Some basic fixes, will work on this some other time.

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -23,10 +23,10 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.world.BlockView;
 import net.minecraft.world.World;
-import net.minecraftforge.common.util.LazyOptional;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Optional;
 
 /**
  * The static entry point to the ComputerCraft API.
@@ -218,7 +218,7 @@ public final class ComputerCraftAPI
      * @see IWiredElement#getNode()
      */
     @Nonnull
-    public static LazyOptional<IWiredElement> getWiredElementAt( @Nonnull BlockView world, @Nonnull BlockPos pos, @Nonnull Direction side )
+    public static Optional<IWiredElement> getWiredElementAt(@Nonnull BlockView world, @Nonnull BlockPos pos, @Nonnull Direction side )
     {
         return getInstance().getWiredElementAt( world, pos, side );
     }
@@ -275,6 +275,6 @@ public final class ComputerCraftAPI
         IWiredNode createWiredNodeForElement( @Nonnull IWiredElement element );
 
         @Nonnull
-        LazyOptional<IWiredElement> getWiredElementAt( @Nonnull BlockView world, @Nonnull BlockPos pos, @Nonnull Direction side );
+        Optional<IWiredElement> getWiredElementAt( @Nonnull BlockView world, @Nonnull BlockPos pos, @Nonnull Direction side );
     }
 }

src/main/java/dan200/computercraft/api/peripheral/IPeripheral.java

@@ -6,7 +6,6 @@
 package dan200.computercraft.api.peripheral;
 
 import dan200.computercraft.api.lua.LuaFunction;
-import net.minecraftforge.common.capabilities.Capability;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -14,8 +13,8 @@ import javax.annotation.Nullable;
 /**
  * The interface that defines a peripheral.
  *
- * In order to expose a peripheral for your block or tile entity, you may either attach a {@link Capability}, or
- * register a {@link IPeripheralProvider}. This <em>cannot</em> be implemented {@link IPeripheral} directly on the tile.
+ * In order to expose a peripheral for your block or tile entity, you register a {@link IPeripheralProvider}.
+ * This <em>cannot</em> be implemented {@link IPeripheral} directly on the tile.
  *
  * Peripherals should provide a series of methods to the user, either using {@link LuaFunction} or by implementing
  * {@link IDynamicPeripheral}.

src/main/java/dan200/computercraft/api/peripheral/IPeripheralProvider.java

@@ -5,17 +5,18 @@
  */
 package dan200.computercraft.api.peripheral;
 
+import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.world.World;
-import net.minecraftforge.common.util.LazyOptional;
 
 import javax.annotation.Nonnull;
+import java.util.Optional;
 
 /**
  * This interface is used to create peripheral implementations for blocks.
  *
- * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively expose the {@link IPeripheral}
+ * If you have a {@link BlockEntity} which acts as a peripheral, you may alternatively expose the {@link IPeripheral}
  * capability.
  *
  * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
@@ -29,9 +30,9 @@ public interface IPeripheralProvider
      * @param world The world the block is in.
      * @param pos   The position the block is at.
      * @param side  The side to get the peripheral from.
-     * @return A peripheral, or {@link LazyOptional#empty()} if there is not a peripheral here you'd like to handle.
+     * @return A peripheral, or {@link Optional#empty()} if there is not a peripheral here you'd like to handle.
      * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
      */
     @Nonnull
-    LazyOptional<IPeripheral> getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
+    Optional<IPeripheral> getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
 }

src/main/java/dan200/computercraft/api/pocket/AbstractPocketUpgrade.java

@@ -10,7 +10,6 @@ import net.minecraft.item.ItemConvertible;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.Util;
-import net.minecraftforge.common.util.NonNullSupplier;
 
 import javax.annotation.Nonnull;
 import java.util.function.Supplier;
@@ -24,49 +23,27 @@ public abstract class AbstractPocketUpgrade implements IPocketUpgrade
 {
     private final Identifier id;
     private final String adjective;
-    private final NonNullSupplier<ItemStack> stack;
+    private final ItemStack stack;
 
-    protected AbstractPocketUpgrade( Identifier id, String adjective, NonNullSupplier<ItemStack> stack )
+    protected AbstractPocketUpgrade( Identifier id, String adjective, ItemConvertible item )
     {
         this.id = id;
         this.adjective = adjective;
-        this.stack = stack;
+        this.stack = new ItemStack(item);
     }
 
