博客
关于我
强烈建议你试试无所不能的chatGPT，快点击我
《Java 2 图形设计卷Ⅱ- SWING》第6章 实用工具
阅读量：5891 次
发布时间：2019-06-19

本文共 24085 字，大约阅读时间需要 80 分钟。

第6章 实用工具

　　Swing包括许多实用工具，本章将介绍这些实用工具。其中有些实用工具（如计时器和由SwingUtilties类提供的static方法）在Swing内部使用，而进度监视器和进度监视器流等其他的实用工具则不是内容使用的。使用Swing的开发人员可以使用本章介绍的所有实用工具。

6.1 计时器

例6-1 使用Swing计时器

import java.awt.*;

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

public class Test implements ActionListener {

private int seconds=1;

public Test() {

Timer oneSecondTimer = new Timer(1000, this);
Timer timerWithInitialDelay = new Timer(2000,
new TimerWithDelayListener());
Timer oneTimeTimer = new Timer(10000,
new OneTimeListener());

timerWithInitialDelay.setInitialDelay(5000);

oneTimeTimer.setRepeats(false);

oneSecondTimer.start();

timerWithInitialDelay.start();
oneTimeTimer.start();
}
public void actionPerformed(ActionEvent e) {
if(seconds == 0)
System.out.println("Time: " + seconds + " second");
else
System.out.println("Time: " + seconds + " seconds");

seconds++;

}
public static void main(String args[]) {
new Test();
while(true);
}
}
class TimerWithDelayListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Timer with Delay Ringing");
}
}
class OneTimeListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("One Time Timer Ringing");
}
}

 

例6-2 重载构造计时器时所指定的延迟

import java.awt.*;

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

public class Test implements ActionListener {

public Test() {
Timer oneSecondTimer = new Timer(1000, this);

oneSecondTimer.setInitialDelay(10000);

oneSecondTimer.setRepeats(false);
oneSecondTimer.start();
}
public void actionPerformed(ActionEvent e) {
System.out.println("ring ...");
}
public static void main(String args[]) {
new Test();
while(true);
}
}

 

例6-3 计时器日志

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

public class Test implements ActionListener {

public Test() {
Timer.setLogTimers(true);

Timer oneSecondTimer = new MyTimer(1000, this);

oneSecondTimer.start();
}
public void actionPerformed(ActionEvent e) {
System.out.println("ring ...");
}
public static void main(String args[]) {
new Test();
while(true);
}
}
class MyTimer extends Timer {
public MyTimer(int delay, ActionListener listener) {
super(delay, listener);
}
public String toString() {
return "MyTimer";
}
}

 

例6-4 与单个计时器相关联的多个动作监听器

import java.awt.*;

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

public class Test implements ActionListener {

private int seconds=1;

public Test() {

Timer oneSecondTimer = new Timer(1000, this);

oneSecondTimer.addActionListener(new SecondListener());

oneSecondTimer.addActionListener(new ThirdListener());
oneSecondTimer.start();
}
public void actionPerformed(ActionEvent e) {
if(seconds == 0)
System.out.println("Time: " + seconds + " second");
else
System.out.println("Time: " + seconds + " seconds");
seconds++;
}
public static void main(String args[]) {
new Test();
while(true);
}
}
class SecondListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Second Listener");
}
}
class ThirdListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Third Listener");
}
}

 

例6-5 合并计时器事件

import java.awt.*;

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

public class Test implements ActionListener {

private boolean firstRing = true;
private int ring = 1;

public Test() {

Timer.setLogTimers(true);

Timer oneSecondTimer = new Timer(1000, this);

// comment out the following line for colaescing

oneSecondTimer.setCoalesce(false);

System.out.println("Timer is coalescing: " +

oneSecondTimer.isCoalesce());

oneSecondTimer.start();

