Scene Builder
Scene Builder is a visual, layout tool for designing JavaFX app UX
...Users can configure component properties, layout constraints, styles, and event handlers through dedicated panels. It supports JavaFX controls, custom components, and external libraries. Scene Builder generates FXML documents that can be integrated into Java applications. Its compatibility with Gluon Mobile and other JavaFX technologies supports desktop and mobile development. Available for Windows, macOS, and Linux, it simplifies Java user interface design.