7027694: /jfc/FileChooserDemo demo needs to be improved

Reviewed-by: rupashka

src/share/demo/jfc/FileChooserDemo/ExampleFileSystemView.java

 /*
- * Copyright (c) 1998, 2005, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,13 +29,12 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/*
- */
 
 import java.io.File;
 import java.io.IOException;
 import javax.swing.filechooser.FileSystemView;
 
+
 /**
  * This is a simple example that uses the FileSystemView class.
  * You can provide a superclass of the FileSystemView class with your own functionality.
@@ -43,6 +42,7 @@ import javax.swing.filechooser.FileSystemView;
  * @author Pavel Porvatov
  */
 public class ExampleFileSystemView extends FileSystemView {
+
     /**
      * Creates a new folder with the default name "New folder". This method is invoked
      * when the user presses the "New folder" button.
@@ -65,8 +65,9 @@ public class ExampleFileSystemView extends FileSystemView {
      * Returns a list which appears in a drop-down list of the FileChooser component.
      * In this implementation only the home directory is returned.
      */
+    @Override
     public File[] getRoots() {
-        return new File[]{getHomeDirectory()};
+        return new File[] { getHomeDirectory() };
     }
 
     /**
@@ -74,9 +75,11 @@ public class ExampleFileSystemView extends FileSystemView {
      * A string with all upper case letters is returned for a directory.
      * A string with all lower case letters is returned for a file.
      */
+    @Override
     public String getSystemDisplayName(File f) {
         String displayName = super.getSystemDisplayName(f);
 
-        return f.isDirectory() ? displayName.toUpperCase() : displayName.toLowerCase();
+        return f.isDirectory() ? displayName.toUpperCase() : displayName.
+                toLowerCase();
     }
 }

src/share/demo/jfc/FileChooserDemo/ExampleFileView.java

 /*
- * Copyright (c) 1998, 2005, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,14 +29,13 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/*
- */
 
 import javax.swing.*;
 import javax.swing.filechooser.*;
-
 import java.io.File;
-import java.util.Hashtable;
+import java.util.HashMap;
+import java.util.Map;
+
 
 /**
  * A convenience implementation of the FileView interface that
@@ -61,15 +60,19 @@ import java.util.Hashtable;
  * @author Jeff Dinkins
  */
 public class ExampleFileView extends FileView {
-    private final Hashtable<String, Icon> icons = new Hashtable<String, Icon>();
-    private final Hashtable<File, String> fileDescriptions = new Hashtable<File, String>();
-    private final Hashtable<String, String> typeDescriptions = new Hashtable<String, String>();
+
+    private final Map<String, Icon> icons = new HashMap<String, Icon>();
+    private final Map<File, String> fileDescriptions =
+            new HashMap<File, String>();
+    private final Map<String, String> typeDescriptions =
+            new HashMap<String, String>();
 
     /**
      * The name of the file.  Do nothing special here. Let
      * the system file view handle this.
      * @see FileView#getName
      */
+    @Override
     public String getName(File f) {
         return null;
     }
@@ -86,6 +89,7 @@ public class ExampleFileView extends FileView {
      *
      * @see FileView#getDescription
      */
+    @Override
     public String getDescription(File f) {
         return fileDescriptions.get(f);
     }
@@ -112,6 +116,7 @@ public class ExampleFileView extends FileView {
      *
      * @see FileView#getTypeDescription
      */
+    @Override
     public String getTypeDescription(File f) {
         return typeDescriptions.get(getExtension(f));
     }
@@ -122,12 +127,12 @@ public class ExampleFileView extends FileView {
      */
     private String getExtension(File f) {
         String name = f.getName();
-        if(name != null) {
+        if (name != null) {
             int extensionIndex = name.lastIndexOf('.');
-            if(extensionIndex < 0) {
+            if (extensionIndex < 0) {
                 return null;
             }
-            return name.substring(extensionIndex+1).toLowerCase();
+            return name.substring(extensionIndex + 1).toLowerCase();
         }
         return null;
     }
@@ -147,10 +152,11 @@ public class ExampleFileView extends FileView {
      *
      * @see FileView#getIcon
      */
+    @Override
     public Icon getIcon(File f) {
         Icon icon = null;
         String extension = getExtension(f);
-        if(extension != null) {
+        if (extension != null) {
             icon = icons.get(extension);
         }
         return icon;
@@ -168,11 +174,11 @@ public class ExampleFileView extends FileView {
      *
      * @see FileView#isTraversable
      */
+    @Override
     public Boolean isTraversable(File f) {
         // if (some_reason) {
         //    return Boolean.FALSE;
         // }
         return null;    // Use default from FileSystemView
     }
-
 }