}
public void actionPerformed(ActionEvent e) {
System.out.println("ring #" + ring++);

if(firstRing) {

// simulate a time consuming operation by sleeping
// for 10 seconds ...
try {
Thread.currentThread().sleep(10000);
}
catch(InterruptedException ex) {
ex.printStackTrace();
}
firstRing = false;
}
}
public static void main(String args[]) {
new Test();
while(true);
}
}

 

6.2 事件监听器列表

 

6.3 Swing实用工具

 

例6-6 计算两个矩形之间的差集、交集和并集

import java.awt.*;

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

public class Test extends JApplet {

Rectangle r1 = new Rectangle(20,20,150,75);
Rectangle r2 = new Rectangle(100,40,100,150);
Rectangle destination;

public Test() {

destination = new Rectangle(r2);

// print out the intersection of r1 and r2 ...

System.out.println("Intersection: " +

SwingUtilities.computeIntersection(r1.x,r1.y,
r1.width,r1.height,destination));
System.out.println();

// print out the union of r1 and r2 ...

System.out.println("Union: " +

SwingUtilities.computeUnion(r1.x,r1.y,
r1.width,r1.height,destination));
System.out.println();

// print out the difference of r1 and r2 ...

Rectangle[] difference =

SwingUtilities.computeDifference(r1, r2);

System.out.println("Difference:");

for(int i=0; i < difference.length; ++i) {

System.out.println(difference[i]);
}
}
public void paint(Graphics g) {
g.setColor(Color.red);
g.fillRect(r1.x, r1.y, r1.width, r1.height);

g.setColor(Color.yellow);

g.fillRect(r2.x, r2.y, r2.width, r2.height);
}
}

　　 <applet archive="s06_tu02.jar" code="Test.class" width="600" height="550"><param name="height" value="550"> <param name="archive" value="s06_tu02.jar"> <param name="width" value="600"> <param name="code" value="Test.class"> <param name="codeBase" value="http://www.web.nyist.net/~rf/gui/"></applet>  
　　　图6-2 转换坐标系统

例6-7 转换鼠标坐标

import java.awt.*;

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

public class Test extends JApplet {

private Point lastScreenPt = null;
private final Container contentPane = getContentPane();
private PanelWithString
outer = new PanelWithString(Color.orange),
inner = new PanelWithString(Color.red),
innermost = new PanelWithString(Color.yellow);

public Test() {

Font font = new Font("Times-Roman", Font.ITALIC, 26);

contentPane.setLayout(new OverlayLayout(contentPane));

contentPane.add(innermost);
contentPane.add(inner);
contentPane.add(outer);

innermost.setMaximumSize(new Dimension(350,50));

inner.setMaximumSize(new Dimension(450,200));
outer.setMaximumSize(new Dimension(550,400));

setFont(font);

innermost.setFont(font);
inner.setFont(font);
outer.setFont(font);

contentPane.addMouseMotionListener(

new MouseMotionAdapter() {
public void mouseMoved(MouseEvent e) {
Point pt = e.getPoint();

outer.setString(SwingUtilities.convertPoint(

contentPane, pt, outer).toString());

inner.setString(SwingUtilities.convertPoint(

contentPane, pt, inner).toString());

innermost.setString(SwingUtilities.convertPoint(

contentPane, pt, innermost).toString());

SwingUtilities.convertPointToScreen(

pt, contentPane);

lastScreenPt = pt;

repaint();
}
});
}
public void paint(Graphics g) {
super.paint(g);

if(lastScreenPt != null) {

String s = new String("Screen: " + lastScreenPt);

g.setColor(getForeground());

g.drawString(s,10,g.getFontMetrics().getHeight());

SwingUtilities.convertPointFromScreen(lastScreenPt,

contentPane);

s = "Content Pane: " + lastScreenPt;

g.drawString(s,10,g.getFontMetrics().getHeight()*2);

