Utilise @Mod.EventBusSubscriber a little more

This offers several advantages

 - Less registration code: the subscribers are reigstered automatically,
   and we don't need to worry about sided-proxies.
 - We no longer have so many .instance() calls.

src/main/java/dan200/computercraft/client/FrameInfo.java

@@ -6,43 +6,40 @@
 
 package dan200.computercraft.client;
 
+import dan200.computercraft.ComputerCraft;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
+import net.minecraftforge.fml.relauncher.Side;
 
-public class FrameInfo
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class FrameInfo
 {
-    private static final FrameInfo instance = new FrameInfo();
+    private static int tick;
-
+    private static long renderFrame;
-    public static FrameInfo instance()
-    {
-        return instance;
-    }
-
-    private int tick;
-    private long renderFrame;
 
     private FrameInfo()
     {
     }
 
-    public boolean getGlobalCursorBlink()
+    public static boolean getGlobalCursorBlink()
     {
         return (tick / 8) % 2 == 0;
     }
 
-    public long getRenderFrame()
+    public static long getRenderFrame()
     {
         return renderFrame;
     }
 
     @SubscribeEvent
-    public void onTick( TickEvent.ClientTickEvent event )
+    public static void onTick( TickEvent.ClientTickEvent event )
     {
         if( event.phase == TickEvent.Phase.START ) tick++;
     }
 
     @SubscribeEvent
-    public void onRenderTick( TickEvent.RenderTickEvent event )
+    public static void onRenderTick( TickEvent.RenderTickEvent event )
     {
         if( event.phase == TickEvent.Phase.START ) renderFrame++;
     }

src/main/java/dan200/computercraft/client/gui/widgets/WidgetTerminal.java

@@ -388,7 +388,7 @@ public class WidgetTerminal extends Widget
                 // Get the data from the terminal first
                 // Unfortunately we have to keep the lock for the whole of drawing, so the text doesn't change under us.
                 FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
-                boolean tblink = m_focus && terminal.getCursorBlink() && FrameInfo.instance().getGlobalCursorBlink();
+                boolean tblink = m_focus && terminal.getCursorBlink() && FrameInfo.getGlobalCursorBlink();
                 int tw = terminal.getWidth();
                 int th = terminal.getHeight();
                 int tx = terminal.getCursorX();

src/main/java/dan200/computercraft/client/proxy/CCTurtleProxyClient.java

@@ -18,7 +18,6 @@ import net.minecraft.client.renderer.ItemMeshDefinition;
 import net.minecraft.client.renderer.block.model.IBakedModel;
 import net.minecraft.client.renderer.block.model.ModelBakery;
 import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.renderer.color.IItemColor;
 import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.resources.IResourceManager;
@@ -83,10 +82,16 @@ public class CCTurtleProxyClient extends CCTurtleProxyCommon
         super.init();
 
         // Setup turtle colours
-        Minecraft.getMinecraft().getItemColors().registerItemColorHandler(
+        Minecraft.getMinecraft().getItemColors().registerItemColorHandler( ( stack, tintIndex ) -> {
-            new TurtleItemColour(),
+            if( tintIndex == 0 )
-            ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced
+            {
-        );
+                ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
+                int colour = turtle.getColour( stack );
+                if( colour != -1 ) return colour;
+            }
+
+            return 0xFFFFFF;
+        }, ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced );
 
         // Setup renderers
         ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
@@ -110,8 +115,7 @@ public class CCTurtleProxyClient extends CCTurtleProxyCommon
 
     private void registerForgeHandlers()
     {
-        ForgeHandlers handlers = new ForgeHandlers();
+        MinecraftForge.EVENT_BUS.register( new ForgeHandlers() );
-        MinecraftForge.EVENT_BUS.register( handlers );
     }
 
     public static class ForgeHandlers
@@ -196,19 +200,4 @@ public class CCTurtleProxyClient extends CCTurtleProxyCommon
         }
     }
 
