第16章 选取器

第16章 选取器

　　本章介绍两个Swing选取器组件，它们是：JFileChooser和JColorChooser，它们分别用于选取文件和颜色。

16.1 JFileChooser

　　文件选取器（与选项窗格一样，参见14.3节“JOptionPane”)是放置在对话框中的轻量组件。一旦创建了一个JFileChooser实例，就可以把这个实例添加到一个对话框中。而且，JFileChooser类还提供了一些方法，这些方法把已存在的文件添加到一个模态对话框中。并且显示这个对话框。这些方法返回一个integer值，指出是激活了选取器的批准按钮还是清除了这个对话框。
　　文件选取器支持三种显示模式：只显示文件、只显示目录和显示文件及目录。另外，文件选取器还支持单文件选取和多文件选取（Swing1.1FCS不完全支持多文件选取。）
　　可以用许多不同的方法来定制文件选取器，如图16-1所示。图１６－１中的上图显示调用JFileChooser.showSaveDialog()后显示的标准对话框。图16-1

例子 16-1 一个简单的文件选取器例子

import java.awt.*;
import java.awt.event.*;
import java.io.File;
import javax.swing.*;
import javax.swing.filechooser.*;
import java.beans.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
JButton button = new JButton("show file chooser ...");

public Test() {
super("Simple File Chooser Application");
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int state = chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();

if(file != null &&
state == JFileChooser.APPROVE_OPTION) {
JOptionPane.showMessageDialog(
null, file.getPath());
}
else if(state == JFileChooser.CANCEL_OPTION) {
JOptionPane.showMessageDialog(
null, "Canceled");
}
else if(state == JFileChooser.ERROR_OPTION) {
JOptionPane.showMessageDialog(
null, "Error!");
}
}
});
}
public static void main(String args[]) {
JFrame f = new Test();
f.setBounds(300,300,350,100);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}

 

16.1.1 文件选取器类型

例子 16-2 缺省的文件选取器类型

import java.awt.*;
import java.awt.event.*;
import java.io.File;
import javax.swing.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
JComboBox comboBox = new JComboBox();
JButton button = new JButton("show file chooser ...");

public Test() {
super("Standard File Chooser Types");
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(comboBox);
contentPane.add(button);

comboBox.addItem("OPEN_DIALOG");
comboBox.addItem("SAVE_DIALOG");
comboBox.addItem("custom dialog");

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String message = "CANCELED";
int state = showChooser(
(String)comboBox.getSelectedItem());
File file = chooser.getSelectedFile();

if(file != null &&
state == JFileChooser.APPROVE_OPTION) {
message = chooser.getApproveButtonText() +
" " + file.getPath();
}
JOptionPane.showMessageDialog(null, message);
}
});
}
private int showChooser(String s) {
int state;

if(s.equals("OPEN_DIALOG")) {
state = chooser.showOpenDialog(null);
}
else if(s.equals("SAVE_DIALOG")) {
state = chooser.showSaveDialog(null);
}
else { // custom dialog
String string = JOptionPane.showInputDialog(
null,
"Button/Title String:");

chooser.setApproveButtonMnemonic(string.charAt(1));
state = chooser.showDialog(Test.this, string);
}
return state;
}
public static void main(String args[]) {
JFrame f = new Test();
f.setBounds(300,300,350,100);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}

 

16.1.2 可访问组件

 

例子 16-3 一个图像预览器可访问组件

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
ImagePreviewer previewer = new ImagePreviewer();

public Test() {
super("Accessory Components");

Container contentPane = getContentPane();
JButton button = new JButton("Select A File");

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

setAccessoryComponent();

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
chooser.showOpenDialog(null);
}
});
}
private void setAccessoryComponent() {
JPanel previewPanel = new JPanel();

previewPanel.setLayout(new BorderLayout());
previewPanel.add(new JLabel("Image Previewer",
SwingConstants.CENTER),
BorderLayout.NORTH);

previewPanel.add(previewer, BorderLayout.CENTER);

previewer.setPreferredSize(new Dimension(200,0));
previewer.setBorder(BorderFactory.createEtchedBorder());

chooser.setAccessory(previewPanel);

new ImagePreviewerAccessoryAdapter(chooser, previewer);
}
public static void main(String a[]) {
JFrame f = new Test();
f.setBounds(300, 300, 300, 75);
f.setVisible(true);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}
class ImagePreviewerAccessoryAdapter extends Object {
public ImagePreviewerAccessoryAdapter(
JFileChooser chooser,
final ImagePreviewer previewer) {
chooser.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
if(e.getPropertyName().equals(
JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {
previewer.update((File)e.getNewValue());
}
}
});
}
}
class ImagePreviewer extends JComponent {
private ImageIcon icon;

