第7章 插入式界面样式

第7章 插入式界面样式

　　插入式界面样式是建立在第3章“Swing组件体系结构”中讨论的组件体系结构基础之上的，即一个组件的界面样式是通过把一个特殊的UI代表插入这个组件来设置的。
　　Swing还提供了一个API来管理界面样式。界面样式的管理包括如下几个方面：定义界面样式、指定当前的界面样式和为当前的界面样式添加附加界面样式等。例如，图7-1示出了一个以不同界面样式运行的小应用程序（顺时针方向，从左上开始分别是Metal、Windows、Motif和Macintoch的界面样式）。这个小应用程序提供了一个组合框，用于为该小应用程序的所有组件选取界面样式。这个小应用程序借助Swing的UIManager类，根据在该组合框中的选择安装界面样式(注：未列出图7-1中示出的小应用程序的代码，例7-3给出了一个改变界面样式的例子)。

7.1 插入式界面样式

7.1.1 界面样式结构

例7-1 一个多行标签

import javax.swing.*;
import javax.swing.plaf.BorderUIResource;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class Test extends JApplet {
public void init() {
Container contentPane = getContentPane();
JLabel label = new JLabel(
"A long string that is high on verbiage and " +
"low on content.");

MultilineLabel multilineLabel = new MultilineLabel(
"A long string that is high on verbiage and " +
"low on content.");

contentPane.setLayout(new BorderLayout(2,10));

contentPane.add(label, BorderLayout.NORTH);
contentPane.add(multilineLabel, BorderLayout.CENTER);
}
}
class MultilineLabel extends JTextArea {
public MultilineLabel(String s) {
super(s);
}
public void updateUI() {
super.updateUI();

// turn on wrapping and disable editing and highlighting

setLineWrap(true);
setWrapStyleWord(true);
setHighlighter(null);
setEditable(false);

// Set the text area's border, colors and font to
// that of a label

LookAndFeel.installBorder(this, "Label.border");

LookAndFeel.installColorsAndFont(this,
"Label.background",
"Label.foreground",
"Label.font");
}
}

7.1.2 界面样式缺省值

例7-2 修改UI缺省值

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

public class Test extends JApplet {
public void init() {
UIManager.put("Tree.background", Color.lightGray);
UIManager.put("Tree.textBackground", Color.lightGray);

//ScrollBar.width is peculiar to Metal L&F
UIManager.put("ScrollBar.width", new Integer(25));
getContentPane().add(new JScrollPane(new JTree()));
}
}

7.1.3 UI管理器

例7-3 变换一个组件树的界面样式

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

import com.sun.java.swing.plaf.motif.MotifLookAndFeel;
import com.sun.java.swing.plaf.windows.WindowsLookAndFeel;
import javax.swing.plaf.metal.MetalLookAndFeel;

import javax.swing.plaf.ColorUIResource;

public class Test extends JApplet {
public void init() {
Container contentPane = getContentPane();

contentPane.add(new ControlPanel(), BorderLayout.NORTH);
contentPane.add(new ComponentPanel(),
BorderLayout.CENTER);
}
class ComponentPanel extends JPanel {
public ComponentPanel() {
JList list;
JScrollBar sb;

setBorder(
BorderFactory.createTitledBorder("Components"));

add(new JCheckBox("check Me"));
add(new JRadioButton("radio button"));
add(new JButton("button"));
add(new JLabel("A Label:"));
add(new JTextField("text field"));
add(new JScrollPane(list = new JList(new Object[] {
"item 1", "item 2", "item 3",
"item 4", "item 5", "item 6",
"item 7", "item 8", "item 9",
})));
add(sb = new JScrollBar(SwingConstants.HORIZONTAL));
sb.setPreferredSize(new Dimension(150,17));

add(sb = new JScrollBar(SwingConstants.VERTICAL));
sb.setPreferredSize(new Dimension(20,175));

list.setVisibleRowCount(5);
}
}
class ControlPanel extends JPanel {
JCheckBox checkBox = new JCheckBox("UIResource");
JRadioButton motifButton = new JRadioButton("Motif"),
windowsButton = new JRadioButton("Windows"),
metalButton = new JRadioButton("Metal");

public ControlPanel() {
ActionListener listener = new RadioHandler();
ButtonGroup group = new ButtonGroup();

group.add(motifButton);
group.add(windowsButton);
group.add(metalButton);

motifButton.addActionListener(listener);
windowsButton.addActionListener(listener);
metalButton.addActionListener(listener);

add(motifButton);
add(windowsButton);
add(metalButton);
}
class RadioHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
JRadioButton src = (JRadioButton)e.getSource();

try {
if(src == motifButton)
UIManager.setLookAndFeel(
"com.sun.java.swing.plaf." +
"motif.MotifLookAndFeel");

else if(src == windowsButton)
UIManager.setLookAndFeel(
"com.sun.java.swing.plaf." +
"windows.WindowsLookAndFeel");

else if(src == metalButton)
UIManager.setLookAndFeel(
"javax.swing.plaf.metal." +
"MetalLookAndFeel");
}
catch(Exception ex) {
ex.printStackTrace();
}
SwingUtilities.updateComponentTreeUI(
getContentPane());
}
}
}
}