-    private static class TurtleItemColour implements IItemColor
-    {
-        @Override
-        public int colorMultiplier( @Nonnull ItemStack stack, int tintIndex )
-        {
-            if( tintIndex == 0 )
-            {
-                ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
-                int colour = turtle.getColour( stack );
-                if( colour != -1 ) return colour;
-            }
-
-            return 0xFFFFFF;
-        }
-    }
 }

src/main/java/dan200/computercraft/client/proxy/ComputerCraftProxyClient.java

@@ -8,8 +8,8 @@ package dan200.computercraft.client.proxy;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.ClientTableFormatter;
-import dan200.computercraft.client.FrameInfo;
+import dan200.computercraft.client.render.TileEntityCableRenderer;
-import dan200.computercraft.client.render.*;
+import dan200.computercraft.client.render.TileEntityMonitorRenderer;
 import dan200.computercraft.shared.command.CommandCopy;
 import dan200.computercraft.shared.command.text.TableBuilder;
 import dan200.computercraft.shared.media.items.ItemDiskLegacy;
@@ -33,9 +33,9 @@ import net.minecraft.world.World;
 import net.minecraftforge.client.ClientCommandHandler;
 import net.minecraftforge.client.event.ModelRegistryEvent;
 import net.minecraftforge.client.model.ModelLoader;
-import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.fml.client.registry.ClientRegistry;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
@@ -50,9 +50,6 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
     {
         super.preInit();
 
-        // Setup client forge handlers
-        registerForgeHandlers();
-
         // Register any client-specific commands
         ClientCommandHandler.instance.registerCommand( CommandCopy.INSTANCE );
     }
@@ -95,8 +92,7 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.disk ), ComputerCraft.Items.disk );
         mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.diskExpanded ), ComputerCraft.Items.diskExpanded );
 
-        mc.getItemColors().registerItemColorHandler( ( stack, layer ) ->
+        mc.getItemColors().registerItemColorHandler( ( stack, layer ) -> {
-        {
             switch( layer )
             {
                 case 0:
@@ -160,15 +156,6 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         return world.getSaveHandler().getWorldDirectory();
     }
 
-    private void registerForgeHandlers()
-    {
-        MinecraftForge.EVENT_BUS.register( new ForgeHandlers() );
-        MinecraftForge.EVENT_BUS.register( new RenderOverlayCable() );
-        MinecraftForge.EVENT_BUS.register( new ItemPocketRenderer() );
-        MinecraftForge.EVENT_BUS.register( new ItemPrintoutRenderer() );
-        MinecraftForge.EVENT_BUS.register( FrameInfo.instance() );
-    }
-
     @Override
     public void playRecordClient( BlockPos pos, SoundEvent record, String info )
     {
@@ -183,10 +170,11 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         ClientTableFormatter.INSTANCE.display( table );
     }
 
-    public class ForgeHandlers
+    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+    public static class ForgeHandlers
     {
         @SubscribeEvent
-        public void onWorldUnload( WorldEvent.Unload event )
+        public static void onWorldUnload( WorldEvent.Unload event )
         {
             if( event.getWorld().isRemote )
             {

src/main/java/dan200/computercraft/client/render/ItemPocketRenderer.java

@@ -24,9 +24,9 @@ import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.client.ForgeHooksClient;
 import net.minecraftforge.client.event.RenderSpecificHandEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
-import net.minecraftforge.fml.relauncher.SideOnly;
 import org.lwjgl.opengl.GL11;
 
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
@@ -35,17 +35,23 @@ import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
 /**
  * Emulates map rendering for pocket computers
  */
-@SideOnly( Side.CLIENT )
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
-public class ItemPocketRenderer extends ItemMapLikeRenderer
+public final class ItemPocketRenderer extends ItemMapLikeRenderer
 {
+    private static final ItemPocketRenderer INSTANCE = new ItemPocketRenderer();
+
+    private ItemPocketRenderer()
+    {
+    }
+
     @SubscribeEvent
-    public void renderItem( RenderSpecificHandEvent event )
+    public static void renderItem( RenderSpecificHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( !(stack.getItem() instanceof ItemPocketComputer) ) return;
 
         event.setCanceled( true );
-        renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
     }
 
     @Override
@@ -145,7 +151,7 @@ public class ItemPocketRenderer extends ItemMapLikeRenderer
 