}
else {
g.setColor(getForeground());
g.drawString("MOVE THE MOUSE IN HERE",10,
g.getFontMetrics().getHeight());
}
}
}
class PanelWithString extends JPanel {
String s;
Color color;

public PanelWithString(Color color) {

this.color = color;
}
public void setString(String s) {
this.s = s;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);

Dimension size = getSize();

g.setColor(color);

g.fillRect(0,0,size.width,size.height);

if(s != null) {

g.setColor(getForeground());
g.drawString(s,10,g.getFontMetrics().getHeight());
}
}
}

 

6.4 Swing常量

 

6.5 Borlayout和Box类

 

 

6.5.1 BoxLayout类

　　 <applet archive="s06_tu03.jar" code="Test.class" width="400" height="250"><param name="height" value="250"> <param name="archive" value="s06_tu03.jar"> <param name="width" value="400"> <param name="code" value="Test.class"> <param name="codeBase" value="http://www.web.nyist.net/~rf/gui/"></applet>

　　　　　　　图6-3 两个使用BoxLayout的容器

 

例6-8 使用BoxLayout

import java.awt.*;

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

public class Test extends JApplet {

public Test() {
Container contentPane = getContentPane();
ContainerWithBoxLayout yaxis =
new ContainerWithBoxLayout(BoxLayout.Y_AXIS);

ContainerWithBoxLayout xaxis =

new ContainerWithBoxLayout(BoxLayout.X_AXIS);

contentPane.setLayout(new FlowLayout());

xaxis.add(new JButton(new ImageIcon("reach.gif")));

xaxis.add(new JButton(new ImageIcon("punch.gif")));
xaxis.add(new JButton(new ImageIcon("open_hand.gif")));

yaxis.add(new JButton(new ImageIcon("ladybug.gif")));

yaxis.add(new JButton(new ImageIcon("crab.gif")));
yaxis.add(new JButton(new ImageIcon("frog.gif")));
yaxis.add(new JButton(new ImageIcon("snail.gif")));

contentPane.add(xaxis);

contentPane.add(yaxis);
}
}
class ContainerWithBoxLayout extends JPanel {
public ContainerWithBoxLayout(int orientation) {
setLayout(new BoxLayout(this, orientation));
}
}

6.5.2 Box类

 

例6-9 使用水平和垂直的膨胀体

6.6 进度监视器

 

6.6.1 ProgressMonitor

　　　　 使用一个进度监视器（注：此为一可点击执行的.jar文件，但需要下载到你的电脑上方可点击执行）

例6-10 使用一个进度监视器

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

public class Test extends JFrame {

private JButton readButton = new JButton("read file");
private BufferedInputStream in;
private ProgressMonitor pm;
private String fileName = "Test.java";

public Test() {

final Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

contentPane.add(readButton);

readButton.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
try {
in = new BufferedInputStream(
new FileInputStream(fileName));

pm = new ProgressMonitor(contentPane,

"Reading File:",
fileName,
0, in.available());
}
catch(FileNotFoundException fnfx) {
fnfx.printStackTrace();
}
catch(IOException iox) {
iox.printStackTrace();
}

ReadThread t = new ReadThread();

t.start();
}
});
}
class ReadThread extends Thread {
int i, cnt=0;
String s;

public void run() {

try {
readButton.setEnabled(false);

while(!pm.isCanceled() && (i = in.read()) != -1) {

try {
Thread.currentThread().sleep(25);
}
catch(InterruptedException ex) {
ex.printStackTrace();
}
System.out.print((char)i);

