Add event for player changing game mode (#7355)

patches/minecraft/net/minecraft/client/network/play/NetworkPlayerInfo.java.patch

@@ -0,0 +1,10 @@
+--- a/net/minecraft/client/network/play/NetworkPlayerInfo.java
++++ b/net/minecraft/client/network/play/NetworkPlayerInfo.java
+@@ -50,6 +50,7 @@
+    }
+ 
+    protected void func_178839_a(GameType p_178839_1_) {
++      net.minecraftforge.client.ForgeHooksClient.onClientChangeGameMode(this, this.field_178866_b, p_178839_1_);
+       this.field_178866_b = p_178839_1_;
+    }
+ 

patches/minecraft/net/minecraft/entity/player/ServerPlayerEntity.java.patch

@@ -130,7 +130,15 @@
     }
  
     protected void func_70670_a(EffectInstance p_70670_1_) {
-@@ -1187,6 +1208,7 @@
+@@ -1139,6 +1160,7 @@
+    }
+ 
+    public void func_71033_a(GameType p_71033_1_) {
++      if (!net.minecraftforge.common.ForgeHooks.onChangeGameMode(this, this.field_71134_c.func_73081_b(), p_71033_1_)) return;
+       this.field_71134_c.func_73076_a(p_71033_1_);
+       this.field_71135_a.func_147359_a(new SChangeGameStatePacket(SChangeGameStatePacket.field_241767_d_, (float)p_71033_1_.func_77148_a()));
+       if (p_71033_1_ == GameType.SPECTATOR) {
+@@ -1187,6 +1209,7 @@
        this.field_71140_co = p_147100_1_.func_149520_f();
        this.func_184212_Q().func_187227_b(field_184827_bp, (byte)p_147100_1_.func_149521_d());
        this.func_184212_Q().func_187227_b(field_184828_bq, (byte)(p_147100_1_.func_186991_f() == HandSide.LEFT ? 0 : 1));
@@ -138,7 +146,7 @@
     }
  
     public ChatVisibility func_147096_v() {
-@@ -1297,14 +1319,14 @@
+@@ -1297,14 +1320,14 @@
        this.func_184210_p();
        if (p_200619_1_ == this.field_70170_p) {
           this.field_71135_a.func_147364_a(p_200619_2_, p_200619_4_, p_200619_6_, p_200619_8_, p_200619_9_);
@@ -156,7 +164,7 @@
           this.func_70012_b(p_200619_2_, p_200619_4_, p_200619_6_, p_200619_8_, p_200619_9_);
           this.func_70029_a(p_200619_1_);
           p_200619_1_.func_217446_a(this);
-@@ -1313,6 +1335,7 @@
+@@ -1313,6 +1336,7 @@
           this.field_71134_c.func_73080_a(p_200619_1_);
           this.field_71133_b.func_184103_al().func_72354_b(this, p_200619_1_);
           this.field_71133_b.func_184103_al().func_72385_f(this);
@@ -164,7 +172,7 @@
        }
  
     }
-@@ -1335,6 +1358,7 @@
+@@ -1335,6 +1359,7 @@
     }
  
     public void func_242111_a(RegistryKey<World> p_242111_1_, @Nullable BlockPos p_242111_2_, float p_242111_3_, boolean p_242111_4_, boolean p_242111_5_) {
@@ -172,7 +180,7 @@
        if (p_242111_2_ != null) {
           boolean flag = p_242111_2_.equals(this.field_241138_cr_) && p_242111_1_.equals(this.field_241137_cq_);
           if (p_242111_5_ && !flag) {
-@@ -1387,6 +1411,8 @@
+@@ -1387,6 +1412,8 @@
        if (itementity == null) {
           return null;
        } else {
@@ -181,7 +189,7 @@
           this.field_70170_p.func_217376_c(itementity);
           ItemStack itemstack = itementity.func_92059_d();
           if (p_146097_3_) {
-@@ -1400,4 +1426,13 @@
+@@ -1400,4 +1427,13 @@
           return itementity;
        }
     }

src/main/java/net/minecraftforge/client/ForgeHooksClient.java

@@ -32,6 +32,7 @@ import net.minecraft.client.gui.ClientBossInfo;
 import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.gui.screen.MainMenuScreen;
 import net.minecraft.client.gui.screen.Screen;
+import net.minecraft.client.network.play.NetworkPlayerInfo;
 import net.minecraft.client.renderer.*;
 import net.minecraft.client.renderer.FogRenderer.FogType;
 import net.minecraft.client.renderer.color.BlockColors;
@@ -72,6 +73,7 @@ import net.minecraft.util.math.vector.Vector3f;
 import net.minecraft.util.text.ITextComponent;
 import net.minecraft.util.text.TextFormatting;
 import net.minecraft.util.text.TranslationTextComponent;
+import net.minecraft.world.GameType;
 import net.minecraft.world.IBlockDisplayReader;
 import net.minecraftforge.client.event.*;
 import net.minecraftforge.client.event.sound.PlaySoundEvent;
@@ -562,6 +564,15 @@ public class ForgeHooksClient
         return event;
     }
 
+    public static void onClientChangeGameMode(NetworkPlayerInfo info, GameType currentGameMode, GameType newGameMode)
+    {
+        if (currentGameMode != newGameMode)
+        {
+            ClientPlayerChangeGameModeEvent evt = new ClientPlayerChangeGameModeEvent(info, currentGameMode, newGameMode);
+            MinecraftForge.EVENT_BUS.post(evt);
+        }
+    }
+
     @SuppressWarnings("deprecation")
     public static IBakedModel handlePerspective(IBakedModel model, ItemCameraTransforms.TransformType type, MatrixStack stack)
     {

src/main/java/net/minecraftforge/client/event/ClientPlayerChangeGameModeEvent.java

