feat(api/entity): add EntityEvent.Push when an entity is pushed

patches/minecraft/net/minecraft/world/entity/Entity.java.patch

@@ -247,6 +247,16 @@
     }
 
     public void m_19920_(float p_19921_, Vec3 p_19922_) {
+@@ -1440,7 +_,8 @@
+    }
+
+    public void m_5997_(double p_20286_, double p_20287_, double p_20288_) {
+-      this.m_20256_(this.m_20184_().m_82520_(p_20286_, p_20287_, p_20288_));
++      var motion = net.minecraftforge.common.ForgeHooks.onPush(this, p_20286_, p_20287_, p_20288_);
++      this.m_20256_(this.m_20184_().m_82520_(motion.m_7096_(), motion.m_7098_(), motion.m_7094_()));
+       this.f_19812_ = true;
+    }
+
 @@ -1620,6 +_,8 @@
              p_20241_.m_128379_("HasVisualFire", this.f_146813_);
           }

patches/minecraft/net/minecraft/world/entity/decoration/HangingEntity.java.patch

@@ -9,3 +9,14 @@
                 if (!blockstate.m_280296_() && !DiodeBlock.m_52586_(blockstate)) {
                    return false;
                 }
+@@ -170,6 +_,10 @@
+    }
+
+    public void m_5997_(double p_31744_, double p_31745_, double p_31746_) {
++      var motion = net.minecraftforge.common.ForgeHooks.onPush(this, p_31744_, p_31745_, p_31746_);
++      p_31744_ = motion.m_7096_();
++      p_31745_ = motion.m_7098_();
++      p_31746_ = motion.m_7094_();
+       if (!this.m_9236_().f_46443_ && !this.m_213877_() && p_31744_ * p_31744_ + p_31745_ * p_31745_ + p_31746_ * p_31746_ > 0.0D) {
+          this.m_6074_();
+          this.m_5553_((Entity)null);

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -376,6 +376,13 @@ public static void onLivingJump(LivingEntity entity)
         MinecraftForge.EVENT_BUS.post(new LivingJumpEvent(entity));
     }
 
+    public static Vec3 onPush(Entity entity, double motionX, double motionY, double motionZ)
+    {
+        var event = new EntityEvent.Push(entity, motionX, motionY, motionZ);
+        MinecraftForge.EVENT_BUS.post(event);
+        return event.getMotion();
+    }
+
     @Nullable
     public static ItemEntity onPlayerTossEvent(@NotNull Player player, @NotNull ItemStack item, boolean includeName)
     {

src/main/java/net/minecraftforge/event/entity/EntityEvent.java

@@ -9,6 +9,7 @@
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.EntityDimensions;
 import net.minecraft.world.entity.Pose;
+import net.minecraft.world.phys.Vec3;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.common.extensions.IForgeEntity;
 import net.minecraftforge.eventbus.api.Cancelable;
@@ -226,4 +227,36 @@ public EyeHeight(Entity entity, Pose pose, EntityDimensions size, float eyeHeigh
         public float getNewEyeHeight() { return newEyeHeight; }
         public void setNewEyeHeight(float newEyeHeight) { this.newEyeHeight = newEyeHeight; }
     }
+
+    /**
+     * This event is fired whenever {@link Entity#push(double, double, double)} gets called.<br>
+     * You can use this to modify the push motion. <br>
+     * Setting the motion on all axies to 0 is equivalent to cancelling the push altogether
+     * <br>
+     * This event is not {@link Cancelable}.<br>
+     * <br>
+     * This event does not have a result. {@link HasResult}
+     * <br>
+     * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
+     **/
+    public static class Push extends EntityEvent
+    {
+        private Vec3 motion;
+
+        public Push(Entity entity, double motionX, double motionY, double motionZ)
+        {
+            super(entity);
+            this.motion = new Vec3(motionX, motionY, motionZ);
+        }
+
+        public Vec3 getMotion()
+        {
+            return this.motion;
+        }
+
+        public void setMotion(Vec3 motion)
+        {
+            this.motion = motion;
+        }
+    }
 }

src/test/java/net/minecraftforge/debug/entity/PushEventTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) Forge Development LLC and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.minecraftforge.debug.entity;
+
+import net.minecraft.world.entity.animal.Cow;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.phys.Vec3;
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.event.entity.EntityEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Mod(PushEventTest.MODID)
+public class PushEventTest
+{
+    public static final boolean ENABLE = true;
+    public static final String MODID = "push_event_test";
+    private static Logger logger = LogManager.getLogger(MODID);
+
+    public PushEventTest()
+    {
+        if (ENABLE)
+        {
+            MinecraftForge.EVENT_BUS.register(this);
+        }
+    }
+
+    @SubscribeEvent
+    public void pushEntity(EntityEvent.Push event)
+    {
+        if (event.getEntity() instanceof Player)
+        {
+            event.setMotion(event.getMotion().scale(100));
+        }
+
+        if (event.getEntity() instanceof Cow)
+        {
+            event.setMotion(Vec3.ZERO);
+        }
+    }
+}

src/test/resources/META-INF/mods.toml

@@ -305,5 +305,7 @@ modId="custom_fluid_container_test"
 modId="alter_ground_event_test"
 [[mods]]
 modId="keymapping_test"
+[[mods]]
+modId="push_event_test"
 
 # ADD ABOVE THIS LINE