There is one GUI builder in Java I forgot the name, a plugin for Eclipse from Google, that allows to build GUI by drag and drop and jump into the code. It works

There is one GUI builder in Java I forgot the name, a plugin for Eclipse from Google, that allows to build GUI by drag and drop and jump into the code. It works directly by reading and writing any java code file, there are no extra files and layers of abstraction. It could understand Swing, SWT and a couple other major UI frameworks. That's the only thing I know that's really seamless like old times.