Replace appendHoverText with component-based tooltips

We have several items (e.g. ComputerItem), which only exist for their
custom tooltip implementation. We remove these, and replace them
vanilla-style component-based tooltips (TooltipProvider).

The implementation here is a little janky — as the vanilla list of
components is hard-coded, and neither mod loader offers a way to extend
it. For now we just use the generic mod-loader tooltip hook — this
probably would be easier with a mixin, but let's do things Properly.

It would be nice to fully remove DiskItem (we only keep this around for
doesSneakBypassUse), but that can be a future task.

Author: SquidDev

projects/common/src/client/java/dan200/computercraft/client/ClientRegistry.java

@@ -25,7 +25,6 @@
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.computer.inventory.AbstractComputerMenu;
-import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.turtle.TurtleOverlay;
 import net.minecraft.Util;
 import net.minecraft.client.Minecraft;
@@ -164,7 +163,7 @@ public static void registerExtraModels(Consumer<ResourceLocation> register, Coll
 
     public static void registerItemColours(BiConsumer<ItemColor, ItemLike> register) {
         register.accept(
-            (stack, layer) -> layer == 1 ? DiskItem.getColour(stack) : -1,
+            (stack, layer) -> layer == 1 ? DyedItemColor.getOrDefault(stack, Colour.WHITE.getARGB()) : -1,
             ModRegistry.Items.DISK.get()
         );
 

projects/common/src/client/java/dan200/computercraft/client/integration/jei/JEIComputerCraft.java

@@ -8,7 +8,6 @@
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.shared.ModRegistry;
 import dan200.computercraft.shared.integration.RecipeModHelpers;
-import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
 import mezz.jei.api.IModPlugin;
@@ -23,6 +22,7 @@
 import net.minecraft.core.RegistryAccess;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.DyedItemColor;
 
 import java.util.List;
 
@@ -100,7 +100,7 @@ public void onRuntimeAvailable(IJeiRuntime runtime) {
     /**
      * Distinguishes disks by colour.
      */
-    private static final IIngredientSubtypeInterpreter<ItemStack> diskSubtype = (stack, ctx) -> Integer.toString(DiskItem.getColour(stack));
+    private static final IIngredientSubtypeInterpreter<ItemStack> diskSubtype = (stack, ctx) -> Integer.toString(DyedItemColor.getOrDefault(stack, -1));
 
     private static RegistryAccess getRegistryAccess() {
         return Minecraft.getInstance().level.registryAccess();

projects/common/src/main/java/dan200/computercraft/shared/CommonHooks.java

@@ -13,7 +13,10 @@
 import dan200.computercraft.shared.peripheral.monitor.MonitorWatcher;
 import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.TickScheduler;
+import net.minecraft.core.component.DataComponentType;
+import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.Registries;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
@@ -25,9 +28,8 @@
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.item.CreativeModeTab;
-import net.minecraft.world.item.CreativeModeTabs;
-import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.*;
+import net.minecraft.world.item.component.TooltipProvider;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.LecternBlock;
@@ -40,8 +42,10 @@
 import net.minecraft.world.phys.BlockHitResult;
 import org.jspecify.annotations.Nullable;
 
+import java.util.List;
 import java.util.Set;
 import java.util.function.BiConsumer;
+import java.util.function.Consumer;
 
