printabletextarea.java

Java编写的记事本程序,对学习Java桌面编程的朋友可能会有帮助!

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

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

class PrintableTextArea extends JTextArea implements Printable {

	String str;

	Font font;

	PrinterJob pj;

	PageFormat defaultFormat;

	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) {
			}
		}
	}

	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 functions PageFormat 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)
 * 
 */