適合嵌入式平台Java ME CLDC的Java AWT的設計

Abstract

就目前的趨勢，Java嵌入式環境是未來的重要的發展。隨著數位化、自動化裝置越來越先進，圖形使用者介面的發展也要隨之跟進，讓科技能進步不會只限於在研究領域，更能讓一般大眾能享受到其中的便利與好處。結合這兩大方向，相信在Java嵌入式環境中開發Graphics User Interface(GUI)系統到未來都會是不斷探討的主題。在分析JavaME CDC/PBP的GUI系統，Java AWT中，我們參考並保留大部分原有的應用程式介面，設計並提出適合在Java ME CLDC環境中的GUI系統，命名為MMES AWT。相較於JavaME CDC/PBP的Java AWT，MMES AWT的class集合較為簡化、需要系統class的支援也較少，native function由KNI實作，需要native graphics library的支援較簡單。並提供thread-safe機制確保Event handling運作安全。目前支援基本的輸出輸入功能。實驗結果在畫面輸出上細微處差異，其他大致相同甚至精緻一點點。輸入的部分也可以正確偵測到滑鼠、鍵盤的訊息。MMES AWT是一個較為簡化的GUI系統，方便移植、實作之外，之後也可以為基礎，深入的發展成其它的用途，例如3D圖形庫等等。

As the trend, Java embedded system is more and more important evolvement. Graphics user interface(GUI) is accompanied with this trend. Advance technology is not common to the public, and it’s not really convenient in practice. Combined above two directions, GUI system in Java embedded environment is a growing research topics in the future. According to Java AWT in JavaME CDC/PBP，we simplified the Java AWT classes, and remains most part of API, and designs a GUI system for JavaME CLDC, named MMES AWT. Compared with Java AWT in JavaME CDC/PBP, MMES AWT has less classes, less system classes supporting, KNI implementing native functions, native graphics library supporting simpler, and provides thread-safe mechanism. MMES AWT experiments two basic GUI system functions, displaying and accepting mouse, keyboard messages. In experiment results, two functions successfully implement and displaying almost looks same with PBP AWT. MMES AWT is a basic, simple GUI system. It’s convenient to implementing in other way or porting to other platform. And it is also a basis for advance development, ex 3D GUI.