src/share/demo/jfc/FileChooserDemo/FileChooserDemo.java

 /*
- * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,34 +29,75 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/*
- */
 
-import javax.swing.*;
-import javax.swing.filechooser.*;
+import java.lang.reflect.InvocationTargetException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.swing.UIManager.LookAndFeelInfo;
+import java.awt.BorderLayout;
+import java.awt.CardLayout;
+import java.awt.Component;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Image;
+import java.awt.Insets;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+import java.util.List;
+import javax.swing.BorderFactory;
+import javax.swing.Box;
+import javax.swing.BoxLayout;
+import javax.swing.ButtonGroup;
+import javax.swing.DefaultComboBoxModel;
+import javax.swing.ImageIcon;
+import javax.swing.JButton;
+import javax.swing.JCheckBox;
+import javax.swing.JComboBox;
+import javax.swing.JComponent;
+import javax.swing.JDialog;
+import javax.swing.JFileChooser;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JOptionPane;
+import javax.swing.JPanel;
+import javax.swing.JRadioButton;
+import javax.swing.JTextField;
+import javax.swing.JToggleButton;
+import javax.swing.LookAndFeel;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.UnsupportedLookAndFeelException;
+import javax.swing.WindowConstants;
+import javax.swing.filechooser.FileFilter;
+import javax.swing.filechooser.FileNameExtensionFilter;
+import javax.swing.filechooser.FileSystemView;
+import java.util.ArrayList;
 import javax.swing.plaf.FileChooserUI;
 import javax.swing.plaf.basic.BasicFileChooserUI;
-
-import java.awt.*;
 import java.io.File;
-import java.awt.event.*;
-import java.beans.*;
-import java.util.Vector;
-
 import static javax.swing.JFileChooser.*;
 
+
 /**
  *
  * A demo which makes extensive use of the file chooser.
  *
  * @author Jeff Dinkins
  */
+@SuppressWarnings("serial")
 public class FileChooserDemo extends JPanel implements ActionListener {
+
+    public static final String NIMBUS_LAF_NAME = "Nimbus";
     private static JFrame frame;
+    private final List<SupportedLaF> supportedLaFs =
+            new ArrayList<SupportedLaF>();
+    private static SupportedLaF nimbusLaF;
 
-    private final Vector<SupportedLaF> supportedLaFs = new Vector();
 
     private static class SupportedLaF {
+
         private final String name;
         private final LookAndFeel laf;
 
@@ -65,18 +106,15 @@ public class FileChooserDemo extends JPanel implements ActionListener {
             this.laf = laf;
         }
 
