Checkbox

Name

Description

The Checkbox is a Component that provides a true or false toggle switch for user input.

Class Definition

public class java.awt.Checkbox extends java.awt.Component implements java.awt.ItemSelectable {
 // Constructors public Checkbox();
public Checkbox (String label);
public Checkbox (String label, boolean state); public Checkbox (String label, boolean state, CheckboxGroup group); public Checkbox (String label, CheckboxGroup group, boolean state); // Instance Methods public void addItemListener (ItemListener l); public void addNotify();
public CheckboxGroup getCheckboxGroup();
public String getLabel();
public Object[] getSelectedObjects(); public boolean getState();
public void removeItemListener (ItemListener l); public void setCheckboxGroup (CheckboxGroup group);
public synchronized void setLabel (String label);
public void setState (boolean state); // Protected Instance Methods protected String paramString(); protected void processEvent (AWTEvent e); protected void processItemEvent (ItemEvent e);
}

Constructors

Checkbox

public Checkbox()

• Description
• Constructs a Checkbox object with no label that is initially false.

public Checkbox (String label)

• Parameters
• • label
  • Text to display with the Checkbox.
• Description
• Constructs a Checkbox object with the given label that is initially false.

public Checkbox (String label, boolean state)

• Parameters
• • label
  • Text to display with the Checkbox.
  • state
  • Intial value of the Checkbox.
• Description
• Constructs a Checkbox with the given label, initialized to the given state.

public Checkbox (String label, boolean state, CheckboxGroup group)

• Parameters
• • label
  • Text to display with the Checkbox.
  • state
  • Intial value of the Checkbox.
  • group
  • The CheckboxGroup this Checkbox should belong to.
• Description
• Constructs a Checkbox with the given label, initialized to the given state and belonging to group.

public Checkbox (String label, CheckboxGroup group, boolean state)

• Parameters
• • label
  • Text to display with the Checkbox.
  • group
  • The CheckboxGroup this Checkbox should belong to.
  • state
  • Intial value of the Checkbox.
• Description
• Constructs a Checkbox object with the given settings.

Instance Methods

addItemListener

public void addItemListener (ItemListener l)

• Parameters
• • l
  • The listener to be added.
• Implements
• ItemSelectable.addItemListener(ItemListener l)
• Description
• Adds a listener for the ItemEvent objects this Checkbox generates.

addNotify

public void addNotify()

• Overrides
• Component.addNotify()
• Description
• Creates Checkbox peer.

getCheckboxGroup

public CheckboxGroup getCheckboxGroup()

• Returns
• The current CheckboxGroup associated with the Checkbox, if any.

getLabel

public String getLabel()

• Returns
• The text associated with the Checkbox.

getSelectedObjects

public Object[] getSelectedObjects()

• Implements
• ItemSelectable.getSelectedObjects()
• Description
• If the Checkbox is checked, returns an array with length 1 containing the label of the Checkbox; otherwise returns null.

getState

public boolean getState()

• Returns
• The current state of the Checkbox.

removeItemListener

public void removeItemListener (ItemListener l)

• Parameters
• • l
  • The listener to be removed.
• Implements
• ItemSelectable.removeItemListener (ItemListener l)
• Description
• Removes the specified ItemListener so it will not receive ItemEvent objects from this Checkbox.

setCheckboxGroup

public void setCheckboxGroup (CheckboxGroup group)

• Parameters
• • group
  • New group in which to place the Checkbox.
• Description
• Associates the Checkbox with a different CheckboxGroup.

setLabel

public synchronized void setLabel (String label)

• Parameters
• • label
  • New text to associate with Checkbox.
• Description
• Changes the text associated with the Checkbox.

setState

public void setState (boolean state)

• Parameters
• • state
  • New state for the Checkbox.
• Description
• Changes the state of the Checkbox.

Protected Instance Methods

paramString

protected String paramString()

• Returns
• String with current settings of Checkbox.
• Overrides
• Component.paramString()
• Description
• Helper method for toString() to generate string of current settings.

processEvent

protected void processEvent(AWTEvent e)

• Parameters
• • e
  • The event to process.
• Description
• Low level AWTEvents are passed to this method for processing.

processItemEvent

protected void processItemEvent(ItemEvent e)

• Parameters
• • e
  • The item event to process.
• Description
• Item events are passed to this method for processing. Normally, this method is called by processEvent().

See Also

CheckboxGroup, Component, ItemEvent, ItemSelectable, String