Enchantment api

library/item/enchantment/build.gradle

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+plugins {
+	id("qsl.module")
+}
+
+qslModule {
+	name = "Quilt Enchantment API"
+	moduleName = "enchantment"
+	id = "quilt_enchantment"
+	description = "An API for custom enchantments."
+	library = "item"
+	moduleDependencies {
+		core {
+			api("qsl_base")
+			testmodOnly("resource_loader")
+		}
+	}
+	accessWidener()
+}

library/item/enchantment/src/main/java/org/quiltmc/qsl/enchantment/api/EnchantmentEvents.java

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+/*
+ * Copyright 2023 QuiltMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.quiltmc.qsl.enchantment.api;
+
+import java.util.List;
+
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.Nullable;
+
+import net.minecraft.enchantment.Enchantment;
+import net.minecraft.enchantment.EnchantmentHelper;
+import net.minecraft.enchantment.EnchantmentLevelEntry;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.screen.AnvilScreenHandler;
+
+import org.quiltmc.qsl.base.api.event.Event;
+import org.quiltmc.qsl.enchantment.api.context.EnchantingContext;
+
+public final class EnchantmentEvents {
+	/**
+	 * An event that is called after random enchantments are generated (e.g. for an enchantment table), but before they are selected to be applied on an item.
+	 * @see EnchantmentHelper#getPossibleEntries(int, ItemStack, boolean)
+	 */
+	public static final Event<ModifyPossibleEnchantments> MODIFY_POSSIBLE_ENCHANTMENTS = Event.create(ModifyPossibleEnchantments.class, callbacks -> (possibleEnchantments, context) -> {
+		for (var callback : callbacks) {
+			callback.modifyPossibleEntries(possibleEnchantments, context);
+		}
+	});
+
+	/**
+	 * An event that is called when applying an {@link Enchantment} to an {@link Item} in an anvil.
+	 * @see AnvilScreenHandler#updateResult()
+	 */
+	public static final Event<AnvilApplication> ANVIL_APPLICATION = Event.create(AnvilApplication.class, callbacks -> (enchantment, context) -> {
+		for (var callback : callbacks) {
+			if (!callback.canApply(enchantment, context)) {
+				return false;
+			}
+		}
+
+		return true;
+	});
+
+	@FunctionalInterface
+	public interface ModifyPossibleEnchantments {
+		@Contract(mutates = "param1")
+		void modifyPossibleEntries(List<EnchantmentLevelEntry> possibleEnchantments, @Nullable EnchantingContext context);
+	}
+
+	@FunctionalInterface
+	public interface AnvilApplication {
+		@Contract(pure = true)
+		boolean canApply(Enchantment enchantment, @Nullable EnchantingContext context);
+	}
+}

library/item/enchantment/src/main/java/org/quiltmc/qsl/enchantment/api/QuiltEnchantableItem.java

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+/*
+ * Copyright 2023 QuiltMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.quiltmc.qsl.enchantment.api;
+
+import org.jetbrains.annotations.Contract;
+
+import net.minecraft.enchantment.Enchantment;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+
+/**
+ * An interface for extending an {@link Item} with additional control over enchanting.
+ */
+public interface QuiltEnchantableItem {
+	/**
+	 * Determines whether the provided enchantment can be applied to this item.
+	 * <p>
+	 * This takes highest priority for applying enchantments.
+	 * @param stack the stack containing this item
+	 * @param enchantment the enchantment to apply to this item
+	 * @return {@code true} if the enchantment can be applied, or {@code false} otherwise
+	 */
+	@Contract(pure = true)
+	default boolean canEnchant(ItemStack stack, Enchantment enchantment) {
+		return enchantment.isAcceptableItem(stack);
+	}
+}

library/item/enchantment/src/main/java/org/quiltmc/qsl/enchantment/api/QuiltEnchantment.java

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+/*
+ * Copyright 2023 QuiltMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.quiltmc.qsl.enchantment.api;
+
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.Range;
+
+import net.minecraft.enchantment.Enchantment;
+import net.minecraft.enchantment.EnchantmentTarget;
+import net.minecraft.entity.EquipmentSlot;
+import net.minecraft.item.ItemGroup;
+import net.minecraft.item.ItemStack;
+
+import org.quiltmc.qsl.enchantment.api.context.EnchantingContext;
+
+/**
+ * An extension of the default {@link Enchantment} class.
+ * <p>
+ * Allows for custom weighting in randomized enchanting contexts, as well as custom logic for application in the anvil.
+ */
+public abstract class QuiltEnchantment extends Enchantment {
+	public QuiltEnchantment(Rarity rarity, @Nullable EnchantmentTarget type, EquipmentSlot[] slotTypes) {
+		super(rarity, type, slotTypes);
+	}
+
+	/**
+	 * Return an integer value that represents the weight of this enchantment given the current context.
+	 * <p>
+	 * If 0, then this enchantment won't be added.
+	 * @param context the context of the enchanting
+	 * @return the context-aware weight for the enchantment
+	 */
+	public @Range(from = 0, to = Integer.MAX_VALUE) int weightFromContext(EnchantingContext context) {
+		return this.getRarity().getWeight();
+	}
+
+	/**
+	 * Determines if the given enchantment can be applied under the current context.
+	 * <p>
+	 * Note: {@link QuiltEnchantableItem#canEnchant(ItemStack, Enchantment)} takes priority.
+	 * @see QuiltEnchantableItem#canEnchant(ItemStack, Enchantment)
+	 * @param context the context of the enchanting
+	 * @return {@code true} if this enchantment can be applied, or {@code false} otherwise
+	 */
+	public boolean isAcceptableContext(EnchantingContext context) {
+		if (!context.ignoresPower() && this.isAcceptablePower(context.getLevel(), context.getPower())) {
+			return false;
+		}
+
+		return this.isAcceptableItem(context.getStack());
+	}
+
+	/**
+	 * Determines if the provided power is within the valid range for this enchantment at the provided level.
+	 * @param level the level of this enchantment being queried
+	 * @param power the power of the current enchanting context
+	 * @return {@code true} if the power is within the valid range, or {@code false} otherwise
+	 */
+	public boolean isAcceptablePower(int level, int power) {
+		return power >= this.getMinPower(level) && power <= this.getMaxPower(level);
+	}
+
+	/**
+	 * Determines if the given enchantment should be visible in the creative tab.
+	 * @param visibility in what context the stack visibility is tested
+	 * @return {@code true} if this enchantment should be visible, or {@code false} otherwise
+	 */
+	public boolean isVisible(ItemGroup.Visibility visibility) {
+		return true;
+	}
+}