 /**
  * Event listeners for server/common code.
@@ -163,4 +167,42 @@ public static void onBuildCreativeTab(ResourceKey<CreativeModeTab> key, Creative
             out.accept(ModRegistry.Items.COMPUTER_COMMAND.get());
         }
     }
+
+    public static void onItemTooltip(ItemStack stack, Item.TooltipContext context, TooltipFlag flags, List<Component> out) {
+        var appender = new TooltipAppender(out);
+        addToTooltip(stack, ModRegistry.DataComponents.PRINTOUT.get(), context, appender, flags);
+        addToTooltip(stack, ModRegistry.DataComponents.TREASURE_DISK.get(), context, appender, flags);
+
+        // Disk and computer IDs require some conditional logic, so we don't bother using TooltipProvider.
+
+        var diskId = stack.get(ModRegistry.DataComponents.DISK_ID.get());
+        if (diskId != null && flags.isAdvanced()) diskId.addToTooltip("gui.computercraft.tooltip.disk_id", appender);
+
+        var computerId = stack.get(ModRegistry.DataComponents.COMPUTER_ID.get());
+        if (computerId != null && (flags.isAdvanced() || !stack.has(DataComponents.CUSTOM_NAME))) {
+            computerId.addToTooltip("gui.computercraft.tooltip.computer_id", appender);
+        }
+    }
+
+    /**
+     * Inserts additional tooltip items directly after the custom name, rather than at the very end.
+     */
+    private static final class TooltipAppender implements Consumer<Component> {
+        private final List<Component> out;
+        private int index = 1;
+
+        private TooltipAppender(List<Component> out) {
+            this.out = out;
+        }
+
+        @Override
+        public void accept(Component component) {
+            out.add(index++, component);
+        }
+    }
+
+    private static <T extends TooltipProvider> void addToTooltip(ItemStack stack, DataComponentType<T> component, Item.TooltipContext context, Consumer<Component> out, TooltipFlag flags) {
+        var provider = stack.get(component);
+        if (provider != null) provider.addToTooltip(context, out, flags);
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -35,8 +35,6 @@
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.inventory.ComputerMenuWithoutInventory;
-import dan200.computercraft.shared.computer.items.ComputerItem;
-import dan200.computercraft.shared.computer.items.CommandComputerItem;
 import dan200.computercraft.shared.computer.items.ServerComputerReference;
 import dan200.computercraft.shared.config.Config;
 import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
@@ -112,10 +110,7 @@
 import net.minecraft.network.codec.StreamCodec;
 import net.minecraft.world.flag.FeatureFlags;
 import net.minecraft.world.inventory.MenuType;
-import net.minecraft.world.item.BlockItem;
-import net.minecraft.world.item.CreativeModeTab;
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.*;
 import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.item.crafting.CustomRecipe;
 import net.minecraft.world.item.crafting.Recipe;
@@ -262,9 +257,9 @@ private static <B extends Block, I extends Item> RegistryEntry<I> ofBlock(Regist
             return REGISTRY.register(parent.id().getPath(), () -> supplier.apply(parent.get(), properties()));
         }
 
-        public static final RegistryEntry<ComputerItem> COMPUTER_NORMAL = ofBlock(Blocks.COMPUTER_NORMAL, ComputerItem::new);
-        public static final RegistryEntry<ComputerItem> COMPUTER_ADVANCED = ofBlock(Blocks.COMPUTER_ADVANCED, ComputerItem::new);
-        public static final RegistryEntry<ComputerItem> COMPUTER_COMMAND = ofBlock(Blocks.COMPUTER_COMMAND, CommandComputerItem::new);
+        public static final RegistryEntry<BlockItem> COMPUTER_NORMAL = ofBlock(Blocks.COMPUTER_NORMAL, BlockItem::new);
+        public static final RegistryEntry<BlockItem> COMPUTER_ADVANCED = ofBlock(Blocks.COMPUTER_ADVANCED, BlockItem::new);
+        public static final RegistryEntry<GameMasterBlockItem> COMPUTER_COMMAND = ofBlock(Blocks.COMPUTER_COMMAND, GameMasterBlockItem::new);
 
         public static final RegistryEntry<PocketComputerItem> POCKET_COMPUTER_NORMAL = REGISTRY.register("pocket_computer_normal",
             () -> new PocketComputerItem(properties().stacksTo(1), ComputerFamily.NORMAL));
@@ -276,8 +271,8 @@ private static <B extends Block, I extends Item> RegistryEntry<I> ofBlock(Regist
 
