fabric-mining-levels-v0 -> fabric-tool-attribute-api-v1 (1.15 edition) (#460)

Moves the ToolManager and tool tags declared in fabric-mining-levels-v0 to a new fabric-tool-attributes-v1, along with adding new interfaces to be implemented on tools so that mining speed, mining level, and entity attribute modifiers can be decided by the itemstack.

fabric-mining-levels-v0/build.gradle

@@ -1,7 +1,8 @@
 archivesBaseName = "fabric-mining-levels-v0"
-version = getSubprojectVersion(project, "0.1.1")
+version = getSubprojectVersion(project, "0.1.2")
 
 dependencies {
     compile project(path: ':fabric-api-base', configuration: 'dev')
     compile project(path: ':fabric-tag-extensions-v0', configuration: 'dev')
+    compile project(path: ':fabric-tool-attribute-api-v1', configuration: 'dev')
 }

fabric-mining-levels-v0/src/main/java/net/fabricmc/fabric/api/tag/FabricItemTags.java

@@ -20,12 +20,12 @@ import net.minecraft.item.Item;
 import net.minecraft.tag.Tag;
 import net.minecraft.util.Identifier;
 
-import net.fabricmc.fabric.api.tools.FabricToolTags;
+import net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags;
 
 /**
  * Item tags provided by Fabric.
  *
- * @deprecated Use dedicated classes, such as {@link net.fabricmc.fabric.api.tools.FabricToolTags}
+ * @deprecated Use dedicated classes, such as {@link FabricToolTags}
  */
 @Deprecated
 public class FabricItemTags {

fabric-mining-levels-v0/src/main/java/net/fabricmc/fabric/api/tools/FabricToolTags.java

@@ -18,23 +18,19 @@ package net.fabricmc.fabric.api.tools;
 
 import net.minecraft.item.Item;
 import net.minecraft.tag.Tag;
-import net.minecraft.util.Identifier;
-
-import net.fabricmc.fabric.api.tag.TagRegistry;
 
 /**
  * Tool item tags provided by Fabric.
+ *
+ * @deprecated Use the moved {@link net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags} class instead
  */
+@Deprecated
 public class FabricToolTags {
-	public static final Tag<Item> AXES = register("axes");
-	public static final Tag<Item> HOES = register("hoes");
-	public static final Tag<Item> PICKAXES = register("pickaxes");
-	public static final Tag<Item> SHOVELS = register("shovels");
-	public static final Tag<Item> SWORDS = register("swords");
+	public static final Tag<Item> AXES = net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags.AXES;
+	public static final Tag<Item> HOES = net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags.HOES;
+	public static final Tag<Item> PICKAXES = net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags.PICKAXES;
+	public static final Tag<Item> SHOVELS = net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags.SHOVELS;
+	public static final Tag<Item> SWORDS = net.fabricmc.fabric.api.tool.attribute.v1.FabricToolTags.SWORDS;
 
 	private FabricToolTags() { }
-
-	private static Tag<Item> register(String id) {
-		return TagRegistry.item(new Identifier("fabric", id));
-	}
 }

fabric-mining-levels-v0/src/main/java/net/fabricmc/fabric/mixin/mining/level/MiningToolItemAccessor.java

@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * 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 net.fabricmc.fabric.mixin.mining.level;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.item.MiningToolItem;
-
-@Mixin(MiningToolItem.class)
-public interface MiningToolItemAccessor {
-	@Accessor
-	float getMiningSpeed();
-}

fabric-mining-levels-v0/src/main/java/net/fabricmc/fabric/mixin/mining/level/MixinItemStack.java