+        @Override
         public String toString() {
             return name;
         }
     }
-
-
     private JButton showButton;
-
     private JCheckBox showAllFilesFilterCheckBox;
     private JCheckBox showImageFilesFilterCheckBox;
     private JCheckBox showFullDescriptionCheckBox;
-
     private JCheckBox useFileViewCheckBox;
     private JCheckBox useFileSystemViewCheckBox;
     private JCheckBox accessoryCheckBox;
@@ -84,46 +122,44 @@ public class FileChooserDemo extends JPanel implements ActionListener {
     private JCheckBox useEmbedInWizardCheckBox;
     private JCheckBox useControlsCheckBox;
     private JCheckBox enableDragCheckBox;
-
     private JRadioButton singleSelectionRadioButton;
     private JRadioButton multiSelectionRadioButton;
-
     private JRadioButton openRadioButton;
     private JRadioButton saveRadioButton;
     private JRadioButton customButton;
-
     private JComboBox lafComboBox;
-
     private JRadioButton justFilesRadioButton;
     private JRadioButton justDirectoriesRadioButton;
     private JRadioButton bothFilesAndDirectoriesRadioButton;
-
     private JTextField customField;
-
     private final ExampleFileView fileView;
-
     private final ExampleFileSystemView fileSystemView;
-
-    private final static Dimension hpad10 = new Dimension(10,1);
-    private final static Dimension vpad20 = new Dimension(1,20);
+    private final static Dimension hpad10 = new Dimension(10, 1);
+    private final static Dimension vpad20 = new Dimension(1, 20);
     private final static Dimension vpad7 = new Dimension(1, 7);
     private final static Dimension vpad4 = new Dimension(1, 4);
     private final static Insets insets = new Insets(5, 10, 0, 10);
-
     private final FilePreviewer previewer;
     private final JFileChooser chooser;
 
+    @SuppressWarnings("LeakingThisInConstructor")
     public FileChooserDemo() {
-        UIManager.LookAndFeelInfo[] installedLafs = UIManager.getInstalledLookAndFeels();
+        UIManager.LookAndFeelInfo[] installedLafs = UIManager.
+                getInstalledLookAndFeels();
         for (UIManager.LookAndFeelInfo lafInfo : installedLafs) {
             try {
-                Class lnfClass = Class.forName(lafInfo.getClassName());
-                LookAndFeel laf = (LookAndFeel)(lnfClass.newInstance());
+                Class<?> lnfClass = Class.forName(lafInfo.getClassName());
+                LookAndFeel laf = (LookAndFeel) (lnfClass.newInstance());
                 if (laf.isSupportedLookAndFeel()) {
                     String name = lafInfo.getName();
-                    supportedLaFs.add(new SupportedLaF(name, laf));
+                    SupportedLaF supportedLaF = new SupportedLaF(name, laf);
+                    supportedLaFs.add(supportedLaF);
+                    if (NIMBUS_LAF_NAME.equals(name)) {
+                        nimbusLaF = supportedLaF;
+                    }
                 }
-            } catch (Exception e) { // If ANYTHING weird happens, don't add it
+            } catch (Exception ignored) {
+                // If ANYTHING weird happens, don't add this L&F
             }
         }
 
@@ -134,8 +170,10 @@ public class FileChooserDemo extends JPanel implements ActionListener {
 
         // Create Custom FileView
         fileView = new ExampleFileView();
-        fileView.putIcon("jpg", new ImageIcon(getClass().getResource("/resources/images/jpgIcon.jpg")));
-        fileView.putIcon("gif", new ImageIcon(getClass().getResource("/resources/images/gifIcon.gif")));
+        fileView.putIcon("jpg", new ImageIcon(getClass().getResource(
+                "/resources/images/jpgIcon.jpg")));
+        fileView.putIcon("gif", new ImageIcon(getClass().getResource(
+                "/resources/images/gifIcon.gif")));
 
         // Create Custom FileSystemView
         fileSystemView = new ExampleFileSystemView();
@@ -155,8 +193,11 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         customButton.addActionListener(optionListener);
 
         customField = new JTextField(8) {
+
+            @Override
             public Dimension getMaximumSize() {
-                return new Dimension(getPreferredSize().width, getPreferredSize().height);
+                return new Dimension(getPreferredSize().width,
+                        getPreferredSize().height);
             }
         };
         customField.setText("Doit");
@@ -220,7 +261,8 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         group3.add(justDirectoriesRadioButton);
         justDirectoriesRadioButton.addActionListener(optionListener);
 
