Small problem with validate()

Question

I have an ArrayList of JPanels in a JApplet. I display the first panel of the array when the applet loads. For traversing through the arrayList i have provided a set of buttons ('first','back','next','last'). When a button is clicked, I remove the currently displayed panel, get the next (or previous) panel from the arrayList and add it to the applet:
public ArrayList arrayOfPanels;
public int sizeOfArrayOfPanels=0,position=0;
public JPanel displayedPanel, buttonPanel;
public JButton firstButton, backButton, nextButton, lastButton;
public void init() {
.......//create array of panels and buttons
buttonPanel.add(firstButton);
buttonPanel.add(backButton);
buttonPanel.add(nextButton);
buttonPanel.add(lastButton);
sizeOfArrayOfPanels=arrayOfPanels.size();
displayedPanel=(JPanel)arrayOfPanels.get(0);
getContentPane().add(displayedPanel);
getContentPane().add(buttonPanel);
public void actionPerformed(ActionEvent e) {
String label=e.getActionCommand();
if(label.equals("Next >")) position=position+1;
else if(label.equals("< Back")) position=position-1;
else if(label.equals("<< First")) position=0;
else if(label.equals("Last >>")) position=sizeOfArrayOfPanels-1;
getContentPane().remove(displayedPanel);
displayedPanel=(JPanel)arrayOfPanels.get(position);
getContentPane().add(displayedPanel);
getContentPane().validate();
if(position==0) {
nextButton.setEnabled(true);
lastButton.setEnabled(true);
firstButton.setEnabled(false);
backButton.setEnabled(false);
else if(position==(sizeOfArrayOfPanels-1)) {
nextButton.setEnabled(false);
lastButton.setEnabled(false);
firstButton.setEnabled(true);
backButton.setEnabled(true);
else {
nextButton.setEnabled(true);
lastButton.setEnabled(true);
firstButton.setEnabled(true);
backButton.setEnabled(true);
My problem is, when i click on a button, the next (or previous panel) does not always get displayed immediately. Only if i minimize the applet and then maximize it, it gets displayed. Though i've included getContentPane().validate(), only the first two times (when i click on the next or last button) a different panel appears, from then on,if i click on a button the applet has to be minimized to view the change. Kindly help me overcome this.

Answer 1

I find that using:
revalidate();
repaint()
works in most situations.
However, you should check out the CardLayout. It was designed for this type of application:
http://java.sun.com/docs/books/tutorial/uiswing/layout/visual.html