@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * 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 net.fabricmc.fabric.mixin.mining.level;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-
-import net.minecraft.block.BlockState;
-import net.minecraft.item.Item;
-import net.minecraft.item.ItemStack;
-
-import net.fabricmc.fabric.api.util.TriState;
-import net.fabricmc.fabric.impl.mining.level.ToolManager;
-
-@Mixin(ItemStack.class)
-public abstract class MixinItemStack {
-	@Shadow
-	public abstract Item getItem();
-
-	@Inject(at = @At("HEAD"), method = "isEffectiveOn", cancellable = true)
-	public void isEffectiveOn(BlockState state, CallbackInfoReturnable<Boolean> info) {
-		TriState triState = ToolManager.handleIsEffectiveOn((ItemStack) (Object) this, state);
-
-		if (triState != TriState.DEFAULT) {
-			info.setReturnValue(triState.get());
-			info.cancel();
-		}
-	}
-
-	@Inject(at = @At("HEAD"), method = "getMiningSpeed", cancellable = true)
-	public void getBlockBreakingSpeed(BlockState state, CallbackInfoReturnable<Float> info) {
-		if (this.getItem() instanceof MiningToolItemAccessor) {
-			TriState triState = ToolManager.handleIsEffectiveOn((ItemStack) (Object) this, state);
-
-			if (triState != TriState.DEFAULT) {
-				info.setReturnValue(triState.get() ? ((MiningToolItemAccessor) this.getItem()).getMiningSpeed() : 1.0F);
-				info.cancel();
-			}
-		}
-	}
-}

fabric-mining-levels-v0/src/main/resources/fabric-mining-levels-v0.mixins.json

@@ -1,12 +0,0 @@
-{
-  "required": true,
-  "package": "net.fabricmc.fabric.mixin.mining.level",
-  "compatibilityLevel": "JAVA_8",
-  "mixins": [
-    "MiningToolItemAccessor",
-    "MixinItemStack"
-  ],
-  "injectors": {
-    "defaultRequire": 1
-  }
-}

fabric-mining-levels-v0/src/main/resources/fabric.mod.json

@@ -18,10 +18,8 @@
   "depends": {
     "fabricloader": ">=0.4.0",
     "fabric-api-base": "*",
-    "fabric-tag-extensions-v0": "*"
+    "fabric-tag-extensions-v0": "*",
+    "fabric-tool-attribute-api-v1": "*"
   },
-  "description": "Block mining level tags for tools.",
-  "mixins": [
-    "fabric-mining-levels-v0.mixins.json"
-  ]
+  "description": "Block mining level tags for tools. Deprecated and replaced by fabric-tool-attribute-v1."
 }

fabric-object-builders-v0/build.gradle

@@ -3,5 +3,5 @@ version = getSubprojectVersion(project, "0.1.4")
 
 dependencies {
     compile project(path: ':fabric-api-base', configuration: 'dev')
-    compile project(path: ':fabric-mining-levels-v0', configuration: 'dev')
+    compile project(path: ':fabric-tool-attribute-api-v1', configuration: 'dev')
 }

fabric-object-builders-v0/src/main/java/net/fabricmc/fabric/api/block/FabricBlockSettings.java

@@ -32,7 +32,7 @@ import net.minecraft.util.DyeColor;
 import net.minecraft.util.Identifier;
 
 import net.fabricmc.fabric.api.event.registry.BlockConstructedCallback;
-import net.fabricmc.fabric.impl.mining.level.ToolManager;
+import net.fabricmc.fabric.impl.tool.attribute.ToolManager;
 
 /**
  * Fabric's version of Block.Settings. Adds additional methods and hooks

fabric-object-builders-v0/src/main/resources/fabric.mod.json

@@ -18,7 +18,7 @@
   "depends": {
     "fabricloader": ">=0.4.0",
     "fabric-api-base": "*",
-    "fabric-mining-levels-v0": "*"
+    "fabric-tool-attribute-api-v1": "*"
   },
   "description": "Builders for objects vanilla has locked down.",
   "mixins": [

