BI-Directional Text Editing And Displaying Based On Android Platform

Smartphone has become one of the main equipment to acquire information with the rapid development of the information technology and particularly the development of the new generation mobile internet devices. Especially since November12,2007, the Open Handset Alliance released the first edition of Google Android SDK. Android operating system swept the world quickly by its huge advantage of open-source. Two years ago,the android operating system has been beyond Nokia’s Symbian operation system which dominates the markets for decades. However, the display of the Arabic characters is not supported on the android platform2.3.To display the Arabic characters on the android2.3platform will promote the development of economic and information in the Middle East region.In this paper, according to the characteristics of Arabic writing, the bi-directional text displaying layout engine were designed and realized based on the existing system, The bidirectional text editor based on Android platform with the this engine was implemented as well. The main content and results of this paper are as follows:1:The design and implementation of the bi-directional text layout engine. The bi-directional text layout engine process is aimed to solve two problems:1):Firstly, the display of the bi-directional text. For bi-directional text, the ordering between logical and visual is various. The logical sequence should be converted to visual order during the display processing. Bi-directional text would be displayed correctly by this way.2):Secondly, the Arabic characters deformation problem. The Arabic characters’ name letters and displaying letters are inconsistent as the same name letter may be written in different displaying forms depending on its position in the sentence. A certain deformation processing is required in order to display Arabic characters correctly.2:The bi-directional text editor is designed and implemented based on android platform by using the realized bi-directional text displaying layout engine. It supports the Arab character inputting, bi-directional text displaying and the basic text manipulation features, such as text saving, creating, deleting, insertion of characters, font size settings, color settings, and text alignment settings.