【正文】 ialog 和 Frame）。 從簡單到先進： Java 2D 在 Java2 平臺之前，語言中的圖形功能相當簡單，僅限于單像素厚度的實線；少數(shù)幾個幾何圖形（如橢圓、弧和多邊形）；和基本的畫圖功能。這種類型的轉(zhuǎn)換示例包括如下的操作：平移、旋轉(zhuǎn)、縮放、剪切或者這些操作的組合。這種新的 API 正在由 Java Community Process 設計。 Advanced Imaging 這個規(guī)范所涵蓋的操作將提高用戶處理圖像的能力。 這些類允許各種幾何圖形建立在雙精度或浮點精度的坐標系上。此包建立在數(shù)據(jù)傳輸?shù)臋C制上，提供了拖放功能，這些功能可以在一個單獨的 Java 應用程序內(nèi)或兩個 Java 應用程序之間以一種平臺無關的方式執(zhí)行。 語言自身已經(jīng)變得不只是一種平臺了， GUI 也正在朝著在所有平臺上都有相同的外觀和行為這種方向轉(zhuǎn)變。例如 Swing 等各種技術都是作為可選的擴展被引入的。ll explore this progression, examine the capabilities of the current version in detail, and finish by looking to the future to see what release will offer. Prior to the release of the Java 2 platform, the Abstract Window Toolkit (AWT) was the extent of the Java platform39。在本文中，我們將探究這個進步，詳細審視當前 版本的功能，最后展望一下未來，看看發(fā)行版 會提供些什么。 AWT 只提供了有限的一套組件，是因為最小公分母方法只有當一個特殊的組件或功能在每個平臺上都可用的時候才能夠被提供。 另外，您可以制作自己的 lookandfeel。如果使用第二種選擇，就可以使用 2D API 的所有附加功能。這個領域的其它 API 還有 Java 3D、 Advanced Imaging（高級圖像處理）、 Image I/O（圖像 I/O）、 Java Media Framework（ JMF，Java 媒體框架）和 Speech（語音）。 Speech Java Speech API 允許開發(fā)人員將語音技術整合到 Java applet 和應用程序的用戶界面中。多數(shù)情況下是使用雙精度值，并且角度是用弧度來度量的（而不是 Arc2D 類中使用的度）。 API 的其它部分由 層次結(jié)構中的其它包提供，包括、 和 。 建立這個橋梁的機制被稱為 可插式 LookandFeel（它很接近主題的概念，在 linux 社區(qū)中非常流行）。例如，在 UNIX 平臺上， 類是用窗口小部件 Motif PushButton 實現(xiàn)的。 a few geometric shapes such as ovals, arcs, and polygons。s take a look at an example. Enabling the disabled: Accessibility The JFC Accessibility API equips Java applications so they can be accessed by users of all abilities, including people with sight, hearing, or dexterityrelated difficulties. These might include the inability to discern visible or auditory cues or to operate a pointing device. Two of the most important features of accessibility support are screen readers and magnifiers. Screen readers allow users to interact with a GUI by creating an offscreen representation of the interface and passing this to a speech synthesizer or a Braille terminal. Screen magnifiers provide an enlarged window of the screen, typically from 2 to 16 times the normal size. They generally keep track of pointer movements and changes in input focus and adjust the enlarged view accordingly. In addition, techniques such as font smoothing may be used to create a clearer picture. The Java Accessibility Bridge Some host systems, such as Microsoft Windows, provide their own accessibility features. By default, Java applications do not fully support them. For example, with native applications the screen magnifier detects when the input focus is switched to a different user interface ponent, such as by using the Tab key, and it adjusts the portion of the screen that is being magnified to show the ponent that now has the input focus. However, Swing applications use lightweight ponents, which are treated as images by the operating system, instead of discrete ponents. This means the screen magnifier cannot track changes in input focus in the same way as with native applications. This is exactly the problem the Java Accessibility Bridge for Windows solves. It creates a map between events relating to lightweight ponents and native system events. By using the Bridge, Java applications that support the Accessibility API are then fully integrated with the Windows accessibility support. From primitive to advanced: Java 2D Before the Java 2 platform, graphical capabilities in the language were rather primitive, limited to solid lines of singlepixel thickness。 當集成有優(yōu)先權時 在 JDK 首次發(fā)行時，與本機平臺的集成被認為具有優(yōu)先權，于是 AWT 提供了一些組件，這些組件使用各平臺的本機組件（在 Java 編程術語中，這些被稱為重量級組件）來實現(xiàn)。相反，它通過提供一個可以返回本機平臺的橋梁，把兩種方法的精華部分結(jié)合起來了。 這個 API的核心是由 類提供的，該類是 的一個子類。 AffineTransform 類的實例可以直接從一個