Add item groups (aka creative tabs)

src/main/java/org/spongepowered/api/item/ItemGroup.java

@@ -0,0 +1,44 @@
+/*
+ * This file is part of SpongeAPI, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.api.item;
+
+import org.spongepowered.api.CatalogType;
+import org.spongepowered.api.text.translation.Translatable;
+import org.spongepowered.api.util.annotation.CatalogedBy;
+
+/**
+ * Represents an item group, or creative tab.
+ *
+ * <p>Item groups are signified by where they show on clients and otherwise have
+ * little usable functionality.</p>
+ */
+@CatalogedBy(ItemGroups.class)
+public interface ItemGroup extends CatalogType, Translatable {
+
+    default boolean contains(ItemType itemType) {
+        return itemType.getItemGroups().contains(this);
+    }
+
+}

src/main/java/org/spongepowered/api/item/ItemGroups.java

@@ -0,0 +1,64 @@
+/*
+ * This file is part of SpongeAPI, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.api.item;
+
+import org.spongepowered.api.util.generator.dummy.DummyObjectProvider;
+
+/**
+ * An enumeration of the known vanilla {@link ItemGroup}s in Minecraft.
+ * Mods may change and/or introduce new groups at runtime.
+ */
+public final class ItemGroups {
+
+    // SORTFIELDS:ON
+
+    public static final ItemGroup BREWING = DummyObjectProvider.createFor(ItemGroup.class, "BREWING");
+
+    public static final ItemGroup BUILDING_BLOCKS = DummyObjectProvider.createFor(ItemGroup.class, "BUILDING_BLOCKS");
+
+    public static final ItemGroup COMBAT = DummyObjectProvider.createFor(ItemGroup.class, "COMBAT");
+
+    public static final ItemGroup DECORATIONS = DummyObjectProvider.createFor(ItemGroup.class, "DECORATIONS");
+
+    public static final ItemGroup FOOD = DummyObjectProvider.createFor(ItemGroup.class, "FOOD");
+
+    public static final ItemGroup MATERIALS = DummyObjectProvider.createFor(ItemGroup.class, "MATERIALS");
+
+    public static final ItemGroup MISC = DummyObjectProvider.createFor(ItemGroup.class, "MISC");
+
+    public static final ItemGroup REDSTONE = DummyObjectProvider.createFor(ItemGroup.class, "REDSTONE");
+
+    public static final ItemGroup TOOLS = DummyObjectProvider.createFor(ItemGroup.class, "TOOLS");
+
+    public static final ItemGroup TRANSPORTATION = DummyObjectProvider.createFor(ItemGroup.class, "TRANSPORTATION");
+
+    // SORTFIELDS:OFF
+
+    // Suppress default constructor to ensure non-instantiability.
+    private ItemGroups() {
+        throw new AssertionError("You should not be attempting to instantiate this class.");
+    }
+
+}

src/main/java/org/spongepowered/api/item/ItemType.java

@@ -35,6 +35,7 @@
 import org.spongepowered.api.text.translation.Translatable;
 import org.spongepowered.api.util.annotation.CatalogedBy;
 
+import java.util.Collection;
 import java.util.Optional;
 
 /**
@@ -61,6 +62,13 @@ public interface ItemType extends CatalogType, Translatable, GameDictionary.Entr
     @Override
     String getName();
 
+    /**
+     * Gets the {@link ItemGroup}s that contain this item.
+     *
+     * @return A collection of item groups, possibly empty
+     */
+    Collection<ItemGroup> getItemGroups();
+
     /**
      * Gets the default maximum quantity for
      * {@link ItemStack}s of this item.