为JEdit设置墙纸(add wallpaper for jedit)

1). 前提(condition)+ jedit4.2final+ jdk 1.42). 步骤(steps)1. add this at org.gjt.sp.jedit.textarea.TextAreaPainterin method paintComponent(...)after:        extensionMgr.paintScreenLineRange(textArea, gfx, firstInvalid,                lastInvalid, y, height);add:        { // paint wallpaper after all that should be paint        Rectangle rect = this.getVisibleRect();        Wallpaper.paintWallpaper(gfx, rect.x, rect.y, rect.width,                rect.width, this);        }        2. add in org.gjt.sp.jedit.textarea.JEditTextArea        //    {{{ changeWallpaperDialog() method   // for change the wallpaper    /**         * Displays the 'changeWallpaperDialog' dialog box.     * @author neoedmund     */    public void changeWallpaperDialog()    {            if (Wallpaper.changeWallpaper(this)){            repaint();                }    } //}}}3. add new class org.gjt.sp.jedit.textarea.Wallpaper/* * Created on 2005-3-26 */package org.gjt.sp.jedit.textarea;import java.awt.AlphaComposite;import java.awt.Composite;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import javax.imageio.ImageIO;import javax.swing.JComponent;import javax.swing.JFileChooser;/** * @author neoe */public class Wallpaper {        static BufferedImage pic;    private static final String DEFALUT_IMG = "org/gjt/sp/jedit/icons/wallpaper.jpg";    static{        System.out.println("hello Wallpaper");        loadPic(ClassLoader                .getSystemResourceAsStream(DEFALUT_IMG));            }        static AlphaComposite alpha = AlphaComposite.getInstance(            AlphaComposite.SRC_OVER, 0.2f);    /**     * @param gfx     * @param width     * @param height     */    public static void paintWallpaper(Graphics2D g, int cx, int cy, int width, int height, JComponent view) {        if (pic==null){            return;        }        int y = 0;        int w = pic.getWidth();        int h = pic.getHeight();        Composite old = g.getComposite();        g.setComposite(alpha);        while (true) {            int x = 0;            while (true) {                g.drawImage(pic, cx+x, cy+y, view);                x += w;                if (w <= 0 || x >= width) {                    break;                }            }            y += h;            if (h <= 0 || y >= height) {                break;            }        }        g.setComposite(old);    }    /**     * @param in     */    private static void loadPic(InputStream in) {        try {            pic = ImageIO.read(in);        } catch (IOException e) {                        e.printStackTrace();        }            }    static File f;    /**     *      */    public static boolean changeWallpaper(JComponent parent) {        JFileChooser jfc = new JFileChooser(f);        int returnVal = jfc.showOpenDialog(parent);        if (returnVal == JFileChooser.APPROVE_OPTION) {            f = jfc.getSelectedFile();            try {                loadPic(new FileInputStream(f));                return true;            } catch (IOException e1) {             &nb