From cac8ace8524139172e0325df5fbf4ef14c849482 Mon Sep 17 00:00:00 2001
From: NichtStudioCode <51272202+NichtStudioCode@users.noreply.github.com>
Date: Sat, 18 Dec 2021 13:15:31 +0100
Subject: [PATCH] Fixed Shift-DoubleClick

---
 .../studiocode/invui/window/impl/BaseWindow.java   | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java b/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
index f6cf8c7..d35961d 100644
--- a/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
+++ b/InvUI/src/main/java/de/studiocode/invui/window/impl/BaseWindow.java
@@ -19,17 +19,22 @@ import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.api.chat.TextComponent;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
+import org.bukkit.NamespacedKey;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryDragEvent;
 import org.bukkit.event.inventory.InventoryOpenEvent;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.bukkit.persistence.PersistentDataType;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 
 public abstract class BaseWindow implements Window {
     
+    private static final NamespacedKey SLOT_KEY = new NamespacedKey(InvUI.getInstance().getPlugin(), "slot");
+    
     private final UUID viewerUUID;
     private final boolean closeOnEvent;
     private final SlotElement[] elementsDisplayed;
@@ -55,7 +60,14 @@ public abstract class BaseWindow implements Window {
     protected void redrawItem(int index, SlotElement element, boolean setItem) {
         // put ItemStack in inventory
         ItemStack itemStack;
-        if (element == null || (element instanceof VISlotElement && element.getItemStack(viewerUUID) == null)) {
+        if (element instanceof ItemSlotElement) {
+            itemStack = element.getItemStack(viewerUUID);
+            
+            // This makes every item unique to prevent Shift-DoubleClick "clicking" multiple items at the same time.
+            ItemMeta itemMeta = itemStack.getItemMeta();
+            itemMeta.getPersistentDataContainer().set(SLOT_KEY, PersistentDataType.BYTE, (byte) index);
+            itemStack.setItemMeta(itemMeta);
+        } else if (element == null || (element instanceof VISlotElement && element.getItemStack(viewerUUID) == null)) {
             ItemProvider background = getGuiAt(index).getFirst().getBackground();
             itemStack = background == null ? null : background.getFor(viewerUUID);
         } else itemStack = element.getItemStack(viewerUUID);