Use Swing in Minecraft
This is a plugin library allowing you to use Swing in Minecraft.
Throw inventory GUI away
You are able to render Swing windows on maps to make interactive ingame GUI by using this repo.
No need to use ugly inventory GUI anymore!
It accepts mouse and keyboard input, so you can use it just as using it on your operating system.
What you can find about Swing are what you can do using this repo. There is no extra limitation. Just do what you want freely.
Refer to Demo.java.