TooltipDataCallback to allow modders add their own tooltips to existing items

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/api/client/rendering/v1/TooltipComponentCallback.java

@@ -27,7 +27,8 @@
 
 /**
  * Allows registering a mapping from {@link TooltipData} to {@link TooltipComponent}.
- * This allows custom tooltips for items: first, override {@link Item#getTooltipData} and return a custom {@code TooltipData}.
+ * This allows custom tooltips for items: first, override {@link Item#getTooltipData} and return a custom {@code TooltipData}, or use
+ * {@link TooltipDataCallback} to add {@link TooltipData} to an existing item.
  * Second, register a listener to this event and convert the data to your component implementation if it's an instance of your data class.
  *
  * <p>Note that failure to map some data to a component will throw an exception,

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/api/client/rendering/v1/TooltipDataCallback.java

@@ -0,0 +1,47 @@
+/*
+ * 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.client.rendering.v1;
+
+import java.util.List;
+
+import net.minecraft.client.gui.tooltip.TooltipComponent;
+import net.minecraft.client.item.TooltipData;
+import net.minecraft.item.ItemStack;
+
+import net.fabricmc.fabric.api.event.Event;
+import net.fabricmc.fabric.api.event.EventFactory;
+
+/**
+ * Allows registering custom {@link TooltipData} object for item.
+ * This allows you to add your own tooltips to existing items.
+ *
+ * <p>Custom {@link TooltipData} should be registered using {@link TooltipComponentCallback},
+ * otherwise game will crash when trying to map {@link TooltipData} to {@link TooltipComponent}.
+ */
+@FunctionalInterface
+public interface TooltipDataCallback {
+	Event<TooltipDataCallback> EVENT = EventFactory.createArrayBacked(TooltipDataCallback.class, callbacks -> (itemStack, tooltipDataList) -> {
+		for (TooltipDataCallback callback : callbacks) {
+			callback.appendTooltipData(itemStack, tooltipDataList);
+		}
+	});
+
+	/**
+	 * Add your own {@link TooltipData} to passed list if itemStack matches your requirements.
+	 */
+	void appendTooltipData(ItemStack itemStack, List<TooltipData> tooltipDataList);
+}

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/impl/client/rendering/tooltip/MultiTooltipComponent.java

@@ -0,0 +1,94 @@
+/*
+ * 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.client.rendering.tooltip;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.joml.Matrix4f;
+
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.font.TextRenderer;
+import net.minecraft.client.gui.DrawContext;
+import net.minecraft.client.gui.tooltip.TooltipComponent;
+import net.minecraft.client.item.TooltipData;
+import net.minecraft.client.render.VertexConsumerProvider;
+
+/**
+ * This class renders multiple tooltip components as one.
+ */
+public class MultiTooltipComponent implements TooltipComponent {
+	private final int height;
+	private final int width;
+	private final List<TooltipComponent> components;
+
+	public static MultiTooltipComponent of(List<TooltipData> data) {
+		var l = new ArrayList<TooltipComponent>(data.size());
+
+		for (TooltipData d : data) {
+			l.add(TooltipComponent.of(d));
+		}
+
+		return new MultiTooltipComponent(l);
+	}
+
+	public MultiTooltipComponent(List<TooltipComponent> components) {
+		this.components = components;
+		int height = 0;
+		int width = 0;
+
+		for (TooltipComponent component : components) {
+			height += component.getHeight();
+			width = Math.max(width, component.getWidth(MinecraftClient.getInstance().textRenderer));
+		}
+
+		this.height = height;
+		this.width = width;
+	}
+
+	@Override
+	public int getHeight() {
+		return height;
+	}
+
+	@Override
+	public int getWidth(TextRenderer textRenderer) {
+		return width;
+	}
+
+	@Override
+	public void drawText(TextRenderer textRenderer, int x, int y, Matrix4f matrix, VertexConsumerProvider.Immediate vertexConsumers) {
+		Matrix4f matrixCopy = new Matrix4f(matrix);
+
+		for (TooltipComponent c : components) {
+			c.drawText(textRenderer, x, y, matrixCopy, vertexConsumers);
+			matrixCopy.translate(0, c.getHeight(), 0);
+		}
+	}
+
+	@Override
+	public void drawItems(TextRenderer textRenderer, int x, int y, DrawContext context) {
+		context.getMatrices().push();
+
+		for (TooltipComponent c : components) {
+			c.drawItems(textRenderer, x, y, context);
+			context.getMatrices().translate(0, c.getHeight(), 0);
+		}
+
+		context.getMatrices().pop();
+	}
+}