-        bothFilesAndDirectoriesRadioButton = new JRadioButton("Select Files or Directories");
+        bothFilesAndDirectoriesRadioButton = new JRadioButton(
+                "Select Files or Directories");
         group3.add(bothFilesAndDirectoriesRadioButton);
         bothFilesAndDirectoriesRadioButton.addActionListener(optionListener);
 
@@ -241,7 +283,8 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         showButton.setMnemonic('s');
 
         // Create laf combo box
-        lafComboBox = new JComboBox(supportedLaFs);
+        lafComboBox = new JComboBox(supportedLaFs.toArray());
+        lafComboBox.setSelectedItem(nimbusLaF);
         lafComboBox.setEditable(false);
         lafComboBox.addActionListener(optionListener);
 
@@ -317,7 +360,8 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         // ************* File & Directory Options *****************
         // ********************************************************
         JPanel control4 = new InsetPanel(insets);
-        control4.setBorder(BorderFactory.createTitledBorder("File and Directory Options"));
+        control4.setBorder(BorderFactory.createTitledBorder(
+                "File and Directory Options"));
         control4.setLayout(new BoxLayout(control4, BoxLayout.Y_AXIS));
         control4.add(Box.createRigidArea(vpad20));
         control4.add(justFilesRadioButton);
@@ -379,7 +423,7 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         // clear the preview from the previous display of the chooser
         JComponent accessory = chooser.getAccessory();
         if (accessory != null) {
-            ((FilePreviewer)accessory).loadImage(null);
+            ((FilePreviewer) accessory).loadImage(null);
         }
 
         if (useEmbedInWizardCheckBox.isSelected()) {
@@ -393,25 +437,28 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         if (retval == APPROVE_OPTION) {
             JOptionPane.showMessageDialog(frame, getResultString());
         } else if (retval == CANCEL_OPTION) {
-            JOptionPane.showMessageDialog(frame, "User cancelled operation. No file was chosen.");
+            JOptionPane.showMessageDialog(frame,
+                    "User cancelled operation. No file was chosen.");
         } else if (retval == ERROR_OPTION) {
-            JOptionPane.showMessageDialog(frame, "An error occured. No file was chosen.");
+            JOptionPane.showMessageDialog(frame,
+                    "An error occured. No file was chosen.");
         } else {
             JOptionPane.showMessageDialog(frame, "Unknown operation occured.");
         }
     }
 
     private void resetFileFilters(boolean enableFilters,
-                                  boolean showExtensionInDescription) {
+            boolean showExtensionInDescription) {
         chooser.resetChoosableFileFilters();
         if (enableFilters) {
-            FileFilter jpgFilter = createFileFilter("JPEG Compressed Image Files",
-                                         showExtensionInDescription, "jpg");
+            FileFilter jpgFilter = createFileFilter(
+                    "JPEG Compressed Image Files",
+                    showExtensionInDescription, "jpg");
             FileFilter gifFilter = createFileFilter("GIF Image Files",
-                                         showExtensionInDescription, "gif");
+                    showExtensionInDescription, "gif");
             FileFilter bothFilter = createFileFilter("JPEG and GIF Image Files",
-                                          showExtensionInDescription, "jpg",
-                                          "gif");
+                    showExtensionInDescription, "jpg",
+                    "gif");
             chooser.addChoosableFileFilter(bothFilter);
             chooser.addChoosableFileFilter(jpgFilter);
             chooser.addChoosableFileFilter(gifFilter);
@@ -419,7 +466,7 @@ public class FileChooserDemo extends JPanel implements ActionListener {
     }
 
