Move material check into book filter

Author: minoneer

src/main/java/me/minoneer/bukkit/bookexploit/BookFilter.java

@@ -2,6 +2,7 @@
 
 import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.api.chat.ClickEvent;
+import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.BookMeta;
 import org.bukkit.inventory.meta.ItemMeta;
@@ -30,6 +31,10 @@ public ItemStack filterBook(@Nullable final ItemStack originalItem) {
             return null;
         }
 
+        if (originalItem.getType() != Material.WRITTEN_BOOK && originalItem.getType() != Material.WRITABLE_BOOK) {
+            return null;
+        }
+
         ItemStack newItem = originalItem.clone();
 
         ItemMeta itemMeta = newItem.getItemMeta();

src/main/java/me/minoneer/bukkit/bookexploit/BookListener.java

@@ -1,6 +1,5 @@
 package me.minoneer.bukkit.bookexploit;
 
-import org.bukkit.Material;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -52,9 +51,6 @@ public void onBookRead(@NotNull final PlayerInteractEvent event) {
         if (event.getAction() != Action.RIGHT_CLICK_AIR && event.getAction() != Action.RIGHT_CLICK_BLOCK) {
             return;
         }
-        if (event.getItem() == null || event.getItem().getType() != Material.WRITTEN_BOOK) {
-            return;
-        }
         if (player.hasPermission("bookfilter.overridefilter")) {
             return;
         }