minecraft-kajetans-mod/src/main/java/me/km/networking/CustomInventory.java

package me.km.networking;

import io.netty.buffer.ByteBuf;
import java.nio.charset.StandardCharsets;
import me.km.inventory.InventoryBase;
import net.minecraft.client.Minecraft;
import net.minecraft.client.entity.EntityPlayerSP;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.IMessageHandler;
import net.minecraftforge.fml.common.network.simpleimpl.MessageContext;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;

public class CustomInventory implements IMessage
{
    private int windowId;
    private String windowTitle;
    private byte slotCount;
    private byte[] data;
    
    public CustomInventory() 
    {
        windowId = -1;
        windowTitle = "";
        slotCount = 9;
        data = new byte[14];
    }
    
    public CustomInventory(int id, InventoryBase inv) 
    {
        windowId = id;
        windowTitle = inv.getName();
        slotCount = (byte) inv.getSizeInventory();
        data = inv.getData();
    }
    
    @Override
    public void fromBytes(ByteBuf buf) 
    {
        windowId = buf.readInt();
        int length = buf.readInt();
        windowTitle = buf.readBytes(length).toString(StandardCharsets.UTF_8);
        slotCount = buf.readByte();
        for(int i = 0; i < 14; i++)
        {
            data[i] = buf.readByte();
        }
    }

    @Override
    public void toBytes(ByteBuf buf) 
    {
        buf.writeInt(windowId);
        byte[] b = windowTitle.getBytes(StandardCharsets.UTF_8);
        buf.writeInt(b.length);
        buf.writeBytes(b);
        buf.writeByte(slotCount);
        buf.writeBytes(data);
    }

    public static class Handler implements IMessageHandler<CustomInventory, IMessage>
    {
        @SideOnly(Side.CLIENT)
        @Override
        public IMessage onMessage(CustomInventory m, MessageContext ctx) 
        {
            Minecraft mc = Minecraft.getMinecraft();
            EntityPlayerSP p = mc.player;
            mc.addScheduledTask(() -> 
            {
                mc.displayGuiScreen(new CustomInventoryGui(p.inventory, new InventoryBase(m.windowTitle, m.data, m.slotCount, p)));
                p.openContainer.windowId = m.windowId;
            });
            return null;
        }
    }
}