Java Image.getGraphics()

public abstract Graphics getGraphics()

/* w  ww. jav  a2 s  .  c  o m*/


import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.ImageProducer;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JFrame implements ActionListener {
  Image img;

  JButton getPictureButton  = new JButton("Get Picture");

  public static void main(String[] args) {
    new Main();
  }

  public Main() {
    this.setSize(300, 300);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel picPanel = new PicturePanel();
    this.add(picPanel, BorderLayout.CENTER);

    JPanel buttonPanel = new JPanel();
    getPictureButton.addActionListener(this);
    buttonPanel.add(getPictureButton);
    this.add(buttonPanel, BorderLayout.SOUTH);

    this.setVisible(true);
  }

  public void actionPerformed(ActionEvent e) {
    String file = "a.png";
    if (file != null) {
      Toolkit kit = Toolkit.getDefaultToolkit();
      img = kit.getImage(file);
      img = img.getScaledInstance(300, -1, Image.SCALE_SMOOTH);
      
      Graphics g = img.getGraphics();
      
      this.repaint();
    }
  }
  class PicturePanel extends JPanel {
    public void paint(Graphics g) {
      g.drawImage(img, 0, 0, this);
    }
  }

}