Add IContainerFactory for reading custom container data on the client

src/main/java/net/minecraftforge/common/extensions/IForgeContainerType.java

@@ -0,0 +1,16 @@
+package net.minecraftforge.common.extensions;
+
+import net.minecraft.entity.player.PlayerInventory;
+import net.minecraft.inventory.container.Container;
+import net.minecraft.inventory.container.ContainerType;
+import net.minecraft.network.PacketBuffer;
+
+public interface IForgeContainerType<T>
+{
+    static <T extends Container> ContainerType<T> create(net.minecraftforge.fml.network.IContainerFactory<T> factory)
+    {
+        return new ContainerType<>(factory);
+    }
+    
+    T create(int windowId, PlayerInventory playerInv, PacketBuffer extraData);
+}

src/main/java/net/minecraftforge/fml/network/FMLPlayMessages.java

@@ -21,11 +21,13 @@ package net.minecraftforge.fml.network;
 
 import io.netty.buffer.Unpooled;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.IHasContainer;
 import net.minecraft.client.gui.ScreenManager;
 import net.minecraft.client.gui.screen.Screen;
 import net.minecraft.client.world.ClientWorld;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
+import net.minecraft.inventory.container.Container;
 import net.minecraft.inventory.container.ContainerType;
 import net.minecraft.network.PacketBuffer;
 import net.minecraft.util.ResourceLocation;
@@ -208,8 +210,14 @@ public class FMLPlayMessages
         public static void handle(OpenContainer msg, Supplier<NetworkEvent.Context> ctx)
         {
             ctx.get().enqueueWork(() -> {
-                // TODO extend IScreenFactory to allow for extra data
-                ScreenManager.openScreen(msg.getType(), Minecraft.getInstance(), msg.getWindowId(), msg.getName());
+                ScreenManager.getScreenFactory(msg.getType(), Minecraft.getInstance(), msg.getWindowId(), msg.getName())
+                             .ifPresent(f -> {
+                                 Container c = msg.getType().create(msg.getWindowId(), Minecraft.getInstance().player.inventory, msg.getAdditionalData());
+                                 @SuppressWarnings("unchecked")
+                                 Screen s = ((ScreenManager.IScreenFactory<Container, ?>)f).create(c, Minecraft.getInstance().player.inventory, msg.getName());
+                                 Minecraft.getInstance().player.openContainer = ((IHasContainer<?>)s).getContainer();
+                                 Minecraft.getInstance().displayGuiScreen(s);
+                             });
             });
             ctx.get().setPacketHandled(true);
         }

src/main/java/net/minecraftforge/fml/network/IContainerFactory.java

@@ -0,0 +1,17 @@
+package net.minecraftforge.fml.network;
+
+import net.minecraft.entity.player.PlayerInventory;
+import net.minecraft.inventory.container.Container;
+import net.minecraft.inventory.container.ContainerType;
+import net.minecraft.network.PacketBuffer;
+
+public interface IContainerFactory<T extends Container> extends ContainerType.IFactory<T>
+{
+    T create(int windowId, PlayerInventory inv, PacketBuffer data);
+    
+    @Override
+    default T create(int p_create_1_, PlayerInventory p_create_2_)
+    {
+        return create(p_create_1_, p_create_2_, null);
+    }
+}