                     // And render the cursor;
                     int tx = terminal.getCursorX(), ty = terminal.getCursorY();
-                    if( terminal.getCursorBlink() && FrameInfo.instance().getGlobalCursorBlink() &&
+                    if( terminal.getCursorBlink() && FrameInfo.getGlobalCursorBlink() &&
                         tx >= 0 && ty >= 0 && tx < tw && ty < th )
                     {
                         TextBuffer cursorColour = new TextBuffer( "0123456789abcdef".charAt( terminal.getTextColour() ), 1 );

src/main/java/dan200/computercraft/client/render/ItemPrintoutRenderer.java

@@ -12,7 +12,9 @@ import net.minecraft.client.renderer.GlStateManager;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.client.event.RenderItemInFrameEvent;
 import net.minecraftforge.client.event.RenderSpecificHandEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
 
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
@@ -20,17 +22,27 @@ import static dan200.computercraft.client.render.PrintoutRenderer.*;
 import static dan200.computercraft.shared.media.items.ItemPrintout.LINES_PER_PAGE;
 import static dan200.computercraft.shared.media.items.ItemPrintout.LINE_MAX_LENGTH;
 
-public class ItemPrintoutRenderer extends ItemMapLikeRenderer
+/**
+ * Emulates map and item-frame rendering for prinouts
+ */
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
 {
+    private static final ItemPrintoutRenderer INSTANCE = new ItemPrintoutRenderer();
+
+    private ItemPrintoutRenderer()
+    {
+    }
+
     @SubscribeEvent
-    public void onRenderInHand( RenderSpecificHandEvent event )
+    public static void onRenderInHand( RenderSpecificHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( stack.getItem() != ComputerCraft.Items.printout ) return;
 
         event.setCanceled( true );
 
-        renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
     }
 
     @Override
@@ -51,7 +63,7 @@ public class ItemPrintoutRenderer extends ItemMapLikeRenderer
     }
 
     @SubscribeEvent
-    public void onRenderInFrame( RenderItemInFrameEvent event )
+    public static void onRenderInFrame( RenderItemInFrameEvent event )
     {
         ItemStack stack = event.getItem();
         if( stack.getItem() != ComputerCraft.Items.printout ) return;
@@ -69,6 +81,7 @@ public class ItemPrintoutRenderer extends ItemMapLikeRenderer
         drawPrintout( stack );
 
         GlStateManager.enableLighting();
+        GlStateManager.disableBlend();
     }
 
     private static void drawPrintout( ItemStack stack )

src/main/java/dan200/computercraft/client/render/RenderOverlayCable.java

@@ -23,17 +23,24 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.World;
 import net.minecraftforge.client.event.DrawBlockHighlightEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
 import org.lwjgl.opengl.GL11;
 
-public class RenderOverlayCable
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class RenderOverlayCable
 {
     private static final float EXPAND = 0.002f;
     private static final double MIN = CableBounds.MIN - EXPAND;
     private static final double MAX = CableBounds.MAX + EXPAND;
 
+    private RenderOverlayCable()
+    {
+    }
+
     @SubscribeEvent
-    public void drawHighlight( DrawBlockHighlightEvent event )
+    public static void drawHighlight( DrawBlockHighlightEvent event )
     {
         if( event.getTarget().typeOfHit != RayTraceResult.Type.BLOCK ) return;
 

src/main/java/dan200/computercraft/client/render/TileEntityMonitorRenderer.java

@@ -49,7 +49,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
         // Ensure each monitor terminal is rendered only once. We allow rendering a specific tile
         // multiple times in a single frame to ensure compatibility with shaders which may run a
         // pass multiple times.
-        long renderFrame = FrameInfo.instance().getRenderFrame();
+        long renderFrame = FrameInfo.getRenderFrame();
         if( originTerminal.lastRenderFrame == renderFrame && !monitorPos.equals( originTerminal.lastRenderPos ) )
         {
             return;
@@ -230,7 +230,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
                                 GlStateManager.glEndList();
                             }
                         }
-                        if( FrameInfo.instance().getGlobalCursorBlink() )
+                        if( FrameInfo.getGlobalCursorBlink() )
                         {
                             GlStateManager.callList( originTerminal.renderDisplayLists[2] );
                             GlStateManager.resetColor();

