setting something disposed or invisible java
- by OVERTONE
this might be simple enough as just inserting the right method but i cant seem to get it right.
i have a simple program with two buttons. each one changes the picture above them. but anytime i click the buttons i get some odd awt event queue error. i think its because im trying to add something to a frame after its already been made.
package icnon;
import javax.imageio.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class FrameIconExample extends JFrame implements ActionListener {
JLabel j;
JPanel p, l, k;
JButton picOne, picTwo;
Container cPane;
public FrameIconExample()
{
JButton picOne = new JButton("picOne");
JButton picTwo = new JButton("picTwo");
picOne.setName("picOne");
picTwo.setName("picTwo");
picOne.addActionListener(this);
picTwo.addActionListener(this);
JPanel p = new JPanel(new GridLayout(2, 1));
JPanel l = new JPanel(new FlowLayout());
JPanel k = new JPanel(new FlowLayout());
cPane = getContentPane();
j = new JLabel(new ImageIcon("../meet/src/images/beautiful-closeup-portrait-photography.jpg"));
l.add(j);
k.add(picOne);
k.add(picTwo);
p.add(l);
p.add(k);
add(p);
}
public static void main(String[] args) {
FrameIconExample frame = new FrameIconExample();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(300, 800));
frame.setTitle("Frame Icon Example");
// Display the form
frame.setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e)
{
JButton temp = (JButton) e.getSource();
String src = "../meet/src/images/Majken Kruse portrait - john.jpg";
//System.out.println(src + " " + temp.getName());
if(temp.getName().equalsIgnoreCase("picOne"))
{
src = "../meet/src/images/beautiful-closeup-portrait-photography.jpg";
System.out.println(src + " " + temp.getName());
Icon img;
j = new JLabel(new ImageIcon(src));
l.add(j);
System.out.println("1");
}
if(temp.getName().equalsIgnoreCase("picTwo"))
{
src = "../icontest/images/Majken Kruse portrait - john.jpg";
System.out.println(src + " " + temp.getName());
Icon img;
j = new JLabel(new ImageIcon(src));
l.add(j);
System.out.println("2");
}
}
}
its all just the one program so if you copy paste it into an editor you can see the stack trace. but the source of the image files wont be there.
does anyone know how id do it? or where im goin wrong?
stack trace:
../meet/src/images/beautiful-closeup-portrait-photography.jpg picOne
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at icnon.FrameIconExample.actionPerformed(FrameIconExample.java:68)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