fabric-tool-attribute-api-v1/build.gradle

@@ -0,0 +1,7 @@
+archivesBaseName = "fabric-tool-attribute-api-v1"
+version = getSubprojectVersion(project, "1.0.0")
+
+dependencies {
+    compile project(path: ':fabric-api-base', configuration: 'dev')
+    compile project(path: ':fabric-tag-extensions-v0', configuration: 'dev')
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/api/tool/attribute/v1/DynamicAttributeTool.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.api.tool.attribute.v1;
+
+import com.google.common.collect.ImmutableSetMultimap;
+import com.google.common.collect.Multimap;
+
+import net.minecraft.entity.EquipmentSlot;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.attribute.EntityAttributeModifier;
+import net.minecraft.item.ItemStack;
+
+/**
+ * Interface for adding various tool attributes to items.
+ */
+public interface DynamicAttributeTool {
+	Multimap<String, EntityAttributeModifier> EMPTY = ImmutableSetMultimap.of();
+
+	/**
+	 * Determines the mining level of the passed stack, which is used for calculating what blocks this tool is allowed to break.
+	 *
+	 * @param stack The stack to check on.
+	 * @param user The current user of the tool, or null if there isn't any.
+	 * @return The mining level of the item. 3 is equal to a diamond pick.
+	 */
+	//TODO: nullable on user once we have an official @Nullable annotation in
+	int getMiningLevel(ItemStack stack, LivingEntity user);
+
+	/**
+	 * Determines the mining speed multiplier of the passed stack, which is one factor in overall mining speed.
+	 *
+	 * @param stack The stack to check on.
+	 * @param user The current user of the tool, or null if there isn't any.
+	 * @return The mining speed multiplier of the item. 8.0 is equal to a diamond pick.
+	 */
+	//TODO: nullable on user once we have an official @Nullable annotation in
+	float getMiningSpeedMultiplier(ItemStack stack, LivingEntity user);
+
+	/**
+	 * Add modifiers for any {@link net.minecraft.entity.attribute.EntityAttributes} your item should give when equipped, based on the stack.
+	 *
+	 * <p>Appends to either attribute modifier NBT or the result from {@link net.minecraft.item.Item#getModifiers(EquipmentSlot)}.</p>
+	 *
+	 * @param slot  The equipment slot this item is equipped in.
+	 * @param stack The stack that's equipped.
+	 * @param user The current user of the tool, or none if there isn't any
+	 * @return The dynamic modifiers to add on top of other modifiers on this stack. If none, return {@link #EMPTY}.
+	 */
+	//TODO: nullable on user once we have an official @Nullable annotation in
+	default Multimap<String, EntityAttributeModifier> getDynamicModifiers(EquipmentSlot slot, ItemStack stack, LivingEntity user) {
+		return EMPTY;
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/api/tool/attribute/v1/FabricToolTags.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.api.tool.attribute.v1;
+
+import net.minecraft.item.Item;
+import net.minecraft.tag.Tag;
+import net.minecraft.util.Identifier;
+
+import net.fabricmc.fabric.api.tag.TagRegistry;
+
+/**
+ * Tool item tags provided by Fabric.
+ */
+public class FabricToolTags {
+	public static final Tag<Item> AXES = register("axes");
+	public static final Tag<Item> HOES = register("hoes");
+	public static final Tag<Item> PICKAXES = register("pickaxes");
+	public static final Tag<Item> SHOVELS = register("shovels");
+	public static final Tag<Item> SWORDS = register("swords");
+	public static final Tag<Item> SHEARS = register("shears");
+
+	private FabricToolTags() { }
+
+	private static Tag<Item> register(String id) {
+		return TagRegistry.item(new Identifier("fabric", id));
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/impl/tool/attribute/AttributeManager.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.impl.tool.attribute;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimap;
+
+import net.minecraft.entity.attribute.EntityAttributeModifier;
+
+public final class AttributeManager {
+	private AttributeManager() { }
+
+	/**
+	 * Merge two multimaps of EntityAttributeModifiers, combining their modifiers to prevent duplicate entries in a tooltip.
+	 *
+	 * @param left  The first of the two multimaps to merge.
+	 * @param right The second of the two multimaps to merge.
+	 * @return The merged form of the two.
+	 */
+	public static Multimap<String, EntityAttributeModifier> mergeAttributes(Multimap<String, EntityAttributeModifier> left, Multimap<String, EntityAttributeModifier> right) {
+		if (left.isEmpty()) return right;
+		if (right.isEmpty()) return left;
+		Multimap<String, EntityAttributeModifier> ret = HashMultimap.create();
+		Set<String> allKeys = new HashSet<>();
+		allKeys.addAll(left.keySet());
+		allKeys.addAll(right.keySet());
+
+		for (String key : allKeys) {
+			double add = 0;
+			double multBase = 1;
+			double multTotal = 1;
+			Collection<EntityAttributeModifier> modifiers;
+
+			if (left.containsKey(key)) {
+				modifiers = left.get(key);
+				if (right.containsKey(key)) modifiers.addAll(right.get(key));
+			} else {
+				//key *must* be in either left or right, so if it's not in left, it *must* be in right
+				modifiers = right.get(key);
+			}
+
+			for (EntityAttributeModifier mod : modifiers) {
+				switch (mod.getOperation()) {
+				case ADDITION:
+					add += mod.getAmount();
+					break;
+				case MULTIPLY_BASE:
+					multBase += mod.getAmount();
+					break;
+				case MULTIPLY_TOTAL:
+					multTotal *= 1 + mod.getAmount();
+					break;
+				default:
+					break;
+				}
+			}
+
+			ret.put(key, new EntityAttributeModifier(key, add, EntityAttributeModifier.Operation.ADDITION));
+			ret.put(key, new EntityAttributeModifier(key, multBase, EntityAttributeModifier.Operation.MULTIPLY_BASE));
+			ret.put(key, new EntityAttributeModifier(key, multTotal, EntityAttributeModifier.Operation.MULTIPLY_TOTAL));
+		}
+
+		return ret;
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/impl/tool/attribute/ToolManager.java