-    protected AbstractPocketUpgrade( Identifier id, NonNullSupplier<ItemStack> item )
+    protected AbstractPocketUpgrade( Identifier id, ItemConvertible item )
     {
         this( id, Util.createTranslationKey( "upgrade", id ) + ".adjective", item );
     }
 
     protected AbstractPocketUpgrade( Identifier id, String adjective, ItemStack stack )
     {
-        this( id, adjective, () -> stack );
+        this.id = id;
+        this.adjective = adjective;
+        this.stack = stack;
     }
 
-    protected AbstractPocketUpgrade( Identifier id, ItemStack stack )
-    {
-        this( id, () -> stack );
-    }
-
-    protected AbstractPocketUpgrade( Identifier id, String adjective, ItemConvertible item )
-    {
-        this( id, adjective, new CachedStack( () -> item ) );
-    }
-
-    protected AbstractPocketUpgrade( Identifier id, ItemConvertible item )
-    {
-        this( id, new CachedStack( () -> item ) );
-    }
-
-    protected AbstractPocketUpgrade( Identifier id, String adjective, Supplier<? extends ItemConvertible> item )
-    {
-        this( id, adjective, new CachedStack( item ) );
-    }
-
-    protected AbstractPocketUpgrade( Identifier id, Supplier<? extends ItemConvertible> item )
-    {
-        this( id, new CachedStack( item ) );
-    }
 
     @Nonnull
     @Override
@@ -86,32 +63,6 @@ public abstract class AbstractPocketUpgrade implements IPocketUpgrade
     @Override
     public final ItemStack getCraftingItem()
     {
-        return stack.get();
-    }
-
-    /**
-     * Caches the construction of an item stack.
-     *
-     * @see dan200.computercraft.api.turtle.AbstractTurtleUpgrade For explanation of this class.
-     */
-    private static final class CachedStack implements NonNullSupplier<ItemStack>
-    {
-        private final Supplier<? extends ItemConvertible> provider;
-        private Item item;
-        private ItemStack stack;
-
-        CachedStack( Supplier<? extends ItemConvertible> provider )
-        {
-            this.provider = provider;
-        }
-
-        @Nonnull
-        @Override
-        public ItemStack get()
-        {
-            Item item = provider.get().asItem();
-            if( item == this.item && stack != null ) return stack;
-            return stack = new ItemStack( this.item = item );
-        }
+        return stack;
     }
 }

src/main/java/dan200/computercraft/api/turtle/AbstractTurtleUpgrade.java

@@ -10,7 +10,6 @@ import net.minecraft.item.ItemConvertible;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.Util;
-import net.minecraftforge.common.util.NonNullSupplier;
 
 import javax.annotation.Nonnull;
 import java.util.function.Supplier;
@@ -25,50 +24,27 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
     private final Identifier id;
     private final TurtleUpgradeType type;
     private final String adjective;
-    private final NonNullSupplier<ItemStack> stack;
+    private final ItemStack stack;
 
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, String adjective, NonNullSupplier<ItemStack> stack )
-    {
+    protected AbstractTurtleUpgrade(Identifier id, TurtleUpgradeType type, String adjective, ItemConvertible item) {
+        this(id, type, adjective, new ItemStack(item));
+    }
+
+    protected AbstractTurtleUpgrade(Identifier id, TurtleUpgradeType type, String adjective, ItemStack stack) {
         this.id = id;
         this.type = type;
         this.adjective = adjective;
         this.stack = stack;
     }
 
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, NonNullSupplier<ItemStack> stack )
-    {
-        this( id, type, Util.createTranslationKey( "upgrade", id ) + ".adjective", stack );
+    protected AbstractTurtleUpgrade(Identifier id, TurtleUpgradeType type, ItemConvertible item) {
+        this(id, type, new ItemStack(item));
     }
 
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, String adjective, ItemStack stack )
-    {
-        this( id, type, adjective, () -> stack );
+    protected AbstractTurtleUpgrade(Identifier id, TurtleUpgradeType type, ItemStack stack) {
+        this(id, type, Util.createTranslationKey("upgrade", id) + ".adjective", stack);
     }
 
