gistfile1.txt

public class MessageKeyPressed implements IMessage, IMessageHandler<MessageKeyPressed, IMessage> {

    private byte keyPressed;

    public MessageKeyPressed() {

    }

    public MessageKeyPressed(Key key) {
        if (key == Key.TRADE) {
            this.keyPressed = (byte) key.TRADE.ordinal();

        } else {
            this.keyPressed = (byte) key.UNKNOWN.ordinal();
        }
    }

    @Override
    public void fromBytes(ByteBuf buf) {
        this.keyPressed = buf.readByte();
    }

    @Override
    public void toBytes(ByteBuf buf) {
        buf.writeByte(keyPressed);
    }

    @Override
    public IMessage onMessage(MessageKeyPressed message, MessageContext ctx) {
        LogHelper.info("Keypressed!");
        EntityPlayer entityPlayer = ctx.getServerHandler().playerEntity;

        if (entityPlayer != null)
        {
            if (message.keyPressed == Key.TRADE.ordinal())
            {
                LogHelper.info("Starting GUI!");
                entityPlayer.openGui(TradeMC.instance, GuiId.TRADE_PLAYER.ordinal(), Minecraft.getMinecraft().theWorld, 0, 0, 0);
            }
        }

        return null;
    }
}