The Engineer

Tool customises computer programs

News

James Fogarty, a University of Washington assistant professor of computer science and engineering, has developed a software tool named Prefab that allows a developer to customise programs such as Microsoft Word or Adobe Photoshop to make them easier to use.

Nearly every modern computer program has a graphical interface that is implemented using some form of user-interface toolkit. These toolkits provide libraries of widgets and associated frameworks that reduce the time, effort and amount of code required to implement interfaces in computer programs.

Although such toolkits provide many important advantages, they create significant challenges for developers who would like to modify a program’s user interface to make it more accessible to those with disabilities.

A variety of target-aware pointing techniques exist that could make many interfaces easier for people with muscular dystrophy, Parkinson’s disease, cerebral palsy or other motor-control disabilities. One such tool - the bubble cursor - highlights the button closest to it, making it easier for people with disabilities to click a button without having to hit it dead on.

But, despite the promise of such interaction techniques, they are not commonly available in widely used applications. The reason for this is that they are not supported by the existing toolkits. Forgaty’s Prefab tool, however, does allow developers to add such pointing techniques to existing interfaces independently of the toolkits that have been used to implement them.

The approach is based on one thing that all user interface tookits have in common - that they paint pixels to a display. Specifically, Forgaty’s technique involves copying pixels from a source window, after which they are interpreted using the Prefab tool. Using these interpretations, enhancements such as the bubble cursor can be added and displayed in a new target window.

Prefab unlocks all previously inaccessible interfaces, allowing people to add the same tools to all the applications they run on their desktop. The system could translate a program’s interface into a different language, for example, or re-order menus to bump up favourite commands.

’Microsoft and Apple aren’t going to open up all their stuff. But they all create programs that put pixels on the screen. And by modifying those pixels, then we can change a program’s apparent behaviour,’ said Fogarty.

The researchers are continuing to develop Prefab and are exploring options for commercialisation.