library/item/enchantment/src/main/java/org/quiltmc/qsl/enchantment/api/QuiltEnchantmentHelper.java

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+/*
+ * Copyright 2023 QuiltMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.quiltmc.qsl.enchantment.api;
+
+import org.jetbrains.annotations.Nullable;
+
+import net.minecraft.enchantment.EnchantmentHelper;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.random.RandomGenerator;
+
+import org.quiltmc.qsl.enchantment.api.context.EnchantingContext;
+
+/**
+ * Allows modded systems that enchant items to apply an enchanting context.
+ */
+public final class QuiltEnchantmentHelper {
+	private static final ThreadLocal<EnchantingContext> CONTEXT = new ThreadLocal<>();
+
+	/**
+	 * Set the enchanting context for enchantments to use.
+	 * <p>
+	 * Note: Almost all the base values, bar the {@link net.minecraft.world.World world}, are provided to the context
+	 * when using {@link EnchantmentHelper#enchant(RandomGenerator, ItemStack, int, boolean)} or
+	 * {@link EnchantmentHelper#generateEnchantments(RandomGenerator, ItemStack, int, boolean)}.
+	 * @param context the enchanting context
+	 */
+	public static void setContext(EnchantingContext context) {
+		CONTEXT.set(context);
+	}
+
+	/**
+	 * Gets the current enchanting context.
+	 * @return the enchanting context
+	 */
+	public static @Nullable EnchantingContext getContext() {
+		return CONTEXT.get();
+	}
+
+	/**
+	 * Clears the current enchanting context.
+	 * <p>
+	 * This should be used to ensure that no information bleeds into other contexts.
+	 */
+	public static void clearContext() {
+		CONTEXT.remove();
+	}
+}

library/item/enchantment/src/main/java/org/quiltmc/qsl/enchantment/api/context/EnchantingContext.java

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+/*
+ * Copyright 2023 QuiltMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.quiltmc.qsl.enchantment.api.context;
+
+import org.jetbrains.annotations.Contract;
+
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.random.RandomGenerator;
+
+/**
+ * A class that contains contextual information about the enchantment process.
+ */
+public class EnchantingContext {
+	protected final int level;
+	protected final int power;
+	protected final ItemStack stack;
+	protected final RandomGenerator random;
+	protected final boolean treasureAllowed;
+
+	public EnchantingContext(int level, int power, ItemStack stack, RandomGenerator random, boolean treasureAllowed) {
+		this.level = level;
+		this.power = power;
+		this.stack = stack;
+		this.random = random;
+		this.treasureAllowed = treasureAllowed;
+	}
+
+	@Contract("_->new")
+	public EnchantingContext withLevel(int level) {
+		return new EnchantingContext(level, this.power, this.stack, this.random, this.treasureAllowed);
+	}
+
+	@Contract("_->new")
+	public EnchantingContext withPower(int power) {
+		return new EnchantingContext(this.level, power, this.stack, this.random, this.treasureAllowed);
+	}
+
+	@Contract("_,_,_->new")
+	public EnchantingContext withCoreContext(ItemStack stack, RandomGenerator random, boolean treasureAllowed) {
+		return new EnchantingContext(this.level, this.power, stack, random, treasureAllowed);
+	}
+
+	/**
+	 * @return an integer representing the current enchantment level being queried (ie. I, II, III, etc
+	 */
+	public int getLevel() {
+		return this.level;
+	}
+
+	/**
+	 * @return the current power of the enchanting context
+	 */
+	public int getPower() {
+		return this.power;
+	}
+
+	/**
+	 * @return the item stack for the enchantment to be applied to
+	 */
+	public ItemStack getStack() {
+		return this.stack;
+	}
+
+	/**
+	 * @return the random used for enchanting
+	 */
+	public RandomGenerator getRandom() {
+		return this.random;
+	}
+
+	/**
+	 * @return {@code true} if treasure enchantments are allowed, or {@code false} otherwise
+	 */
+	public boolean treasureAllowed() {
+		return this.treasureAllowed;
+	}
+
+	/**
+	 * @return {@code true} if this context ignores power (i.e. Applying enchantments in an anvil), or {@code false} otherwise
+	 */
+	public boolean ignoresPower() {
+		return this.power <= 0;
+	}
+}