7.1.4 UI资源

例7-4 UI资源

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

import com.sun.java.swing.plaf.motif.MotifLookAndFeel;
import javax.swing.plaf.metal.MetalLookAndFeel;

import javax.swing.plaf.ColorUIResource;

public class Test extends JApplet {
private JButton button = new JButton("App Resource");

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

contentPane.add(new ControlPanel(), BorderLayout.NORTH);
contentPane.add(button, BorderLayout.CENTER);
}
class ControlPanel extends JPanel {
boolean resource = false;
JButton colorSetButton = new JButton("Set Color ...");
JCheckBox checkBox = new JCheckBox("UIResource");
JRadioButton motifButton = new JRadioButton("Motif"),
metalButton = new JRadioButton("Metal");

public ControlPanel() {
ActionListener listener = new RadioHandler();
ButtonGroup group = new ButtonGroup();

group.add(motifButton);
group.add(metalButton);

motifButton.addActionListener(listener);
metalButton.addActionListener(listener);

metalButton.setSelected(true);

add(motifButton);
add(metalButton);
add(Box.createHorizontalStrut(25));
add(colorSetButton);
add(checkBox);

Font buttonFont = button.getFont();
button.setFont(new Font(buttonFont.getFamily(),
Font.ITALIC, 56));

colorSetButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
updateButtonColor();
}
});
checkBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
resource = checkBox.isSelected();
updateButtonColor();
}
});
}
private void updateButtonColor() {
Color c = JColorChooser.showDialog(
getContentPane(), // parent component
"Choose a Color", // title
getBackground()); // initial color

if(resource) {
button.setText("UI Resource");
button.setForeground(new ColorUIResource(c));
}
else {
button.setText("App Resource");
button.setForeground(c);
}
}
class RadioHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
JRadioButton src = (JRadioButton)e.getSource();

try {
if(src == motifButton)
UIManager.setLookAndFeel(
"com.sun.java.swing.plaf." +
"motif.MotifLookAndFeel");
else if(src == metalButton)
UIManager.setLookAndFeel(
"javax.swing.plaf.metal." +
"MetalLookAndFeel");
}
catch(Exception ex) {
ex.printStackTrace();
}
SwingUtilities.updateComponentTreeUI(
getContentPane());
}
}
}
}

7.2 Java界面样式

例7-5 Metal客户属性

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

public class Test extends JApplet {
JDesktopPane desktopPane = new JDesktopPane();

JInternalFrame jif = new JInternalFrame(
"Internal Frame ", // title
true, // resizable
true, // closable
true, // maximizable
true); // iconifiable

JScrollBar scrollbar = new JScrollBar();
JSlider slider = new JSlider();
JToolBar toolbar = new JToolBar();
JTree tree = new JTree();

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

jif.setPreferredSize(new Dimension(550, 450));
jif.getContentPane().setLayout(new FlowLayout());
jif.getContentPane().add(new ComponentPanel());

desktopPane.setLayout(new FlowLayout());
desktopPane.add(jif);

contentPane.add(new ControlPanel(), BorderLayout.NORTH);
contentPane.add(desktopPane, BorderLayout.CENTER);

}
class ComponentPanel extends JPanel {
public ComponentPanel() {
JPanel panel = new JPanel();

setLayout(new BorderLayout());
add(toolbar, BorderLayout.NORTH);
add(panel, BorderLayout.CENTER);

panel.add(scrollbar);
panel.add(slider);
panel.add(new JScrollPane(tree));

tree.setPreferredSize(new Dimension(200,100));

toolbar.add(new JButton("button"));
}
}
class ControlPanel extends JPanel {
JCheckBox rollover = new JCheckBox(
"JToolBar.rollover");
JCheckBox palette = new JCheckBox(
"JInternalFrame.palette");
JCheckBox filled = new JCheckBox(
"JSlider.isFilled");
JCheckBox freeStanding = new JCheckBox(
" JScrollBar.freeStanding");

JRadioButton none = new JRadioButton("none");
JRadioButton horizontal = new JRadioButton("horizontal");
JRadioButton angled = new JRadioButton("angled");

public ControlPanel() {
ActionListener checkBoxListener =
new CheckBoxListener();
ActionListener radioButtonListener =
new RadioButtonListener();

palette.addActionListener(checkBoxListener);
filled.addActionListener(checkBoxListener);
rollover.addActionListener(checkBoxListener);
freeStanding.addActionListener(checkBoxListener);

none.addActionListener(radioButtonListener);
horizontal.addActionListener(radioButtonListener);
angled.addActionListener(radioButtonListener);

