Java/Swing JFC/Basics
Содержание
- 1 CelsiusConverter: the use of JButton, JTextField and JLabel
- 2 Creates two JPanels (opaque), one containing another opaque JPanel, and the other containing a non-opaque JPanel
- 3 GUI invoked from the event-dispatching thread
- 4 Hello World Swing
- 5 LunarPhases: the use of JButton, JTextField and JLabel
- 6 Separating GUI logic and business objects
- 7 Standalone GUI program that shows paint, repaint, and update
- 8 Swing Application
- 9 The revalidate method to dynamically update the
- 10 This example demonstrates the use of JButton, JTextField and JLabel
CelsiusConverter: the use of JButton, JTextField and JLabel
<source lang="java">
/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
// v 1.3 import java.awt.BorderLayout; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; // This example demonstrates the use of JButton, JTextField and JLabel. public class CelsiusConverter implements ActionListener {
JFrame converterFrame;
JPanel converterPanel;
JTextField tempCelsius;
JLabel celsiusLabel, fahrenheitLabel;
JButton convertTemp;
// Constructor
public CelsiusConverter() {
// Create the frame and container.
converterFrame = new JFrame("Convert Celsius to Fahrenheit");
converterPanel = new JPanel();
converterPanel.setLayout(new GridLayout(2, 2));
// Add the widgets.
addWidgets();
// Add the panel to the frame.
converterFrame.getContentPane()
.add(converterPanel, BorderLayout.CENTER);
// Exit when the window is closed.
converterFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Show the converter.
converterFrame.pack();
converterFrame.setVisible(true);
}
// Create and add the widgets for converter.
private void addWidgets() {
// Create widgets.
tempCelsius = new JTextField(2);
celsiusLabel = new JLabel("Celsius", SwingConstants.LEFT);
convertTemp = new JButton("Convert...");
fahrenheitLabel = new JLabel("Fahrenheit", SwingConstants.LEFT);
// Listen to events from Convert button.
convertTemp.addActionListener(this);
// Add widgets to container.
converterPanel.add(tempCelsius);
converterPanel.add(celsiusLabel);
converterPanel.add(convertTemp);
converterPanel.add(fahrenheitLabel);
celsiusLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
fahrenheitLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
}
// Implementation of ActionListener interface.
public void actionPerformed(ActionEvent event) {
// Parse degrees Celsius as a double and convert to Fahrenheit.
int tempFahr = (int) ((Double.parseDouble(tempCelsius.getText())) * 1.8 + 32);
fahrenheitLabel.setText(tempFahr + " Fahrenheit");
}
// main method
public static void main(String[] args) {
// Set the look and feel.
try {
UIManager.setLookAndFeel(UIManager
.getCrossPlatformLookAndFeelClassName());
} catch (Exception e) {
}
CelsiusConverter converter = new CelsiusConverter();
}
}
</source>
Creates two JPanels (opaque), one containing another opaque JPanel, and the other containing a non-opaque JPanel
<source lang="java">
import java.awt.Color;
import java.awt.FlowLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class OpaqueExample extends JFrame {
public OpaqueExample() {
super("Opaque JPanel Demo");
setSize(400, 200);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel opaque = createNested(true);
JPanel notOpaque = createNested(false);
// Throw it all together
getContentPane().setLayout(new FlowLayout());
getContentPane().add(opaque);
getContentPane().add(notOpaque);
}
public static void main(String[] args) {
OpaqueExample oe = new OpaqueExample();
oe.setVisible(true);
}
public JPanel createNested(boolean opaque) {
JPanel outer = new JPanel(new FlowLayout());
JPanel inner = new JPanel(new FlowLayout());
outer.setBackground(Color.white);
inner.setBackground(Color.black);
inner.setOpaque(opaque);
inner.setBorder(BorderFactory.createLineBorder(Color.gray));
inner.add(new JButton("Button"));
outer.add(inner);
return outer;
}
}
</source>
GUI invoked from the event-dispatching thread
<source lang="java">
/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JMenuBar; /* TopLevelDemo.java requires no other files. */ public class TopLevelDemo {
/**
* Create the GUI and show it. For thread safety, this method should be
* invoked from the event-dispatching thread.
*/
private static void createAndShowGUI() {
//Make sure we have nice window decorations.
JFrame.setDefaultLookAndFeelDecorated(true);
//Create and set up the window.
JFrame frame = new JFrame("TopLevelDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create the menu bar. Make it have a cyan background.
