Add the PlayerXpEvent events (add XP points/level, pickup XP orb)

patchwork-events-entity/src/main/java/net/minecraftforge/event/entity/player/PlayerPickupXpEvent.java

@@ -0,0 +1,34 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2020, 2019-2020
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.event.entity.player;
+
+import net.minecraft.entity.ExperienceOrbEntity;
+import net.minecraft.entity.player.PlayerEntity;
+
+/**
+ * Legacy version of PlayerXpEvent.PickupXp. Mods should move to PickupXp, and
+ * this class is removed in 1.15.
+ */
+@Deprecated
+public class PlayerPickupXpEvent extends PlayerXpEvent.PickupXp {
+	public PlayerPickupXpEvent(PlayerEntity player, ExperienceOrbEntity orb) {
+		super(player, orb);
+	}
+}

patchwork-events-entity/src/main/java/net/minecraftforge/event/entity/player/PlayerXpEvent.java

@@ -0,0 +1,90 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2020, 2019-2020
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.event.entity.player;
+
+import net.minecraft.entity.ExperienceOrbEntity;
+import net.minecraft.entity.player.PlayerEntity;
+
+public abstract class PlayerXpEvent extends PlayerEvent {
+	public PlayerXpEvent(PlayerEntity player) {
+		super(player);
+	}
+
+	// For legacy reasons, the instances of this class should actually be of
+	// type PlayerPickupXpEvent
+	public static class PickupXp extends CancelablePlayerXpEvent {
+		private final ExperienceOrbEntity orb;
+
+		public PickupXp(PlayerEntity player, ExperienceOrbEntity orb) {
+			super(player);
+			this.orb = orb;
+		}
+
+		public ExperienceOrbEntity getOrb() {
+			return orb;
+		}
+	}
+
+	public static class XpChange extends CancelablePlayerXpEvent {
+		private int amount;
+
+		public XpChange(PlayerEntity player, int amount) {
+			super(player);
+			this.amount = amount;
+		}
+
+		public int getAmount() {
+			return amount;
+		}
+
+		public void setAmount(int amount) {
+			this.amount = amount;
+		}
+	}
+
+	public static class LevelChange extends CancelablePlayerXpEvent {
+		private int levels;
+
+		public LevelChange(PlayerEntity player, int levels) {
+			super(player);
+			this.levels = levels;
+		}
+
+		public int getLevels() {
+			return this.levels;
+		}
+
+		public void setLevels(int levels) {
+			this.levels = levels;
+		}
+	}
+
+	// Helper, so we don't have to repeat isCancelable all the time
+	private static class CancelablePlayerXpEvent extends PlayerXpEvent {
+		private CancelablePlayerXpEvent(PlayerEntity player) {
+			super(player);
+		}
+
+		@Override
+		public boolean isCancelable() {
+			return true;
+		}
+	}
+}

patchwork-events-entity/src/main/java/net/patchworkmc/mixin/event/entity/MixinExperienceOrbEntity.java

@@ -0,0 +1,47 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2020, 2019-2020
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.patchworkmc.mixin.event.entity;
+
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.event.entity.player.PlayerPickupXpEvent;
+import org.objectweb.asm.Opcodes;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.entity.ExperienceOrbEntity;
+
+@Mixin(ExperienceOrbEntity.class)
+public class MixinExperienceOrbEntity {
+	// After checking we're on the server and the player is ready to pick up the orb, the first
+	// thing the target method does is set experiencePickUpDelay, hence hook just before that.
+	@Inject(method = "onPlayerCollision", cancellable = true, at = @At(value = "FIELD", opcode = Opcodes.H_PUTFIELD, ordinal = 0,
+			target = "net/minecraft/entity/player/PlayerEntity.experiencePickUpDelay:I"))
+	private void hookOnPlayerCollisionForPickup(PlayerEntity player, CallbackInfo ci) {
+		@SuppressWarnings("ConstantConditions")
+		ExperienceOrbEntity entity = (ExperienceOrbEntity) (Object) this;
+
+		if (MinecraftForge.EVENT_BUS.post(new PlayerPickupXpEvent(player, entity))) {
+			ci.cancel();
+		}
+	}
+}

patchwork-events-entity/src/main/java/net/patchworkmc/mixin/event/entity/MixinPlayerEntity.java

@@ -19,6 +19,8 @@
 
 package net.patchworkmc.mixin.event.entity;
 
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.event.entity.player.PlayerXpEvent;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
@@ -128,4 +130,28 @@ private void onAttackEntity(Entity target, CallbackInfo callback) {
 			callback.cancel();
 		}
 	}
+
+	@ModifyVariable(method = "addExperience", at = @At("HEAD"), ordinal = 0)
+	private int onAddExperience(int points) {
+		@SuppressWarnings("ConstantConditions")
+		PlayerEntity player = (PlayerEntity) (Object) this;
+
+		PlayerXpEvent.XpChange event = new PlayerXpEvent.XpChange(player, points);
+		MinecraftForge.EVENT_BUS.post(event);
+
+		// The only effect of passing in zero is a call to addScore(0), which shouldn't have any effect.
+		return event.isCanceled() ? 0 : event.getAmount();
+	}
+
+	@ModifyVariable(method = "addExperienceLevels", at = @At("HEAD"), ordinal = 0)
+	private int onAddExperienceLevels(int levels) {
+		@SuppressWarnings("ConstantConditions")
+		PlayerEntity player = (PlayerEntity) (Object) this;
+
+		PlayerXpEvent.LevelChange event = new PlayerXpEvent.LevelChange(player, levels);
+		MinecraftForge.EVENT_BUS.post(event);
+
+		// There are no effects from passing in zero levels, so do that if we've been canceled
+		return event.isCanceled() ? 0 : event.getLevels();
+	}
 }

patchwork-events-entity/src/main/resources/patchwork-events-entity.mixins.json

@@ -5,6 +5,7 @@
   "mixins": [
     "MixinEntity",
     "MixinEntityType",
+    "MixinExperienceOrbEntity",
     "MixinLivingEntity",
     "MixinMobEntity",
     "MixinMobSpawnerLogic",