Software Engineering-Implementing Tools

Once a design model is created, it is implemented as a prototype, examined by users (who fit the user model described earlier) and modified based on their comments. To accommodate this iterative design approach, a broad class of interface design and prototyping tools has evolved. Called user-interface toolkits or user-interface development systems (UIDS), these tools provide components or objects that facilitate creation of windows, menus, device interaction, error messages, commands, and many other elements of an interactive environment.

Using prepackaged software components to create a user interface, a UIDS provides built-in mechanisms for

• managing input devices (such as a mouse or keyboard)
• validating user input
• handling errors and displaying error messages
• providing feedback (e.g., automatic input echo)
• providing help and prompts

• handling windows and fields, scrolling within windows
• establishing connections between application software and the interface
• insulating the application from interface management functions
• allowing the user to customize the interface
These functions can be implemented using either a language-based or graphical approach.