Added EntityTotemActivateEvent (#48)

* Added EntityTotemActivateEvent

* Made the mixin not dumb and cleaned up.

* Check isClient before invoking event

* Return early for the isClient check

* Fix the isClient check

src/main/java/xyz/nucleoid/stimuli/event/entity/EntityActivateTotemEvent.java

@@ -0,0 +1,37 @@
+package xyz.nucleoid.stimuli.event.entity;
+
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.damage.DamageSource;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.ActionResult;
+import xyz.nucleoid.stimuli.event.StimulusEvent;
+
+/**
+ * Called when a {@link LivingEntity} activates a totem of undying.
+ *
+ * <p>Upon return:
+ * <ul>
+ * <li>{@link ActionResult#SUCCESS} cancels further processing and activates the totem.
+ * <li>{@link ActionResult#FAIL} cancels further processing and does not activate the totem.
+ * <li>{@link ActionResult#PASS} moves on to the next listener.
+ * </ul>
+ * </p>
+ */
+public interface EntityActivateTotemEvent {
+
+    StimulusEvent<EntityActivateTotemEvent> EVENT = StimulusEvent.create(EntityActivateTotemEvent.class, ctx -> (entity, source, itemStack) -> {
+        try {
+            for (var listener : ctx.getListeners()) {
+                var result = listener.onTotemActivate(entity, source, itemStack);
+                if (result != ActionResult.PASS) {
+                    return result;
+                }
+            }
+        } catch (Throwable t) {
+            ctx.handleException(t);
+        }
+        return ActionResult.PASS;
+    });
+
+    ActionResult onTotemActivate(LivingEntity entity, DamageSource source, ItemStack itemStack);
+}

src/main/java/xyz/nucleoid/stimuli/mixin/entity/LivingEntityMixin.java

@@ -2,6 +2,7 @@
 
 import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
 import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import com.llamalad7.mixinextras.sugar.Local;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.LivingEntity;
@@ -17,6 +18,7 @@
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 import xyz.nucleoid.stimuli.Stimuli;
+import xyz.nucleoid.stimuli.event.entity.EntityActivateTotemEvent;
 import xyz.nucleoid.stimuli.event.entity.EntityDamageEvent;
 import xyz.nucleoid.stimuli.event.entity.EntityDeathEvent;
 import xyz.nucleoid.stimuli.event.entity.EntityDropItemsEvent;
@@ -81,4 +83,19 @@ private void modifyDroppedLoot(LootTable instance, LootContextParameterSet param
             }
         }
     }
+
+    @Inject(method = "tryUseTotem", at = @At(value = "INVOKE", target = "Lnet/minecraft/item/ItemStack;decrement(I)V"), cancellable = true)
+    private void tryUseTotem(DamageSource source, CallbackInfoReturnable<Boolean> cir, @Local(ordinal = 1) ItemStack itemStack) {
+        if (this.getWorld().isClient) {
+            return;
+        }
+
+        var entity = (LivingEntity) (Object) this;
+        try (var invokers = Stimuli.select().forEntity(entity)) {
+            var result = invokers.get(EntityActivateTotemEvent.EVENT).onTotemActivate(entity, source, itemStack);
+            if (result == ActionResult.FAIL) {
+                cir.setReturnValue(false);
+            }
+        }
+    }
 }