【作者】 康鹏；

【导师】 张永亮；

【作者基本信息】 北京工业大学 ， 计算机应用， 2003， 硕士

【摘要】 随着嵌入式设备在人们日常生活中日益广泛的使用，人们对高性能嵌入式人机图形交互界面的要求也越来越迫切。因此，嵌入式系统的关键技术——嵌入式GUI技术的研究有着相当重要的实际意义。本文论述了基于Linux的嵌入式GUI技术的研究和实践。课题以一款数字卫星机顶盒的开发为研究背景，目标是针对设备的软硬件及功能需求，在其嵌入式Linux系统之上，为图形界面应用程序开发人员搭建了一个GUI系统平台。GUI系统的整体设计涉及到GUI技术的各个方面。首先从分析OSD图形层的设备驱动入手，提出了图形显示内存和图形内存缓冲区的设计方案，为图形引擎的实现奠定了基础。随后在核心机制的考虑中充分借鉴windows的消息机制，x windows的分层思想，及嵌入式GUI系统MiniGUI的一些理论，提出了有针对性的方案。如采用了服务线程设计思想，完成外部输入事件及定时器事件的收集；GUI系统采用消息驱动的机制，对消息分发的设计中引入了窗口管理和活动窗体的概念；提出了父子关系的窗口，子窗口优先处理消息的原则。对于窗口元素的设计，我们有针对性地选择了三类窗口元素，并给出了实现方案；考虑了资源与字体支持在嵌入式系统的实现特点。在上述设计的基础上，给出了GUI软件实现部分的分层结构和模块化设计。为下一步的实现提供了清晰的思路。实现部分着重对核心机制模块重要API实现进行了说明。文章的最后2节中首先定义了一些具体窗口的数据结构及重要函数，随后给出了在该GUI系统下,使用上节提供的具体窗口来搭建一个用户图形界面的编程示例。在实际应用中所设计GUI平台有效地降低了用户图形界面开发的复杂性, 提高了开发的效率，同时程序结构比较清晰。更多还原

【Abstract】 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.更多还原