polymorphicjlist.java

oraily的Swing hacks code

import java.awt.*;
import javax.swing.*;
import java.io.*;
import java.util.*;

public class PolymorphicJList extends JList {

    static Color listForeground, listBackground,
        listSelectionForeground, listSelectionBackground;
    static {
        UIDefaults uid = UIManager.getLookAndFeel().getDefaults();
        listForeground =  uid.getColor ("List.foreground");
        listBackground =  uid.getColor ("List.background");
        listSelectionForeground =  uid.getColor ("List.selectionForeground");
        listSelectionBackground =  uid.getColor ("List.selectionBackground");
    }

    ImageIcon fileIcon, textFileIcon, directoryIcon,
        imageFileIcon, pngFileIcon, gifFileIcon,
        jpegFileIcon;
    JComponent fileCellPrototype, textCellPrototype,
        imageCellPrototype, directoryCellPrototype;
    JLabel fileNameLabel, textNameLabel,
        directoryNameLabel, imageNameLabel,
        fileSizeLabel,
        textSizeLabel, textWordCountLabel,
        directoryCountLabel,
        imageSizeLabel, imageIconLabel;

    public PolymorphicJList  (File dir) {
        super();
        buildPrototypeCells();
        setCellRenderer (new PolyRenderer());
        setModel (new DefaultListModel());
        if (! dir.isDirectory())
            dir = new File (dir.getParent());
        buildModelFromDir (dir);
    }
    
    public static void main (String[] args) {
        File dir = new File (".");
        if (args.length > 0)
            dir = new File (args[0]);
        JList list = new PolymorphicJList (dir);
        JScrollPane pain =
            new JScrollPane (list,
                             ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                             ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        JFrame frame = new JFrame ("PolymorphicJList");
        frame.getContentPane().add (pain);
        frame.pack();
        frame.setVisible(true);
    }

    protected void buildModelFromDir (File dir) {
        File[] files = dir.listFiles();
        DefaultListModel mod = (DefaultListModel) getModel();
        for (int i=0; i<files.length; i++) {
            if (isTextFile (files[i]))
                mod.addElement (new TextFileItem (files[i]));
            else if (isImageFile (files [i]))
                mod.addElement (new ImageFileItem (files[i]));
            else if (files[i].isDirectory())
                mod.addElement (new DirectoryItem (files[i]));
            else
                mod.addElement (new FileItem (files[i]));
        }
    }

    protected boolean isImageFile(File f) {
        if (f.isDirectory())
            return false;
        String name = f.getName();
        return name.endsWith (".gif") || name.endsWith (".GIF") ||
            name.endsWith (".jpg") || name.endsWith (".JPG") ||
            name.endsWith (".jpeg") || name.endsWith (".JPEG") ||
            name.endsWith (".bmp") || name.endsWith (".BMP") ||
            name.endsWith (".png") || name.endsWith (".PNG");
    }

    protected boolean isTextFile(File f) {
        if (f.isDirectory())
            return false;
        String name = f.getName();
        return name.endsWith (".txt") || name.endsWith (".html") ||
            name.endsWith (".xml") || name.endsWith (".xhtml") ||
            name.endsWith (".java") || name.endsWith (".c") ||
            name.endsWith (".cpp") || name.endsWith (".c++") ||
            name.endsWith (".m") || name.endsWith (".h");
    }

    protected void buildIcons() {
        String SEP = System.getProperty ("file.separator");
        fileIcon = new ImageIcon ("images" + SEP + "generic.gif");
        textFileIcon = new ImageIcon ("images" + SEP + "text.gif");
        directoryIcon = new ImageIcon ("images" + SEP + "folder.gif");
        imageFileIcon = new ImageIcon ("images" + SEP + "image.gif");
        pngFileIcon = new ImageIcon ("images" + SEP + "png.gif");
        gifFileIcon = new ImageIcon ("images" + SEP + "gif.gif");
        jpegFileIcon = new ImageIcon ("images" + SEP + "jpeg.gif");
    }

