Preventing item movement in inventory

src/me/yaruma/fightsystem/FightSystem.java

@@ -80,6 +80,7 @@ public class FightSystem extends JavaPlugin {
         pm.registerEvents(new PlayerTeleportListener(), plugin);
         pm.registerEvents(new ProjectileLaunchListener(), plugin);
         pm.registerEvents(new PistonListener(), plugin);
+        pm.registerEvents(new InventoryListener(), plugin);
 
         //WinConditions
         if(Config.AllDead) pm.registerEvents(new WinconditionAllDead(), plugin);

src/me/yaruma/fightsystem/listener/InventoryListener.java

@@ -0,0 +1,56 @@
+package me.yaruma.fightsystem.listener;
+
+import me.yaruma.fightsystem.FightSystem;
+import me.yaruma.fightsystem.fight.FightState;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryDragEvent;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.ItemStack;
+
+public class InventoryListener implements Listener {
+
+    @EventHandler
+    public void onInventoryClick(InventoryClickEvent event) {
+        if(FightSystem.getFightState() == FightState.SETUP){
+            event.setCancelled(true);
+            return;
+        }
+
+        Inventory clicked = event.getClickedInventory();
+        if (event.getClick().isShiftClick()) {
+                ItemStack clickedOn = event.getCurrentItem();
+
+                if (clickedOn != null && event.getView().getTopInventory().getType() != InventoryType.CRAFTING && clicked == event.getWhoClicked().getInventory()) {
+                    event.setCancelled(true);
+                }
+        }else if (clicked != event.getWhoClicked().getInventory()) {
+            ItemStack onCursor = event.getCurrentItem();
+
+            if (onCursor != null && event.getClickedInventory().getType() != InventoryType.PLAYER){
+                event.setCancelled(true);
+            }
+        }
+    }
+
+    @EventHandler
+    public void onInventoryDrag(InventoryDragEvent event) {
+        if(FightSystem.getFightState() == FightState.SETUP){
+            event.setCancelled(true);
+            return;
+        }
+
+        if (event.getInventory().getType() != InventoryType.PLAYER) {
+            int inventorySize = event.getInventory().getSize();
+
+            for (int i : event.getRawSlots()) {
+                if (i < inventorySize) {
+                    event.setCancelled(true);
+                    break;
+                }
+            }
+        }
+    }
+}