@@ -14,18 +14,19 @@
  * limitations under the License.
  */
 
-package net.fabricmc.fabric.impl.mining.level;
+package net.fabricmc.fabric.impl.tool.attribute;
 
 import java.util.HashMap;
 import java.util.Map;
 
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
+import net.minecraft.entity.LivingEntity;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
-import net.minecraft.item.ToolItem;
 import net.minecraft.tag.Tag;
 
+import net.fabricmc.fabric.api.tool.attribute.v1.DynamicAttributeTool;
 import net.fabricmc.fabric.api.util.TriState;
 
 public final class ToolManager {
@@ -85,9 +86,10 @@ public final class ToolManager {
 		entry(block).putBreakByTool(tag, miningLevel);
 	}
 
-	private static int getMiningLevel(ItemStack stack) {
-		if (stack.getItem() instanceof ToolItem) {
-			return ((ToolItem) stack.getItem()).getMaterial().getMiningLevel();
+	//TODO: nullable on user once we have an official @Nullable annotation in
+	private static int getMiningLevel(ItemStack stack, LivingEntity user) {
+		if (stack.getItem() instanceof DynamicAttributeTool) {
+			return ((DynamicAttributeTool) stack.getItem()).getMiningLevel(stack, user);
 		} else {
 			return 0;
 		}
@@ -96,7 +98,8 @@ public final class ToolManager {
 	/**
 	 * Hook for ItemStack.isEffectiveOn and similar methods.
 	 */
-	public static TriState handleIsEffectiveOn(ItemStack stack, BlockState state) {
+	//TODO: nullable on user once we have an official @Nullable annotation in
+	public static TriState handleIsEffectiveOn(ItemStack stack, BlockState state, LivingEntity user) {
 		EntryImpl entry = entries.get(state.getBlock());
 
 		if (entry != null) {
@@ -104,7 +107,7 @@ public final class ToolManager {
 
 			for (int i = 0; i < entry.tags.length; i++) {
 				if (item.isIn(entry.tags[i])) {
-					return TriState.of(getMiningLevel(stack) >= entry.tagLevels[i]);
+					return TriState.of(getMiningLevel(stack, user) >= entry.tagLevels[i]);
 				}
 			}
 