public void update(File file) {
Dimension size = getSize();
Insets insets = getInsets();

icon = new ImageIcon(file.getPath());

icon.setImage(icon.getImage().getScaledInstance(
size.width - insets.left - insets.right,
size.height - insets.top - insets.bottom,
Image.SCALE_SMOOTH));

if(isShowing()) {
repaint();
}
}
public void paintComponent(Graphics g) {
Insets insets = getInsets();

super.paintComponent(g);

if(icon != null)
icon.paintIcon(this, g, insets.left, insets.top);
}
}

16.1.3 过滤文件类型

 

例子 16-4 一个文本文件过滤器和预览器

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
import java.util.*;
import java.net.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
TextPreviewer previewer = new TextPreviewer();
JPanel previewPanel = new PreviewPanel();

class PreviewPanel extends JPanel {
public PreviewPanel() {
JLabel label = new JLabel("Text Previewer",
SwingConstants.CENTER);
setPreferredSize(new Dimension(250,0));
setBorder(BorderFactory.createEtchedBorder());

setLayout(new BorderLayout());

label.setBorder(BorderFactory.createEtchedBorder());
add(label, BorderLayout.NORTH);
add(previewer, BorderLayout.CENTER);
}
}
public Test() {
super("Accessory Components");

Container contentPane = getContentPane();
JButton button = new JButton("Select A File");

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

chooser.setAccessory(previewPanel);
chooser.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
if(e.getPropertyName().equals(
JFileChooser.SELECTED_FILE_CHANGED_PROPERTY))
previewer.update((File)e.getNewValue());
}
});
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
chooser.showOpenDialog(null);
}
});
}
public static void main(String a[]) {
JFrame f = new Test();
f.setBounds(300, 300, 300, 75);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}
class TextPreviewer extends JComponent {
private ImageIcon icon;
private JTextArea textArea = new JTextArea();

public TextPreviewer() {
setBorder(BorderFactory.createEtchedBorder());
setLayout(new BorderLayout());
add(new JScrollPane(textArea), BorderLayout.CENTER);
}
public void update(File file) {
textArea.setText(contentsOfFile(file));

if(isShowing()) {
textArea.revalidate();
}
}
static String contentsOfFile(File file) {
String s = new String();
char[] buff = new char[50000];
InputStream is;
InputStreamReader reader;
URL url;

try {
reader = new FileReader(file);

int nch;

while ((
nch = reader.read(buff, 0, buff.length)) != -1) {
s = s + new String(buff, 0, nch);
}
}
catch (java.io.IOException ex) {
s = "Could not load file";
}
return s;
}
}

例子 16-5 多种文件过滤器

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
import java.net.URL;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
TextPreviewer previewer = new TextPreviewer();
PreviewPanel previewPanel = new PreviewPanel();

class PreviewPanel extends JPanel {
public PreviewPanel() {
JLabel label = new JLabel("Text Previewer",
SwingConstants.CENTER);
setPreferredSize(new Dimension(350,0));
setBorder(BorderFactory.createEtchedBorder());

setLayout(new BorderLayout());

label.setBorder(BorderFactory.createEtchedBorder());
add(label, BorderLayout.NORTH);
add(previewer, BorderLayout.CENTER);
}
}
public Test() {
super("Filtering Files");

Container contentPane = getContentPane();
JButton button = new JButton("Select A File");

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int state = chooser.showOpenDialog(null);
String s = "CANCELED";

if(state == JFileChooser.APPROVE_OPTION) {
s = "File Selected: " +
chooser.getSelectedFile().getPath();
}
JOptionPane.showMessageDialog(null, s);
}
});

chooser.setAccessory(previewPanel);
chooser.addChoosableFileFilter(new TextFilter());
chooser.addChoosableFileFilter(new JavaCodeFilter());

chooser.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
if(e.getPropertyName().equals(
JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {
previewer.configure((File)e.getNewValue());
}
}
});
}
public static void main(String a[]) {
JFrame f = new Test();
f.setBounds(300, 300, 300, 75);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}
abstract class SuffixAwareFilter
extends javax.swing.filechooser.FileFilter {
public String getSuffix(File f) {
String s = f.getPath(), suffix = null;
int i = s.lastIndexOf('.');

if(i > 0 && i < s.length() - 1)
suffix = s.substring(i+1).toLowerCase();

