Visual Composition of Component Systems

Component composition has been remaining over a decade a (design) concept, but not found its way into practical programming which is usually still done in the classical reference-based way. A new generation of component languages like ArchJava has pushed forwards composition of subcomponents. But these languages fall back into class-based programming of methods when Java program code is to be written e.g. as a filter among subcomponents. In contrast, the CompJava Designer, a graphical editor, allows constructing relatively complex and distributed component systems for practical applications by a seamless visual composition process. It uses extended UML 2 component diagrams that allow visualizing the compositional structure of components in order to better understand and communicate it. The designer is based on the component language CompJava that has introduced component fragments and plugs as means for composing a component both from subcomponents and structured units of code.