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/mixin/tool/attribute/MixinItemStack.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.mixin.tool.attribute;
+
+import com.google.common.collect.Multimap;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.entity.EquipmentSlot;
+import net.minecraft.entity.attribute.EntityAttributeModifier;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+
+import net.fabricmc.fabric.api.tool.attribute.v1.DynamicAttributeTool;
+import net.fabricmc.fabric.api.util.TriState;
+import net.fabricmc.fabric.impl.tool.attribute.AttributeManager;
+import net.fabricmc.fabric.impl.tool.attribute.ToolManager;
+
+@Mixin(ItemStack.class)
+public abstract class MixinItemStack {
+	@Shadow
+	public abstract Item getItem();
+
+	@Inject(at = @At("HEAD"), method = "isEffectiveOn", cancellable = true)
+	public void isEffectiveOn(BlockState state, CallbackInfoReturnable<Boolean> info) {
+		TriState triState = ToolManager.handleIsEffectiveOn((ItemStack) (Object) this, state, null);
+
+		if (triState != TriState.DEFAULT) {
+			info.setReturnValue(triState.get());
+			info.cancel();
+		}
+	}
+
+	@Inject(at = @At("HEAD"), method = "getMiningSpeed", cancellable = true)
+	public void getMiningSpeed(BlockState state, CallbackInfoReturnable<Float> info) {
+		TriState triState = ToolManager.handleIsEffectiveOn((ItemStack) (Object) this, state, null);
+
+		if (triState != TriState.DEFAULT) {
+			Item item = this.getItem();
+			float miningSpeed;
+
+			if (item instanceof DynamicAttributeTool) {
+				miningSpeed = ((DynamicAttributeTool) this.getItem()).getMiningSpeedMultiplier((ItemStack) (Object) this, null);
+			} else {
+				return;
+			}
+
+			info.setReturnValue(triState.get() ? miningSpeed : 1.0F);
+		}
+	}
+
+	@Inject(at = @At("RETURN"), method = "getAttributeModifiers", cancellable = true, locals = LocalCapture.CAPTURE_FAILEXCEPTION)
+	public void getAttributeModifiers(EquipmentSlot slot, CallbackInfoReturnable<Multimap<String, EntityAttributeModifier>> info, Multimap<String, EntityAttributeModifier> multimap) {
+		ItemStack stack = (ItemStack) (Object) this;
+
+		if (stack.getItem() instanceof DynamicAttributeTool) {
+			DynamicAttributeTool holder = (DynamicAttributeTool) stack.getItem();
+			Multimap<String, EntityAttributeModifier> ret = AttributeManager.mergeAttributes(multimap, (holder).getDynamicModifiers(slot, stack, null));
+			info.setReturnValue(ret);
+		}
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/mixin/tool/attribute/MixinLivingEntity.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.mixin.tool.attribute;
+
+import com.google.common.collect.Multimap;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.EquipmentSlot;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.attribute.EntityAttributeModifier;
+import net.minecraft.item.ItemStack;
+import net.minecraft.world.World;
+
+import net.fabricmc.fabric.api.tool.attribute.v1.DynamicAttributeTool;
+import net.fabricmc.fabric.impl.tool.attribute.AttributeManager;
+
+@Mixin(LivingEntity.class)
+public abstract class MixinLivingEntity extends Entity {
+	public MixinLivingEntity(EntityType<?> type, World world) {
+		super(type, world);
+	}
+
+	/**
+	 * @author B0undarybreaker
+	 * @reason get entity attribute modifiers for dynamic tools
+	 */
+	@Redirect(method = "tick", at = @At(value = "INVOKE", target = "Lnet/minecraft/item/ItemStack;getAttributeModifiers(Lnet/minecraft/entity/EquipmentSlot;)Lcom/google/common/collect/Multimap;"))
+	public Multimap<String, EntityAttributeModifier> actTickModifiers(ItemStack stack, EquipmentSlot slot) {
+		return actModifiers(stack, slot, (LivingEntity) (Object) this);
+	}
+
+	private static Multimap<String, EntityAttributeModifier> actModifiers(ItemStack stack, EquipmentSlot slot, LivingEntity user) {
+		Multimap<String, EntityAttributeModifier> original = stack.getAttributeModifiers(slot);
+
+		if (stack.getItem() instanceof DynamicAttributeTool) {
+			DynamicAttributeTool tool = (DynamicAttributeTool) stack.getItem();
+			return (AttributeManager.mergeAttributes(original, tool.getDynamicModifiers(slot, stack, user)));
+		}
+
+		return original;
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/mixin/tool/attribute/MixinPlayerInventory.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.mixin.tool.attribute;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.entity.player.PlayerInventory;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.DefaultedList;
+
+import net.fabricmc.fabric.api.tool.attribute.v1.DynamicAttributeTool;
+import net.fabricmc.fabric.api.util.TriState;
+import net.fabricmc.fabric.impl.tool.attribute.ToolManager;
+
+@Mixin(PlayerInventory.class)
+public abstract class MixinPlayerInventory {
+	@Shadow
+	@Final
+	public DefaultedList<ItemStack> main;
+
+	@Shadow
+	public int selectedSlot;
+
+	@Shadow
+	@Final
+	public PlayerEntity player;
+
+	@Shadow
+	public abstract ItemStack getInvStack(int int_1);
+
+	@Inject(method = "isUsingEffectiveTool", at = @At("HEAD"))
+	public void actMiningLevel(BlockState state, CallbackInfoReturnable<Boolean> info) {
+		ItemStack stack = this.getInvStack(this.selectedSlot);
+
+		if (stack.getItem() instanceof DynamicAttributeTool) {
+			TriState ret = ToolManager.handleIsEffectiveOn(stack, state, player);
+
+			if (ret != TriState.DEFAULT) {
+				info.setReturnValue(ret.get());
+			}
+		}
+	}
+
+	@Inject(method = "getBlockBreakingSpeed", at = @At("HEAD"))
+	public void actMiningSleed(BlockState state, CallbackInfoReturnable<Float> info) {
+		ItemStack stack = this.main.get(this.selectedSlot);
+
+		if (stack.getItem() instanceof DynamicAttributeTool) {
+			info.setReturnValue(((DynamicAttributeTool) stack.getItem()).getMiningSpeedMultiplier(stack, player));
+		}
+	}
+}