SwingUtilities.invokeLater(new Runnable(){

public void run() {
pm.setProgress(++cnt);
}
});
}
if(pm.isCanceled())
JOptionPane.showMessageDialog(
Test.this,
"Operation Canceled!",
"Cancellation",
JOptionPane.ERROR_MESSAGE);
}
catch(IOException ex) {
ex.printStackTrace();
}
finally {
try {
in.close();
}
catch(IOException ex2) {
ex2.printStackTrace();
}
}
readButton.setEnabled(true);
}
}
public static void main(String args[]) {
GJApp.launch(new Test(),
"Using Progress Monitors",300,300,450,300);
}
}
class GJApp extends WindowAdapter {
static private JPanel statusArea = new JPanel();
static private JLabel status = new JLabel(" ");
static private ResourceBundle resources;

public static void launch(final JFrame f, String title,

final int x, final int y,
final int w, int h) {
launch(f,title,x,y,w,h,null);
}
public static void launch(final JFrame f, String title,
final int x, final int y,
final int w, int h,
String propertiesFilename) {
f.setTitle(title);
f.setBounds(x,y,w,h);
f.setVisible(true);

statusArea.setBorder(BorderFactory.createEtchedBorder());

statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
statusArea.add(status);
status.setHorizontalAlignment(JLabel.LEFT);

f.setDefaultCloseOperation(

WindowConstants.DISPOSE_ON_CLOSE);

if(propertiesFilename != null) {

resources = ResourceBundle.getBundle(
propertiesFilename, Locale.getDefault());
}

f.addWindowListener(new WindowAdapter() {

public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
static public JPanel getStatusArea() {
return statusArea;
}
static public void showStatus(String s) {
status.setText(s);
}
static Object getResource(String key) {
if(resources != null) {
return resources.getString(key);
}
return null;
}
}

6.6.2 PropressMonitorInputStream

 

例6-11 使用ProgressMonitorInputStream

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

public class Test extends JFrame {

private ProgressMonitorInputStream in;
private JButton readButton = new JButton("read file");

public Test() {

final Container contentPane = getContentPane();
final String fileName = "Test.java";

contentPane.setLayout(new FlowLayout());

contentPane.add(readButton);

readButton.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
try {
in = new ProgressMonitorInputStream(
contentPane,
"Reading " + fileName,
new FileInputStream(fileName));
}
catch(FileNotFoundException ex) {
ex.printStackTrace();
}

ReadThread t = new ReadThread();

readButton.setEnabled(false);
t.start();
}
});
}
class ReadThread extends Thread {
public void run() {
int i;

try {

while((i = in.read()) != -1) {
System.out.print((char)i);
try {
Thread.currentThread().sleep(10);
}
catch(Exception ex) {
ex.printStackTrace();
}
}
in.close();
}
catch(IOException ex) {
JOptionPane.showMessageDialog(
Test.this,
"Operation Canceled!",
"Cancellation",
JOptionPane.ERROR_MESSAGE);
}
readButton.setEnabled(true);
}
}
public static void main(String args[]) {
GJApp.launch(new Test(),
"Using ProgressMonitorInputStream",
300,300,450,300);
}
}
class GJApp extends WindowAdapter {
static private JPanel statusArea = new JPanel();
static private JLabel status = new JLabel(" ");
static private ResourceBundle resources;

public static void launch(final JFrame f, String title,

final int x, final int y,
final int w, int h) {
launch(f,title,x,y,w,h,null);
}
public static void launch(final JFrame f, String title,
final int x, final int y,
final int w, int h,
String propertiesFilename) {
f.setTitle(title);
f.setBounds(x,y,w,h);
f.setVisible(true);

statusArea.setBorder(BorderFactory.createEtchedBorder());

statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
statusArea.add(status);
status.setHorizontalAlignment(JLabel.LEFT);

f.setDefaultCloseOperation(

WindowConstants.DISPOSE_ON_CLOSE);

if(propertiesFilename != null) {

resources = ResourceBundle.getBundle(
propertiesFilename, Locale.getDefault());
}

f.addWindowListener(new WindowAdapter() {

public void windowClosed(WindowEvent e) {
System.exit(0);
}
});
}
static public JPanel getStatusArea() {
return statusArea;
}
static public void showStatus(String s) {
status.setText(s);
}
static Object getResource(String key) {
if(resources != null) {
return resources.getString(key);
}
return null;
}
}

