构建不规则窗体
在开发一个新浪微博Swing客户端的过程中希望能展现不规则的窗体界面，原来
JDK 6 update 10提供了创建指定形状窗体的特性，简单易用，记于此处。(2010.05.31最后更新)
Java从JDK 6 update 10开始将内建支持构建指定形状的窗体，类com.sun.awt.AWTUtilities中的方法setWindowShape会根据不同的Shape实现去构造相应形状的窗体。AWTUtilities类是放在SUN的包中，在使用该方法时应该通过反射去进行调用，如下代码所示，
Class<?> clazz = Class.forName("com.sun.awt.AWTUtilities");
Method method = clazz.getMethod("setWindowShape", Window.class, Shape.class);
1. 创建正常窗体
先创建一个简单的界面，它使用BorderLayout，在其中安放5个JButton，如下代码所示，
public class ShapedFrame extends JFrame {
private static final long serialVersionUID = -2291343874280454383L;
private JButton centerButton = new JButton("Center");
public ShapedFrame() {
super("Shaped Frame");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initUI();
}
private void initUI() {
Container container = getContentPane();
container.setLayout(new BorderLayout());
container.add(new JButton("TOP"), BorderLayout.PAGE_START);
container.add(new JButton("RIGHT"), BorderLayout.LINE_END);
container.add(new JButton("BOTTOM"), BorderLayout.PAGE_END);
container.add(new JButton("LEFT"), BorderLayout.LINE_START);
container.add(centerButton, BorderLayout.CENTER);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ShapedFrame frame = new ShapedFrame();
frame.setSize(new Dimension(400, 300));
frame.setUndecorated(true);
setAtCenter(frame);
frame.setVisible(true);
}
});
}
// 将Window置于屏幕正中
private static void setAtCenter(Window window) {
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
window.setLocation((screenSize.width - window.getWidth()) / 2,
(screenSize.height - window.getHeight()) / 2);
}
}
执行上述程序的效果如下图所示，
2. 创建不规则窗体
基于上述程序创建不规则窗体，使整个窗体正好缺失掉RIGHT JButton所在的区域，如下代码所示，
public class ShapedFrame extends JFrame {
private static final long serialVersionUID = -2291343874280454383L;
private static Method method = null;
static {
try {
Class<?> clazz = Class.forName("com.sun.awt.AWTUtilities");
method = clazz.getMethod("setWindowShape", Window.class, Shape.class);
} catch (Exception e) {
e.printStackTrace();
}
}
private JButton centerButton = new JButton("Center");
public ShapedFrame() {
super("Shaped Frame");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initUI();
addComponentListener(componentListener);
}
private void initUI() {
Container container = getContentPane();
container.setLayout(new BorderLayout());
container.add(new JButton("TOP"), BorderLayout.PAGE_START);
container.add(new JButton("RIGHT"), BorderLayout.LINE_END);
container.add(new JButton("BOTTOM"), BorderLayout.PAGE_END);
container.add(new JButton("LEFT"), BorderLayout.LINE_START);
container.add(centerButton, BorderLayout.CENTER);
}
private ComponentListener componentListener = new ComponentAdapter() {
@Override
public void componentResized(ComponentEvent evt) { // 当UI组件(JFrame)的尺寸发生改变时，调用该方法
Rectangle frameRect = getBounds();
Rectangle spaceRect = centerButton.getBounds();
Point o1 = new Point(0, 0);
Point o2 = new Point(frameRect.width, 0);
Point o3 = new Point(frameRect.width, frameRect.height);
Point o4 = new Point(0, frameRect.height);
Point i1 = new Point(spaceRect.x + spaceRect.width, spaceRect.y);
Point i2 = new Point(frameRect.width, spaceRect.y);
Point i3 = new Point(frameRect.width, spaceRect.y
+ spaceRect.height);
Point i4 = new Point(spaceRect.x + spaceRect.width, spaceRect.y + spaceRect.height);
int[] xpoints = new int[] { o1.x, o2.x, i2.x, i1.x, i4.x, i3.x, o3.x, o4.x };
int[] ypoints = new int[] { o1.y, o2.y, i2.y, i1.y, i4.y, i3.y, o3.y, o4.y };
int npoints = 8
// 构建一个六边形，将RIGHT JButton所处的位置空缺出来
Shape shape = new Polygon(xpoints, ypoints, npoints);
setWindowShape(ShapedFrame.this, shape);
}
};
// 设置Window的形状
private static void setWindowShape(Window window, Shape shape) {
try {
method.invoke(null, window, shape);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ShapedFrame frame = new ShapedFrame();
frame.setSize(new Dimension(400, 300));
frame.setUndecorated(true);
setAtCenter(frame);
frame.setVisible(true);
}
});
}
// 将Window置于屏幕正中
private static void setAtCenter(Window window) {
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
window.setLocation((screenSize.width - window.getWidth()) / 2,
(screenSize.height - window.getHeight()) / 2);
}
}
执行上述程序后，会有如下图所示的效果，
