After market research , mobile terminals especially , boundary and responsibility of gui system are determined . and from a configurative perspective , three subsystems are defined and their interactions are set down ; from a portative perspective , the hierarchic architecture of gui is devised 通过研究应用领域,尤其是移动通信终端领域,来确定系统边界,明确系统责任;在总体上,从可裁减性角度划定嵌入式gui的功能子系统及其交互关系,从可移植性角度设计嵌入式gui的层次体系结构;接着,具体设计实现gdi模块。