6.7 撤消/重复

 

6.7.1一个简单的撤消/重复样例

 

例6-12 一个简单的撤消/重复样例

import javax.swing.*;

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

public class Test extends JApplet {

private JPanel colorPanel = new JPanel();
private BackgroundColorEdit undo = new BackgroundColorEdit();
private Color oldColor;

public void init() {

colorPanel.setBorder(
BorderFactory.createTitledBorder(
"Change color and subsequently undo " +
"from the Edit menu"));

makeMenuBar();

getContentPane().add(colorPanel, BorderLayout.CENTER);
}
private void makeMenuBar() {
JMenuBar menuBar = new JMenuBar();
JMenu editMenu = new JMenu("Edit");

editMenu.add(new SetColorAction());

editMenu.add(new UndoAction());

menuBar.add(editMenu);

setJMenuBar(menuBar);
}
class SetColorAction extends AbstractAction {
public SetColorAction() {
super("Set color ...");
}
public void actionPerformed(ActionEvent e) {
Color color = JColorChooser.showDialog(
Test.this, // parent component
"Pick A Color", // dialog title
null); // initial color

if(color != null) {

oldColor = colorPanel.getBackground();
colorPanel.setBackground(color);
}
}
}
class UndoAction extends AbstractAction {
public UndoAction() {
putValue(Action.NAME, undo.getUndoPresentationName());
}
public void actionPerformed(ActionEvent e) {
String name = (String)getValue(Action.NAME);
boolean isUndo = name.equals(
undo.getUndoPresentationName());

if(isUndo) {

undo.undo();
putValue(Action.NAME,
undo.getRedoPresentationName());
}
else {
undo.redo();
putValue(Action.NAME,
undo.getUndoPresentationName());
}
}
}
class BackgroundColorEdit extends AbstractUndoableEdit {
public void undo() throws CannotUndoException {
super.undo();
toggleColor();
}
public void redo() throws CannotRedoException {
super.redo();
toggleColor();
}
public String getUndoPresentationName() {
return "Undo";
}
public String getRedoPresentationName() {
return "Redo";
}
private void toggleColor() {
Color color = colorPanel.getBackground();
colorPanel.setBackground(oldColor);
oldColor = color;
}
}
}

6.7.2 UndoableEditSupport

 

例6-13 使用UndoableEditSupport

import javax.swing.*;

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

public class Test extends JApplet {

private ColorPanel colorPanel = new ColorPanel();
private UndoAction undoAction = new UndoAction();

public void init() {

colorPanel.setBorder(
BorderFactory.createTitledBorder(
"Change color and subsequently undo " +
"from the Edit menu"));

makeMenuBar();

colorPanel.addUndoableEditListener(undoAction);
getContentPane().add(colorPanel, BorderLayout.CENTER);
}
private void makeMenuBar() {
JMenuBar menuBar = new JMenuBar();
JMenu editMenu = new JMenu("Edit");

editMenu.add(new SetColorAction());

editMenu.add(undoAction);

menuBar.add(editMenu);

setJMenuBar(menuBar);
}
class UndoAction extends AbstractAction
implements UndoableEditListener {
UndoableEdit lastEdit;

public UndoAction() {

putValue(Action.NAME, "Undo");
setEnabled(false);
}
public void actionPerformed(ActionEvent e) {
String name = (String)getValue(Action.NAME);
boolean isUndo = name.equals(
lastEdit.getUndoPresentationName());
if(isUndo) {
lastEdit.undo();
putValue(Action.NAME,
lastEdit.getRedoPresentationName());
}
else {
lastEdit.redo();
putValue(Action.NAME,
lastEdit.getUndoPresentationName());
}
}
public void undoableEditHappened(UndoableEditEvent e) {
lastEdit = e.getEdit();

