printabletextarea.java

用java编制的记事本

//MenuFont version 1.0 alpha1
//09/12/2001
//author [e-mail]

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.awt.print.*;

import javax.swing.*;
import javax.swing.text.*;

class PrintableTextArea extends JTextArea
                        implements Printable {

  String str = null;
  Font font = null;
  PrinterJob pj = null;
  PageFormat defaultFormat = null;
  int visiblePageWidth = 0, visiblePageHeight = 0;
  final static int PageX = 10, PageY = 10;

  PrintableTextArea(int rows, int columns) {
    super(rows, columns);
  }

  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) {
      }
    }
  }
  //todo... use java.awt.print.Book instead of page print
  //only the first page to be printed now.
  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 {
          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;
  }

  public static void main(String[] args) {
    JFrame jfr = new JFrame();
    final PrintableTextArea ta = new PrintableTextArea(10,10);
    jfr.getContentPane().add("Center", ta);
    JButton jb = new JButton("Print");
    jfr.getContentPane().add("South", jb);
    jb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        JOptionPane.showMessageDialog(null, " 请连接好打印机.", "Print", JOptionPane.INFORMATION_MESSAGE);
        ta.printIt(ta.getText(), ta.getFont());
      }
    });
    jfr.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    jfr.setSize(320,240);
    jfr.show();
  }

}// end of class PrintableTextArea