From 0daae4d831978624554fcc600eea918126886721 Mon Sep 17 00:00:00 2001
From: jglrxavpok <jglrxavpok@gmail.com>
Date: Thu, 7 May 2020 16:00:52 +0200
Subject: [PATCH] EntityTickEvent and tick counter in Entity

---
 .../net/minestom/server/entity/Entity.java    | 18 ++++++++++++++++
 .../server/event/entity/EntityTickEvent.java  | 21 +++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 src/main/java/net/minestom/server/event/entity/EntityTickEvent.java

diff --git a/src/main/java/net/minestom/server/entity/Entity.java b/src/main/java/net/minestom/server/entity/Entity.java
index 99471d683..6c4ade79c 100644
--- a/src/main/java/net/minestom/server/entity/Entity.java
+++ b/src/main/java/net/minestom/server/entity/Entity.java
@@ -10,6 +10,7 @@ import net.minestom.server.event.CancellableEvent;
 import net.minestom.server.event.entity.EntitySpawnEvent;
 import net.minestom.server.event.Event;
 import net.minestom.server.event.EventCallback;
+import net.minestom.server.event.entity.EntityTickEvent;
 import net.minestom.server.instance.Chunk;
 import net.minestom.server.instance.Instance;
 import net.minestom.server.instance.block.CustomBlock;
@@ -88,9 +89,15 @@ public abstract class Entity implements Viewable, DataContainer {
     protected boolean silent;
     protected boolean noGravity;
     protected Pose pose = Pose.STANDING;
+
+
     private long velocityUpdatePeriod;
     protected boolean onGround;
 
+    // Tick related
+    private long ticks;
+    private final EntityTickEvent tickEvent = new EntityTickEvent(this);
+
     public Entity(int entityType, Position spawnPosition) {
         this.id = generateId();
         this.entityType = entityType;
@@ -315,6 +322,9 @@ public abstract class Entity implements Viewable, DataContainer {
             // Call the abstract update method
             update();
 
+            ticks++;
+            callEvent(EntityTickEvent.class, tickEvent); // reuse tickEvent to avoid recreating it each tick
+
             // Scheduled synchronization
             if (time - lastSynchronizationTime >= synchronizationDelay) {
                 lastSynchronizationTime = time;
@@ -327,6 +337,14 @@ public abstract class Entity implements Viewable, DataContainer {
         }
     }
 
+    /**
+     * Returns the number of ticks this entity has been active for
+     * @return
+     */
+    public long getAliveTicks() {
+        return ticks;
+    }
+
     /**
      * How does this entity handle being in the void?
      */
diff --git a/src/main/java/net/minestom/server/event/entity/EntityTickEvent.java b/src/main/java/net/minestom/server/event/entity/EntityTickEvent.java
new file mode 100644
index 000000000..cdb69b3cd
--- /dev/null
+++ b/src/main/java/net/minestom/server/event/entity/EntityTickEvent.java
@@ -0,0 +1,21 @@
+package net.minestom.server.event.entity;
+
+import net.minestom.server.entity.Entity;
+import net.minestom.server.event.Event;
+
+/**
+ * Called when an entity ticks itself.
+ * Same instance used for all tick events for the same entity
+ */
+public class EntityTickEvent extends Event {
+
+    private final Entity entity;
+
+    public EntityTickEvent(Entity entity) {
+        this.entity = entity;
+    }
+
+    public Entity getEntity() {
+        return entity;
+    }
+}