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, ItemStack stack )
-    {
-        this( id, type, () -> stack );
-    }
-
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, String adjective, ItemConvertible item )
-    {
-        this( id, type, adjective, new CachedStack( () -> item ) );
-    }
-
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, ItemConvertible item )
-    {
-        this( id, type, new CachedStack( () -> item ) );
-    }
-
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, String adjective, Supplier<? extends ItemConvertible> item )
-    {
-        this( id, type, adjective, new CachedStack( item ) );
-    }
-
-    protected AbstractTurtleUpgrade( Identifier id, TurtleUpgradeType type, Supplier<? extends ItemConvertible> item )
-    {
-        this( id, type, new CachedStack( item ) );
-    }
 
     @Nonnull
     @Override
@@ -95,32 +71,6 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
     @Override
     public final ItemStack getCraftingItem()
     {
-        return stack.get();
-    }
-
-    /**
-     * A supplier which converts an item into an item stack.
-     *
-     * Constructing item stacks is somewhat expensive due to attaching capabilities. We cache it if given a consistent item.
-     */
-    private static final class CachedStack implements NonNullSupplier<ItemStack>
-    {
-        private final Supplier<? extends ItemConvertible> provider;
-        private Item item;
-        private ItemStack stack;
-
-        CachedStack( Supplier<? extends ItemConvertible> provider )
-        {
-            this.provider = provider;
-        }
-
-        @Nonnull
-        @Override
-        public ItemStack get()
-        {
-            Item item = provider.get().asItem();
-            if( item == this.item && stack != null ) return stack;
-            return stack = new ItemStack( this.item = item );
-        }
+        return stack;
     }
 }

