feat: middle mouse to select blocks in build mode

src/main/java/com/lovetropics/gamemodebuild/ItemFilter.java

@@ -1,5 +1,6 @@
 package com.lovetropics.gamemodebuild;
 
+import it.unimi.dsi.fastutil.objects.ObjectOpenCustomHashSet;
 import net.minecraft.Util;
 import net.minecraft.core.HolderLookup;
 import net.minecraft.core.RegistryAccess;
@@ -66,17 +67,27 @@ private static Predicate<Item> parsePredicate(String predicate) {
 	private final List<Predicate<Item>> whitelistPredicates;
 	private final List<Predicate<Item>> blacklistPredicates;
 	private final SingleKeyCache<Key, List<ItemStack>> cache;
+	private final SingleKeyCache<Key, Predicate<ItemStack>> predicateCache;
 
 	private ItemFilter(List<Predicate<Item>> whitelist, List<Predicate<Item>> blacklist) {
 		this.whitelistPredicates = new ArrayList<>(whitelist);
 		this.blacklistPredicates = new ArrayList<>(blacklist);
 		cache = Util.singleKeyCache(key -> computeStacks(key.featureFlags(), key.registryAccess()));
+		predicateCache = Util.singleKeyCache(key -> {
+			List<ItemStack> stacks = cache.getValue(key);
+			Set<ItemStack> set = new ObjectOpenCustomHashSet<>(stacks, ItemStackLinkedSet.TYPE_AND_TAG);
+			return set::contains;
+		});
 	}
-	
+
 	public List<ItemStack> getAllStacks(FeatureFlagSet enabledFeatures, RegistryAccess registryAccess) {
 		return cache.getValue(new Key(enabledFeatures, registryAccess));
 	}
 
+	public Predicate<ItemStack> getStackPredicate(FeatureFlagSet enabledFeatures, RegistryAccess registryAccess) {
+		return predicateCache.getValue(new Key(enabledFeatures, registryAccess));
+	}
+
 	private List<ItemStack> computeStacks(FeatureFlagSet enabledFeatures, HolderLookup.Provider registryAccess) {
 		if (whitelistPredicates.isEmpty()) {
 			return List.of();

src/main/java/com/lovetropics/gamemodebuild/client/GBClient.java

@@ -2,16 +2,38 @@
 
 import com.lovetropics.gamemodebuild.GamemodeBuild;
 import com.lovetropics.gamemodebuild.container.BuildContainer;
+import com.lovetropics.gamemodebuild.message.SetGamemodeBuildSlotPacket;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.player.LocalPlayer;
+import net.minecraft.world.phys.BlockHitResult;
+import net.minecraft.world.phys.HitResult;
 import net.neoforged.api.distmarker.Dist;
 import net.neoforged.bus.api.IEventBus;
+import net.neoforged.bus.api.SubscribeEvent;
+import net.neoforged.fml.common.EventBusSubscriber;
 import net.neoforged.fml.common.Mod;
+import net.neoforged.neoforge.client.event.InputEvent;
 import net.neoforged.neoforge.client.event.RegisterMenuScreensEvent;
 
 @Mod(value = GamemodeBuild.MODID, dist = Dist.CLIENT)
+@EventBusSubscriber(modid = GamemodeBuild.MODID, value = Dist.CLIENT)
 public class GBClient {
     public GBClient(IEventBus bus) {
         bus.addListener((final RegisterMenuScreensEvent event) -> {
             event.register(BuildContainer.TYPE.get(), BuildScreen::new);
         });
     }
+
+    @SubscribeEvent
+    public static void onInputTriggered(InputEvent.InteractionKeyMappingTriggered event) {
+        Minecraft minecraft = Minecraft.getInstance();
+        LocalPlayer player = minecraft.player;
+        if (event.isPickBlock() && player != null && GamemodeBuild.isActive(player)) {
+            event.setCanceled(true);
+            HitResult hitResult = minecraft.hitResult;
+            if (hitResult != null && hitResult.getType() == HitResult.Type.BLOCK) {
+                player.connection.send(new SetGamemodeBuildSlotPacket(((BlockHitResult) hitResult).getBlockPos()));
+            }
+        }
+    }
 }

src/main/java/com/lovetropics/gamemodebuild/command/GamemodeBuildCommand.java

@@ -30,6 +30,7 @@
 
 import javax.annotation.Nullable;
 import java.util.Collection;
+import java.util.Optional;
 