    protected void buildPrototypeCells() {
        buildIcons();
        fileCellPrototype = new JPanel();
        fileCellPrototype.setLayout (new GridBagLayout());
        addWithGridBag (new JLabel(fileIcon), fileCellPrototype,
                        0, 0, 1, 2,
                        GridBagConstraints.WEST, GridBagConstraints.BOTH, 0, 0);
        fileNameLabel = new JLabel();
        Font defaultLabelFont = fileNameLabel.getFont();
        Font nameFont = defaultLabelFont.deriveFont (Font.BOLD,
                                                     defaultLabelFont.getSize()+2);
        fileNameLabel.setFont (nameFont);
        addWithGridBag (fileNameLabel, fileCellPrototype,
                        1, 0, 1, 1,
                        GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, 1, 0);
        fileSizeLabel = new JLabel();
        addWithGridBag (fileSizeLabel, fileCellPrototype,
                        1, 1, 1, 1,
                        GridBagConstraints.SOUTH, GridBagConstraints.HORIZONTAL, 1, 0);
        opacify (fileCellPrototype);
        // text file
        textCellPrototype = new JPanel();
        textCellPrototype.setLayout (new GridBagLayout());
        addWithGridBag (new JLabel(textFileIcon), textCellPrototype,
                        0, 0, 1, 2,
                        GridBagConstraints.WEST, GridBagConstraints.BOTH, 0, 0);
        textNameLabel = new JLabel();
        textNameLabel.setFont (nameFont);
        addWithGridBag (textNameLabel, textCellPrototype,
                        1, 0, 2, 1,
                        GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, 1, 0);
        textSizeLabel = new JLabel();
        textWordCountLabel = new JLabel();
        addWithGridBag (textSizeLabel, textCellPrototype,
                        1, 1, 1, 1,
                        GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, 0, 0);
        addWithGridBag (textWordCountLabel, textCellPrototype,
                        2, 1, 1, 1,
                        GridBagConstraints.SOUTH, GridBagConstraints.HORIZONTAL, 1, 0);

        opacify (textCellPrototype);
        // directory
        directoryCellPrototype = new JPanel();
        directoryCellPrototype.setLayout (new GridBagLayout());
        addWithGridBag (new JLabel(directoryIcon), directoryCellPrototype,
                        0, 0, 1, 2,
                        GridBagConstraints.WEST, GridBagConstraints.BOTH, 0, 0);
        directoryNameLabel = new JLabel();
        directoryNameLabel.setFont (nameFont);
        addWithGridBag (directoryNameLabel, directoryCellPrototype,
                        1, 0, 1, 1,
                        GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, 1, 0);
        directoryCountLabel = new JLabel();
        addWithGridBag (directoryCountLabel, directoryCellPrototype,
                        1, 1, 1, 1,
                        GridBagConstraints.SOUTH, GridBagConstraints.HORIZONTAL, 1, 0);
        opacify (directoryCellPrototype);
        // image 
        imageCellPrototype = new JPanel();
        imageCellPrototype.setLayout (new GridBagLayout());
        addWithGridBag (new JLabel(imageFileIcon), imageCellPrototype,
                        0, 0, 1, 2,
                        GridBagConstraints.WEST, GridBagConstraints.BOTH, 0, 0);
        imageNameLabel = new JLabel();
        imageNameLabel.setFont (nameFont);
        addWithGridBag (imageNameLabel, imageCellPrototype,
                        1, 0, 1, 1,
                        GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, 1, 0);
        imageSizeLabel = new JLabel();
        addWithGridBag (imageSizeLabel, imageCellPrototype,
                        1, 1, 1, 1,
                        GridBagConstraints.SOUTH, GridBagConstraints.HORIZONTAL, 1, 0);
        imageIconLabel = new JLabel();
        addWithGridBag (imageIconLabel, imageCellPrototype,
                        2, 0, 1, 2,
                        GridBagConstraints.EAST, GridBagConstraints.VERTICAL, 0, 0);
        opacify (imageCellPrototype);
    }

    private void addWithGridBag (Component comp, Container cont,
                                 int x, int y,
                                 int width, int height,
                                 int anchor, int fill,
                                 int weightx, int weighty) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = x;
        gbc.gridy = y;
        gbc.gridwidth = width;
        gbc.gridheight = height;
        gbc.anchor = anchor;
        gbc.fill = fill;
        gbc.weightx = weightx;
        gbc.weighty = weighty;
        cont.add (comp, gbc);
    }