@@ -0,0 +1,37 @@
+package net.minecraftforge.client.event;
+
+import net.minecraft.client.network.play.NetworkPlayerInfo;
+import net.minecraft.world.GameType;
+import net.minecraftforge.eventbus.api.Event;
+
+/**
+ * Fired before the client player is notified of a change in game mode from the server.
+ */
+public class ClientPlayerChangeGameModeEvent extends Event
+{
+    private final NetworkPlayerInfo info;
+    private final GameType currentGameMode;
+    private final GameType newGameMode;
+
+    public ClientPlayerChangeGameModeEvent(NetworkPlayerInfo info, GameType currentGameMode, GameType newGameMode)
+    {
+        this.info = info;
+        this.currentGameMode = currentGameMode;
+        this.newGameMode = newGameMode;
+    }
+
+    public NetworkPlayerInfo getInfo()
+    {
+        return info;
+    }
+
+    public GameType getCurrentGameMode()
+    {
+        return currentGameMode;
+    }
+
+    public GameType getNewGameMode()
+    {
+        return newGameMode;
+    }
+}

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -789,6 +789,17 @@ public class ForgeHooks
         MinecraftForge.EVENT_BUS.post(new PlayerInteractEvent.LeftClickEmpty(player));
     }
 
+    public static boolean onChangeGameMode(PlayerEntity player, GameType currentGameMode, GameType newGameMode)
+    {
+        if (currentGameMode != newGameMode)
+        {
+            PlayerEvent.PlayerChangeGameModeEvent evt = new PlayerEvent.PlayerChangeGameModeEvent(player, currentGameMode, newGameMode);
+            MinecraftForge.EVENT_BUS.post(evt);
+            return !evt.isCanceled();
+        }
+        return true;
+    }
+
     private static ThreadLocal<Deque<LootTableContext>> lootContext = new ThreadLocal<Deque<LootTableContext>>();
     private static LootTableContext getLootTableContext()
     {

src/main/java/net/minecraftforge/event/entity/player/PlayerEvent.java

@@ -25,6 +25,7 @@ import net.minecraft.entity.item.ItemEntity;
 import net.minecraft.inventory.IInventory;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.RegistryKey;
+import net.minecraft.world.GameType;
 import net.minecraft.world.World;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.ForgeEventFactory;
@@ -510,4 +511,40 @@ public class PlayerEvent extends LivingEvent
             return this.toDim;
         }
     }
+
+    /**
+     * Fired when the game type of a server player is changed to a different value than what it was previously. Eg Creative to Survival, not Survival to Survival.
+     * If the event is cancelled the game mode of the player is not changed and the value of <code>newGameMode</code> is ignored.
+     */
+    @Cancelable
+    public static class PlayerChangeGameModeEvent extends PlayerEvent
+    {
+        private final GameType currentGameMode;
+        private GameType newGameMode;
+
+        public PlayerChangeGameModeEvent(PlayerEntity player, GameType currentGameMode, GameType newGameMode)
+        {
+            super(player);
+            this.currentGameMode = currentGameMode;
+            this.newGameMode = newGameMode;
+        }
+
+        public GameType getCurrentGameMode()
+        {
+            return currentGameMode;
+        }
+
+        public GameType getNewGameMode()
+        {
+            return newGameMode;
+        }
+
+        /**
+         * Sets the game mode the player will be changed to if this event is not cancelled.
+         */
+        public void setNewGameMode(GameType newGameMode)
+        {
+            this.newGameMode = newGameMode;
+        }
+    }
 }

src/test/java/net/minecraftforge/debug/entity/player/PlayerGameModeEventTest.java

@@ -0,0 +1,53 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.debug.entity.player;
+
+import net.minecraft.world.GameType;
+import net.minecraftforge.client.event.ClientPlayerChangeGameModeEvent;
+import net.minecraftforge.event.entity.player.PlayerEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Mod("player_game_mode_event_test")
+@Mod.EventBusSubscriber()
+public class PlayerGameModeEventTest
+{
+    private static final boolean ENABLE = false;
+    private static final Logger LOGGER = LogManager.getLogger(PlayerGameModeEventTest.class);
+
+    @SubscribeEvent
+    public static void onPlayerChangeGameModeEvent(PlayerEvent.PlayerChangeGameModeEvent event)
+    {
+        if (!ENABLE) return;
+        LOGGER.info("{} changed game mode. Current GameType: {}. New Game Type: {}", event.getPlayer(), event.getCurrentGameMode(), event.getNewGameMode());
+        if (event.getNewGameMode() == GameType.SURVIVAL)
+            event.setCanceled(true);
+    }
+
+    @SubscribeEvent
+    public static void onClientPlayerChangeGameModeEvent(ClientPlayerChangeGameModeEvent event)
+    {
+        if (!ENABLE) return;
+        LOGGER.info("Client notified of changed game mode from '{}'. Current GameType: {}. New Game Type: {}", event.getInfo().getGameProfile(), event.getCurrentGameMode(), event.getNewGameMode());
+    }
+}

src/test/resources/META-INF/mods.toml

@@ -88,5 +88,7 @@ license="LGPL v2.1"
     modId="custom_tag_types_test"
 [[mods]]
     modId="biome_loading_event_test"
+[[mods]]
+    modId="player_game_mode_event_test"
 [[mods]]
     modId="structure_spawn_list_event_test"