src/main/java/dan200/computercraft/api/turtle/FakePlayer.java

@@ -0,0 +1,267 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2018. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.api.turtle;
+
+import java.util.Collection;
+import java.util.OptionalInt;
+import java.util.UUID;
+
+import javax.annotation.Nullable;
+import javax.crypto.SecretKey;
+
+import com.mojang.authlib.GameProfile;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.util.concurrent.Future;
+import io.netty.util.concurrent.GenericFutureListener;
+
+import net.minecraft.block.entity.CommandBlockBlockEntity;
+import net.minecraft.block.entity.SignBlockEntity;
+import net.minecraft.command.argument.EntityAnchorArgumentType;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.damage.DamageSource;
+import net.minecraft.entity.effect.StatusEffectInstance;
+import net.minecraft.entity.passive.HorseBaseEntity;
+import net.minecraft.inventory.Inventory;
+import net.minecraft.item.ItemStack;
+import net.minecraft.network.ClientConnection;
+import net.minecraft.network.MessageType;
+import net.minecraft.network.NetworkSide;
+import net.minecraft.network.NetworkState;
+import net.minecraft.network.Packet;
+import net.minecraft.network.packet.c2s.play.RequestCommandCompletionsC2SPacket;
+import net.minecraft.network.packet.c2s.play.VehicleMoveC2SPacket;
+import net.minecraft.recipe.Recipe;
+import net.minecraft.screen.NamedScreenHandlerFactory;
+import net.minecraft.screen.ScreenHandler;
+import net.minecraft.server.network.ServerPlayNetworkHandler;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.server.network.ServerPlayerInteractionManager;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.sound.SoundCategory;
+import net.minecraft.sound.SoundEvent;
+import net.minecraft.text.Text;
+import net.minecraft.util.Hand;
+import net.minecraft.util.collection.DefaultedList;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.village.TraderOfferList;
+import net.minecraft.world.GameMode;
+import net.minecraft.world.dimension.DimensionType;
+
+/**
+ * A wrapper for {@link ServerPlayerEntity} which denotes a "fake" player.
+ *
+ * Please note that this does not implement any of the traditional fake player behaviour. It simply exists to prevent me passing in normal players.
+ */
+public class FakePlayer extends ServerPlayerEntity {
+    public FakePlayer(ServerWorld world, GameProfile gameProfile) {
+        super(world.getServer(), world, gameProfile, new ServerPlayerInteractionManager(world));
+        this.networkHandler = new FakeNetHandler(this);
+    }
+
+    // region Direct networkHandler access
+    @Override
+    public void enterCombat() { }
+
+    @Override
+    public void endCombat() { }
+
+    @Override
+    public void tick() { }
+
+    @Override
+    public void playerTick() { }
+
+    @Override
+    public void onDeath(DamageSource damage) { }
+
+    @Override
+    public boolean startRiding(Entity entity, boolean flag) {
+        return false;
+    }
+
+    @Override
+    public void stopRiding() { }
+
+    @Override
+    public void openEditSignScreen(SignBlockEntity tile) { }
+
+    @Override
+    public OptionalInt openHandledScreen(@Nullable NamedScreenHandlerFactory container) {
+        return OptionalInt.empty();
+    }
+
+    @Override
+    public void sendTradeOffers(int id, TraderOfferList list, int level, int experience, boolean levelled, boolean refreshable) { }
+
+    @Override
+    public void openHorseInventory(HorseBaseEntity horse, Inventory inventory) { }
+
+    @Override
+    public void openEditBookScreen(ItemStack stack, Hand hand) { }
+
+    @Override
+    public void openCommandBlockScreen(CommandBlockBlockEntity block) { }
+
+    @Override
+    public void onSlotUpdate(ScreenHandler container, int slot, ItemStack stack) { }
+
+    @Override
+    public void onHandlerRegistered(ScreenHandler container, DefaultedList<ItemStack> defaultedList) { }
+
+    @Override
+    public void onPropertyUpdate(ScreenHandler container, int key, int value) { }
+
+    @Override
+    public void closeHandledScreen() { }
+
+    @Override
+    public void updateCursorStack() { }
+
+    @Override
+    public int unlockRecipes(Collection<Recipe<?>> recipes) {
+        return 0;
+    }
+
+    // Indirect
+    @Override
+    public int lockRecipes(Collection<Recipe<?>> recipes) {
+        return 0;
+    }
+
+    @Override
+    public void sendMessage(Text textComponent, boolean status) { }
+
+    @Override
+    protected void consumeItem() { }
+
+    @Override
+    public void lookAt(EntityAnchorArgumentType.EntityAnchor anchor, Vec3d vec3d) {}
+
+    @Override
+    public void method_14222(EntityAnchorArgumentType.EntityAnchor self, Entity entity, EntityAnchorArgumentType.EntityAnchor target) { }
+
+    @Override
+    protected void onStatusEffectApplied(StatusEffectInstance statusEffectInstance) { }
+
+    @Override
+    protected void onStatusEffectUpgraded(StatusEffectInstance statusEffectInstance, boolean particles) { }
+
+    @Override
+    protected void onStatusEffectRemoved(StatusEffectInstance statusEffectInstance) { }
+
+    @Override
+    public void requestTeleport(double x, double y, double z) { }
+
+    @Override
+    public void setGameMode(GameMode gameMode) { }
+
+    @Override
+    public String getIp() {
+        return "[Fake Player]";
+    }
+
+    @Override
+    public void sendResourcePackUrl(String url, String hash) { }
+
+    @Override
+    public void onStoppedTracking(Entity entity) { }
+
+    @Override
+    public void setCameraEntity(Entity entity) { }
+
+    @Override
+    public void teleport(ServerWorld serverWorld, double x, double y, double z, float pitch, float yaw) { }
+
+    @Override
+    public void sendInitialChunkPackets(ChunkPos chunkPos, Packet<?> packet, Packet<?> packet2) { }
+
+    @Override
+    public void sendUnloadChunkPacket(ChunkPos chunkPos) { }
+
+    @Override
+    public void playSound(SoundEvent soundEvent, SoundCategory soundCategory, float volume, float pitch) { }
+
+    @Override
+    public Entity moveToWorld(ServerWorld destination) {
+        return this;
+    }
+
+    @Override
+    public void wakeUp(boolean bl, boolean updateSleepingPlayers) {
+
+    }
+
+    @Override
+    public void sendMessage(Text message, MessageType type, UUID senderUuid) {
+
+    }
+
+    private static class FakeNetHandler extends ServerPlayNetworkHandler {
+        FakeNetHandler(ServerPlayerEntity player) {
+            super(player.server, new FakeConnection(), player);
+        }
+
+        @Override
+        public void disconnect(Text message) { }
+
+        @Override
+        public void onVehicleMove(VehicleMoveC2SPacket move) { }
+
+        @Override
+        public void onRequestCommandCompletions(RequestCommandCompletionsC2SPacket packet) { }
+
+        @Override
+        public void sendPacket(Packet<?> packet, @Nullable GenericFutureListener<? extends Future<? super Void>> listener) { }
+    }
+
+    private static class FakeConnection extends ClientConnection {
+        FakeConnection() {
+            super(NetworkSide.CLIENTBOUND);
+        }
+
+        @Override
+        public void channelActive(ChannelHandlerContext active) {
+        }
+
+        @Override
+        public void setState(NetworkState state) {
+        }
+
+        @Override
+        public void exceptionCaught(ChannelHandlerContext context, Throwable err) {
+        }
+
+        @Override
+        protected void channelRead0(ChannelHandlerContext context, Packet<?> packet) {
+        }
+
+        @Override
+        public void send(Packet<?> packet, @Nullable GenericFutureListener<? extends Future<? super Void>> listener) {
+        }
+
+        @Override
+        public void tick() {
+        }
+
+        @Override
+        public void disconnect(Text message) {
+        }
+
+        @Override
+        public void setupEncryption(SecretKey key) {
+        }
+
+        @Override
+        public void disableAutoRead() {
+        }
+
+        @Override
+        public void setCompressionThreshold(int size) {
+        }
+    }
+}