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/impl/client/rendering/tooltip/MultiTooltipComponentRegister.java

@@ -0,0 +1,33 @@
+/*
+ * 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.client.rendering.tooltip;
+
+import net.fabricmc.api.ClientModInitializer;
+import net.fabricmc.fabric.api.client.rendering.v1.TooltipComponentCallback;
+
+public class MultiTooltipComponentRegister implements ClientModInitializer {
+	@Override
+	public void onInitializeClient() {
+		TooltipComponentCallback.EVENT.register((tooltipData) -> {
+			if (tooltipData instanceof MultiTooltipData multiTooltipData) {
+				return MultiTooltipComponent.of(multiTooltipData.tooltipData());
+			}
+
+			return null;
+		});
+	}
+}

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/impl/client/rendering/tooltip/MultiTooltipData.java

@@ -0,0 +1,27 @@
+/*
+ * 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.client.rendering.tooltip;
+
+import java.util.List;
+
+import net.minecraft.client.item.TooltipData;
+
+/**
+ * This class stores multiple TooltipData object to their further mapping to MultiTooltipComponent.
+ */
+public record MultiTooltipData(List<TooltipData> tooltipData) implements TooltipData {
+}

fabric-rendering-v1/src/client/java/net/fabricmc/fabric/mixin/client/rendering/HandledScreenMixin.java

@@ -0,0 +1,52 @@
+/*
+ * 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.client.rendering;
+
+import java.util.ArrayList;
+import java.util.Optional;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import net.minecraft.client.gui.screen.ingame.HandledScreen;
+import net.minecraft.client.item.TooltipData;
+import net.minecraft.item.ItemStack;
+
+import net.fabricmc.fabric.api.client.rendering.v1.TooltipDataCallback;
+import net.fabricmc.fabric.impl.client.rendering.tooltip.MultiTooltipData;
+
+@Mixin(HandledScreen.class)
+class HandledScreenMixin {
+	@Redirect(method = "drawMouseoverTooltip", at = @At(value = "INVOKE", target = "Lnet/minecraft/item/ItemStack;getTooltipData()Ljava/util/Optional;"))
+	Optional<TooltipData> addMultiData(ItemStack stack) {
+		Optional<TooltipData> original = stack.getTooltipData();
+		var multiData = new MultiTooltipData(new ArrayList<>());
+		original.ifPresent(multiData.tooltipData()::add);
+		TooltipDataCallback.EVENT.invoker().appendTooltipData(stack, multiData.tooltipData());
+
+		if (multiData.tooltipData().isEmpty()) {
+			return original;
+		}
+
+		if (multiData.tooltipData().size() == 1){
+			return Optional.of(multiData.tooltipData().get(0));
+		}
+
+		return Optional.of(multiData);
+	}
+}

fabric-rendering-v1/src/client/resources/fabric-rendering-v1.mixins.json

@@ -12,6 +12,7 @@
     "EntityModelLayersAccessor",
     "EntityModelsMixin",
     "EntityRenderersMixin",
+    "HandledScreenMixin",
     "InGameHudMixin",
     "ItemColorsMixin",
     "LivingEntityRendererAccessor",

