Go check it out!
https://www.bit-101.com/MinimalDesigner/
Still lots to do. As far as the properties panel goes, the first column should pretty much work. The second column partially works. The others, not at all. As far as code generation, it just generates a list of the components with constructors and sets any properties (right now only width and height, as needed). Eventually, I plan to make it generate a full class. Also, you have a limited list of components to work with. No container classes (Panel, Window, HBox, or VBox) yet, and none of the more esoteric components. But this should be enough to do some basic layouts, which will actually compile. 🙂
I’m not even sure if anyone will even find this useful, but I’m having a lot of fun making it, so there you go.