Restrictions In An Interactive Graphical User Interface To Meet With Debugging

In interactive GUI, a constraint is a relation that must be maintained. As a type of tools to maintain constraints automatically, constraint solver is advantaged in the separation of the description of constraint with constraint, so the user would not do the real work, all they should do is to give the description of constraints. Many user interface toolkits use constraint solver to maintain geometric relationships between graphic objects. These toolkits usually use a efficient and flexible technique桵ulti- Way Local Propagation, where constraints are represented by sets of method procedure. In this dissertation, I have designed and implemented three subsystems to demonstrate the use of constraint solver in Ul: 1. SkyBlue Solver SkyBlue Solver is a kind of constraint solver based on C++, it interpreters the description of constraint and translates them into the maintaining work efficiently. Its algorithm is SkyBlue, which is an incremental algoriffim. SkyBlue is an incremental constraint solver that uses local propagation to maintain a set of constraints as individual constraints are added and removed. If all of the constraints cannot be satisfied, SkyBlue leaves weaker constraints unsatisfied in order to satisfy stronger constraints (maintaining a constrain t hierarchy). Because of the multi-output and the cycle solving, SkyBlue Solver is very flexible. 2. COOIGT COOIGT is an interactive graphics toolkit based on constraint, it is a good proof for successful migration for Skyl3lue Solver to OOIGT. COOIGT is clear-hierarchy, efficiently and easy to programming, it抯 a powerful foi programmer to develop 2 ~ ;fl~ application which has mainframe window. 3. COOIGT Debugger it抯 very difficult for programmer to understand and control constraints when the application become difficult. COOIGT Debugger is a constraint network debug tool based on COOIGT, it can help programmer to develop exc.ellent GUI by visualizing constraint network.