Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Image;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    Image img = null;
                    img = ImageIO.read(new URL("http://www.java2s.com/style/download.png"));

                    JFrame frame = new JFrame();
                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    frame.setLayout(new BorderLayout());
                    frame.add(new ImagePanel(img));
                    frame.pack();
                    frame.setVisible(true);
                } catch (Exception exp) {
                    exp.printStackTrace();
                }
            }
        });
    }

}

class ImagePanel extends JPanel {

    private static final long serialVersionUID = 1L;

    private Image img;
    private Image scaled;

    public ImagePanel(String img) {
        this(new ImageIcon(img).getImage());
    }

    public ImagePanel(Image img) {
        this.img = img;
    }

    @Override
    public void invalidate() {
        super.invalidate();
        int width = getWidth();
        int height = getHeight();

        if (width > 0 && height > 0) {
            scaled = img.getScaledInstance(getWidth(), getHeight(), Image.SCALE_SMOOTH);
        }
    }

    @Override
    public Dimension getPreferredSize() {
        return img == null ? new Dimension(200, 200) : new Dimension(img.getWidth(this), img.getHeight(this));
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(scaled, 0, 0, null);
    }
}