Resizing JComponent not displaying in packed frame

Question

Please help, I'm trying to dynamically resize a dialog when a component expands/collapses, and when I set the component visible it is not firing a component resize event, as I believe I am setting minimum and preferred size properly. The code I am using is posted below. TriangleIcon is a triangle icon, which will point in any of the SwingConstants directions.
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
public class TestPackedFrame extends JDialog {
     public TestPackedFrame() {
          setModal(true);
          Container contentPane = getContentPane();
          contentPane.setLayout(new BorderLayout());
          PreviewPane previewPane = new PreviewPane(new JLabel("Display Hidden"));
          previewPane.addComponentListener(new ComponentAdapter() {
               public void componentResized(ComponentEvent e) {
                    pack();
          contentPane.add(previewPane,BorderLayout.CENTER);
          JButton closeButton = new JButton("Close");
          closeButton.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    setVisible(false);
          contentPane.add(closeButton,BorderLayout.PAGE_END);
     public static void main(String[] args) {
          JDialog.setDefaultLookAndFeelDecorated(true);
          Toolkit.getDefaultToolkit().setDynamicLayout(true);
          System.setProperty("sun.awt.noerasebackground", "true");
          TestPackedFrame frame = new TestPackedFrame();
          frame.setDefaultCloseOperation(JDialog.HIDE_ON_CLOSE);
          frame.pack();
          frame.setVisible(true);
          frame.dispose();
          System.exit(0);
class PreviewPane extends JComponent implements MouseListener {
     private boolean expanded;
     private JLabel arrowLabel;
     private Component view;
     public PreviewPane(Component view) {
          this(view, false);
     public PreviewPane(Component view, boolean expanded) {
          this.setLayout(new BorderLayout());
          arrowLabel = new JLabel("Preview", new TriangleIcon(true,
                    SwingConstants.EAST, 6), SwingConstants.LEFT);
          arrowLabel.addMouseListener(this);
          this.add(arrowLabel, BorderLayout.NORTH);
          this.view = view;
          setExpanded(expanded);
          this.add(view, BorderLayout.CENTER);
     public void setExpanded(boolean expanded) {
          this.expanded = expanded;
          view.setVisible(expanded);
          if (expanded)
               view.repaint();
     public boolean isExpanded() {
          return expanded;
     public void paint(Graphics g) {
          super.paint(g);
     public void mouseClicked(MouseEvent e) {
     public void mousePressed(MouseEvent e) {
          Object source = e.getSource();
          if (source == arrowLabel) {
               TriangleIcon currentIcon = (TriangleIcon) arrowLabel.getIcon();
               if (currentIcon.getDirection() == SwingConstants.EAST) {
                    arrowLabel.setIcon(new TriangleIcon(true, SwingConstants.SOUTH,
                              6));
                    setExpanded(true);
                    repaint();
               } else if (currentIcon.getDirection() == SwingConstants.SOUTH) {
                    arrowLabel.setIcon(new TriangleIcon(true, SwingConstants.EAST,
                              6));
                    setExpanded(false);
     public Dimension getMinimumSize() {
          Dimension arrowSize = arrowLabel.getMinimumSize();
          Dimension viewSize = isExpanded() ? view.getMinimumSize()
                    : new Dimension(0, 0);
          return new Dimension(Math.max(arrowSize.width, viewSize.width),
                    arrowSize.height + viewSize.height);
     public Dimension getPreferredSize() {
          Dimension arrowSize = arrowLabel.getPreferredSize();
          Dimension viewSize = isExpanded() ? view.getPreferredSize()
                    : new Dimension(0, 0);
          return new Dimension(Math.max(arrowSize.width, viewSize.width),
                    arrowSize.height + viewSize.height);
     public void mouseReleased(MouseEvent e) {
     public void mouseEntered(MouseEvent e) {
     public void mouseExited(MouseEvent e) {
}Edited by: stringman520 on Jan 27, 2008 1:20 AM

Answer 1

Here is the code for TriangleIcon. How could I call pack directly when the component is displayed? The PreviewPane doesn't receive the window object, so while I can pack the dialog directly when it is displayed, subsequent changes do nothing.
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Polygon;
import javax.swing.Icon;
import javax.swing.SwingConstants;
public class TriangleIcon implements Icon, SwingConstants {
     public static int DEFAULT_TRIANGLE_SIZE = 3;
     private boolean enabled;
     private int direction;
     private int triangleSize;
     public TriangleIcon() {
          this(false);
     public TriangleIcon(boolean enabled) {
          this(enabled,NORTH);
     public TriangleIcon(boolean enabled, int direction) {
          this(enabled, direction, DEFAULT_TRIANGLE_SIZE);
     public TriangleIcon(boolean enabled, int direction, int triangleSize) {
          this.enabled = enabled;
          this.direction = direction;
          this.triangleSize = triangleSize;
     public void paintIcon(Component c, Graphics g, int x, int y) {
          if (enabled) {
               g.setColor(Color.BLACK);
          } else {
               g.setColor(Color.LIGHT_GRAY);
          Polygon triangle = new Polygon();
          switch (direction) {
          case NORTH:
               triangle.addPoint(x, y + triangleSize);
               triangle.addPoint(x + triangleSize, y);
               triangle.addPoint(x + triangleSize * 2, y + triangleSize);
               triangle.addPoint(x, y + triangleSize);
               break;
          case EAST:
               triangle.addPoint(x, y);
               triangle.addPoint(x + triangleSize, y + triangleSize);
               triangle.addPoint(x, y + triangleSize * 2);
               triangle.addPoint(x, y);
               break;
          case SOUTH:
               triangle.addPoint(x, y);
               triangle.addPoint(x + triangleSize * 2, y);
               triangle.addPoint(x + triangleSize, y + triangleSize);
               triangle.addPoint(x, y);
               break;
          case WEST:
               triangle.addPoint(x + triangleSize, y);
               triangle.addPoint(x, y + triangleSize);
               triangle.addPoint(x + triangleSize, y + triangleSize * 2);
               triangle.addPoint(x+triangleSize,y);
               break;
          g.fillPolygon(triangle);
     public int getIconWidth() {
          switch (direction) {
          case NORTH:
          case SOUTH:
               return triangleSize*2;
          case EAST:
          case WEST:
               return triangleSize;
          return 0;
     public int getIconHeight() {
          switch (direction) {
          case NORTH:
          case SOUTH:
               return triangleSize;
          case EAST:
          case WEST:
               return triangleSize*2;
          return 0;
     public int getDirection() {
          return direction;
}