fabric-rendering-v1/src/client/resources/fabric.mod.json

@@ -19,6 +19,11 @@
     "fabricloader": ">=0.4.0",
     "fabric-api-base": "*"
   },
+  "entrypoints": {
+    "client": [
+      "net.fabricmc.fabric.impl.client.rendering.tooltip.MultiTooltipComponentRegister"
+    ]
+  },
   "description": "Hooks and registries for rendering-related things.",
   "mixins": [
     "fabric-rendering-v1.mixins.json"

fabric-rendering-v1/src/testmod/resources/fabric.mod.json

@@ -15,7 +15,10 @@
       "net.fabricmc.fabric.test.rendering.client.FeatureRendererTest",
       "net.fabricmc.fabric.test.rendering.client.TooltipComponentTests",
       "net.fabricmc.fabric.test.rendering.client.DimensionalRenderingTest",
-      "net.fabricmc.fabric.test.rendering.client.HudAndShaderTest"
+      "net.fabricmc.fabric.test.rendering.client.HudAndShaderTest",
+      "net.fabricmc.fabric.test.rendering.client.tooltip.BundleFullnessTooltipTest",
+      "net.fabricmc.fabric.test.rendering.client.tooltip.DurabilityTooltipTest",
+      "net.fabricmc.fabric.test.rendering.client.tooltip.FoodTooltipTest"
     ]
   }
 }

fabric-rendering-v1/src/testmodClient/java/net/fabricmc/fabric/test/rendering/client/tooltip/BundleFullnessTooltipTest.java

@@ -0,0 +1,82 @@
+/*
+ * 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.test.rendering.client.tooltip;
+
+import net.minecraft.client.font.TextRenderer;
+import net.minecraft.client.gui.DrawContext;
+import net.minecraft.client.gui.tooltip.TooltipComponent;
+import net.minecraft.client.item.TooltipData;
+import net.minecraft.item.BundleItem;
+
+import net.fabricmc.api.ClientModInitializer;
+import net.fabricmc.fabric.api.client.rendering.v1.TooltipComponentCallback;
+import net.fabricmc.fabric.api.client.rendering.v1.TooltipDataCallback;
+
+public class BundleFullnessTooltipTest implements ClientModInitializer {
+	@Override
+	public void onInitializeClient() {
+		TooltipDataCallback.EVENT.register((itemStack, tooltipDataList) -> {
+			if (itemStack.getItem() instanceof BundleItem bundle) {
+				tooltipDataList.add(0, new BundleCustomTooltipData(BundleItem.getAmountFilled(itemStack)));
+			}
+		});
+		TooltipComponentCallback.EVENT.register(data -> {
+			if (data instanceof BundleCustomTooltipData bundleCustomTooltipData) {
+				return new BundleFullnessTooltipComponent(bundleCustomTooltipData.fullness);
+			}
+
+			return null;
+		});
+	}
+
+	private static class BundleCustomTooltipData implements TooltipData {
+		private final float fullness;
+		BundleCustomTooltipData(float fullness) {
+			this.fullness = fullness;
+		}
+	}
+
+	private static class BundleFullnessTooltipComponent implements TooltipComponent {
+		private static final int BAR_WIDTH = 40;
+		private static final int BAR_HEIGHT = 10;
+		private static final int GAP = 2;
+		private final float fullness;
+
+		BundleFullnessTooltipComponent(float fullness) {
+			this.fullness = fullness;
+		}
+
+		@Override
+		public int getHeight() {
+			return BAR_HEIGHT + GAP;
+		}
+
+		@Override
+		public int getWidth(TextRenderer textRenderer) {
+			return BAR_WIDTH;
+		}
+
+		@Override
+		public void drawItems(TextRenderer textRenderer, int x, int y, DrawContext context) {
+			context.getMatrices().push();
+			context.getMatrices().translate(x, y, 0);
+			context.fill(0, 0, BAR_WIDTH, BAR_HEIGHT, 0xFF3F007F);
+			context.fill(0, 0, (int) (BAR_WIDTH * fullness), BAR_HEIGHT, 0xFF7F00FF);
+			context.getMatrices().pop();
+		}
+	}
+}