         public static final RegistryEntry<DiskItem> DISK =
             REGISTRY.register("disk", () -> new DiskItem(properties().stacksTo(1)));
-        public static final RegistryEntry<TreasureDiskItem> TREASURE_DISK =
-            REGISTRY.register("treasure_disk", () -> new TreasureDiskItem(properties().stacksTo(1)));
+        public static final RegistryEntry<DiskItem> TREASURE_DISK =
+            REGISTRY.register("treasure_disk", () -> new DiskItem(properties().stacksTo(1)));
 
         private static Item.Properties printoutProperties() {
             return properties().stacksTo(1).component(DataComponents.PRINTOUT.get(), PrintoutData.EMPTY);
@@ -315,20 +310,13 @@ private static <T> RegistryEntry<DataComponentType<T>> register(String name, Una
 
         /**
          * The id of a computer.
-         *
-         * @see ComputerItem
-         * @see PocketComputerItem
          */
         public static final RegistryEntry<DataComponentType<NonNegativeId>> COMPUTER_ID = register("computer_id", b -> b
             .persistent(NonNegativeId.CODEC).networkSynchronized(NonNegativeId.STREAM_CODEC)
         );
 
         /**
          * The storage capacity of a computer or disk.
-         *
-         * @see ComputerItem
-         * @see PocketComputerItem
-         * @see DiskItem
          */
         public static final RegistryEntry<DataComponentType<StorageCapacity>> STORAGE_CAPACITY = register("storage_capacity", b -> b
             .persistent(StorageCapacity.CODEC).networkSynchronized(StorageCapacity.STREAM_CODEC)
@@ -397,18 +385,13 @@ private static <T> RegistryEntry<DataComponentType<T>> register(String name, Una
 
         /**
          * Information about a treasure disk's mount.
-         *
-         * @see TreasureDiskItem
-         * @see TreasureDisk
          */
         public static final RegistryEntry<DataComponentType<TreasureDisk>> TREASURE_DISK = register("treasure_disk", b -> b
             .persistent(TreasureDisk.CODEC).networkSynchronized(TreasureDisk.STREAM_CODEC)
         );
 
         /**
          * The id of a disk.
-         *
-         * @see DiskItem
          */
         public static final RegistryEntry<DataComponentType<NonNegativeId>> DISK_ID = register("disk_id", b -> b
             .persistent(NonNegativeId.CODEC).networkSynchronized(NonNegativeId.STREAM_CODEC)

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/CommandComputerBlock.java

@@ -16,7 +16,6 @@
  * permission.
  *
  * @param <T> The type of the computer block entity.
- * @see dan200.computercraft.shared.computer.items.CommandComputerItem
  */
 public class CommandComputerBlock<T extends ComputerBlockEntity> extends ComputerBlock<T> implements GameMasterBlock {
     private static final MapCodec<CommandComputerBlock<?>> CODEC = RecordCodecBuilder.mapCodec(instance -> instance.group(

projects/common/src/main/java/dan200/computercraft/shared/computer/items/CommandComputerItem.java

@@ -8,9 +8,7 @@
 import dan200.computercraft.api.filesystem.Mount;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.items.ComputerItem;
 import dan200.computercraft.shared.config.ConfigSpec;
-import dan200.computercraft.shared.media.items.DiskItem;
 import dan200.computercraft.shared.util.DataComponentUtil;
 import dan200.computercraft.shared.util.NonNegativeId;
 import dan200.computercraft.shared.util.StorageCapacity;
@@ -27,12 +25,12 @@
  */
 public final class MountMedia implements IMedia {
     /**
-     * A {@link MountMedia} implementation for {@linkplain ComputerItem computers}.
+     * A {@link MountMedia} implementation for {@linkplain ModRegistry.DataComponents#COMPUTER_ID computers}.
      */
     public static final IMedia COMPUTER = new MountMedia("computer", ModRegistry.DataComponents.COMPUTER_ID, false, ConfigSpec.computerSpaceLimit);
 