 import static net.minecraft.commands.Commands.argument;
 import static net.minecraft.commands.Commands.literal;
@@ -136,7 +137,7 @@ private static Command<CommandSourceStack> getListAddCommand(boolean whitelist)
 			} else {
 				GBConfigs.SERVER.addToBlacklist(name, entry, true);
 			}
-			PacketDistributor.sendToAllPlayers(new ListUpdateMessage(ListUpdateMessage.Operation.ADD, whitelist, name, entry));
+			PacketDistributor.sendToAllPlayers(new ListUpdateMessage(ListUpdateMessage.Operation.ADD, whitelist, name, Optional.of(entry)));
 			ctx.getSource().sendSuccess(() -> Component.literal("Added '" + entry + "' to " + name + (whitelist ? " whitelist" : " blacklist")), false);
 
 			return Command.SINGLE_SUCCESS;
@@ -152,7 +153,7 @@ private static Command<CommandSourceStack> getListRemoveCommand(boolean whitelis
 			boolean found = whitelist ? GBConfigs.SERVER.removeFromWhitelist(name, entry, true) : GBConfigs.SERVER.removeFromBlacklist(name, entry, true);
 			if (!found) throw FILTER_DID_NOT_EXIST.create();
 
-			PacketDistributor.sendToAllPlayers(new ListUpdateMessage(ListUpdateMessage.Operation.REMOVE, whitelist, name, entry));
+			PacketDistributor.sendToAllPlayers(new ListUpdateMessage(ListUpdateMessage.Operation.REMOVE, whitelist, name, Optional.of(entry)));
 			ctx.getSource().sendSuccess(() -> Component.literal("Removed '" + entry + "' from " + name + (whitelist ? " whitelist" : " blacklist")), false);
 
 			return Command.SINGLE_SUCCESS;

src/main/java/com/lovetropics/gamemodebuild/message/GBNetwork.java

@@ -22,6 +22,11 @@ public static void register(RegisterPayloadHandlersEvent event) {
 				UpdateFilterMessage.CODEC,
 				UpdateFilterMessage::handle
 		);
+		registrar.playToServer(
+				SetGamemodeBuildSlotPacket.TYPE,
+				SetGamemodeBuildSlotPacket.CODEC,
+				SetGamemodeBuildSlotPacket::handle
+		);
 
 		registrar.playBidirectional(
 				SetActiveMessage.TYPE,

src/main/java/com/lovetropics/gamemodebuild/message/ListUpdateMessage.java

@@ -8,21 +8,20 @@
 import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 import net.neoforged.neoforge.network.handling.IPayloadContext;
 
-public record ListUpdateMessage(Operation operation, boolean whitelist, String name, String entry) implements CustomPacketPayload {
+import java.util.Optional;
+
+public record ListUpdateMessage(Operation operation, boolean whitelist, String name, Optional<String> entry) implements CustomPacketPayload {
 	public static final Type<ListUpdateMessage> TYPE = new Type<>(GamemodeBuild.rl("update_list"));
 	public static final StreamCodec<RegistryFriendlyByteBuf, ListUpdateMessage> CODEC = StreamCodec.composite(
-			ByteBufCodecs.idMapper(i -> Operation.values()[i], Operation::ordinal),
-			ListUpdateMessage::operation,
-			ByteBufCodecs.BOOL,
-			ListUpdateMessage::whitelist,
-			ByteBufCodecs.STRING_UTF8,
-			ListUpdateMessage::name,
-			ByteBufCodecs.STRING_UTF8,
-			ListUpdateMessage::entry,
+			ByteBufCodecs.idMapper(i -> Operation.values()[i], Operation::ordinal), ListUpdateMessage::operation,
+			ByteBufCodecs.BOOL, ListUpdateMessage::whitelist,
+			ByteBufCodecs.STRING_UTF8, ListUpdateMessage::name,
+			ByteBufCodecs.STRING_UTF8.apply(ByteBufCodecs::optional), ListUpdateMessage::entry,
 			ListUpdateMessage::new
 	);
 
 	public void handle(IPayloadContext context) {
+		String entry = this.entry.orElse("");
 		switch (operation) {
 			case ADD -> {
 				if (whitelist) {

src/main/java/com/lovetropics/gamemodebuild/message/SetGamemodeBuildSlotPacket.java

