The Design And Implementation Of Widget Architecture In Three-dimensional Graphics System

In the current post-PC era with rapid development of information technology, embedded systems have been widely infiltrated into every aspect of people's daily life. The great integration of IT technology and the"triple play"speed up the industrialization process of the embedded system. As to digital home appliances and network development, embedded devices can now be connected to the Internet through home gateway, and constitute a family information network, so that people can enjoy the Internet services anytime, anywhere.Widget becomes nowadays the most popular element in smart phones, tablet PCs and other high-end embedded devices. Widget is a collection of small tools, refers to a variety of practical functions of entertainment, work and study. These small tools display different user customized information, such as weather, news, stocks, ticket inquires, etc., which are characterized by smart, practical, and the colorful and highly personalized appearance. The emergence of widget has made the desktop applications clear and concise but colorful, lively and interesting.Based on this background, this article has proposed a three-dimensional graphics widget structure which features cross-platform and scalable. With a clear design goals and requirements, the widget system has been implemented by two layers: the widget engine layer and the widget application layer. The article focuses on the various functional modules'design and implementation methods in widget engine layer, which is independent of specific applications and provides public function calls to the application layer with a cross-platform feature. This paper discusses program design of Clutter-based three-dimensional graphics engine; analyses the advantages and disadvantages of XML's two main parsing methods, chooses the open-source software library SCEW as XML parsing engine of the system; designs the message engine interfaces based on libdbus-glib library in detail; compares among the current main HTTP client software, chooses the open-source software library libcurl as file transfer engine, and discusses program design method based on libcurl; designs several INI file read-write APIs.The article also illustrates the main design ideas of the widget application layers, and its relations with among the various modules of the widget engine layers. The widget application layer is related with specific application. Finally, the paper implements a weather widget as an example to validate the whole widget structure. Designs its main control module and download module, and demonstrates its data structure, message definitions and work flow. The software can display short-term weather forecast of several user-customized cities, and features in facility, beautiful user interface, and various three-dimensional animations.