukkit.event.HandlerList;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Called when a player's experience cooldown changes.
+ */
+@ApiStatus.Experimental
+public class PlayerExpCooldownChangeEvent extends PlayerEvent {
+
+    private static final HandlerList handlers = new HandlerList();
+    private int newCooldown;
+    private final ChangeReason reason;
+
+    public PlayerExpCooldownChangeEvent(@NotNull final Player player, int newcooldown, @NotNull ChangeReason reason) {
+        super(player);
+        this.newCooldown = newcooldown;
+        this.reason = reason;
+    }
+
+    /**
+     * Gets the reason for the change.
+     *
+     * @return The reason for the change
+     */
+    @NotNull
+    public ChangeReason getReason() {
+        return reason;
+    }
+
+    /**
+     * Gets the new cooldown for the player.
+     *
+     * @return The new cooldown
+     * @see Player#getExpCooldown()
+     */
+    public int getNewCooldown() {
+        return newCooldown;
+    }
+
+    /**
+     * Sets the new cooldown for the player.
+     *
+     * @param newCooldown The new cooldown to set
+     * @see Player#setExpCooldown(int)
+     */
+    public void setNewCooldown(int newCooldown) {
+        this.newCooldown = newCooldown;
+    }
+
+    @NotNull
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    @NotNull
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    public enum ChangeReason {
+
+        /**
+         * The cooldown was set by picking up an experience orb.
+         */
+        PICKUP_ORB,
+        /**
+         * The cooldown was set by a plugin.
+         *
+         * @see Player#setExpCooldown(int)
+         */
+        PLUGIN;
+    }
+}