/* * 文件名:PrintableTextArea.java * 說  明:文本編輯框,實現了Printable接口,可打印文字 */// 導入相關包import java.awt.*;import java.io.*;import java.awt.print.*;import javax.swing.*;import javax.swing.text.*;// 主類PrintableTextAreaclass PrintableTextArea extends JTextArea                        implements Printable {  // 屬性聲明  String str;  Font font;  PrinterJob pj;  PageFormat defaultFormat;  int visiblePageWidth = 0, visiblePageHeight = 0;  final static int PageX = 10, PageY = 10;    // 構造方法  PrintableTextArea(int rows, int columns) {    super(rows, columns);  }    // 打印方法  public void printIt(String str, Font font) {    this.str = str;    this.font = font;    pj = PrinterJob.getPrinterJob();    defaultFormat = pj.defaultPage();    pj.setPrintable(this, defaultFormat);    visiblePageWidth = (int)defaultFormat.getImageableWidth();    visiblePageHeight = (int)defaultFormat.getImageableHeight();    if(pj.printDialog()) {      try {        pj.print();      } catch(PrinterException e) {      }    }  }  // print方法  public int print(Graphics g, PageFormat pf, int page) throws PrinterException {    if(page >= 1)      return Printable.NO_SUCH_PAGE;    Graphics2D g2 = (Graphics2D) g;    g2.translate((int)pf.getImageableX(), (int)pf.getImageableY());    g2.setFont(font);    int fontHeight = 0, fontStringWidth = 0;    int line = 0;    String s = null;    FontMetrics fm = getFontMetrics(font);    fontHeight = fm.getHeight();    try{      DataOutputStream osw = new DataOutputStream(new FileOutputStream("$temp.$$p"));      osw.writeBytes(str);      osw.close();    } catch(IOException e) {    }    try {      BufferedReader br = new BufferedReader(new FileReader("$temp.$$p"));      s = br.readLine();      while(s != null) {        if(s.length() == 0)          g2.drawString(" ", PageX, PageY + fontHeight*(line++));        else {          //g2.drawString(s, PageX, PageY + fontHeight*(line++));          fontStringWidth = fm.stringWidth(s);          if(fontStringWidth > visiblePageWidth) {            String s1, s2;            int goBack = 0;            while( fm.stringWidth(s1 = s.substring(0, s.length() - goBack)) >                   visiblePageWidth) {              goBack++;            }            s1 = s.substring(0, s.length() - goBack);            s2 = s.substring(s.length() - goBack - 1);            g2.drawString(s1, PageX, PageY + fontHeight*(line++));            g2.drawString(s2, PageX, PageY + fontHeight*(line++));          }          else {            g2.drawString(s, PageX, PageY + fontHeight*(line++));          }        }        s = br.readLine();      }      br.close();    } catch(IOException e) {    }    return Printable.PAGE_EXISTS;  }}/* other usefull functionsPageFormat defaultFormat = pj.defaultPage();defaultFormat.getImageableX();defaultFormat.getImageableY();defaultFormat.getWidth();defaultFormat.getHeight();defaultFormat.getImageableWidth();defaultFormat.getImageableHeight();PageFormat selectedFormat = pj.pageDialog(defaultFormat);selectFormat.getImageableX();selectFormat.getImageableY();selectFormat.getWidth();selectFormat.getHeight();selectFormat.getImageableWidth();selectFormat.getImageableHeight();stringWidth(String str)*/