return suffix;
}
public boolean accept(File f) {
return f.isDirectory();
}
}
class ImageFilter extends SuffixAwareFilter {
public boolean accept(File f) {
boolean accept = super.accept(f);

if( ! accept) {
String suffix = getSuffix(f);

if(suffix != null)
accept = super.accept(f) || suffix.equals("jpg")
|| suffix.equals("gif");
}
return accept;
}
public String getDescription() {
return "Java Source Code Files(*.java)";
}
}
class JavaCodeFilter extends SuffixAwareFilter {
public boolean accept(File f) {
boolean accept = super.accept(f);

if( ! accept) {
String suffix = getSuffix(f);

if(suffix != null)
accept = super.accept(f) || suffix.equals("java");
}
return accept;
}
public String getDescription() {
return "Java Source Code Files(*.java)";
}
}
class TextFilter extends SuffixAwareFilter {
public boolean accept(File f) {
String suffix = getSuffix(f);

if(suffix != null)
return super.accept(f) || suffix.equals("txt");

return false;
}
public String getDescription() {
return "Text Files(*.txt)";
}
}
class TextPreviewer extends JComponent {
private JTextArea textArea = new JTextArea();
private JScrollPane scrollPane = new JScrollPane(textArea);

public TextPreviewer() {
textArea.setEditable(false);

setBorder(BorderFactory.createEtchedBorder());
setLayout(new BorderLayout());
add(scrollPane, BorderLayout.CENTER);
}
public void configure(File file) {
textArea.setText(contentsOfFile(file));

SwingUtilities.invokeLater(new Runnable() {
public void run() {
JViewport vp = scrollPane.getViewport();

vp.setViewPosition(new Point(0,0));
}
});
}
static String contentsOfFile(File file) {
String s = new String();
char[] buff = new char[50000];
InputStream is;
InputStreamReader reader;
URL url;

try {
reader = new FileReader(file);

int nch;

while ((
nch = reader.read(buff, 0, buff.length)) != -1) {
s = s + new String(buff, 0, nch);
}
}
catch (java.io.IOException ex) {
s = "Could not load file";
}
return s;
}
}

 

16.1.4 文件视图

 

例子 16-6 一个定制的文件视图

import javax.swing.*;
import javax.swing.filechooser.FileView;
import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
JButton button = new JButton("show file chooser ...");

public Test() {
super("Custom File View Example");
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

chooser.setFileView(new CustomFileView());

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int state = chooser.showSaveDialog(null);
File file = chooser.getSelectedFile();
String s = "CANCELED";

if(state == JFileChooser.APPROVE_OPTION)
s = "File: " + file.getPath();

JOptionPane.showMessageDialog(null, s);
}
});
}
public static void main(String args[]) {
JFrame f = new Test();
f.setBounds(300,300,350,100);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}
class CustomFileView extends FileView {
private Icon fileIcon = new ImageIcon("file.gif"),
directoryIcon = new ImageIcon("folder.gif"),
imageIcon = new ImageIcon("photo.jpg");

public String getName(File f) { return null; }
public String getDescription(File f) { return null; }
public String getTypeDescription(File f) { return null; }

public Icon getIcon(File f) {
Icon icon = null;

if(isImage(f)) icon = imageIcon;
else if(f.isDirectory()) icon = directoryIcon;
else icon = fileIcon;

return icon;
}
public Boolean isTraversable(File f) {
Boolean b = null;

if(f.getPath().equals("D://file.txt")) {
b = new Boolean(false);
}
else if(f.getPath().equals("D://books")) {
b = new Boolean(false);
}
return b == null ? new Boolean(true) : b;
}
private boolean isImage(File f) {
String suffix = getSuffix(f);
boolean isImage = false;

if(suffix != null) {
isImage = suffix.equals("gif") ||
suffix.equals("bmp") ||
suffix.equals("jpg");
}
return isImage;
}
private String getSuffix(File file) {
String filestr = file.getPath(), suffix = null;
int i = filestr.lastIndexOf('.');

if(i > 0 && i < filestr.length()) {
suffix = filestr.substring(i+1).toLowerCase();
}
return suffix;
}
}

16.1.5 多文件选取

 

例子 16-7 文件选取器的多文件选取

import java.awt.*;
import java.awt.event.*;
import java.io.File;
import javax.swing.*;
import java.beans.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
JButton button = new JButton("show file chooser ...");

public Test() {
super("Simple File Chooser Application");
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

chooser.setMultiSelectionEnabled(true);

