Merge pull request #14 from valoeghese/misaka_mikoto

Block Place Event

src/main/java/io/github/fabriccommunity/events/impl/InteractionsImpl.java

@@ -18,7 +18,7 @@ private InteractionsImpl() {
 	public static ItemStack eatFood(LivingEntity self, World world, ItemStack original) {
 		AtomicReference<ItemStack> eaten = new AtomicReference<>(original);
 		AtomicReference<ItemStack> moddedResultReference = new AtomicReference<>();
-		ActionResult eventResult = ItemEvents.EAT_FOOD.invoker().onPlayerEat(self, world, original, eaten, moddedResultReference);
+		ActionResult eventResult = ItemEvents.EAT_FOOD.invoker().onEatFood(self, world, original, eaten, moddedResultReference);
 
 		ItemStack defaultResult = eventResult == ActionResult.FAIL ? original : self.eatFood(world, eaten.get());
 		ItemStack moddedResult = moddedResultReference.get();

src/main/java/io/github/fabriccommunity/events/mixin/item/MixinBlockItem.java

@@ -0,0 +1,51 @@
+package io.github.fabriccommunity.events.mixin.item;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import io.github.fabriccommunity.events.play.ItemEvents;
+import net.minecraft.block.BlockState;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.BlockItem;
+import net.minecraft.item.ItemPlacementContext;
+import net.minecraft.network.packet.s2c.play.ScreenHandlerSlotUpdateS2CPacket;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.ActionResult;
+
+@Mixin(BlockItem.class)
+public abstract class MixinBlockItem {
+	@Shadow
+	protected abstract BlockState getPlacementState(ItemPlacementContext context);
+
+	/**
+	 * @reason getPlacementState is often overriden (has two vanilla overrides, could have more in modded). Therefore using a redirect rather than inject at return in {@code getPlacementState} is more compatible with other mods.
+	 */
+	@Redirect(at = @At(value = "INVOKE", target = "Lnet/minecraft/item/BlockItem;getPlacementState(Lnet/minecraft/item/ItemPlacementContext;)Lnet/minecraft/block/BlockState;"),
+			method = "place")
+	private BlockState onGetPlacementState(BlockItem self, ItemPlacementContext placementContext) {
+		BlockState original = this.getPlacementState(placementContext);
+		AtomicReference<BlockState> state = new AtomicReference<>(original);
+
+		ActionResult result = ItemEvents.PLACED.invoker().onBlockPlaced(placementContext, original, state);
+		BlockState modified = state.get();
+
+		if (result == ActionResult.FAIL) {
+			PlayerEntity entity = placementContext.getPlayer();
+
+			if (entity instanceof ServerPlayerEntity) {
+				int selectedSlot = entity.inventory.selectedSlot;
+				((ServerPlayerEntity) entity).networkHandler.sendPacket(new ScreenHandlerSlotUpdateS2CPacket(-2, selectedSlot, entity.inventory.getStack(selectedSlot)));
+			}
+
+			return null;
+		} else if (result == ActionResult.SUCCESS || (original != modified)) {
+			return modified;
+		} else {
+			return original;
+		}
+	}
+}

src/main/java/io/github/fabriccommunity/events/play/ItemEvents.java

@@ -4,7 +4,9 @@
 
 import net.fabricmc.fabric.api.event.Event;
 import net.fabricmc.fabric.api.event.EventFactory;
+import net.minecraft.block.BlockState;
 import net.minecraft.entity.LivingEntity;
+import net.minecraft.item.ItemPlacementContext;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.ActionResult;
 import net.minecraft.world.World;
@@ -18,7 +20,22 @@ public final class ItemEvents {
 	 */
 	public static final Event<EatFood> EAT_FOOD = EventFactory.createArrayBacked(EatFood.class, listeners -> (entity, world, original, eaten, result) -> {
 		for (EatFood listener : listeners) {
-			ActionResult eventResult = listener.onPlayerEat(entity, world, original, eaten, result);
+			ActionResult eventResult = listener.onEatFood(entity, world, original, eaten, result);
+
+			if (eventResult != ActionResult.PASS) {
+				return eventResult;
+			}
+		}
+
+		return ActionResult.PASS;
+	});
+
+	/**
+	 * Called when a block item is placed. Is configured to work server side.
+	 */
+	public static final Event<Placed> PLACED = EventFactory.createArrayBacked(Placed.class, listeners -> (context, original, state) -> {
+		for (Placed listener : listeners) {
+			ActionResult eventResult = listener.onBlockPlaced(context, original, state);
 