src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java

@@ -21,38 +21,23 @@ import dan200.computercraft.shared.turtle.items.ItemTurtleLegacy;
 import dan200.computercraft.shared.turtle.items.ItemTurtleNormal;
 import dan200.computercraft.shared.turtle.items.TurtleItemFactory;
 import dan200.computercraft.shared.turtle.upgrades.*;
-import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.ImpostorRecipe;
 import net.minecraft.block.Block;
-import net.minecraft.entity.Entity;
 import net.minecraft.init.Items;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.item.crafting.IRecipe;
 import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.math.AxisAlignedBB;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.RegistryEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.registry.EntityRegistry;
 import net.minecraftforge.fml.common.registry.GameRegistry;
 import net.minecraftforge.registries.IForgeRegistry;
 
-import java.lang.ref.WeakReference;
-import java.util.List;
-import java.util.function.Function;
-
 public abstract class CCTurtleProxyCommon implements ICCTurtleProxy
 {
-    private Function<ItemStack, ItemStack> dropConsumer;
-    private List<ItemStack> remainingDrops;
-    private WeakReference<World> dropWorld;
-    private BlockPos dropPos;
-    private AxisAlignedBB dropBounds;
-    private WeakReference<Entity> dropEntity;
-
     @Override
     public void preInit()
     {
@@ -67,7 +52,6 @@ public abstract class CCTurtleProxyCommon implements ICCTurtleProxy
     @Override
     public void init()
     {
-        registerForgeHandlers();
         registerTileEntities();
     }
 
@@ -248,16 +232,11 @@ public abstract class CCTurtleProxyCommon implements ICCTurtleProxy
         GameRegistry.registerTileEntity( TileTurtleAdvanced.class, new ResourceLocation( ComputerCraft.MOD_ID, "turtleadv" ) );
     }
 
-    private void registerForgeHandlers()
+    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
-    {
+    public static class ForgeHandlers
-        MinecraftForge.EVENT_BUS.register( new ForgeHandlers() );
-        MinecraftForge.EVENT_BUS.register( DropConsumer.instance() );
-    }
-
-    private class ForgeHandlers
     {
         @SubscribeEvent
-        public void onTurtleAction( TurtleActionEvent event )
+        public static void onTurtleAction( TurtleActionEvent event )
         {
             if( ComputerCraft.turtleDisabledActions.contains( event.getAction() ) )
             {

src/main/java/dan200/computercraft/shared/proxy/ComputerCraftProxyCommon.java

@@ -85,10 +85,10 @@ import net.minecraft.world.World;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.RegistryEvent;
 import net.minecraftforge.event.entity.player.PlayerContainerEvent;
-import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.fml.client.event.ConfigChangedEvent;
 import net.minecraftforge.fml.common.FMLCommonHandler;
 import net.minecraftforge.fml.common.Loader;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
 import net.minecraftforge.fml.common.network.FMLNetworkEvent;
@@ -371,9 +371,7 @@ public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
 
     private void registerForgeHandlers()
     {
-        ForgeHandlers handlers = new ForgeHandlers();
+        NetworkRegistry.INSTANCE.registerGuiHandler( ComputerCraft.instance, new GuiHandler() );
-        MinecraftForge.EVENT_BUS.register( handlers );
-        NetworkRegistry.INSTANCE.registerGuiHandler( ComputerCraft.instance, handlers );
     }
 
     private void registerNetwork()
@@ -421,14 +419,12 @@ public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
             showTableClient( packet.getTable() ) );
     }
 
-    public class ForgeHandlers implements IGuiHandler
+    public class GuiHandler implements IGuiHandler
     {
-        private ForgeHandlers()
+        private GuiHandler()
         {
         }
 
-        // IGuiHandler implementation
-
         @Override
         public Object getServerGuiElement( int id, EntityPlayer player, World world, int x, int y, int z )
         {
@@ -561,23 +557,29 @@ public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
                     return null;
             }
         }
+    }
 