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int state = chooser.showOpenDialog(null);
File[] files = chooser.getSelectedFiles();
String[] filenames = getFilenames(files);

if(filenames != null &&
state == JFileChooser.APPROVE_OPTION) {
JOptionPane.showMessageDialog(null,filenames);
}
else if(state == JFileChooser.CANCEL_OPTION) {
JOptionPane.showMessageDialog(
null, "Canceled");
}
else if(state == JFileChooser.ERROR_OPTION) {
JOptionPane.showMessageDialog(
null, "Error!");
}
}
});
}
private String[] getFilenames(File[] files) {
String[] filenames = null;
int numFiles = files.length;

System.out.println(numFiles);

if(files.length > 0) {
filenames = new String[numFiles];

for(int i=0; i < numFiles; ++i) {
filenames[i] = files[i].getPath();
System.out.println(filenames[i]);
}
}
return filenames;
}
public static void main(String args[]) {
JFrame f = new Test();
f.setBounds(300,300,350,100);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}

16.1.6 JFileChooser属性

 

16.1.7 JFileChooser事件

 

例子 16-8 JFileChooser动作事件

import java.awt.*;
import java.awt.event.*;
import java.io.File;
import javax.swing.*;

public class Test extends JFrame {
JFileChooser chooser = new JFileChooser();
JDialog dialog;
JButton button = new JButton("show file chooser ...");

public Test() {
super("Simple File Chooser Application");
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button);

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String title = chooser.getDialogTitle();

if(title == null)
chooser.getUI().getDialogTitle(chooser);

dialog = new JDialog((Frame)null, title, false);

Container dialogContentPane =
dialog.getContentPane();

dialogContentPane.setLayout(new BorderLayout());
dialogContentPane.add(chooser,
BorderLayout.CENTER);

dialog.setTitle("Non-Modal File Chooser");

dialog.pack();
dialog.setLocationRelativeTo(Test.this);

dialog.setVisible(true);
}
});
chooser.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String state = (String)e.getActionCommand();

if(state.equals(JFileChooser.APPROVE_SELECTION)) {
File file = chooser.getSelectedFile();

JOptionPane.showMessageDialog(
null, file.getPath());
}
else if(
state.equals(JFileChooser.CANCEL_SELECTION)) {
JOptionPane.showMessageDialog(
null, "Canceled");
}
// JFileChooser action listeners are notified
// when one either the approve button or
// cancel button is activated
dialog.setVisible(false);

}
});
}
public static void main(String args[]) {
JFrame f = new Test();
f.setBounds(300,300,350,100);
f.setVisible(true);

f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE);

f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
}

16.1.8 JFileChooser类总结

 

16.1.9 AWT兼容

 

 

16.2 JColorChooser

 

例16-9 在一个小应用程序中显示的颜色选取器

import javax.swing.*;
import javax.swing.colorchooser.*;
import javax.swing.event.*;
import java.awt.*;

public class Test extends JApplet {
JColorChooser chooser = new JColorChooser();
ColorSelectionModel model = chooser.getSelectionModel();

public void init() {
getContentPane().add(chooser, BorderLayout.CENTER);

model.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
showStatus("Color: " + chooser.getColor());
}
});
}
}

16.2.1 在对话框中显示颜色选取器

 

例16-10 在对话框中显示的颜色选取器

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Test extends JApplet {
public void init() {
getContentPane().add(new Palette(), BorderLayout.CENTER);
}
}
class Palette extends JPanel {
private Color[] defaultColors = new Color[] {
Color.blue, Color.red, Color.yellow, Color.green,
Color.magenta, Color.darkGray, Color.white, Color.orange,
Color.pink, Color.cyan, Color.lightGray, Color.gray,
};

public Palette() {
int columns = 3;

setBorder(
BorderFactory.createTitledBorder("Color Palette"));

setLayout(new GridLayout(columns,0,1,1));

for(int i=0; i < defaultColors.length; ++i)
add(new ColorPatch(defaultColors[i]));
}
}
class ColorPatch extends JPanel {
JApplet applet;
Color selectedColor;

public ColorPatch(Color color) {
setBorder(BorderFactory.createEtchedBorder());
setBackground(color);

addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
selectedColor = JColorChooser.showDialog(
ColorPatch.this, // parent comp
"Pick A Color", // dialog title
getBackground()); // initial color

if(selectedColor == null) {
JOptionPane.showMessageDialog(ColorPatch.this,
"ColorChooser Canceled");
}
else {
setBackground(selectedColor);
repaint();

JOptionPane.showMessageDialog(ColorPatch.this,
"Color Selected: " + selectedColor);
}
}
});
}
}

16.2.2 定制颜色选取器

 

