The Research And Implementation Of Graphic User System Based On Qt/Embedded In Power Quality Monitoring Instrument

Because the popularization of the Windows series operating system makes the graphic operation rooted in the hearts of the people, at the same time as information white goods, handheld device , wireless terminal, complicated industry equipment accuse of the rapid development, the demand of embedded system increase gradually, and require even high. To offer the embedded system one friendship convenient and reliable GUI system becomes urgent demand.This thesis regards power quality monitoring instruments as the background of using, GUI system in embedded Linux system as the research object, from the theory, technology, design and using three levels to carry on research and will put the emphases in Qt/Embedded system especially.Embedded GUI is a graphic user interface system designed for specific software and hardware equipment or environment in the embedded system. The design philosophy of embedded GUI system and basic principle theoretically is analyzed at first in this paper. Then some embedded GUI systems are analyzed and compared in structure, implementation method and performance. The leading Qt/Embedded system on technology is analyzed deeply. Qt/Embedded adopts the system structure of layers. The graphic engine in the bottom has abandoned Xlib, and can operate the framebuffer directly. The engine has realized not only such basic graphic functions as pixel, line, packing, clipping, area, etc. but also such advanced functions as Alpha mixture. The window system of the intermediate level bases on the steady server/customer mode, and supports the thread mechanism. Compatible Qt families API are offered in the upper layer.The graphic user system in the power quality monitoring instruments has such special demands as process independence, communication and cross-platform capacity, therefore Qt/Embedded is chosen as supporting platform. Two key questions about the embedded development of Qt/Embedded are put forward. One is cross-platform porting the other is localization. A frame of framebuffer driver is described in this paper. The localization of Qt/Embedded lies how to display and input Chinese characters. The displaying of Chinese would be implemented through the...