A component- and message-based architectural style for GUI software

TLDR

GUI development consumes a large portion of application code, yet reuse has largely been limited to widget toolkits, and the proposed style may extend beyond GUI applications. The authors introduce a novel architectural style aimed at enabling larger‑grain reuse and flexible system composition. The style facilitates distributed, concurrent applications by using only asynchronous notification and request messages for intercomponent communication, while keeping components independent of lower‑level UI toolkits and unaware of the recipients of their notifications. Several trial applications demonstrate the applicability of the style.

Abstract

While a large fraction of application code is devoted to graphical user interface (GUI) functions, support for reuse in this domain has largely been confined to the creation of GUI toolkits ("widgets"). We present a novel architectural style directed at supporting larger grain reuse and flexible system composition. Moreover, the style supports design of distributed, concurrent applications. Asynchronous notification messages and asynchronous request messages are the sole basis for intercomponent communication. A key aspect of the style is that components are not built with any dependencies on what typically would be considered lower-level components, such as user interface toolkits. Indeed, all components are oblivious to the existence of any components to which notification messages are sent. While our focus has been on applications involving graphical user interfaces, the style has the potential for broader applicability. Several trial applications using the style are described.