Layout managers are used to control the placement of widgets in graphical user interfaces (GUIs). Constraint-based layout managers are more powerful than other ones. However, they are also more complex and their layouts are prone to problems that usually require direct editing of constraints. Today, designers commonly use GUI builders to specify GUIs. The complexities of traditional approaches ...

This paper introduces PROOFTOOL, the graphical user interface for the General Architecture for Proof Theory (GAPT) framework. Its features are described with a focus not only on the visualization but also on the analysis and transformation of proofs and related tree-like structures, and its implementation is explained. Finally, PROOFTOOL is compared with three other graphical interfaces for pro...

Using template structures is an interesting approach to develop user interfaces. A designer can predefine such structures, following best user interface practices, to be constantly reused. However, it may be a problem to navigate through a repository of templates to find a suitable one for a certain application. Therefore, we propose a retrieval mechanism for templates based on its supported ta...

P eople rely on and use software for many tasks, ranging from launching spacecraft, writing reports, and communicating with other people. But, because of bugs, people are not always happy with software. Sometimes, software does not do what it should and this can make users unhappy or sometimes have very serious effects on the world. Software should be a tool that people can rely on, but often i...

Icons, widely used in computer programs, are part of the Graphical User Interface (GUI). They facilitate computer use regardless of users’ level of expertise. The authors report the results of a study focused on measuring performance of computer users in correctly and quickly associating toolbar icons and the action they represent in GUI. The study aimed to investigate the relationships between...