JMenuBar cyanMenuBar = new JMenuBar();
cyanMenuBar.setOpaque(true);
cyanMenuBar.setBackground(Color.cyan);
cyanMenuBar.setPreferredSize(new Dimension(200, 20));
//Create a yellow label to put in the content pane.
JLabel yellowLabel = new JLabel();
yellowLabel.setOpaque(true);
yellowLabel.setBackground(Color.yellow);
yellowLabel.setPreferredSize(new Dimension(200, 180));
//Set the menu bar and add the label to the content pane.
frame.setJMenuBar(cyanMenuBar);
frame.getContentPane().add(yellowLabel, BorderLayout.CENTER);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application"s GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
</source>
Hello World Swing
<source lang="java">
import javax.swing.JFrame; import javax.swing.JLabel; public class HelloWorldSwing {
public static void main(String[] args) {
JFrame frame = new JFrame("HelloWorldSwing");
final JLabel label = new JLabel("Hello World");
frame.getContentPane().add(label);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
</source>
LunarPhases: the use of JButton, JTextField and JLabel
<source lang="java">
/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
// v 1.3 import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.net.URL; import javax.swing.BorderFactory; import javax.swing.ImageIcon; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.UIManager; // This example demonstrates the use of JButton, JTextField // and JLabel. public class LunarPhases implements ActionListener {
final static int NUM_IMAGES = 8;
final static int START_INDEX = 3;
ImageIcon[] images = new ImageIcon[NUM_IMAGES];
JPanel mainPanel, selectPanel, displayPanel;
JComboBox phaseChoices = null;
JLabel phaseIconLabel = null;
// Constructor
public LunarPhases() {
// Create the phase selection and display panels.
selectPanel = new JPanel();
displayPanel = new JPanel();
// Add various widgets to the sub panels.
addWidgets();
// Create the main panel to contain the two sub panels.
mainPanel = new JPanel();
mainPanel.setLayout(new GridLayout(2, 1, 5, 5));
mainPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
// Add the select and display panels to the main panel.
mainPanel.add(selectPanel);
mainPanel.add(displayPanel);
}
// Create and the widgets to select and display the phases of the moon.
private void addWidgets() {
// Get the images and put them into an array of ImageIcon.
for (int i = 0; i < NUM_IMAGES; i++) {
String imageName = "images/image" + i + ".jpg";
System.out.println("getting image: " + imageName);
// URL iconURL = ClassLoader.getSystemResource(imageName);
// ImageIcon icon = new ImageIcon(iconURL);
images[i] = icon;
}
// Create label for displaying moon phase images and put a border around
// it.
phaseIconLabel = new JLabel();
phaseIconLabel.setHorizontalAlignment(JLabel.CENTER);
phaseIconLabel.setVerticalAlignment(JLabel.CENTER);
phaseIconLabel.setVerticalTextPosition(JLabel.CENTER);
phaseIconLabel.setHorizontalTextPosition(JLabel.CENTER);
phaseIconLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createLoweredBevelBorder(), BorderFactory
.createEmptyBorder(5, 5, 5, 5)));
phaseIconLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createEmptyBorder(0, 0, 10, 0), phaseIconLabel
.getBorder()));
// Create combo box with lunar phase choices.
String[] phases = { "New", "Waxing Crescent", "First Quarter",
"Waxing Gibbous", "Full", "Waning Gibbous", "Third Quarter",
"Waning Crescent" };
phaseChoices = new JComboBox(phases);
phaseChoices.setSelectedIndex(START_INDEX);
// Display the first image.
phaseIconLabel.setIcon(images[START_INDEX]);
phaseIconLabel.setText("");
// Add border around the select panel.
selectPanel.setBorder(BorderFactory.createCompoundBorder(BorderFactory
.createTitledBorder("Select Phase"), BorderFactory
.createEmptyBorder(5, 5, 5, 5)));
// Add border around the display panel.
displayPanel.setBorder(BorderFactory.createCompoundBorder(BorderFactory
.createTitledBorder("Display Phase"), BorderFactory
.createEmptyBorder(5, 5, 5, 5)));
// Add moon phases combo box to select panel and image label to
// displayPanel.
selectPanel.add(phaseChoices);
displayPanel.add(phaseIconLabel);
// Listen to events from combo box.
phaseChoices.addActionListener(this);
}
// Implementation of ActionListener interface.
public void actionPerformed(ActionEvent event) {
if ("comboBoxChanged".equals(event.getActionCommand())) {
// update the icon to display the new phase
phaseIconLabel.setIcon(images[phaseChoices.getSelectedIndex()]);
}
}
// main method
public static void main(String[] args) {
// create a new instance of LunarPhases
LunarPhases phases = new LunarPhases();
// Create a frame and container for the panels.