src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -15,7 +15,6 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
-import net.minecraftforge.items.IItemHandlerModifiable;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -148,24 +147,10 @@ public interface ITurtleAccess
      * Note: this inventory should only be accessed and modified on the server thread.
      *
      * @return This turtle's inventory
-     * @see #getItemHandler()
      */
     @Nonnull
     Inventory getInventory();
 
-    /**
-     * Get the inventory of this turtle as an {@link IItemHandlerModifiable}.
-     *
-     * Note: this inventory should only be accessed and modified on the server thread.
-     *
-     * @return This turtle's inventory
-     * @see #getInventory()
-     * @see IItemHandlerModifiable
-     * @see net.minecraftforge.items.CapabilityItemHandler#ITEM_HANDLER_CAPABILITY
-     */
-    @Nonnull
-    IItemHandlerModifiable getItemHandler();
-
     /**
      * Determine whether this turtle will require fuel when performing actions.
      *

src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -8,17 +8,11 @@ package dan200.computercraft.api.turtle;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.api.turtle.event.TurtleAttackEvent;
-import dan200.computercraft.api.turtle.event.TurtleBlockEvent;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.math.Direction;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.api.distmarker.OnlyIn;
-import net.minecraftforge.event.entity.player.AttackEntityEvent;
-import net.minecraftforge.event.world.BlockEvent;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -96,9 +90,6 @@ public interface ITurtleUpgrade
      * Will only be called for Tool turtle. Called when turtle.dig() or turtle.attack() is called
      * by the turtle, and the tool is required to do some work.
      *
-     * Conforming implementations should fire {@link BlockEvent.BreakEvent} and {@link TurtleBlockEvent.Dig} for
-     * digging, {@link AttackEntityEvent} and {@link TurtleAttackEvent} for attacking.
-     *
      * @param turtle    Access to the turtle that the tool resides on.
      * @param side      Which side of the turtle (left or right) the tool resides on.
      * @param verb      Which action (dig or attack) the turtle is being called on to perform.
@@ -119,10 +110,6 @@ public interface ITurtleUpgrade
     /**
      * Called to obtain the model to be used when rendering a turtle peripheral.
      *
-     * This can be obtained from {@link net.minecraft.client.renderer.ItemModelMesher#getItemModel(ItemStack)},
-     * {@link net.minecraft.client.renderer.model.ModelManager#getModel(ModelResourceLocation)} or any other
-     * source.
-     *
      * @param turtle Access to the turtle that the upgrade resides on. This will be null when getting item models!
      * @param side   Which side of the turtle (left or right) the upgrade resides on.
      * @return The model that you wish to be used to render your upgrade.

src/main/java/dan200/computercraft/api/turtle/event/TurtleActionEvent.java

@@ -7,7 +7,6 @@ package dan200.computercraft.api.turtle.event;
 