@@ -0,0 +1,101 @@
+package com.lovetropics.gamemodebuild.message;
+
+import com.lovetropics.gamemodebuild.GBConfigs;
+import com.lovetropics.gamemodebuild.GamemodeBuild;
+import com.lovetropics.gamemodebuild.container.GBStackMarker;
+import com.lovetropics.gamemodebuild.state.GBPlayerStore;
+import com.lovetropics.gamemodebuild.state.GBServerState;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
+import net.minecraft.network.protocol.game.ClientboundSetCarriedItemPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.flag.FeatureFlagSet;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.phys.BlockHitResult;
+import net.minecraft.world.phys.Vec3;
+import net.neoforged.neoforge.network.handling.IPayloadContext;
+
+import java.util.function.Predicate;
+
+// TODO: Won't need a custom packet in 1.21.4+ - it's server-authoritative
+public record SetGamemodeBuildSlotPacket(BlockPos blockPos) implements CustomPacketPayload {
+    public static final Type<SetGamemodeBuildSlotPacket> TYPE = new Type<>(GamemodeBuild.rl("pick_block"));
+
+    public static final StreamCodec<RegistryFriendlyByteBuf, SetGamemodeBuildSlotPacket> CODEC = StreamCodec.composite(
+            BlockPos.STREAM_CODEC, SetGamemodeBuildSlotPacket::blockPos,
+            SetGamemodeBuildSlotPacket::new
+    );
+
+    public static void handle(SetGamemodeBuildSlotPacket packet, IPayloadContext ctx) {
+        if (!(ctx.player() instanceof ServerPlayer player) || !GBServerState.isActiveFor(player)) {
+            return;
+        }
+
+        BlockPos blockPos = packet.blockPos;
+        if (!player.canInteractWithBlock(blockPos, ServerPlayer.INTERACTION_DISTANCE_VERIFICATION_BUFFER)) {
+            return;
+        }
+
+        BlockState blockState = player.level().getBlockState(blockPos);
+
+        // Just fake it, it's not important
+        BlockHitResult hitResult = new BlockHitResult(Vec3.atCenterOf(blockPos), Direction.UP, blockPos, false);
+        ItemStack itemStack = blockState.getCloneItemStack(hitResult, player.level(), blockPos, player);
+        if (itemStack.isEmpty()) {
+            return;
+        }
+
+        FeatureFlagSet enabledFeatures = player.level().enabledFeatures();
+        RegistryAccess registryAccess = player.level().registryAccess();
+        Predicate<ItemStack> predicate = GBConfigs.SERVER.getFilter(GBPlayerStore.getList(player)).getStackPredicate(enabledFeatures, registryAccess);
+        if (!predicate.test(itemStack)) {
+            return;
+        }
+
+        GBStackMarker.mark(itemStack);
+
+        pickItem(player, itemStack);
+    }
+
+    private static void pickItem(ServerPlayer player, ItemStack itemStack) {
+        Inventory inventory = player.getInventory();
+        int slotWithItem = inventory.findSlotMatchingItem(itemStack);
+        if (slotWithItem == Inventory.NOT_FOUND_INDEX) {
+            pickFreshItem(inventory, itemStack);
+        } else {
+            pickExistingItem(inventory, slotWithItem);
+        }
+        player.connection.send(new ClientboundSetCarriedItemPacket(inventory.selected));
+        player.inventoryMenu.broadcastChanges();
+    }
+
+    private static void pickExistingItem(Inventory inventory, int slot) {
+        if (Inventory.isHotbarSlot(slot)) {
+            inventory.selected = slot;
+        } else {
+            inventory.pickSlot(slot);
+        }
+    }
+
+    private static void pickFreshItem(Inventory inventory, ItemStack itemStack) {
+        inventory.selected = inventory.getSuitableHotbarSlot();
+        if (!inventory.getItem(inventory.selected).isEmpty()) {
+            int freeSlot = inventory.getFreeSlot();
+            if (freeSlot != Inventory.NOT_FOUND_INDEX) {
+                inventory.setItem(freeSlot, inventory.getItem(inventory.selected));
+            }
+        }
+        inventory.setItem(inventory.selected, itemStack);
+    }
+
+    @Override
+    public Type<SetGamemodeBuildSlotPacket> type() {
+        return TYPE;
+    }
+}

src/main/resources/gamemodebuild.mixins.json

@@ -8,5 +8,7 @@
   "injectors": {
     "defaultRequire": 1
   },
-  "minVersion": "0.8"
+  "minVersion": "0.8",
+  "client": [
+  ]
 }