Add GuiItemInfoEvent

Author: Fox2Code

loader/src/main/java/com/fox2code/foxloader/event/client/GuiItemInfoEvent.java

@@ -0,0 +1,86 @@
+/*
+ * MIT License
+ * 
+ * Copyright (c) 2023-2025 Fox2Code
+ * 
+ * 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 com.fox2code.foxloader.event.client;
+
+import net.minecraft.client.gui.GuiScreen;
+import net.minecraft.common.item.ItemStack;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public final class GuiItemInfoEvent extends GuiScreenEvent {
+    private final ItemStack itemStack;
+    private List<String> description;
+
+    public GuiItemInfoEvent(GuiScreen guiScreen, ItemStack itemStack, List<String> description) {
+        super(guiScreen);
+        this.itemStack = itemStack;
+        this.description = description;
+    }
+
+    public ItemStack getItemStack() {
+        return this.itemStack;
+    }
+
+    public List<String> getDescription() {
+        return this.description;
+    }
+
+    public void setDescription(List<String> description) {
+        this.description = description == null ?
+                Collections.emptyList() : description;
+    }
+
+    public void addDescriptionLine(String line) {
+        try {
+            this.description.add(line);
+        } catch (UnsupportedOperationException e) {
+            this.description = new ArrayList<>(this.description);
+            this.description.add(line);
+        }
+    }
+
+    public void addDescriptionLine(int index, String line) {
+        int size = this.description.size();
+        if (index < 0 || index > size) {
+            throw new IndexOutOfBoundsException("Index: " + index);
+        }
+        try {
+            this.description.add(index, line);
+        } catch (UnsupportedOperationException e) {
+            this.description = new ArrayList<>(this.description);
+            this.description.add(index, line);
+        }
+    }
+
+    public boolean removeDescriptionLine(String line) {
+        try {
+            return this.description.remove(line);
+        } catch (UnsupportedOperationException e) {
+            this.description = new ArrayList<>(this.description);
+            return this.description.remove(line);
+        }
+    }
+}

loader/src/main/java/com/fox2code/foxloader/internal/InternalScreenHooks.java

@@ -24,20 +24,31 @@
 package com.fox2code.foxloader.internal;
 
 import com.fox2code.foxevents.EventHolder;
+import com.fox2code.foxloader.event.client.GuiItemInfoEvent;
 import com.fox2code.foxloader.event.client.GuiScreenInitEvent;
 import net.minecraft.client.gui.GuiElement;
 import net.minecraft.client.gui.GuiScreen;
+import net.minecraft.common.item.ItemStack;
 
 import java.util.List;
 
 public final class InternalScreenHooks {
     private static final EventHolder<GuiScreenInitEvent> GUI_SCREEN_INIT_EVENT =
             EventHolder.getHolderFromEvent(GuiScreenInitEvent.class);
+    private static final EventHolder<GuiItemInfoEvent> GUI_ITEM_INFO_EVENT =
+            EventHolder.getHolderFromEvent(GuiItemInfoEvent.class);
 
     private InternalScreenHooks() {}
 
     public static void onGuiScreenInitHook(GuiScreen guiScreen, List<GuiElement> controlList) {
         if (GUI_SCREEN_INIT_EVENT.isEmpty()) return;
         GUI_SCREEN_INIT_EVENT.callEvent(new GuiScreenInitEvent(guiScreen, controlList));
     }
+
+    public static List<String> onGuiGetItemInfoHook(List<String> description, GuiScreen guiScreen, ItemStack itemStack) {
+        if (GUI_ITEM_INFO_EVENT.isEmpty()) return description;
+        GuiItemInfoEvent guiItemInfoEvent = new GuiItemInfoEvent(guiScreen, itemStack, description);
+        GUI_ITEM_INFO_EVENT.callEvent(guiItemInfoEvent);
+        return guiItemInfoEvent.getDescription();
+    }
 }

patching/src/main/java/com/fox2code/foxloader/patching/game/GuiScreenPatch.java

@@ -28,6 +28,7 @@
 import org.objectweb.asm.tree.*;
 
 public final class GuiScreenPatch extends GamePatch {
+    private static final String ItemStack = "net/minecraft/common/item/ItemStack";
     private static final String Minecraft = "net/minecraft/client/Minecraft";
     private static final String GuiDebug = "net/minecraft/client/gui/GuiDebug";
     private static final String GuiScreen = "net/minecraft/client/gui/GuiScreen";
@@ -108,6 +109,18 @@ private static void patchGuiScreen(ClassNode classNode) {
         insnList.add(new MethodInsnNode(INVOKESTATIC, InternalScreenHooks,
                 "onGuiScreenInitHook", "(L" + GuiScreen + ";Ljava/util/List;)V"));
         TransformerUtils.insertToEndOfCode(setWorldAndResolution, insnList);
+        MethodNode getItemInfo = TransformerUtils.getMethod(classNode, "getItemInfo");
+        for (AbstractInsnNode abstractInsnNode : getItemInfo.instructions) {
+            if (abstractInsnNode.getOpcode() == ARETURN && abstractInsnNode.getPrevious().getOpcode() != ACONST_NULL) {
+                InsnList itemDescHook = new InsnList();
+                itemDescHook.add(new VarInsnNode(ALOAD, 0));
+                itemDescHook.add(new VarInsnNode(ALOAD, 1));
+                itemDescHook.add(new MethodInsnNode(INVOKESTATIC, InternalScreenHooks, "onGuiGetItemInfoHook",
+                        "(Ljava/util/List;L" +  GuiScreen + ";L" + ItemStack + ";)Ljava/util/List;", false));
+                getItemInfo.instructions.insertBefore(abstractInsnNode, itemDescHook);
+                break;
+            }
+        }
     }
 
     private void patchGuiContainer(ClassNode classNode) {