Java Notepad application implements a four-phase login-to-editor sequence where User interacts with LoginFrame, validates credentials via JOptionPane, then transitions to the active Notepad editor. The diagram traces synchronous calls (solid arrows), returns (dashed arrows), and self-calls across User, LoginFrame, JOptionPane, and Notepad components during startup, authentication, instantiation, and active editing phases. This architecture enforces LoginFrame as a mandatory authentication gateway, preventing direct access to the editor and demonstrating secure state management in Swing-based desktop applications. Fork this diagram on Diagrams.so to customize authentication logic, add database integration, or adapt the sequence for your own Java GUI projects. The constraint that LoginFrame gates editor access illustrates the principle of enforcing security boundaries before granting access to protected resources.