Using Taps to Separate the User Interface from the Application Code

摘要

A new mechanism based on taps is introduced to separate the output from theapplication code in graphical interactive interfaces. The mechanism is implemented in GINA, an object-oriented application framework. Taps maintain a functional mapping from application data to interface objects that is described in a general-purpose programming language. Taps are triggered automatically by user actions. Compared to constraints or the Model-View-Controller (MVC) model, taps do not need execution or memory support from the application objects, at the expense of a performance penalty. Screen updates, which pose the largest performance problem, are minimized by checking for attribute changes and window visibility. A comparison operation is used to maintain structural consistency between hierarchies of application and interface objects. Taps can be defined interactively using formulas in a spreadsheet-like tool. (Copyright (c) GMD 1992.)