ScreenCapture.java Source code

Introduction

Here is the source code for ScreenCapture.java

Source

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.Iterator;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class ScreenCapture extends JFrame {
    ImageArea ia = new ImageArea();

    Rectangle rectScreenSize = new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());

    static Robot robot;

    JScrollPane jsp;

    public ScreenCapture(String title) {
        super(title);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        JMenuBar mb = new JMenuBar();
        JMenu menu = new JMenu("File");
        ActionListener al;

        JMenuItem mi = new JMenuItem("Save");
        al = new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                save();
            }
        };

        mi.addActionListener(al);
        menu.add(mi);
        mb.add(menu);

        menu = new JMenu("Capture");

        mi = new JMenuItem("Capture");
        al = new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                setVisible(false);

                BufferedImage biScreen = robot.createScreenCapture(rectScreenSize);
                setVisible(true);

                ia.setImage(biScreen);

                jsp.getHorizontalScrollBar().setValue(0);
                jsp.getVerticalScrollBar().setValue(0);
            }
        };

        mi.addActionListener(al);
        menu.add(mi);

        mb.add(menu);

        mi = new JMenuItem("Crop");
        al = new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                if (ia.crop()) {
                    jsp.getHorizontalScrollBar().setValue(0);
                    jsp.getVerticalScrollBar().setValue(0);
                }
            }
        };

        mi.addActionListener(al);
        menu.add(mi);

        mb.add(menu);
        setJMenuBar(mb);
        getContentPane().add(jsp = new JScrollPane(ia));
        setVisible(true);
    }

    private void save() {
        if (ia.getImage() == null) {
            System.out.println("No captured image.");
            return;
        }
        ImageWriter writer = null;
        ImageOutputStream ios = null;

        try {
            Iterator iter = ImageIO.getImageWritersByFormatName("jpeg");

            if (!iter.hasNext()) {
                System.out.println("Unable to save image to jpeg file type.");
                return;
            }
            writer = (ImageWriter) iter.next();
            ios = ImageIO.createImageOutputStream(new File("c:\\a.jpg"));
            writer.setOutput(ios);
            ImageWriteParam iwp = writer.getDefaultWriteParam();
            iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
            iwp.setCompressionQuality(0.95f);
            writer.write(null, new IIOImage((BufferedImage) ia.getImage(), null, null), iwp);
        } catch (Exception e2) {
            e2.printStackTrace();
        }

    }

    public static void main(String[] args) throws Exception {
        robot = new Robot();
        new ScreenCapture("Capture");
    }
}

class ImageArea extends JPanel {
    private Image image;

    Point startPoint = new Point(), endPoint = new Point();

    private Rectangle selectedRectangle = new Rectangle();

    public ImageArea() {
        addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                if (image == null)
                    return;
                startPoint = endPoint = e.getPoint();
                repaint();
            }
        });

        addMouseMotionListener(new MouseMotionAdapter() {
            public void mouseDragged(MouseEvent e) {
                if (image == null)
                    return;

                endPoint = e.getPoint();
                repaint();
            }
        });
    }

    public boolean crop() {
        if (startPoint.equals(endPoint))
            return true;

        boolean succeeded = true;

        int x1 = (startPoint.x < endPoint.x) ? startPoint.x : endPoint.x;
        int y1 = (startPoint.y < endPoint.y) ? startPoint.y : endPoint.y;

        int x2 = (startPoint.x > endPoint.x) ? startPoint.x : endPoint.x;
        int y2 = (startPoint.y > endPoint.y) ? startPoint.y : endPoint.y;

        int width = (x2 - x1) + 1;
        int height = (y2 - y1) + 1;

        BufferedImage biCrop = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = biCrop.createGraphics();
        BufferedImage bi = (BufferedImage) image;
        BufferedImage bi2 = bi.getSubimage(x1, y1, width, height);
        g2d.drawImage(bi2, null, 0, 0);

        g2d.dispose();

        if (succeeded)
            setImage(biCrop);
        else {
            startPoint.x = endPoint.x;
            startPoint.y = endPoint.y;
            repaint();
        }

        return succeeded;
    }

    public Image getImage() {
        return image;
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (image != null)
            g.drawImage(image, 0, 0, this);

        if (startPoint.x != endPoint.x || startPoint.y != endPoint.y) {
            int x1 = (startPoint.x < endPoint.x) ? startPoint.x : endPoint.x;
            int y1 = (startPoint.y < endPoint.y) ? startPoint.y : endPoint.y;
            int x2 = (startPoint.x > endPoint.x) ? startPoint.x : endPoint.x;
            int y2 = (startPoint.y > endPoint.y) ? startPoint.y : endPoint.y;
            selectedRectangle.x = x1;
            selectedRectangle.y = y1;
            selectedRectangle.width = (x2 - x1) + 1;
            selectedRectangle.height = (y2 - y1) + 1;
            Graphics2D g2d = (Graphics2D) g;
            g2d.draw(selectedRectangle);
        }
    }

    public void setImage(Image image) {
        this.image = image;
        setPreferredSize(new Dimension(image.getWidth(this), image.getHeight(this)));
        revalidate();
        startPoint.x = endPoint.x;
        startPoint.y = endPoint.y;
        repaint();
    }
}