import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.imageio.*;
import java.io.*;

/**
 * This program illustrates the display of an image stored in
 * a database as a Blob.
**/

public class Blobber implements ActionListener {
  private JFrame frame;
  private JPanel inputPanel;
  private Canvas imageCanvas;
  private JComboBox<String> nameBox;
  private Image image;
  private DatabaseAccess dlink;

  public Blobber(DatabaseAccess dlink) {
    this.dlink = dlink;

    // Set up the frame
    frame = new JFrame("Blob Test");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Set up the input panel
    inputPanel = new JPanel(new FlowLayout());
    inputPanel.setBackground(Color.LIGHT_GRAY);

    // Add the combo box to the input panel
    nameBox = new JComboBox<String>(dlink.getCarList().toArray(new String[1]));
    nameBox.setSelectedIndex(0);
    nameBox.addActionListener(this);
    inputPanel.add(nameBox);

    // Put the input panel in the frame
    frame.getContentPane().add(inputPanel, BorderLayout.SOUTH);
    
    // Create the image canvas and put it in the frame
    imageCanvas = new Canvas(){
	    public void paint(Graphics g){
		g.drawImage(image,0,0,null);
	    }
	};
    imageCanvas.setSize(500,500);

    frame.getContentPane().add(imageCanvas, BorderLayout.CENTER);
    
    frame.pack();

    // Display the frame
    frame.setVisible(true);
  }

  /* Listener method to handle events */
  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == nameBox) { // event came from the combo box
      String name = (String) nameBox.getSelectedItem();
      getImage(name);
      imageCanvas.repaint();
    }
  }

  /* retrieve the car's picture and display it */
  private void getImage(String name) {
    InputStream imageStream = dlink.getImageStream(name);
    try {
      image = ImageIO.read(imageStream);
      int w = image.getWidth(frame);
      int h = image.getHeight(frame);
      imageCanvas.setSize(w,h);
      frame.pack();
    }
    catch (IOException e){
      warnUser(e.getMessage());
    }
  }

  /**
   * Display a pop-up window to the use
   */
  private void warnUser(String message) {
    JOptionPane.showMessageDialog(frame, message, "Error",
				  JOptionPane.WARNING_MESSAGE);
  }

  public static void main(String [] args) {
     Blobber x = new Blobber(new DatabaseAccess());
  }
}