     private FileFilter createFileFilter(String description,
-            boolean showExtensionInDescription, String...extensions) {
+            boolean showExtensionInDescription, String... extensions) {
         if (showExtensionInDescription) {
             description = createFileNameFilterDescriptionFromExtensions(
                     description, extensions);
@@ -429,8 +476,8 @@ public class FileChooserDemo extends JPanel implements ActionListener {
 
     private String createFileNameFilterDescriptionFromExtensions(
             String description, String[] extensions) {
-        String fullDescription = (description == null) ?
-                "(" : description + " (";
+        String fullDescription = (description == null) ? "(" : description
+                + " (";
         // build the description from the extension list
         fullDescription += "." + extensions[0];
         for (int i = 1; i < extensions.length; i++) {
@@ -441,12 +488,15 @@ public class FileChooserDemo extends JPanel implements ActionListener {
         return fullDescription;
     }
 
+
     private class WizardDialog extends JDialog implements ActionListener {
+
         CardLayout cardLayout;
         JPanel cardPanel;
         JLabel messageLabel;
         JButton backButton, nextButton, closeButton;
 
+        @SuppressWarnings("LeakingThisInConstructor")
         WizardDialog(JFrame frame, boolean modal) {
             super(frame, "Embedded JFileChooser Demo", modal);
 
@@ -494,15 +544,16 @@ public class FileChooserDemo extends JPanel implements ActionListener {
                     // Workaround for bug 4528663. This is necessary to
                     // pick up the contents of the file chooser text field.
                     // This will trigger an APPROVE_SELECTION action.
-                    ((BasicFileChooserUI)ui).getApproveSelectionAction().actionPerformed(null);
+                    ((BasicFileChooserUI) ui).getApproveSelectionAction().
+                            actionPerformed(null);
                 } else {
                     next();
                 }
             } else if (src == closeButton) {
                 close();
-            } else if (cmd == APPROVE_SELECTION) {
+            } else if (APPROVE_SELECTION.equals(cmd)) {
                 next();
-            } else if (cmd == CANCEL_SELECTION) {
+            } else if (CANCEL_SELECTION.equals(cmd)) {
                 close();
             }
         }
@@ -528,6 +579,7 @@ public class FileChooserDemo extends JPanel implements ActionListener {
             setVisible(false);
         }
 
+        @Override
         public void dispose() {
             chooser.removeActionListener(this);
 
@@ -542,13 +594,18 @@ public class FileChooserDemo extends JPanel implements ActionListener {
 
     private String getResultString() {
         String resultString;
-        String filter = chooser.getFileFilter().getDescription();
+        String filter;
+        if (chooser.getFileFilter() == null) {
+            filter = "";
+        } else {
+            filter = chooser.getFileFilter().getDescription();
+        }
         String path = null;
         boolean isDirMode = (chooser.getFileSelectionMode() == DIRECTORIES_ONLY);
         boolean isMulti = chooser.isMultiSelectionEnabled();
 
         if (isMulti) {
-            File [] files = chooser.getSelectedFiles();
+            File[] files = chooser.getSelectedFiles();
             if (files != null && files.length > 0) {
                 path = "";
                 for (File file : files) {
@@ -565,11 +622,10 @@ public class FileChooserDemo extends JPanel implements ActionListener {
             path = path.replace(" ", "&nbsp;");
             filter = filter.replace(" ", "&nbsp;");
             resultString =
-                "<html>You chose " + (isMulti ? "these" : "this") + " " +
-                (isDirMode ? (isMulti ? "directories" : "directory")
-                           : (isMulti ? "files" : "file")) +
-                ": <code>" + path +
-                "</code><br><br>with filter: <br><code>" + filter;
+                    "<html>You chose " + (isMulti ? "these" : "this") + " " + (isDirMode ? (isMulti
+                    ? "directories" : "directory")
+                    : (isMulti ? "files" : "file")) + ": <code>" + path
+                    + "</code><br><br>with filter: <br><code>" + filter;
         } else {
             resultString = "Nothing was chosen";
         }
@@ -577,15 +633,14 @@ public class FileChooserDemo extends JPanel implements ActionListener {
     }
 
