Re: Show the most recent image, display only it.

On Aug 30, 2:50 pm, bH <bherbs...@hotmail.com> wrote:


I am still not sure I understand what you want,
but if that is 'only ever one image on-screen',
you might do it this way.

<sscce>
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;

import javax.imageio.*;

import java.io.*;

import java.net.*;

public class GDP extends JFrame
  implements ActionListener {

// private Icon myImage = new ImageIcon();
  private JButton b1 = new JButton("Get Drawing");
  private JButton b2 = new JButton("Drawing is >>>");
  private JButton b3= new JButton("Close");
  private Boolean counterFlag = false;
  private BufferedImage image;

  /** We keep a reference to a single JLabel, and
  reuse it for each icon. */
  JLabel label;

  public static void main(String[] args){
    new GDP ().go();
  }
  void go()
  {
    JPanel labelPanel = new JPanel();
    JPanel btnPanel = new JPanel();
    btnPanel.add(b1);
    b1.addActionListener(this);
    btnPanel.add(b2);
    b2.addActionListener(this);
    btnPanel.add(b3);
    b3.addActionListener(this);

    Container contentPane= getContentPane();
    contentPane.setLayout( new FlowLayout() );
    setSize(350,200);
    contentPane.add(btnPanel );
    contentPane.add(labelPanel);
    this.setResizable(false);
    setVisible(true);
  }

  public void actionPerformed(ActionEvent e) {
    String udp1 = "http://www.extension.iastate.edu/gif/"+
    "Balls/l_green.gif";
    String udp2 = "http://www.extension.iastate.edu/gif/"+
    "Balls/l_red.gif";
    String udp = "";
    if(e.getSource() == b1){
      try {
        if(counterFlag == false){
          udp = udp1;
        }
        else{
          udp = udp2;
        }
        URL url = new URL(udp);
        image = ImageIO.read(url);
        counterFlag = true;
      }
      catch (IOException em) {
        System.out.println("import Data: I/O exception");
      }
      System.out.println
        ("Now press Drawing Is >>> if you want to see it");

    } //end b1
    if(e.getSource() == b2){
      Image img = image ;
      if (label==null) {
        label = new JLabel(new ImageIcon(img)) ;
          getContentPane().add(label) ;
    } else {
      label.setIcon(new ImageIcon(img)) ;
    }
      setVisible( true );

    } //end b2

    if(e.getSource() == b3){
      System.exit(0);

    } //end b3
  } // action draw picture
}
</sscce>

--
Andrew Thompson
http://pscode.org/