Framework For Operating System Internationalization: Research And Implementation

Operating system provides internationalization services for applications, which generally indicates that to what extent internationalization of applications can be attained. A well built-in internationalization framework can be easily localized to adapt to all sorts of different local environments by means of separating culture-related or script-related data from common processes. Based on comparing and categorizing the orthographies of the world's scripts, the most important parts of operating system internationalization have been working on in this dissertation and six achievements have been obtained.First, after analyzing the limitations derived from POSIX, an implementation framework of operating system based on Unicode standard has been described. This framework can extend the scope of processing multi-script text in file system and run-time libraries of operating system. Owing to the compatibility with POSIX, a solution utilizing the encoding of UTF-8 has been adopted.Second, an international text processing reference model based on pipe-filter paradigm has been presented, which aims to enhance the ability to support those new scripts more easily in operating system. This reference model consists of several parts, which include: the scope and content of text processing are clarified; the strategy on processing multi-script text is proposed; the structure of this model is proposed, which differentiates between general modules and those modules related to scripts; technical solutions are discussed to solve all sorts of different features of the world's scripts; a standardized process of international text processing is summarized. Based on this reference model, Qt library has been extended to satisfy the requirement of international text processing.Third, a GUI multi-script adaptability model at the widget level has been proposed, which aims to meet the requirement of international GUI. Based on an analysis of writingstyles of the world's scripts, different GUI styles are discussed. To achieve script-oriented adaptability of GUI, any interactive widget or layout object is considered as a combination of logical object, which is design-time object, and interactive object, which is run-time object. Thus by means of a graphical library conforming to this model it can be available to develop GUI of international application which is developed once and can run in any local environment related to certain script. An extension of Qt library conforming to this model has been fulfilled.Fourth, traditional Mongolian localized system has been designed. Because traditional Mongolian is written vertically from top to bottom in columns advancing from left to right and its letters always change their shapes depending on different conditions, it's more difficult to implement a operating system supporting this script. There is no operating system fully supporting this script yet. Based on above models, designs related to this script are detailed, which include: displaying transformed forms of its letters, presenting Mongolian text vertically and adopting GUI with a style of IS_TTB-LTR.Fifth, Tibetan localized system has been designed, which conforms to ISO/IEC 10646. Tibetan text is spelled by overlapping its characters to form some vertically stacked characters, which is considered as a bottleneck to presenting Tibetan text. Within the framework of text processing reference model the most important issues are detailed, which include: displaying Tibetan stacked characters by a way of partitioning Tibetan syllables and applying an OpenType font, analyzing transformation of consonants and presenting Tibetan text transliterating Sanskrit text.Sixth, Uighur localized system has been designed. Uighur script used in China is written from right to left. Same letter may be written in different forms depending on how it joins with its neighbors. Some issues related to this script are discussed, which include: displaying transformed forms of Uighur characters, handling bidirectionality of Uighur script and adopting GUI with a style of IS.RTL...