 
-
-
     /** An ActionListener that listens to the radio buttons. */
     private class OptionListener implements ActionListener {
+
         public void actionPerformed(ActionEvent e) {
             JComponent c = (JComponent) e.getSource();
             boolean selected = false;
             if (c instanceof JToggleButton) {
-                selected = ((JToggleButton)c).isSelected();
+                selected = ((JToggleButton) c).isSelected();
             }
 
             if (c == openRadioButton) {
@@ -612,7 +667,7 @@ public class FileChooserDemo extends JPanel implements ActionListener {
                 chooser.setAcceptAllFileFilterUsed(selected);
             } else if (c == showImageFilesFilterCheckBox) {
                 resetFileFilters(selected,
-                                 showFullDescriptionCheckBox.isSelected());
+                        showFullDescriptionCheckBox.isSelected());
                 showFullDescriptionCheckBox.setEnabled(selected);
             } else if (c == setHiddenCheckBox) {
                 chooser.setFileHidingEnabled(!selected);
@@ -637,7 +692,7 @@ public class FileChooserDemo extends JPanel implements ActionListener {
                 }
             } else if (c == showFullDescriptionCheckBox) {
                 resetFileFilters(showImageFilesFilterCheckBox.isSelected(),
-                                 selected);
+                        selected);
             } else if (c == justFilesRadioButton) {
                 chooser.setFileSelectionMode(FILES_ONLY);
             } else if (c == justDirectoriesRadioButton) {
@@ -653,27 +708,33 @@ public class FileChooserDemo extends JPanel implements ActionListener {
                     chooser.setMultiSelectionEnabled(true);
                 }
             } else if (c == lafComboBox) {
-                SupportedLaF supportedLaF = ((SupportedLaF)lafComboBox.getSelectedItem());
+                SupportedLaF supportedLaF = ((SupportedLaF) lafComboBox.
+                        getSelectedItem());
                 LookAndFeel laf = supportedLaF.laf;
                 try {
                     UIManager.setLookAndFeel(laf);
                     SwingUtilities.updateComponentTreeUI(frame);
-                    if(chooser != null) {
+                    if (chooser != null) {
                         SwingUtilities.updateComponentTreeUI(chooser);
                     }
                     frame.pack();
                 } catch (UnsupportedLookAndFeelException exc) {
                     // This should not happen because we already checked
-                    ((DefaultComboBoxModel)lafComboBox.getModel()).removeElement(supportedLaF);
+                    ((DefaultComboBoxModel) lafComboBox.getModel()).
+                            removeElement(supportedLaF);
                 }
             }
 
         }
     }
 
-    private class FilePreviewer extends JComponent implements PropertyChangeListener {
+
+    private class FilePreviewer extends JComponent implements
+            PropertyChangeListener {
+
         ImageIcon thumbnail = null;
 
+        @SuppressWarnings("LeakingThisInConstructor")
         public FilePreviewer(JFileChooser fc) {
             setPreferredSize(new Dimension(100, 50));
             fc.addPropertyChangeListener(this);
@@ -684,9 +745,10 @@ public class FileChooserDemo extends JPanel implements ActionListener {
                 thumbnail = null;
             } else {
                 ImageIcon tmpIcon = new ImageIcon(f.getPath());
-                if(tmpIcon.getIconWidth() > 90) {
+                if (tmpIcon.getIconWidth() > 90) {
                     thumbnail = new ImageIcon(
-                        tmpIcon.getImage().getScaledInstance(90, -1, Image.SCALE_DEFAULT));
+                            tmpIcon.getImage().getScaledInstance(90, -1,
+                            Image.SCALE_DEFAULT));
                 } else {
                     thumbnail = tmpIcon;
                 }
@@ -695,23 +757,24 @@ public class FileChooserDemo extends JPanel implements ActionListener {
 
         public void propertyChange(PropertyChangeEvent e) {
             String prop = e.getPropertyName();
-            if (prop == SELECTED_FILE_CHANGED_PROPERTY) {
-                if(isShowing()) {
+            if (SELECTED_FILE_CHANGED_PROPERTY.equals(prop)) {
+                if (isShowing()) {
                     loadImage((File) e.getNewValue());
                     repaint();
                 }
             }
         }
 
