The Implement Of GUI On UITron Real-Time Operation System

Historically speaking, graphical user interfaces have almost exclusively been the domain of desktop personal computers. This has been the result of two main factors: the cost of graphical display hardware and the lack of GUI software suitable for use embedded systems.In the fast-changing world of handheld and wireless devices, with the great performance improvement of the hardware, we think that the need for embedded GUI systems is urgent.Although users want the "look and feel" of Windows desktop systems, embedded systems are slower with smaller CPUs and constrained for code and variable data space with limited ROM and RAM, respectively. So GUI system for embedded systems is designed to overcome these design constraints with efficient code use while providing a sophisticated user interface.In this article, we describe the design process of an embedded GUI system and implement of its component. Firstly we set an example by introducing some kinds of embedded GUI system. Secondly, we discuss features of our RTOS - uITron and what kind of service it can provide. Thirdly, we build system architecture through OOD methods; fill in the layers by detailed component objects. In implement process, we analyze GUI architecture and find that a GUI package is basically made up of three levels: application interface, windowing, and device drivers. We describe how to build device driver and drawing interface; event and message routes; and how to implement basic window elements: desktop, window, control and their communication mechanism. At last we introduce the an example of embedded GUI system.