 			if (eventResult != ActionResult.PASS) {
 				return eventResult;
@@ -48,6 +65,27 @@ public interface EatFood {
 		 * <li>{@code FAIL} to cancel further event processing and do not eat the food.
 		 * </ul>
 		 */
-		ActionResult onPlayerEat(LivingEntity entity, World world, final ItemStack original, AtomicReference<ItemStack> eaten, AtomicReference<ItemStack> result);
+		ActionResult onEatFood(LivingEntity entity, World world, final ItemStack original, AtomicReference<ItemStack> eaten, AtomicReference<ItemStack> result);
+	}
+
+	/**
+	 * Called when a block item is placed. Is configured to work server side.
+	 * @author Valoeghese
+	 */
+	@FunctionalInterface
+	public interface Placed {
+		/**
+		 * @param context the context of the block item placement.
+		 * @param original the original blockstate to be placed.
+		 * @param state the state to be placed. If the value stored herein differs from {@code original}, another mod has modified it.
+		 * @return
+		 * <ul>
+		 * <li>{@code SUCCESS} to cancel further event processing place the block state in {@code state}<br/>
+		 * <li>{@code CONSUME} to cancel further event processing and fall back to vanilla behaviour (not modifying the block).<br/>
+		 * <li>{@code PASS} pass event handling on to further processing. If all listeners pass, it is treated as a {@code SUCCESS} if the block state has been modified from the original, and treated as a {@code CONSUME} if the block state has not been modified from the original.
+		 * <li>{@code FAIL} to cancel further event processing and not place the block.
+		 * </ul>
+		 */
+		ActionResult onBlockPlaced(ItemPlacementContext context, final BlockState original, AtomicReference<BlockState> state);
 	}
 }

src/main/resources/toomanyevents.mixins.json

@@ -7,6 +7,7 @@
     "biomegen.MixinMultiNoiseBiomeSource",
     "biomegen.MixinTheEndBiomeSource",
     "biomegen.MixinVanillaLayeredBiomeSource",
+    "item.MixinBlockItem",
     "item.MixinItem",
     "player.MixinHungerManager",
     "player.MixinPlayerEntity",

src/test/java/io/github/fabriccommunity/events/test/BlockPlaceTest.java

@@ -0,0 +1,29 @@
+package io.github.fabriccommunity.events.test;
+
+import io.github.fabriccommunity.events.play.ItemEvents;
+import net.fabricmc.api.ModInitializer;
+import net.minecraft.block.Blocks;
+import net.minecraft.util.ActionResult;
+
+/**
+ * @author Valoeghese
+ */
+public class BlockPlaceTest implements ModInitializer {
+	public static boolean ENABLED = true;
+
+	@Override
+	public void onInitialize() {
+		if (ENABLED) {
+			ItemEvents.PLACED.register((context, original, state) -> {
+				if (context.getBlockPos().getY() == 63) {
+					return ActionResult.FAIL;
+				} else if (context.getBlockPos().getY() == 64) {
+					state.set(Blocks.GOLD_BLOCK.getDefaultState());
+					return ActionResult.SUCCESS;
+				}
+
+				return ActionResult.PASS;
+			});
+		}
+	}
+}

src/test/java/io/github/fabriccommunity/events/test/client/ClientPlayerInteractionTest.java

@@ -9,7 +9,7 @@
  * @author leocth
  */
 public class ClientPlayerInteractionTest implements ClientModInitializer {
-    public static final boolean ENABLED = true;
+    public static final boolean ENABLED = false;
 
     @Override
     public void onInitializeClient() {

src/test/resources/fabric.mod.json

@@ -16,6 +16,7 @@
   "entrypoints": {
     "main": [
       "io.github.fabriccommunity.events.test.BiomePlacementTest",
+      "io.github.fabriccommunity.events.test.BlockPlaceTest",
       "io.github.fabriccommunity.events.test.FoodTest",
       "io.github.fabriccommunity.events.test.EntitySpawnTest",
       "io.github.fabriccommunity.events.test.PlayerInteractionTest"