Research And Implementation Of Efficient Extensible Graphical User Interface In Embedded Linux Environment

Along with the IT and electronic products'evolution, the embedded Linux system has been widely adopted in the field of production and life. Many embedded Linux based devices need an efficient extensible graphical user interface.In the embedded Linux environment, the overall GUI framework is similar to desktop Linux environment, but considering the system resources limit and portability, some redesign and cut out must be done on desktop Linux GUI. Currently, there are many embedded Linux GUI solutions which have different architecture and implementation, advantages and tradeoffs. In this situation, the implementation of an efficient, extensible and portable embedded GUI, has great research significance and the application value.This dissertation analyzed GUI system design principle through its concepts, studied the message driven mechanism, the window management, I/O and some other important GUI modules'principle and realization along with the GUI correlation techniques of Linux, summarized a high efficient extensible GUI system framework under the demand of low memory usage, high efficiency, reliability and portability. In addition, it also designs and implements a prototype of GUI system whose function and effectiveness is tested and validated. Specifically, the main work done in this dissertation is as follows:①It does a profound research on the GUI system structure, as well as Framebuffer, interprocess communication, I/O multiplexing and other Linux features. It also divided the GUI system into three layers, six modules. Moreover, it adopted the multi-task C/S model architecture, argued over the advantages and tradeoffs of the synchronous/asynchronous message handling, summarized the concepts of z-order, clip region, etc., formed the effective window clipping algorithm, and pointed out that the module division of graphic library, I/O abstract layer and controls has import meaning regarding the system's extension and the probability.②Based on the GUI architecture summarized previously, the present study also designs and implements a prototype of GUI system, in which, features the C/S correspondence using UNIX domain sockets, the synchronous/asynchronous message handling using I/O multiplexing and prioritized message queue, C/S display synchronization through shared memory. Meanwhile, some crucial design and implementing issues are analyzed in detail.③It validates the correctness and effectiveness of the system in simulated environment. As expected, the system can perform the window management and display function with reliability. Besides, the system has better performance on keeping the load balance between C/S hosts, improves the overall efficiency. Therefore, the design summarized in the study is proved to be effective and feasible.