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
-import net.minecraftforge.eventbus.api.Cancelable;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -16,11 +15,11 @@ import java.util.Objects;
 /**
  * An event fired when a turtle is performing a known action.
  */
-@Cancelable
 public class TurtleActionEvent extends TurtleEvent
 {
     private final TurtleAction action;
     private String failureMessage;
+    private boolean cancelled = false;
 
     public TurtleActionEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleAction action )
     {
@@ -44,7 +43,6 @@ public class TurtleActionEvent extends TurtleEvent
      * @see TurtleCommandResult#failure()
      * @deprecated Use {@link #setCanceled(boolean, String)} instead.
      */
-    @Override
     @Deprecated
     public void setCanceled( boolean cancel )
     {
@@ -62,7 +60,7 @@ public class TurtleActionEvent extends TurtleEvent
      */
     public void setCanceled( boolean cancel, @Nullable String failureMessage )
     {
-        super.setCanceled( cancel );
+        this.cancelled = true;
         this.failureMessage = cancel ? failureMessage : null;
     }
 
@@ -78,4 +76,8 @@ public class TurtleActionEvent extends TurtleEvent
     {
         return failureMessage;
     }
+
+    public boolean isCancelled() {
+        return cancelled;
+    }
 }

src/main/java/dan200/computercraft/api/turtle/event/TurtleAttackEvent.java

@@ -5,13 +5,8 @@
  */
 package dan200.computercraft.api.turtle.event;
 
-import dan200.computercraft.api.turtle.ITurtleAccess;
-import dan200.computercraft.api.turtle.ITurtleUpgrade;
-import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.api.turtle.TurtleVerb;
+import dan200.computercraft.api.turtle.*;
 import net.minecraft.entity.Entity;
-import net.minecraftforge.common.util.FakePlayer;
-import net.minecraftforge.event.entity.player.AttackEntityEvent;
 
 import javax.annotation.Nonnull;
 import java.util.Objects;
@@ -19,11 +14,6 @@ import java.util.Objects;
 /**
  * Fired when a turtle attempts to attack an entity.
  *
- * This must be fired by {@link ITurtleUpgrade#useTool(ITurtleAccess, TurtleSide, TurtleVerb, Direction)},
- * as the base {@code turtle.attack()} command does not fire it.
- *
- * Note that such commands should also fire {@link AttackEntityEvent}, so you do not need to listen to both.
- *
  * @see TurtleAction#ATTACK
  */
 public class TurtleAttackEvent extends TurtlePlayerEvent
@@ -32,7 +22,7 @@ public class TurtleAttackEvent extends TurtlePlayerEvent
     private final ITurtleUpgrade upgrade;
     private final TurtleSide side;
 
-    public TurtleAttackEvent( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull Entity target, @Nonnull ITurtleUpgrade upgrade, @Nonnull TurtleSide side )
+    public TurtleAttackEvent(@Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull Entity target, @Nonnull ITurtleUpgrade upgrade, @Nonnull TurtleSide side )
     {
         super( turtle, TurtleAction.ATTACK, player );
         Objects.requireNonNull( target, "target cannot be null" );

src/main/java/dan200/computercraft/api/turtle/event/TurtleBlockEvent.java

@@ -6,16 +6,11 @@
 package dan200.computercraft.api.turtle.event;
 
 import dan200.computercraft.api.lua.MethodResult;
-import dan200.computercraft.api.turtle.ITurtleAccess;
-import dan200.computercraft.api.turtle.ITurtleUpgrade;
-import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.api.turtle.TurtleVerb;
+import dan200.computercraft.api.turtle.*;
 import net.minecraft.block.BlockState;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
-import net.minecraftforge.common.util.FakePlayer;
-import net.minecraftforge.event.world.BlockEvent;
 
 import javax.annotation.Nonnull;
 import java.util.Map;
@@ -38,7 +33,7 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
     private final World world;
     private final BlockPos pos;
 
-    protected TurtleBlockEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleAction action, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos )
+    protected TurtleBlockEvent(@Nonnull ITurtleAccess turtle, @Nonnull TurtleAction action, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos )
     {
         super( turtle, action, player );
 