putValue(Action.NAME,

lastEdit.getUndoPresentationName());

if(lastEdit.canUndo())

setEnabled(true);
}
}
class SetColorAction extends AbstractAction {
public SetColorAction() {
super("Set color ...");
}
public void actionPerformed(ActionEvent e) {
Color color = JColorChooser.showDialog(
Test.this, // parent component
"Pick A Color", // dialog title
null); // initial color

if(color != null) {

colorPanel.setBackground(color);
}
}
}
}
class ColorPanel extends JPanel {
UndoableEditSupport support;
BackgroundColorEdit edit = new BackgroundColorEdit();
Color oldColor;

public void addUndoableEditListener(

UndoableEditListener l) {
support.addUndoableEditListener(l);
}
public void removeUndoableEditListener(
UndoableEditListener l) {
support.removeUndoableEditListener(l);
}
public void setBackground(Color color) {
oldColor = getBackground();
super.setBackground(color);

if(support == null)

support = new UndoableEditSupport();

support.postEdit(edit);

}
class BackgroundColorEdit extends AbstractUndoableEdit {
public void undo() throws CannotUndoException {
super.undo();
toggleColor();
}
public void redo() throws CannotRedoException {
super.redo();
toggleColor();
}
public String getUndoPresentationName() {
return "Undo Background Color Change";
}
public String getRedoPresentationName() {
return "Redo Background Color Change";
}
private void toggleColor() {
Color color = getBackground();
setBackground(oldColor);
oldColor = color;
}
}
}

6.7.3组合编辑

 

例6-14 使用组合编辑

import javax.swing.*;

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

public class Test extends JApplet {

private UndoableList list = new UndoableList();
private JScrollPane scrollPane = new JScrollPane(list);

private JButton addButton = new JButton("Add Item"),

endButton = new JButton("End"),
undoButton = new JButton("Undo");

private UndoAction undoAction = new UndoAction();

private CompoundEdit compoundEdit = new CompoundEdit();
private int cnt=0;

public void init() {

Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

contentPane.add(addButton);
contentPane.add(endButton);
contentPane.add(undoButton);
contentPane.add(scrollPane);

scrollPane.setPreferredSize(new Dimension(150,150));

list.addUndoableEditListener(undoAction);

endButton.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
compoundEdit.end();
updateButtonsEnabledState();
}
});
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
list.undoableAdd("item #" + cnt++);
updateButtonsEnabledState();
}
});
undoButton.addActionListener(undoAction);

endButton.setEnabled(false);

undoButton.setEnabled(false);
}
private void updateButtonsEnabledState() {
boolean inProgress = compoundEdit.isInProgress();

endButton.setEnabled(inProgress);

addButton.setEnabled(inProgress);

if(undoButton.getText().equals("Undo"))

undoButton.setEnabled(compoundEdit.canUndo());
else
undoButton.setEnabled(compoundEdit.canRedo());
}
class UndoAction extends AbstractAction
implements UndoableEditListener {

public UndoAction() {

putValue(Action.NAME, "Undo");
}
public void actionPerformed(ActionEvent e) {
String name = undoButton.getText();
boolean isUndo = name.equals("Undo");

if(isUndo) compoundEdit.undo();

else compoundEdit.redo();

undoButton.setText(isUndo ? "Redo" : "Undo");

}
public void undoableEditHappened(UndoableEditEvent e) {
UndoableEdit edit = e.getEdit();
compoundEdit.addEdit(edit);
endButton.setEnabled(true);
}
}
}
class UndoableList extends JList {
UndoableEditSupport support = new UndoableEditSupport();
DefaultListModel model;

public UndoableList() {

setModel(model = new DefaultListModel());
}
public void addUndoableEditListener(UndoableEditListener l) {
support.addUndoableEditListener(l);
}
public void removeUndoableEditListener(
UndoableEditListener l) {
support.removeUndoableEditListener(l);
}
public void undoableAdd(Object s) {
model.addElement(s);
support.postEdit(new AddItemEdit());
}
class AddItemEdit extends AbstractUndoableEdit {
Object lastItemAdded;

public void undo() throws CannotUndoException {

super.undo();
lastItemAdded = model.getElementAt(model.getSize()-1);
model.removeElement(lastItemAdded);
}
public void redo() throws CannotRedoException {
super.redo();
model.addElement(lastItemAdded);
}
}
}

