From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Mon, 23 Nov 2020 12:58:51 -0800
Subject: [PATCH] Added PlayerLecternPageChangeEvent


diff --git a/src/main/java/net/minecraft/world/inventory/AbstractContainerMenu.java b/src/main/java/net/minecraft/world/inventory/AbstractContainerMenu.java
index bc39e7464646d712b085251dc0277a5b1ec0a393..b5d79635cd8b0eb6b17962450b347010aeb52654 100644
--- a/src/main/java/net/minecraft/world/inventory/AbstractContainerMenu.java
+++ b/src/main/java/net/minecraft/world/inventory/AbstractContainerMenu.java
@@ -561,6 +561,7 @@ public abstract class AbstractContainerMenu {
         this.getSlot(slot).set(stack);
     }
 
+    public void setData(int index, int value) { this.setData(index, value); } // Paper - OBFHELPER
     public void setData(int id, int value) {
         ((DataSlot) this.dataSlots.get(id)).set(value);
     }
diff --git a/src/main/java/net/minecraft/world/inventory/LecternMenu.java b/src/main/java/net/minecraft/world/inventory/LecternMenu.java
index 29e8dbc6be57faf50a8ca68eed6bf2e203b7e87a..a7be91a9336065899c409526a890e55f37b98751 100644
--- a/src/main/java/net/minecraft/world/inventory/LecternMenu.java
+++ b/src/main/java/net/minecraft/world/inventory/LecternMenu.java
@@ -11,6 +11,7 @@ import org.bukkit.craftbukkit.inventory.CraftInventoryView;
 import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerTakeLecternBookEvent;
 // CraftBukkit end
+import io.papermc.paper.event.player.PlayerLecternPageChangeEvent; // Paper
 
 public class LecternMenu extends AbstractContainerMenu {
 
@@ -58,6 +59,7 @@ public class LecternMenu extends AbstractContainerMenu {
     @Override
     public boolean clickMenuButton(net.minecraft.world.entity.player.Player player, int id) {
         int j;
+        PlayerLecternPageChangeEvent playerLecternPageChangeEvent; CraftInventoryLectern bukkitView; // Paper
 
         if (id >= 100) {
             j = id - 100;
@@ -67,11 +69,25 @@ public class LecternMenu extends AbstractContainerMenu {
             switch (id) {
                 case 1:
                     j = this.lecternData.get(0);
-                    this.setData(0, j - 1);
+                    // Paper start
+                    bukkitView = (CraftInventoryLectern) getBukkitView().getTopInventory();
+                    playerLecternPageChangeEvent = new PlayerLecternPageChangeEvent((org.bukkit.entity.Player) player.getBukkitEntity(), bukkitView.getHolder(), bukkitView.getBook(), PlayerLecternPageChangeEvent.PageChangeDirection.LEFT, j, j - 1);
+                    if (!playerLecternPageChangeEvent.callEvent()) {
+                        return false;
+                    }
+                    this.setData(0, playerLecternPageChangeEvent.getNewPage());
+                    // Paper end
                     return true;
                 case 2:
                     j = this.lecternData.get(0);
-                    this.setData(0, j + 1);
+                    // Paper start
+                    bukkitView = (CraftInventoryLectern) getBukkitView().getTopInventory();
+                    playerLecternPageChangeEvent = new PlayerLecternPageChangeEvent((org.bukkit.entity.Player) player.getBukkitEntity(), bukkitView.getHolder(), bukkitView.getBook(), PlayerLecternPageChangeEvent.PageChangeDirection.RIGHT, j, j + 1);
+                    if (!playerLecternPageChangeEvent.callEvent()) {
+                        return false;
+                    }
+                    this.setData(0, playerLecternPageChangeEvent.getNewPage());
+                    // Paper end
                     return true;
                 case 3:
                     if (!player.mayBuild()) {