
- SWING Tutorial
- SWING - Home
- SWING - Overview
- SWING - Environment
- SWING - Controls
- SWING - Event Handling
- SWING - Event Classes
- SWING - Event Listeners
- SWING - Event Adapters
- SWING - Layouts
- SWING - Menu
- SWING - Containers
- SWING Useful Resources
- SWING - Quick Guide
- SWING - Useful Resources
- SWING - Discussion
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
SWING - FocusAdapter Class
Introduction
The class FocusAdapter is an abstract (adapter) class for receiving keyboard focus events. All methods of this class are empty. This class is convenience class for creating listener objects.
Class Declaration
Following is the declaration for java.awt.event.FocusAdapter class −
public abstract class FocusAdapter extends Object implements FocusListener
Class Constructors
Sr.No. | Constructor & Description |
---|---|
1 |
FocusAdapter() |
Class Methods
Sr.No. | Method & Description |
---|---|
1 |
void focusGained(FocusEvent e) Invoked when a component gains the keyboard focus. |
Methods Inherited
This class inherits methods from the following classes −
- java.lang.Object
FocusAdapter Example
Create the following Java program using any editor of your choice in say D:/ > SWING > com > tutorialspoint > gui >
SwingAdapterDemo.java
package com.tutorialspoint.gui; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class SwingAdapterDemo { private JFrame mainFrame; private JLabel headerLabel; private JLabel statusLabel; private JPanel controlPanel; public SwingAdapterDemo(){ prepareGUI(); } public static void main(String[] args){ SwingAdapterDemo swingAdapterDemo = new SwingAdapterDemo(); swingAdapterDemo.showFocusAdapterDemo(); } private void prepareGUI(){ mainFrame = new JFrame("Java SWING Examples"); mainFrame.setSize(400,400); mainFrame.setLayout(new GridLayout(3, 1)); headerLabel = new JLabel("",JLabel.CENTER ); statusLabel = new JLabel("",JLabel.CENTER); statusLabel.setSize(350,100); mainFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent windowEvent){ System.exit(0); } }); controlPanel = new JPanel(); controlPanel.setLayout(new FlowLayout()); mainFrame.add(headerLabel); mainFrame.add(controlPanel); mainFrame.add(statusLabel); mainFrame.setVisible(true); } private void showFocusAdapterDemo(){ headerLabel.setText("Listener in action: FocusAdapter"); JButton okButton = new JButton("OK"); JButton cancelButton = new JButton("Cancel"); okButton.addFocusListener(new FocusAdapter() { public void focusGained(FocusEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " gained focus. "); } }); cancelButton.addFocusListener(new FocusAdapter(){ public void focusLost(FocusEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " lost focus. "); } }); controlPanel.add(okButton); controlPanel.add(cancelButton); mainFrame.setVisible(true); } }
Compile the program using the command prompt. Go to D:/ > SWING and type the following command.
D:\SWING>javac com\tutorialspoint\gui\SwingAdapterDemo.java
If no error occurs, it means the compilation is successful. Run the program using the following command.
D:\SWING>java com.tutorialspoint.gui.SwingAdapterDemo
Verify the following output.
