fix: prevent items from being dropped

Author: DebitCardz

src/main/kotlin/me/tech/mcchestui/GUI.kt

@@ -7,16 +7,20 @@
 
 package me.tech.mcchestui
 
-import me.tech.mcchestui.attached.*
-import me.tech.mcchestui.item.*
-import me.tech.mcchestui.listeners.*
-import me.tech.mcchestui.listeners.hotbar.*
-import me.tech.mcchestui.listeners.item.*
+import me.tech.mcchestui.attached.AttachedInventoryCache
+import me.tech.mcchestui.attached.MemoryAttachedInventoryCache
+import me.tech.mcchestui.item.GUIItem
+import me.tech.mcchestui.listeners.GUICloseListener
+import me.tech.mcchestui.listeners.GUISlotClickListener
+import me.tech.mcchestui.listeners.hotbar.GUIHotbarListener
+import me.tech.mcchestui.listeners.item.GUIItemDragListener
+import me.tech.mcchestui.listeners.item.GUIItemPickupListener
+import me.tech.mcchestui.listeners.item.GUIItemPlaceListener
 import me.tech.mcchestui.utils.*
 import net.kyori.adventure.text.Component
-import org.bukkit.Material
 import org.bukkit.entity.Player
-import org.bukkit.event.*
+import org.bukkit.event.HandlerList
+import org.bukkit.event.Listener
 import org.bukkit.inventory.Inventory
 import org.bukkit.inventory.ItemStack
 import org.bukkit.inventory.PlayerInventory

src/main/kotlin/me/tech/mcchestui/listeners/GUISlotClickListener.kt

@@ -3,6 +3,7 @@ package me.tech.mcchestui.listeners
 import me.tech.mcchestui.GUI
 import org.bukkit.entity.Player
 import org.bukkit.event.EventHandler
+import org.bukkit.event.inventory.ClickType
 import org.bukkit.event.inventory.InventoryClickEvent
 
 internal class GUISlotClickListener(gui: GUI) : GUIEventListener(gui) {
@@ -16,6 +17,12 @@ internal class GUISlotClickListener(gui: GUI) : GUIEventListener(gui) {
         val guiSlot = gui.slots.getOrNull(slot)
             ?: return // handle cancellation of task in onPlace.
 
+        if(click == ClickType.DROP || click == ClickType.CONTROL_DROP) {
+            if(!guiSlot.allowPickup) {
+                isCancelled = true
+            }
+        }
+
         guiSlot.onClick?.let { uiEvent ->
             uiEvent(this, whoClicked as Player)
         }

src/main/kotlin/me/tech/mcchestui/listeners/hotbar/GUIHotbarListener.kt

@@ -2,7 +2,6 @@ package me.tech.mcchestui.listeners.hotbar
 
 import me.tech.mcchestui.GUI
 import me.tech.mcchestui.listeners.GUIEventListener
-import org.bukkit.Bukkit
 import org.bukkit.Material
 import org.bukkit.entity.Player
 import org.bukkit.event.EventHandler