-        // Event handlers
+    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
+    public final static class ForgeHandlers
+    {
+        private ForgeHandlers()
+        {
+        }
 
         @SubscribeEvent
-        public void onConnectionOpened( FMLNetworkEvent.ClientConnectedToServerEvent event )
+        public static void onConnectionOpened( FMLNetworkEvent.ClientConnectedToServerEvent event )
         {
             ComputerCraft.clientComputerRegistry.reset();
         }
 
         @SubscribeEvent
-        public void onConnectionClosed( FMLNetworkEvent.ClientDisconnectionFromServerEvent event )
+        public static void onConnectionClosed( FMLNetworkEvent.ClientDisconnectionFromServerEvent event )
         {
             ComputerCraft.clientComputerRegistry.reset();
         }
 
         @SubscribeEvent
-        public void onClientTick( TickEvent.ClientTickEvent event )
+        public static void onClientTick( TickEvent.ClientTickEvent event )
         {
             if( event.phase == TickEvent.Phase.START )
             {
@@ -586,7 +588,7 @@ public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
         }
 
         @SubscribeEvent
-        public void onServerTick( TickEvent.ServerTickEvent event )
+        public static void onServerTick( TickEvent.ServerTickEvent event )
         {
             if( event.phase == TickEvent.Phase.START )
             {
@@ -596,23 +598,13 @@ public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
         }
 
         @SubscribeEvent
-        public void onWorldLoad( WorldEvent.Load event )
+        public static void onConfigChanged( ConfigChangedEvent.OnConfigChangedEvent event )
-        {
-        }
-
-        @SubscribeEvent
-        public void onWorldUnload( WorldEvent.Unload event )
-        {
-        }
-
-        @SubscribeEvent
-        public void onConfigChanged( ConfigChangedEvent.OnConfigChangedEvent event )
         {
             if( event.getModID().equals( ComputerCraft.MOD_ID ) ) Config.sync();
         }
 
         @SubscribeEvent
-        public void onContainerOpen( PlayerContainerEvent.Open event )
+        public static void onContainerOpen( PlayerContainerEvent.Open event )
         {
             // If we're opening a computer container then broadcast the terminal state
             Container container = event.getContainer();

src/main/java/dan200/computercraft/shared/turtle/core/TurtlePlaceCommand.java

@@ -226,7 +226,7 @@ public class TurtlePlaceCommand implements ITurtleCommand
         // Start claiming entity drops
         Entity hitEntity = hit.getKey();
         Vec3d hitPos = hit.getValue();
-        DropConsumer.instance().set(
+        DropConsumer.set(
             hitEntity,
             drop -> InventoryUtil.storeItems( drop, turtle.getItemHandler(), turtle.getSelectedSlot() )
         );
@@ -266,7 +266,7 @@ public class TurtlePlaceCommand implements ITurtleCommand
         }
 
         // Stop claiming drops
-        List<ItemStack> remainingDrops = DropConsumer.instance().clear();
+        List<ItemStack> remainingDrops = DropConsumer.clear();
         for( ItemStack remaining : remainingDrops )
         {
             WorldUtil.dropItemStack( remaining, world, position, turtle.getDirection().getOpposite() );

src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java

@@ -135,7 +135,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
             }
 
             // Start claiming entity drops
-            DropConsumer.instance().set( hitEntity, turtleDropConsumer( turtle ) );
+            DropConsumer.set( hitEntity, turtleDropConsumer( turtle ) );
 
             // Attack the entity
             boolean attacked = false;
@@ -225,7 +225,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
         }
 
         // Consume the items the block drops
-        DropConsumer.instance().set( world, blockPosition, turtleDropConsumer( turtle ) );
+        DropConsumer.set( world, blockPosition, turtleDropConsumer( turtle ) );
 
         TileEntity tile = world.getTileEntity( blockPosition );
 
