Java AWT CheckboxGroup
Java AWT CheckboxGroup is a class that is used to create checkboxes and group a set of checkbox buttons together. Many components in the CheckboxGroup separate, which serves as a means to group a set of checkboxes. In this clause, we will delve into the CheckboxGroup class, and its methods, and demo its usage through a very simple example.
Class Declaration of CheckboxGroup
The CheckboxGroup class is declared as follows:
public class CheckboxGroup extends Object implements Serializable
Here, it extends the Object class and implements the Serializable interface.
Class Constructors
The CheckboxGroup class has a single constructor:
CheckboxGroup()
This constructor creates a new instance of CheckboxGroup.
Class Methods in Java AWT CheckboxGroup
Method |
Description |
---|---|
Checkbox getCurrent() |
(Deprecated): As of JDK version 1.1, this method is deprecated and replaced by getSelectedCheckbox() |
Checkbox getSelectedCheckbox() |
Checkbox getSelectedCheckbox() |
Checkbox getSelectedCheckbox() |
(Deprecated): As of JDK version 1.1, this method is deprecated and replaced by setSelectedCheckbox(Checkbox) |
void setSelectedCheckbox(Checkbox box) |
Sets the currently selected checkbox in this group to be the specified checkbox. |
String toString() |
Returns a string representation of this checkbox group, including the value of its current selection. |
Example of AWT CheckboxGroup with ItemListener
Java
// Java Program to implement AWT // CheckboxGroup with ItemListener import java.awt.*; import java.awt.event.*; // Driver Class public class BeginnerCheckboxGroupDemo { // Components for the GUI private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; // Constructor to set up the GUI public BeginnerCheckboxGroupDemo() { prepareGUI(); } // Method to set up the basic structure of the GUI private void prepareGUI() { // Create the main frame mainFrame = new Frame( "w3wiki AWT Examples" ); mainFrame.setSize( 400 , 400 ); mainFrame.setLayout( new GridLayout( 3 , 1 )); mainFrame.addWindowListener( new WindowAdapter() { public void windowClosing(WindowEvent windowEvent) { System.exit( 0 ); } }); // Create labels for header and status headerLabel = new Label(); headerLabel.setAlignment(Label.CENTER); statusLabel = new Label(); statusLabel.setAlignment(Label.CENTER); statusLabel.setSize( 350 , 100 ); // Create a panel for controls controlPanel = new Panel(); controlPanel.setLayout( new FlowLayout()); // Add components to the frame mainFrame.add(headerLabel); mainFrame.add(controlPanel); mainFrame.add(statusLabel); mainFrame.setVisible( true ); } // Method to show the CheckboxGroup demo private void showCheckboxGroupDemo() { // Set the header label headerLabel.setText( "Control in action: BeginnerCheckboxGroup" ); // Create a CheckboxGroup CheckboxGroup categoryGroup = new CheckboxGroup(); // Create checkboxes with different names Checkbox chkJava = new Checkbox( "Java" , categoryGroup, true ); Checkbox chkPython = new Checkbox( "Python" , categoryGroup, false ); Checkbox chkCSharp = new Checkbox( "C#" , categoryGroup, false ); // Add item listeners to each checkbox chkJava.addItemListener(getCheckboxItemListener( "Java" )); chkPython.addItemListener(getCheckboxItemListener( "Python" )); chkCSharp.addItemListener(getCheckboxItemListener( "C#" )); // Add checkboxes to the control panel controlPanel.add(chkJava); controlPanel.add(chkPython); controlPanel.add(chkCSharp); // Display the frame mainFrame.setVisible( true ); } // Method to create an ItemListener for a given category private ItemListener getCheckboxItemListener( final String categoryName) { // Return an ItemListener for the given category return new ItemListener() { public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { statusLabel.setText(categoryName + " Checkbox: checked" ); } else { statusLabel.setText(categoryName + " Checkbox: unchecked" ); } } }; } // Main method to create an instance and show the demo public static void main(String[] args) { // Create an instance of BeginnerCheckboxGroupDemo and show the demo BeginnerCheckboxGroupDemo checkboxGroupDemo = new BeginnerCheckboxGroupDemo(); checkboxGroupDemo.showCheckboxGroupDemo(); } } |
Output:
that