0068-event-Add-PlayerTrackEntityEvent.patch

From c8c2aa31661e8b65a2a512eadf8a56d50ce01bc1 Mon Sep 17 00:00:00 2001
From: Archer <archer@beezig.eu>
Date: Thu, 3 Feb 2022 04:55:02 +0100
Subject: [PATCH] event: Add PlayerTrackEntityEvent

This commit adds an event that gets fired whenever an entity is added to
a player's entity tracker. Cancelling this event prevents the entity
from being added, and consequently, the entity is never sent (nor
updated) for the player. While this is essentially the same method that
Bukkit's hidden player system uses, simply cancelling the event does
not make sure that the entity is not interacted with, and the player can
still see them in some places (e.g. in the player list and the
scoreboard).

diff --git a/src/main/java/dev/rocco/kig/paper/api/event/PlayerTrackEntityEvent.java b/src/main/java/dev/rocco/kig/paper/api/event/PlayerTrackEntityEvent.java
new file mode 100644
index 00000000..848ffcae
--- /dev/null
+++ b/src/main/java/dev/rocco/kig/paper/api/event/PlayerTrackEntityEvent.java
@@ -0,0 +1,71 @@
+package dev.rocco.kig.paper.api.event;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+
+/**
+ * Fired when an {@link Entity} is added to a {@link Player}'s entity tracker.
+ * Cancelling the event will prevent the given entity from entering the player's
+ * entity tracker.
+ */
+public class PlayerTrackEntityEvent extends PlayerEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
+
+    private final Entity tracked;
+    private boolean cancelled;
+
+    /**
+     * Creates a new {@code PlayerTrackEntityEvent} for the given player and tracked entity.
+     *
+     * @param player  the player who the entity is added for
+     * @param tracked the entity that is to be added to the player's entity tracker
+     */
+    public PlayerTrackEntityEvent(Player player, Entity tracked) {
+        super(player);
+        this.tracked = tracked;
+    }
+
+    /**
+     * Returns the list of handlers that handle a {@code PlayerTrackEntityEvent}.
+     */
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    /**
+     * Returns the list of handlers that handle a {@code PlayerTrackEntityEvent}.
+     */
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    /**
+     * Returns the entity that is to be tracked in the player's tracker
+     */
+    public Entity getTracked() {
+        return tracked;
+    }
+
+    /**
+     * Returns whether this event is cancelled.
+     */
+    @Override
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    /**
+     * Sets the cancelled status of this event. Cancelling the event will prevent the entity from being added to the
+     * player's entity tracker.
+     *
+     * @param cancel true if you wish to cancel this event
+     */
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancelled = cancel;
+    }
+}
-- 
2.35.1