@@ -257,7 +257,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
 
     private void stopConsuming( ITurtleAccess turtle )
     {
-        List<ItemStack> extra = DropConsumer.instance().clear();
+        List<ItemStack> extra = DropConsumer.clear();
         for( ItemStack remainder : extra )
         {
             WorldUtil.dropItemStack( remainder, turtle.getWorld(), turtle.getPosition(), turtle.getDirection().getOpposite() );

src/main/java/dan200/computercraft/shared/util/DropConsumer.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.shared.util;
 
+import dan200.computercraft.ComputerCraft;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.item.EntityItem;
 import net.minecraft.item.ItemStack;
@@ -15,6 +16,7 @@ import net.minecraft.world.World;
 import net.minecraftforge.event.entity.EntityJoinWorldEvent;
 import net.minecraftforge.event.entity.living.LivingDropsEvent;
 import net.minecraftforge.event.world.BlockEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.EventPriority;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 
@@ -23,23 +25,21 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Function;
 
-public class DropConsumer
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
+public final class DropConsumer
 {
-    private static final DropConsumer instance = new DropConsumer();
+    private DropConsumer()
-
-    public static DropConsumer instance()
     {
-        return instance;
     }
 
-    private Function<ItemStack, ItemStack> dropConsumer;
+    private static Function<ItemStack, ItemStack> dropConsumer;
-    private List<ItemStack> remainingDrops;
+    private static List<ItemStack> remainingDrops;
-    private WeakReference<World> dropWorld;
+    private static WeakReference<World> dropWorld;
-    private BlockPos dropPos;
+    private static BlockPos dropPos;
-    private AxisAlignedBB dropBounds;
+    private static AxisAlignedBB dropBounds;
-    private WeakReference<Entity> dropEntity;
+    private static WeakReference<Entity> dropEntity;
 
-    public void set( Entity entity, Function<ItemStack, ItemStack> consumer )
+    public static void set( Entity entity, Function<ItemStack, ItemStack> consumer )
     {
         dropConsumer = consumer;
         remainingDrops = new ArrayList<>();
@@ -51,7 +51,7 @@ public class DropConsumer
         entity.captureDrops = true;
     }
 
-    public void set( World world, BlockPos pos, Function<ItemStack, ItemStack> consumer )
+    public static void set( World world, BlockPos pos, Function<ItemStack, ItemStack> consumer )
     {
         dropConsumer = consumer;
         remainingDrops = new ArrayList<>();
@@ -61,7 +61,7 @@ public class DropConsumer
         dropBounds = new AxisAlignedBB( pos ).grow( 2, 2, 2 );
     }
 
-    public List<ItemStack> clear()
+    public static List<ItemStack> clear()
     {
         if( dropEntity != null )
         {
@@ -89,14 +89,14 @@ public class DropConsumer
         return remainingStacks;
     }
 
-    private void handleDrops( ItemStack stack )
+    private static void handleDrops( ItemStack stack )
     {
         ItemStack remaining = dropConsumer.apply( stack );
         if( !remaining.isEmpty() ) remainingDrops.add( remaining );
     }
 
     @SubscribeEvent( priority = EventPriority.LOWEST )
-    public void onEntityLivingDrops( LivingDropsEvent event )
+    public static void onEntityLivingDrops( LivingDropsEvent event )
     {
         // Capture any mob drops for the current entity
         if( dropEntity != null && event.getEntity() == dropEntity.get() )
@@ -108,7 +108,7 @@ public class DropConsumer
     }
 
     @SubscribeEvent( priority = EventPriority.LOWEST )
-    public void onHarvestDrops( BlockEvent.HarvestDropsEvent event )
+    public static void onHarvestDrops( BlockEvent.HarvestDropsEvent event )
     {
         // Capture block drops for the current entity
         if( dropWorld != null && dropWorld.get() == event.getWorld()
@@ -123,7 +123,7 @@ public class DropConsumer
     }
 
     @SubscribeEvent( priority = EventPriority.LOWEST )
-    public void onEntitySpawn( EntityJoinWorldEvent event )
+    public static void onEntitySpawn( EntityJoinWorldEvent event )
     {
         // Capture any nearby item spawns
         if( dropWorld != null && dropWorld.get() == event.getWorld() && event.getEntity() instanceof EntityItem