The Design And Implement Of Graphical User Interface Framework Based On Stb System

As embedded devices are used everywhere, the requirement of the high performance embedded graphics user interface is demanded. Thus, the research of the key technology of embedded system——Embedded GUI technology is most important .This article describes the research and practice based on embedded GUI technology of Linux. Our project regard the development of a digital set top box as the background of studying, aiming at the implement of a GUI system based on the embedded Linux system. The design of GUI system involves most respects of GUI technology. Firstly, we analysed the OSD graphics device driver, puting forward the design of graphical display memory and memory buffer. This is the foundation for the development of the graphics engine. Secondly, on the consideration of the key mechanism, we learn from the message mechanism of windows, layer thoughts of x windows and some theories of embedded GUI system MiniGUI. Then we put forward the scheme, in which server threads are used to get message from input devices, and GUI system adopts the mechanism drived by the message. In the design of message distribution, we introduce the concepts of windows' management and active window body. The sub-window has priority to deal with the messages. In the design of windows' elements, we choose three kinds of window elements as the main objects and realized them.Based on the methods mentioned above, we put forward layers of structure and module designs of GUI systems, which offer the theoretic foundation for the next work. Consequently, we put emphasis on the implementation of the core APIs. In the end of the paper, we define data structures and some important windows' functions, on which the graphic user interface is builded.In practice, the GUI platform we proposed has reduced the complication of GUI programming effectively. Besides, the structure of programming on this platform becomes clear.