6.7.4 UndoManager

 

6.7.5状态编辑

 

例6-15 使用状态编辑

import javax.swing.*;

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

public class Test extends JApplet {

private TextFieldPanel panel = new TextFieldPanel();
private StateEdit stateEdit;

private JButton startButton = new JButton("Start Edit"),

endButton = new JButton("End Edit"),
undoButton = new JButton("Undo");

public void init() {

Container contentPane = getContentPane();

contentPane.setLayout(new FlowLayout());

contentPane.add(startButton);
contentPane.add(endButton);
contentPane.add(undoButton);
contentPane.add(panel);

endButton.setEnabled(false);

undoButton.setEnabled(false);

startButton.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
stateEdit = new StateEdit(panel);
endButton.setEnabled(true);
startButton.setEnabled(false);
}
});
endButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
stateEdit.end();
undoButton.setEnabled(true);
endButton.setEnabled(false);
}
});
undoButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String name = undoButton.getText();
boolean isUndo = name.equals("Undo");

if(isUndo) stateEdit.undo();

else stateEdit.redo();

undoButton.setText(isUndo ? "Redo" : "Undo");

}
});
}
}
class TextFieldPanel extends JPanel implements StateEditable {
JTextField[] fields = new JTextField[] {
new JTextField("text field 1"),
new JTextField("text field 2"),
new JTextField("text field 3"),
new JTextField("text field 4"),
};

public TextFieldPanel() {

setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

for(int i=0; i < fields.length; ++i)

add(fields[i]);
}
public void storeState(Hashtable hashtable) {
for(int i=0; i < fields.length; ++i)
hashtable.put(fields[i], fields[i].getText());
}
public void restoreState(Hashtable hashtable) {
Enumeration keys = hashtable.keys();

while(keys.hasMoreElements()) {

JTextField field = (JTextField)keys.nextElement();
field.setText((String)hashtable.get(field));
}
}
}

6.8 本章回顾

 

转载地址：http://wnbsx.baihongyu.com/

你可能感兴趣的文章
【转载】 Asp.net Mvc 3当然也不会例
查看>>
容器相关概念
查看>>
day28-python阶段性复习-基础二
查看>>
16-angular.isFunction
查看>>
java前后向查找个人理解
查看>>
.net/MVC 中Json 的使用（一）
查看>>
ubuntu18.04-换源
查看>>
iOS分组通讯录效果+側滑菜单(MMDrawerController)
查看>>
鼠标放上图片变大特效
查看>>
三十道linux内核面试题
查看>>
MySql 存储过程
查看>>
用Hexo搭建属于自己的Blog
查看>>
Xshell登录Docker
查看>>
XML 序列化出错
查看>>
web前端面试题整理
查看>>
记初学Python
查看>>
python基础数据类型
查看>>
扩展欧几里德算法
查看>>
mobile deeplearning
查看>>
C#窗体 WinForm 进程，线程
查看>>
喝酒易醉，品茶养心，人生如梦，品茶悟道，何以解忧？唯有杜康！-- 愿君每日到此一游！
当前时间: 2024-12-26 13:13:40   当前IP: 18.119.28.173   联系邮箱:javaeecc@qq.com     Copyright © 2020 - 2022 baihongyu.com 京ICP备2021015314号-2
强烈建议你试试无所不能的CHAT-GPT，快点击我
强烈建议你试试无所不能的CHAT-GPT，快点击我