ButtonGroup group = new ButtonGroup();
group.add(none);
group.add(horizontal);
group.add(filled);

none.setSelected(true);
freeStanding.setSelected(true);

add(palette);
add(filled);
add(rollover);
add(freeStanding);
add(Box.createHorizontalStrut(10));
add(new JLabel("Tree: "));
add(none);
add(horizontal);
add(angled);
}
class RadioButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
JRadioButton rb = (JRadioButton)e.getSource();

if(rb == none) {
tree.putClientProperty(
"JTree.lineStyle", "None");
}
if(rb == horizontal) {
tree.putClientProperty(
"JTree.lineStyle", "Horizontal");
}
if(rb == angled) {
tree.putClientProperty(
"JTree.lineStyle", "Angled");
}
tree.repaint();
}
}
class CheckBoxListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
JCheckBox cb = (JCheckBox)e.getSource();

if(cb == palette) {
palette.putClientProperty(
"JInternalFrame.isPalette",
new Boolean(cb.isSelected()));

jif.revalidate();
}
else if(cb == filled) {
slider.putClientProperty(
"JSlider.isFilled",
new Boolean(cb.isSelected()));

slider.repaint();
}
else if(cb == rollover) {
toolbar.putClientProperty(
"JToolBar.isRollover",
new Boolean(cb.isSelected()));

toolbar.repaint();
}
else if(cb == freeStanding) {
scrollbar.putClientProperty(
"JScrollBar.isFreeStanding",
new Boolean(cb.isSelected()));

scrollbar.repaint();
}
}
}
}
}

7.2.1 客户属性

7.2.2 主题

例7-6 一个简单的定制主题

import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.*;
import javax.swing.plaf.metal.*;
import javax.swing.plaf.*;

public class Test extends JApplet {
public void init() {
Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

setMetalTheme(new ExperimentalTheme());

contentPane.add(new JButton("button"));
contentPane.add(new JCheckBox("check me"));
}
private void setMetalTheme(MetalTheme theme) {
MetalLookAndFeel.setCurrentTheme(new ExperimentalTheme());

// Metal Look and Feel must be (re)loaded for the
// new theme to take effect ...

try {
UIManager.setLookAndFeel(
"javax.swing.plaf.metal.MetalLookAndFeel");
}
catch(IllegalAccessException e1) {}
catch(UnsupportedLookAndFeelException e2) {}
catch(InstantiationException e3) {}
catch(ClassNotFoundException e4) {}
}
}
class ExperimentalTheme extends DefaultMetalTheme {
public FontUIResource getControlTextFont() {
return new FontUIResource("SanSerif",
Font.BOLD + Font.ITALIC, 24);
}
}

例7-7 安装一个附加界面样式

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

public class Test extends JApplet {
public void init() {
UIManager.addAuxiliaryLookAndFeel(
new ExampleAuxiliaryLookAndFeel());

Container contentPane = getContentPane();
JButton button = new JButton("button");

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

例7-8 附加界面样式的例子

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

public class ExampleAuxiliaryLookAndFeel extends LookAndFeel {
public String getDescription(){
return "example auxiliary look and feel";
}
public String getID() {
return "example";
}
public String getName() {
return "example auxiliary";
}
public boolean isNativeLookAndFeel() {
return false;
}
public boolean isSupportedLookAndFeel() {
return true;
}
public UIDefaults getDefaults() {
UIDefaults table = new UIDefaults();

Object[] uiDefaults = {
"ButtonUI", "AuxiliaryButtonUI"
};

table.putDefaults(uiDefaults);
return table;
}
}

例7-9 一个附加UI

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

public class AuxiliaryButtonUI extends ComponentUI {
private static ComponentUI cui = new AuxiliaryButtonUI();
private static AuxiliaryButtonMouseListener ml =
new AuxiliaryButtonMouseListener();

// must be implemented
public static ComponentUI createUI(JComponent c) {
return cui;
}
public void installUI(JComponent c) {
c.addMouseListener(ml);
}
public void uninstallUI(JComponent c) {
c.removeMouseListener(ml);
}
public void update(Graphics g, JComponent c) {
// don't want ComponentUI default behavior, which is
// to clear the background
}
}
class AuxiliaryButtonMouseListener extends MouseAdapter {
public void mouseEntered(MouseEvent e) {
JComponent c = (JComponent)e.getSource();
AccessibleContext ac = c.getAccessibleContext();
String role = ac.getAccessibleRole().toString();
String name = ac.getAccessibleName();

System.out.println("mouse entered component of type " +
role + " named " + name);
}
}

7.3 附加UI

7.4 本章回顾