@@ -72,11 +67,6 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
     /**
      * Fired when a turtle attempts to dig a block.
      *
-     * This must be fired by {@link ITurtleUpgrade#useTool(ITurtleAccess, TurtleSide, TurtleVerb, Direction)},
-     * as the base {@code turtle.dig()} command does not fire it.
-     *
-     * Note that such commands should also fire {@link BlockEvent.BreakEvent}, so you do not need to listen to both.
-     *
      * @see TurtleAction#DIG
      */
     public static class Dig extends TurtleBlockEvent

src/main/java/dan200/computercraft/api/turtle/event/TurtleEvent.java

@@ -5,8 +5,8 @@
  */
 package dan200.computercraft.api.turtle.event;
 
+import com.google.common.eventbus.EventBus;
 import dan200.computercraft.api.turtle.ITurtleAccess;
-import net.minecraftforge.eventbus.api.Event;
 
 import javax.annotation.Nonnull;
 import java.util.Objects;
@@ -19,24 +19,30 @@ import java.util.Objects;
  *
  * @see TurtleActionEvent
  */
-public abstract class TurtleEvent extends Event
+public abstract class TurtleEvent
 {
+    public static final EventBus EVENT_BUS = new EventBus();
+
     private final ITurtleAccess turtle;
 
-    protected TurtleEvent( @Nonnull ITurtleAccess turtle )
-    {
-        Objects.requireNonNull( turtle, "turtle cannot be null" );
+    protected TurtleEvent(@Nonnull ITurtleAccess turtle) {
+        Objects.requireNonNull(turtle, "turtle cannot be null");
         this.turtle = turtle;
     }
 
+    public static boolean post(TurtleActionEvent event) {
+        EVENT_BUS.post(event);
+        return event.isCancelled();
+    }
+
     /**
      * Get the turtle which is performing this action.
      *
      * @return The access for this turtle.
      */
     @Nonnull
-    public ITurtleAccess getTurtle()
-    {
-        return turtle;
+    public ITurtleAccess getTurtle() {
+        return this.turtle;
     }
+
 }

src/main/java/dan200/computercraft/api/turtle/event/TurtleInventoryEvent.java

@@ -5,12 +5,12 @@
  */
 package dan200.computercraft.api.turtle.event;
 
+import dan200.computercraft.api.turtle.FakePlayer;
 import dan200.computercraft.api.turtle.ITurtleAccess;
+import net.minecraft.inventory.Inventory;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
-import net.minecraftforge.common.util.FakePlayer;
-import net.minecraftforge.items.IItemHandler;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -21,9 +21,9 @@ import java.util.Objects;
  */
 public abstract class TurtleInventoryEvent extends TurtleBlockEvent
 {
-    private final IItemHandler handler;
+    private final Inventory handler;
 
-    protected TurtleInventoryEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleAction action, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable IItemHandler handler )
+    protected TurtleInventoryEvent(@Nonnull ITurtleAccess turtle, @Nonnull TurtleAction action, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable Inventory handler )
     {
         super( turtle, action, player, world, pos );
         this.handler = handler;
@@ -35,7 +35,7 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
      * @return The inventory being interacted with, {@code null} if the item will be dropped to/sucked from the world.
      */
     @Nullable
-    public IItemHandler getItemHandler()
+    public Inventory getItemHandler()
     {
         return handler;
     }
@@ -47,7 +47,7 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
      */
     public static class Suck extends TurtleInventoryEvent
     {
-        public Suck( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable IItemHandler handler )
+        public Suck( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable Inventory handler )
         {
             super( turtle, TurtleAction.SUCK, player, world, pos, handler );
         }
@@ -62,7 +62,7 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
     {
         private final ItemStack stack;
 
-        public Drop( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable IItemHandler handler, @Nonnull ItemStack stack )
+        public Drop( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable Inventory handler, @Nonnull ItemStack stack )
         {
             super( turtle, TurtleAction.DROP, player, world, pos, handler );
 

src/main/java/dan200/computercraft/api/turtle/event/TurtlePlayerEvent.java

@@ -5,8 +5,8 @@
  */
 package dan200.computercraft.api.turtle.event;
 
+import dan200.computercraft.api.turtle.FakePlayer;
 import dan200.computercraft.api.turtle.ITurtleAccess;
-import net.minecraftforge.common.util.FakePlayer;
 
 import javax.annotation.Nonnull;
 import java.util.Objects;