Clarify API for ISubtypeInterpreter (#983)

gradle.properties

@@ -5,4 +5,4 @@ curse_project_id=238222
 
 version_major=4
 version_minor=7
-version_patch=7
+version_patch=8

src/api/java/mezz/jei/api/ISubtypeRegistry.java

@@ -5,6 +5,8 @@
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 
+import java.util.function.Function;
+
 /**
  * Tell JEI how to interpret NBT tags and capabilities when comparing and looking up items.
  * <p>
@@ -59,13 +61,30 @@ public interface ISubtypeRegistry {
 	boolean hasSubtypeInterpreter(ItemStack itemStack);
 
 	@FunctionalInterface
-	interface ISubtypeInterpreter {
+	interface ISubtypeInterpreter extends Function<ItemStack, String> {
+		String NONE = "";
+
+		/**
+		 * Get the data from an itemStack that is relevant to telling subtypes apart.
+		 * This should account for meta, nbt, and anything else that's relevant.
+		 * Return {@link #NONE} if there is no data used for subtypes.
+		 *
+		 * @since JEI 4.7.8
+		 */
+		@Override
+		String apply(ItemStack itemStack);
+
 		/**
 		 * Get the data from an itemStack that is relevant to telling subtypes apart.
 		 * This should account for meta, nbt, and anything else that's relevant.
 		 * Returns null if there is no data used for subtypes.
+		 *
+		 * @deprecated since JEI 4.7.8
 		 */
+		@Deprecated
 		@Nullable
-		String getSubtypeInfo(ItemStack itemStack);
+		default String getSubtypeInfo(ItemStack itemStack) {
+			return apply(itemStack);
+		}
 	}
 }

src/main/java/mezz/jei/plugins/vanilla/VanillaPlugin.java

@@ -83,7 +83,7 @@ public void registerItemSubtypes(ISubtypeRegistry subtypeRegistry) {
 		});
 		subtypeRegistry.registerSubtypeInterpreter(Items.SPAWN_EGG, itemStack -> {
 			ResourceLocation resourceLocation = ItemMonsterPlacer.getNamedIdFrom(itemStack);
-			return resourceLocation == null ? null : resourceLocation.toString();
+			return resourceLocation == null ? ISubtypeRegistry.ISubtypeInterpreter.NONE : resourceLocation.toString();
 		});
 	}
 

src/main/java/mezz/jei/plugins/vanilla/brewing/PotionSubtypeInterpreter.java

@@ -1,6 +1,5 @@
 package mezz.jei.plugins.vanilla.brewing;
 
-import javax.annotation.Nullable;
 import java.util.List;
 
 import mezz.jei.api.ISubtypeRegistry;
@@ -16,11 +15,10 @@ private PotionSubtypeInterpreter() {
 
 	}
 
-	@Nullable
 	@Override
-	public String getSubtypeInfo(ItemStack itemStack) {
+	public String apply(ItemStack itemStack) {
 		if (!itemStack.hasTagCompound()) {
-			return null;
+			return ISubtypeRegistry.ISubtypeInterpreter.NONE;
 		}
 		PotionType potionType = PotionUtils.getPotionFromItem(itemStack);
 		String potionTypeString = potionType.getNamePrefixed("");

src/main/java/mezz/jei/plugins/vanilla/ingredients/ItemStackListFactory.java

@@ -154,9 +154,8 @@ private FluidSubtypeInterpreter() {
 
 		}
 
-		@Nullable
 		@Override
-		public String getSubtypeInfo(ItemStack itemStack) {
+		public String apply(ItemStack itemStack) {
 			if (itemStack.hasCapability(CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null)) {
 				IFluidHandler capability = itemStack.getCapability(CapabilityFluidHandler.FLUID_HANDLER_ITEM_CAPABILITY, null);
 				if (capability != null) {
@@ -178,7 +177,7 @@ public String getSubtypeInfo(ItemStack itemStack) {
 					}
 				}
 			}
-			return null;
+			return ISubtypeRegistry.ISubtypeInterpreter.NONE;
 		}
 
 		@Nullable

src/main/java/mezz/jei/runtime/SubtypeRegistry.java

@@ -67,12 +67,11 @@ private static class AllNbt implements ISubtypeInterpreter {
 		private AllNbt() {
 		}
 
-		@Nullable
 		@Override
-		public String getSubtypeInfo(ItemStack itemStack) {
+		public String apply(ItemStack itemStack) {
 			NBTTagCompound nbtTagCompound = itemStack.getTagCompound();
 			if (nbtTagCompound == null || nbtTagCompound.hasNoTags()) {
-				return null;
+				return ISubtypeInterpreter.NONE;
 			}
 			return nbtTagCompound.toString();
 		}

src/main/java/mezz/jei/startup/StackHelper.java

@@ -382,7 +382,9 @@ public String getUniqueIdentifierForStack(ItemStack stack, UidMode mode) {
 		if (mode != UidMode.WILDCARD && metadata != OreDictionary.WILDCARD_VALUE) {
 			String subtypeInfo = subtypeRegistry.getSubtypeInfo(stack);
 			if (subtypeInfo != null) {
-				itemKey.append(':').append(subtypeInfo);
+				if (!subtypeInfo.isEmpty()) {
+					itemKey.append(':').append(subtypeInfo);
+				}
 			} else {
 				if (mode == UidMode.FULL) {
 					itemKey.append(':').append(metadata);