    private void opacify (Container prototype) {
        Component[] comps = prototype.getComponents();
        for (int i=0; i<comps.length; i++) {
            if (comps[i] instanceof JComponent)
                ((JComponent)comps[i]).setOpaque(true);
        }
    }

    
    class FileItem extends Object {
        File file;
        public FileItem (File f) {
            file = f;
        }
    }

    class ImageFileItem extends FileItem {
        ImageIcon icon;
        public ImageFileItem (File f) {
            super(f);
            initIcon();
        }
        void initIcon() { 
            icon = new ImageIcon (file.getPath());
            // scale to 32 pix in largest dimension
            Image img = icon.getImage();
            float factor = 1.0f;
            if (img.getWidth(null) > img.getHeight(null))
                factor = Math.min (32f / img.getWidth(null), 1.0f);
            else
                factor = Math.min (32f / img.getHeight(null), 1.0f);
            Image scaledImage =
                img.getScaledInstance ((int) (img.getWidth(null) * factor),
                                       (int) (img.getHeight(null) * factor),
                                       Image.SCALE_FAST);
            icon.setImage(scaledImage);
        }
    }


    class DirectoryItem extends FileItem {
        int childCount;
        public DirectoryItem (File f) {
            super(f);
            initChildCount();
        }
        public int getChildCount() { return childCount; }
        void initChildCount () {
            if (! file.isDirectory())
                childCount = -1;
            else
                childCount = file.listFiles().length;
            System.out.println (file.getPath() + ": " + childCount + " items");
        }
    }


    class TextFileItem extends FileItem {
        int wordCount = -1;
        public TextFileItem (File f) {
            super(f);
            initWordCount();
        }
        public int getWordCount() { return wordCount; }
        protected void initWordCount() {
            try {
                StreamTokenizer izer =
                    new StreamTokenizer (new BufferedReader (new FileReader(file)));
                while (izer.nextToken() != StreamTokenizer.TT_EOF)
                    wordCount++;
            } catch (Exception e) {
                e.printStackTrace();
                wordCount = -1;
            }
            System.out.println (file.getPath() + ": " + wordCount + " words");
        }
    }

    class PolyRenderer extends Object
        implements ListCellRenderer {

        public Component getListCellRendererComponent(JList list,
                                                      Object value,
                                                      int index,
                                                      boolean isSelected,
                                                      boolean cellHasFocus) {
            if (value instanceof DirectoryItem) {
                DirectoryItem item = (DirectoryItem) value;
                directoryNameLabel.setText (item.file.getName());
                directoryCountLabel.setText (item.getChildCount() + " items");
                setColorsForSelectionState (directoryCellPrototype, isSelected);
                return directoryCellPrototype;
            } else if (value instanceof TextFileItem) {
                TextFileItem item = (TextFileItem) value;
                // populate values
                textNameLabel.setText (item.file.getName());
                textSizeLabel.setText (item.file.length() + " bytes  ");
                textWordCountLabel.setText (item.getWordCount() + " words");
                setColorsForSelectionState (textCellPrototype, isSelected);
                return textCellPrototype;
            } else if (value instanceof ImageFileItem) {
                ImageFileItem item = (ImageFileItem) value;
                // pouplate values
                imageNameLabel.setText (item.file.getName());
                imageSizeLabel.setText (item.file.length() + " bytes");
                imageIconLabel.setIcon (item.icon);
                setColorsForSelectionState (imageCellPrototype, isSelected);
                return imageCellPrototype;
            } else {
                FileItem item = (FileItem) value;
                // pouplate values
                fileNameLabel.setText (item.file.getName());
                fileSizeLabel.setText (item.file.length() + " bytes");
                setColorsForSelectionState (fileCellPrototype, isSelected);
                return fileCellPrototype;
            }
        }
        private void setColorsForSelectionState (Container prototype,
                                                 boolean isSelected) {
            Component[] comps = prototype.getComponents();
            for (int i=0; i<comps.length; i++) {
                if (isSelected) {
                    comps[i].setForeground (listSelectionForeground);
                    comps[i].setBackground (listSelectionBackground);
                } else {
                    comps[i].setForeground (listForeground);
                    comps[i].setBackground (listBackground);
                }
            }
        }
    }
}