import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.ImageIcon;
import javax.swing.KeyStroke;
import java.awt.FileDialog;
import java.awt.Toolkit;
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.io.File;
import java.io.IOException;
import java.net.URL;
public final class Picture implements ActionListener {
private BufferedImage image; // the rasterized image
private JFrame frame; // on-screen view
private String filename; // name of file
// create a blank w-by-h image
public Picture(int w, int h) {
image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
// set to TYPE_INT_ARGB to support transparency
filename = w + "-by-" + h;
}
// create an image by reading in the PNG, GIF, or JPEG from a filename
public Picture(String filename) {
this.filename = filename;
try {
// try to read from file in working directory
File file = new File(filename);
if (file.isFile()) {
image = ImageIO.read(file);
}
// now try to read from file in same directory as this .class file
else {
URL url = getClass().getResource(filename);
if (url == null) { url = new URL(filename); }
image = ImageIO.read(url);
}
}
catch (IOException e) {
// e.printStackTrace();
throw new RuntimeException("Could not open file: " + filename);
}
// check that image was read in
if (image == null) {
throw new RuntimeException("Invalid image file: " + filename);
}
}
// create an image by reading in the PNG, GIF, or JPEG from a file
public Picture(File file) {
try { image = ImageIO.read(file); }
catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Could not open file: " + file);
}
if (image == null) {
throw new RuntimeException("Invalid image file: " + file);
}
}
// to embed in a JPanel, JFrame or other GUI widget
public JLabel getJLabel() {
if (image == null) { return null; } // no image available
ImageIcon icon = new ImageIcon(image);
return new JLabel(icon);
}
// view on-screen, creating new frame if necessary
public void show() {
// create the GUI for viewing the image if needed
if (frame == null) {
frame = new JFrame();
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("File");
menuBar.add(menu);
JMenuItem menuItem1 = new JMenuItem(" Save... ");
menuItem1.addActionListener(this);
menuItem1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,
Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));
menu.add(menuItem1);
frame.setJMenuBar(menuBar);
frame.setContentPane(getJLabel());
// f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setTitle(filename);
frame.setResizable(false);
frame.pack();
frame.setVisible(true);
}
// draw
frame.repaint();
}
// accessor methods
public int height() { return image.getHeight(null); }
public int width() { return image.getWidth(null); }
// return Color of pixel (i, j)
public Color get(int i, int j) {
return new Color(image.getRGB(i, j));
}
// change color of pixel (i, j) to c
public void set(int i, int j, Color c) {
if (c == null) { throw new RuntimeException("can't set Color to null"); }
image.setRGB(i, j, c.getRGB());
}
// save to given filename - suffix must be png, jpg, or gif
public void save(String name) {
save(new File(name));
}
// save to given filename - suffix must be png, jpg, or gif
public void save(File file) {
this.filename = file.getName();
if (frame != null) { frame.setTitle(filename); }
String suffix = filename.substring(filename.lastIndexOf('.') + 1);
suffix = suffix.toLowerCase();
if (suffix.equals("jpg") || suffix.equals("png")) {
try { ImageIO.write(image, suffix, file); }
catch (IOException e) { e.printStackTrace(); }
}
else {
System.out.println("Error: filename must end in .jpg or .png");
}
}
// open a save dialog when the user selects "Save As" from the menu
public void actionPerformed(ActionEvent e) {
FileDialog chooser = new FileDialog(frame,
"Use a .png or .jpg extension", FileDialog.SAVE);
chooser.setVisible(true);
if (chooser.getFile() != null) {
save(chooser.getDirectory() + File.separator + chooser.getFile());
}
}
// test client: read in input file and display
public static void main(String[] args) {
Picture pic = new Picture(args[0]);
pic.show();
}
}
Linear Mode
