hiresprintexample.java

一个用java开发界面的程序集(jfc核心编程)

package JFCBook.Chapter4.jdk13;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;

public class HiResPrintExample {

    // Create default page and job attributes
    static void print(Image image) {
        PageAttributes page = new PageAttributes();
        JobAttributes job = new JobAttributes();

        // Set up to use the printable area and install
        // the desired resolution.
        page.setColor(PageAttributes.ColorType.COLOR);
        page.setOrigin(PageAttributes.OriginType.PRINTABLE);
        int dpi = 72;
        try {
            dpi = Integer.parseInt(resolution.getText());
        } catch (NumberFormatException e) {
            System.out.println("Illegal resolution - using 72dpi");
        }
        System.out.println("Printing at " + dpi + " dpi.");
        page.setPrinterResolution(dpi);

        PrintJob pj = Toolkit.getDefaultToolkit().getPrintJob(
                    frame, "Print Image", job, page);
        if (pj == null) {
            // Cancelled by user
            return;
        }

        // Print the image centered on the paper
        Dimension pageSize = new Dimension(pj.getPageDimension());
        int imageWidth = image.getWidth(null);
        int imageHeight = image.getHeight(null);

        // Use try/finally to release PrintJob even if we get an exception
        try {
            Graphics g = pj.getGraphics();

            g.drawImage(image, (pageSize.width - imageWidth)/2,
                (pageSize.height - imageHeight)/2, null);

            g.dispose();					// Print the last page

        } catch (Exception e) {
            System.out.println("Exception while printing image: " + e);
        } finally {
            // Always terminate the print job
            pj.end();
            System.out.println("Printing completed");
        }
    }

    public static void main(String[] args) {
        // Load the image
        URL imageURL = HiResPrintExample.class.getResource("images/earth.jpg");
        ImageIcon imageIcon = new ImageIcon(imageURL);
        final Image image = imageIcon.getImage();
        JLabel label = new JLabel(imageIcon);
        frame.getContentPane().add(label, BorderLayout.CENTER);

        JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        panel.add(new JLabel("Resolution: "));
        panel.add(resolution);
        panel.add(button);
        frame.getContentPane().add(panel, BorderLayout.SOUTH);

        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                print(image);
            }
        });

        frame.pack();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent evt) {
                System.exit(0);
            }
        });
        frame.setVisible(true);
    }

    static JFrame frame = new JFrame("Hi-res Printing Example");
    static JTextField resolution = new JTextField("72", 10);
    static JButton button = new JButton("Print...");
}