From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Brokkonaut <hannos17@gmx.de>
Date: Mon, 18 Jun 2018 15:40:39 +0200
Subject: [PATCH] Add EntityKnockbackByEntityEvent and
 EntityPushedByEntityAttackEvent

Co-authored-by: aerulion <aerulion@gmail.com>

diff --git a/src/main/java/com/destroystokyo/paper/event/entity/EntityKnockbackByEntityEvent.java b/src/main/java/com/destroystokyo/paper/event/entity/EntityKnockbackByEntityEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..e0ba692c9b107f2b042a9c06549185e1c4777e27
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/entity/EntityKnockbackByEntityEvent.java
@@ -0,0 +1,48 @@
+package com.destroystokyo.paper.event.entity;
+
+import io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.util.Vector;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Fired when an Entity is knocked back by the hit of another Entity. The acceleration
+ * vector can be modified. If this event is cancelled, the entity is not knocked back.
+ */
+public class EntityKnockbackByEntityEvent extends EntityPushedByEntityAttackEvent {
+
+    private final float knockbackStrength;
+
+    @ApiStatus.Internal
+    public EntityKnockbackByEntityEvent(@NotNull LivingEntity entity, @NotNull Entity hitBy, float knockbackStrength, @NotNull Vector acceleration) {
+        super(entity, hitBy, acceleration);
+        this.knockbackStrength = knockbackStrength;
+    }
+
+    /**
+     * @return the entity which was knocked back
+     */
+    @NotNull
+    @Override
+    public LivingEntity getEntity() {
+        return (LivingEntity) super.getEntity();
+    }
+
+    /**
+     * @return the original knockback strength.
+     */
+    public float getKnockbackStrength() {
+        return this.knockbackStrength;
+    }
+
+    /**
+     * @return the Entity which hit
+     */
+    @NotNull
+    public Entity getHitBy() {
+        return super.getPushedBy();
+    }
+
+}
diff --git a/src/main/java/io/papermc/paper/event/entity/EntityPushedByEntityAttackEvent.java b/src/main/java/io/papermc/paper/event/entity/EntityPushedByEntityAttackEvent.java
new file mode 100644
index 0000000000000000000000000000000000000000..404bec776244fd776566c81f671f1009830c6d6e
--- /dev/null
+++ b/src/main/java/io/papermc/paper/event/entity/EntityPushedByEntityAttackEvent.java
@@ -0,0 +1,82 @@
+package io.papermc.paper.event.entity;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.entity.EntityEvent;
+import org.bukkit.util.Vector;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Fired when an entity is pushed by another entity's attack. The acceleration vector can be
+ * modified. If this event is cancelled, the entity will not get pushed.
+ * <p>
+ * Note: Some entities might trigger this multiple times on the same entity
+ * as multiple acceleration calculations are done.
+ */
+public class EntityPushedByEntityAttackEvent extends EntityEvent implements Cancellable {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private final @NotNull Entity pushedBy;
+    private @NotNull Vector acceleration;
+    private boolean cancelled;
+
+    @ApiStatus.Internal
+    public EntityPushedByEntityAttackEvent(@NotNull Entity entity, @NotNull Entity pushedBy, @NotNull Vector acceleration) {
+        super(entity);
+        this.pushedBy = pushedBy;
+        this.acceleration = acceleration;
+    }
+
+    /**
+     * Gets the entity which pushed the affected entity.
+     *
+     * @return the pushing entity
+     */
+    @NotNull
+    public Entity getPushedBy() {
+        return this.pushedBy;
+    }
+
+    /**
+     * Gets the acceleration that will be applied to the affected entity.
+     *
+     * @return the acceleration vector
+     */
+    @NotNull
+    public Vector getAcceleration() {
+        return this.acceleration; // TODO Clone in 1.21 to not instantly break what was technically already modifiable
+    }
+
+    /**
+     * Sets the relative acceleration that will be applied to the affected entity.
+     *
+     * @param acceleration the new acceleration vector
+     */
+    public void setAcceleration(final @NotNull Vector acceleration) {
+        this.acceleration = acceleration.clone();
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @NotNull
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    @NotNull
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}
diff --git a/src/main/java/org/bukkit/event/entity/EntityKnockbackByEntityEvent.java b/src/main/java/org/bukkit/event/entity/EntityKnockbackByEntityEvent.java
index 3f17290c0863cc1d452bb50c524c18b6ab255d70..bd44bc5ed9e20148f9b2ab3d2049187280f3eb18 100644
--- a/src/main/java/org/bukkit/event/entity/EntityKnockbackByEntityEvent.java
+++ b/src/main/java/org/bukkit/event/entity/EntityKnockbackByEntityEvent.java
@@ -7,7 +7,10 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Called when an entity receives knockback from another entity.
+ *
+ * @deprecated use {@link com.destroystokyo.paper.event.entity.EntityKnockbackByEntityEvent}
  */
+@Deprecated(forRemoval = true) // Paper
 public class EntityKnockbackByEntityEvent extends EntityKnockbackEvent {
 
     private final Entity source;
diff --git a/src/main/java/org/bukkit/event/entity/EntityKnockbackEvent.java b/src/main/java/org/bukkit/event/entity/EntityKnockbackEvent.java
index 9355efbbd4625e34d6c9d26bcbd02272202dec79..fe3374fbbfef728358e4a15bbf2deb238a1e0bfd 100644
--- a/src/main/java/org/bukkit/event/entity/EntityKnockbackEvent.java
+++ b/src/main/java/org/bukkit/event/entity/EntityKnockbackEvent.java
@@ -11,7 +11,10 @@ import org.jetbrains.annotations.NotNull;
 
 /**
  * Called when a living entity receives knockback.
+ *
+ * @deprecated use {@link com.destroystokyo.paper.event.entity.EntityKnockbackByEntityEvent} or {@link io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent}
  */
+@Deprecated(forRemoval = true) // Paper
 public class EntityKnockbackEvent extends EntityEvent implements Cancellable {
 
     private static final HandlerList handlers = new HandlerList();