JFrame lunarPhasesFrame = new JFrame("Lunar Phases");
// Set the look and feel.
try {
UIManager.setLookAndFeel(UIManager
.getCrossPlatformLookAndFeelClassName());
} catch (Exception e) {
}
lunarPhasesFrame.setContentPane(phases.mainPanel);
// Exit when the window is closed.
lunarPhasesFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Show the converter.
lunarPhasesFrame.pack();
lunarPhasesFrame.setVisible(true);
}
}
</source>
Separating GUI logic and business objects
<source lang="java">
// : c14:Separation.java // Separating GUI logic and business objects. // <applet code=Separation width=250 height=150></applet> // From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002 // www.BruceEckel.ru. See copyright notice in CopyRight.txt. import java.awt.Container; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JApplet; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; class BusinessLogic {
private int modifier;
public BusinessLogic(int mod) {
modifier = mod;
}
public void setModifier(int mod) {
modifier = mod;
}
public int getModifier() {
return modifier;
}
// Some business operations:
public int calculation1(int arg) {
return arg * modifier;
}
public int calculation2(int arg) {
return arg + modifier;
}
} public class Separation extends JApplet {
private JTextField t = new JTextField(15), mod = new JTextField(15);
private JButton calc1 = new JButton("Calculation 1"), calc2 = new JButton(
"Calculation 2");
private BusinessLogic bl = new BusinessLogic(2);
public static int getValue(JTextField tf) {
try {
return Integer.parseInt(tf.getText());
} catch (NumberFormatException e) {
return 0;
}
}
class Calc1L implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText(Integer.toString(bl.calculation1(getValue(t))));
}
}
class Calc2L implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText(Integer.toString(bl.calculation2(getValue(t))));
}
}
// If you want something to happen whenever
// a JTextField changes, add this listener:
class ModL implements DocumentListener {
public void changedUpdate(DocumentEvent e) {
}
public void insertUpdate(DocumentEvent e) {
bl.setModifier(getValue(mod));
}
public void removeUpdate(DocumentEvent e) {
bl.setModifier(getValue(mod));
}
}
public void init() {
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(t);
calc1.addActionListener(new Calc1L());
calc2.addActionListener(new Calc2L());
JPanel p1 = new JPanel();
p1.add(calc1);
p1.add(calc2);
cp.add(p1);
mod.getDocument().addDocumentListener(new ModL());
JPanel p2 = new JPanel();
p2.add(new JLabel("Modifier:"));
p2.add(mod);
cp.add(p2);
}
public static void main(String[] args) {
run(new Separation(), 250, 100);
}
public static void run(JApplet applet, int width, int height) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(applet);
frame.setSize(width, height);
applet.init();
applet.start();
frame.setVisible(true);
}
} ///:~
</source>
Standalone GUI program that shows paint, repaint, and update
<source lang="java">
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002. * All rights reserved. Software written by Ian F. Darwin and others. * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS"" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */
/// import java.awt.Graphics; import javax.swing.JFrame; import javax.swing.JLabel; /** Standalone GUI program that shows paint, repaint, and update */ public class PaintMethods extends JLabel {
/** "main program" method - construct and show */
public static void main(String[] av) {
final JFrame f = new JFrame("PaintMethods demo");
f.getContentPane().add("Center", new PaintMethods("Testing 1 2 3"));
f.pack();
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public PaintMethods(String s) {
super(s);
}
public void paint(Graphics g) {
System.out.println("Paint");
super.paint(g);
}
public void repaint() {
System.out.println("repaint");
super.repaint();
}
public void update(Graphics g) {
System.out.println("update");
super.update(g);
}
}
</source>
Swing Application
<source lang="java">
/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
// v 1.3 import java.awt.BorderLayout; import java.awt.ruponent; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.UIManager; public class SwingApplication {
private static String labelPrefix = "Number of button clicks: ";
private int numClicks = 0;
public Component createComponents() {
final JLabel label = new JLabel(labelPrefix + "0 ");
JButton button = new JButton("I"m a Swing button!");
button.setMnemonic(KeyEvent.VK_I);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
numClicks++;
label.setText(labelPrefix + numClicks);
}
});
label.setLabelFor(button);
/*
* An easy way to put space between a top-level container and its
* contents is to put the contents in a JPanel that has an "empty"
* border.