+        @Override
         public void paint(Graphics g) {
-            if(thumbnail != null) {
-                int x = getWidth()/2 - thumbnail.getIconWidth()/2;
-                int y = getHeight()/2 - thumbnail.getIconHeight()/2;
-                if(y < 0) {
+            if (thumbnail != null) {
+                int x = getWidth() / 2 - thumbnail.getIconWidth() / 2;
+                int y = getHeight() / 2 - thumbnail.getIconHeight() / 2;
+                if (y < 0) {
                     y = 0;
                 }
 
-                if(x < 5) {
+                if (x < 5) {
                     x = 5;
                 }
                 thumbnail.paintIcon(this, g, x, y);
@@ -720,46 +783,57 @@ public class FileChooserDemo extends JPanel implements ActionListener {
     }
 
     public static void main(String s[]) {
-        /*
-           NOTE: By default, the look and feel will be set to the
-           Cross Platform Look and Feel (which is currently Metal).
-           The user may someday be able to override the default
-           via a system property. If you as the developer want to
-           be sure that a particular L&F is set, you can do so
-           by calling UIManager.setLookAndFeel(). For example, the
-           first code snippet below forcibly sets the UI to be the
-           System Look and Feel. The second code snippet forcibly
-           sets the look and feel to the Cross Platform L&F.
-
-           Snippet 1:
-           try {
-              UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-           } catch (Exception exc) {
-              System.err.println("Error loading L&F: " + exc);
-           }
-
-           Snippet 2:
-           try {
-              UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
-           } catch (Exception exc) {
-              System.err.println("Error loading L&F: " + exc);
-           }
-        */
-
-        FileChooserDemo panel = new FileChooserDemo();
-
-        frame = new JFrame("FileChooserDemo");
-        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
-        frame.getContentPane().add("Center", panel);
-        frame.pack();
-        frame.setVisible(true);
+        try {
+            SwingUtilities.invokeAndWait(new Runnable() {
+
+                public void run() {
+                    /*
+                     * NOTE: By default, the look and feel will be set to the
+                     * Cross Platform Look and Feel (which is currently Metal).
+                     * The following code tries to set the Look and Feel to Nimbus.
+                     * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/nimbus.html
+                     */
+                    try {
+                        for (LookAndFeelInfo info : UIManager.
+                                getInstalledLookAndFeels()) {
+                            if (NIMBUS_LAF_NAME.equals(info.getName())) {
+                                UIManager.setLookAndFeel(info.getClassName());
+                                break;
+                            }
+                        }
+                    } catch (Exception ignored) {
+                    }
+
+                    FileChooserDemo panel = new FileChooserDemo();
+
+                    frame = new JFrame("FileChooserDemo");
+                    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+                    frame.getContentPane().add("Center", panel);
+                    frame.pack();
+                    frame.setVisible(true);
+                }
+            });
+        } catch (InterruptedException ex) {
+            Logger.getLogger(FileChooserDemo.class.getName()).log(Level.SEVERE,
+                    null,
+                    ex);
+        } catch (InvocationTargetException ex) {
+            Logger.getLogger(FileChooserDemo.class.getName()).log(Level.SEVERE,
+                    null,
+                    ex);
+        }
     }
 
+
     private static class InsetPanel extends JPanel {
+
         Insets i;
+
         InsetPanel(Insets i) {
             this.i = i;
         }
+
+        @Override
         public Insets getInsets() {
             return i;
         }