例16-11 颜色选取器中的一个定制预览

import javax.swing.*;
import javax.swing.colorchooser.*;
import java.awt.*;
import java.awt.event.*;

public class Test extends JApplet {
private JColorChooser chooser = new JColorChooser();
private JButton button = new JButton("Show Color Chooser");
private JDialog dialog;

public void init() {
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button, BorderLayout.CENTER);

chooser.setPreviewPanel(new PreviewPanel());

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {

if(dialog == null)
dialog = JColorChooser.createDialog(
Test.this, // parent comp
"Pick A Color", // dialog title
false, // modality
chooser,
null, null);

dialog.setVisible(true);
}
});
}
class PreviewPanel extends JPanel {
public PreviewPanel() {
setPreferredSize(new Dimension(0,100));
setBorder(BorderFactory.createRaisedBevelBorder());
}
public void paintComponent(Graphics g) {
Dimension size = getSize();

g.setColor(getForeground());
g.fillRect(0,0,size.width,size.height);
}
}
}

例16-12 实现一个定制颜色选取器面板

import javax.swing.*;
import javax.swing.event.*;
import javax.swing.colorchooser.*;
import java.awt.*;
import java.awt.event.*;

public class Test extends JApplet {
private JColorChooser chooser = new JColorChooser();
private AbstractColorChooserPanel colorPanels[] =
new AbstractColorChooserPanel[] {
new ListPanel(),
};
private JButton button = new JButton("Show Color Chooser");
private JDialog dialog;

public void init() {
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());
contentPane.add(button, BorderLayout.CENTER);

chooser.setChooserPanels(colorPanels);

button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(dialog == null)
dialog = JColorChooser.createDialog(
Test.this, // parent comp
"Pick A Color", // dialog title
false, // modality
chooser,
null, null);

dialog.setVisible(true);
}
});
}
}
class ListPanel extends AbstractColorChooserPanel
implements ListSelectionListener {
private JPanel labelPanel = new JPanel(),
listPanel = new JPanel();

private JList redList = new JList(), blueList = new JList(),
greenList = new JList();

private DefaultListModel redModel = new DefaultListModel(),
blueModel = new DefaultListModel(),
greenModel = new DefaultListModel();

private boolean isAdjusting = false;

public void updateChooser() {
if( ! isAdjusting) {
isAdjusting = true;

Color color = getColorFromModel();
int r = color.getRed(), g = color.getGreen(),
b = color.getBlue();

redList.setSelectedIndex(r);
redList.ensureIndexIsVisible(r);

blueList.setSelectedIndex(b);
blueList.ensureIndexIsVisible(b);

greenList.setSelectedIndex(g);
greenList.ensureIndexIsVisible(g);

isAdjusting = false;
}
}
protected void buildChooser() {
redList.setFixedCellWidth(50);
greenList.setFixedCellWidth(50);
blueList.setFixedCellWidth(50);

for(int i=0; i < 256; ++i) {
redModel.addElement(Integer.toString(i));
greenModel.addElement(Integer.toString(i));
blueModel.addElement(Integer.toString(i));
}

redList.setModel(redModel);
greenList.setModel(greenModel);
blueList.setModel(blueModel);

listPanel.setLayout(new GridLayout(0,3,10,0));

listPanel.add(new JScrollPane(redList));
listPanel.add(new JScrollPane(blueList));
listPanel.add(new JScrollPane(greenList));

labelPanel.setLayout(new GridLayout(0,3,10,0));

labelPanel.add(new JLabel("Red"));
labelPanel.add(new JLabel("Blue"));
labelPanel.add(new JLabel("Green"));

setLayout(new BorderLayout());
add(labelPanel, BorderLayout.NORTH);
add(listPanel, BorderLayout.CENTER);

redList.addListSelectionListener(this);
greenList.addListSelectionListener(this);
blueList.addListSelectionListener(this);
}
public void valueChanged(ListSelectionEvent e) {
int r = redList.getSelectedIndex(),
b = blueList.getSelectedIndex(),
g = greenList.getSelectedIndex();

if(r != -1 && g != -1 && b != -1)
getColorSelectionModel().setSelectedColor(
new Color(r,g,b));
}
public String getDisplayName() {
return "display name";
}
public Icon getSmallDisplayIcon() {
return null;
}
public Icon getLargeDisplayIcon() {
return null;
}
}

 

16.2.3 JColorChooser属性

 

16.2.4 JColorChooser事件

 

16.2.5 JColorChooser类总结

 

16.2.6 AWT兼容

 

16.3 本章回顾

  略