*/
JPanel pane = new JPanel();
pane.setBorder(BorderFactory.createEmptyBorder(30, //top
30, //left
10, //bottom
30) //right
);
pane.setLayout(new GridLayout(0, 1));
pane.add(button);
pane.add(label);
return pane;
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager
.getCrossPlatformLookAndFeelClassName());
} catch (Exception e) {
}
//Create the top-level container and add contents to it.
JFrame frame = new JFrame("SwingApplication");
SwingApplication app = new SwingApplication();
Component contents = app.createComponents();
frame.getContentPane().add(contents, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
</source>
The revalidate method to dynamically update the
<source lang="java">
import java.awt.Container; import java.awt.FlowLayout; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; public class RevalidateExample extends JFrame {
public RevalidateExample() {
super("Revalidation Demo");
setSize(300, 150);
setDefaultCloseOperation(EXIT_ON_CLOSE);
Font font = new Font("Dialog", Font.PLAIN, 10);
final JButton b = new JButton("Add");
b.setFont(font);
Container c = getContentPane();
c.setLayout(new FlowLayout());
c.add(b);
b.addActionListener(new ActionListener() {
// Increase the size of the button"s font each time it"s clicked
int size = 20;
public void actionPerformed(ActionEvent ev) {
b.setFont(new Font("Dialog", Font.PLAIN, ++size));
b.revalidate(); // invalidates the button & validates its root pane
}
});
}
public static void main(String[] args) {
RevalidateExample re = new RevalidateExample();
re.setVisible(true);
}
}
</source>
This example demonstrates the use of JButton, JTextField and JLabel
<source lang="java">
/* From http://java.sun.ru/docs/books/tutorial/index.html */ /*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
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// v 1.3 import java.awt.BorderLayout; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.BorderFactory; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; // This example demonstrates the use of JButton, JTextField and JLabel. public class CelsiusConverter2 implements ActionListener {
JFrame converterFrame;
JPanel converterPanel;
JTextField tempCelsius;
JLabel celsiusLabel, fahrenheitLabel;
JButton convertTemp;
// Constructor
public CelsiusConverter2() {
// Create the frame and container.
converterFrame = new JFrame("Convert Celsius to Fahrenheit");
converterPanel = new JPanel();
converterPanel.setLayout(new GridLayout(2, 2));
// Add the widgets.
addWidgets();
// Add the panel to the frame.
converterFrame.getContentPane()
.add(converterPanel, BorderLayout.CENTER);
// Exit when the window is closed.
converterFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Show the converter.
converterFrame.pack();
converterFrame.setVisible(true);
}
// Create and add the widgets for converter.
private void addWidgets() {
// Create widgets.
ImageIcon icon = new ImageIcon("images/convert.gif",
"Convert temperature");
tempCelsius = new JTextField(2);
celsiusLabel = new JLabel("Celsius", SwingConstants.LEFT);
convertTemp = new JButton(icon);
fahrenheitLabel = new JLabel("Fahrenheit", SwingConstants.LEFT);
celsiusLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
fahrenheitLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
// Listen to events from Convert button.
convertTemp.addActionListener(this);
// Add widgets to container.
converterPanel.add(tempCelsius);
converterPanel.add(celsiusLabel);
converterPanel.add(convertTemp);
converterPanel.add(fahrenheitLabel);
}
// Implementation of ActionListener interface.
public void actionPerformed(ActionEvent event) {
// Parse degrees Celsius as a double and convert to Fahrenheit.
int tempFahr = (int) ((Double.parseDouble(tempCelsius.getText())) * 1.8 + 32);
// Set fahrenheitLabel to new value and set font color based on the
// temperature.
if (tempFahr <= 32) {
fahrenheitLabel
.setText("<html>"
+ tempFahr
+ "° Fahrenheit</html>");
} else if (tempFahr <= 80) {
fahrenheitLabel
.setText("<html>"
+ tempFahr
+ "° Fahrenheit </html>");
} else {
fahrenheitLabel
.setText("<html>"
+ tempFahr
+ "° Fahrenheit</html>");
}
}
// main method
public static void main(String[] args) {
// set the look and feel
try {
UIManager.setLookAndFeel(UIManager
.getCrossPlatformLookAndFeelClassName());
} catch (Exception e) {
}
CelsiusConverter2 converter = new CelsiusConverter2();
}
}
</source>