fabric-tool-attribute-api-v1/src/main/java/net/fabricmc/fabric/mixin/tool/attribute/MixinToolItem.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * 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 net.fabricmc.fabric.mixin.tool.attribute;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.ToolItem;
+import net.minecraft.item.ToolMaterial;
+
+import net.fabricmc.fabric.api.tool.attribute.v1.DynamicAttributeTool;
+
+@Mixin(ToolItem.class)
+public abstract class MixinToolItem extends Item implements DynamicAttributeTool {
+	@Shadow
+	public abstract ToolMaterial getMaterial();
+
+	public MixinToolItem(Settings settings) {
+		super(settings);
+	}
+
+	@Override
+	public int getMiningLevel(ItemStack stack, LivingEntity user) {
+		return this.getMaterial().getMiningLevel();
+	}
+
+	@Override
+	public float getMiningSpeedMultiplier(ItemStack stack, LivingEntity user) {
+		return this.getMaterial().getMiningSpeed();
+	}
+}

fabric-tool-attribute-api-v1/src/main/resources/data/fabric/tags/items/shears.json

@@ -0,0 +1,6 @@
+{
+  "replace": false,
+  "values": [
+    "minecraft:shears"
+  ]
+}

fabric-tool-attribute-api-v1/src/main/resources/fabric-tool-attribute-api-v1.mixins.json

@@ -0,0 +1,14 @@
+{
+  "required": true,
+  "package": "net.fabricmc.fabric.mixin.tool.attribute",
+  "compatibilityLevel": "JAVA_8",
+  "mixins": [
+    "MixinItemStack",
+    "MixinLivingEntity",
+    "MixinPlayerInventory",
+    "MixinToolItem"
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}

fabric-tool-attribute-api-v1/src/main/resources/fabric.mod.json

@@ -0,0 +1,27 @@
+{
+  "schemaVersion": 1,
+  "id": "fabric-tool-attribute-api-v1",
+  "name": "Fabric Tool Attribute API (v1)",
+  "version": "${version}",
+  "environment": "*",
+  "license": "Apache-2.0",
+  "icon": "assets/fabric-tool-attribute0api-v1/icon.png",
+  "contact": {
+    "homepage": "https://fabricmc.net",
+    "irc": "irc://irc.esper.net:6667/fabric",
+    "issues": "https://github.com/FabricMC/fabric/issues",
+    "sources": "https://github.com/FabricMC/fabric"
+  },
+  "authors": [
+    "FabricMC"
+  ],
+  "depends": {
+    "fabricloader": ">=0.4.0",
+    "fabric-api-base": "*",
+    "fabric-tag-extensions-v0": "*"
+  },
+  "description": "Dynamic atttributes for tools.",
+  "mixins": [
+    "fabric-tool-attribute-api-v1.mixins.json"
+  ]
+}

settings.gradle

@@ -43,3 +43,4 @@ include 'fabric-resource-loader-v0'
 include 'fabric-tag-extensions-v0'
 include 'fabric-textures-v0'
 include 'fabric-dimensions-v1'
+include 'fabric-tool-attribute-api-v1'