     /**
-     * A {@link MountMedia} implementation for {@linkplain DiskItem disks}.
+     * A {@link MountMedia} implementation for {@linkplain ModRegistry.Items#DISK disks}.
      */
     public static final IMedia DISK = new MountMedia("disk", ModRegistry.DataComponents.DISK_ID, true, ConfigSpec.floppySpaceLimit);
 

projects/common/src/main/java/dan200/computercraft/shared/computer/items/ComputerItem.java

@@ -1,51 +1,27 @@
-// Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+// SPDX-FileCopyrightText: 2025 The CC: Tweaked Developers
 //
-// SPDX-License-Identifier: LicenseRef-CCPL
+// SPDX-License-Identifier: MPL-2.0
 
 package dan200.computercraft.shared.media.items;
 
 import dan200.computercraft.annotations.ForgeOverride;
-import dan200.computercraft.core.util.Colour;
-import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.util.NonNegativeId;
-import net.minecraft.ChatFormatting;
+import dan200.computercraft.shared.peripheral.diskdrive.DiskDriveBlock;
 import net.minecraft.core.BlockPos;
-import net.minecraft.network.chat.Component;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.TooltipFlag;
-import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.level.LevelReader;
 
-import java.util.List;
-
+/**
+ * An item that can be shift-right-clicked into a {@link DiskDriveBlock}.
+ */
 public class DiskItem extends Item {
     public DiskItem(Properties settings) {
         super(settings);
     }
 
-    @Override
-    public void appendHoverText(ItemStack stack, TooltipContext context, List<Component> list, TooltipFlag options) {
-        if (options.isAdvanced()) {
-            var id = stack.get(ModRegistry.DataComponents.DISK_ID.get());
-            if (id != null) {
-                list.add(Component.translatable("gui.computercraft.tooltip.disk_id", id.id())
-                    .withStyle(ChatFormatting.GRAY));
-            }
-        }
-    }
-
     @ForgeOverride
     public boolean doesSneakBypassUse(ItemStack stack, LevelReader world, BlockPos pos, Player player) {
         return true;
     }
-
-    public static int getDiskID(ItemStack stack) {
-        return NonNegativeId.getId(stack.get(ModRegistry.DataComponents.DISK_ID.get()));
-    }
-
-    public static int getColour(ItemStack stack) {
-        return DyedItemColor.getOrDefault(stack, Colour.WHITE.getARGB());
-    }
 }

projects/common/src/main/java/dan200/computercraft/shared/media/MountMedia.java

@@ -12,11 +12,16 @@
 import dan200.computercraft.shared.ModRegistry;
 import io.netty.buffer.ByteBuf;
 import net.minecraft.core.component.DataComponentHolder;
+import net.minecraft.network.chat.Component;
 import net.minecraft.network.codec.ByteBufCodecs;
 import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.TooltipFlag;
+import net.minecraft.world.item.component.TooltipProvider;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.function.Consumer;
 import java.util.stream.Stream;
 
 /**
@@ -27,7 +32,7 @@
  * @see PrintoutItem
  * @see dan200.computercraft.shared.ModRegistry.DataComponents#PRINTOUT
  */
-public record PrintoutData(String title, List<Line> lines) implements PrintoutContents {
+public record PrintoutData(String title, List<Line> lines) implements PrintoutContents, TooltipProvider {
     public static final int LINE_LENGTH = 25;
     public static final int LINES_PER_PAGE = 21;
     public static final int MAX_PAGES = 16;
@@ -71,6 +76,11 @@ public record PrintoutData(String title, List<Line> lines) implements PrintoutCo
         PrintoutData::new
     );
 
+    @Override
+    public void addToTooltip(Item.TooltipContext context, Consumer<Component> out, TooltipFlag flag) {
+        if (!title().isEmpty()) out.accept(Component.literal(title()));
+    }
+
     /**
      * A single line on our printed pages.
      *