public class

ContainerEvent

extends ComponentEvent
java.lang.Object
   ↳ java.util.EventObject
     ↳ java.awt.AWTEvent
       ↳ java.awt.event.ComponentEvent
         ↳ java.awt.event.ContainerEvent

Class Overview

A low-level event which indicates that a container's contents changed because a component was added or removed.

Container events are provided for notification purposes ONLY; The AWT will automatically handle changes to the containers contents internally so that the program works properly regardless of whether the program is receiving these events or not.

This low-level event is generated by a container object (such as a Panel) when a component is added to it or removed from it. The event is passed to every ContainerListener or ContainerAdapter object which registered to receive such events using the component's addContainerListener method. (ContainerAdapter objects implement the ContainerListener interface.) Each such listener object gets this ContainerEvent when the event occurs.

Summary

Constants
int COMPONENT_ADDED This event indicates that a component was added to the container.
int COMPONENT_REMOVED This event indicates that a component was removed from the container.
int CONTAINER_FIRST The first number in the range of ids used for container events.
int CONTAINER_LAST The last number in the range of ids used for container events.
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Inherited Constants
From class java.awt.event.ComponentEvent
From class java.awt.AWTEvent
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Inherited Fields
From class java.awt.AWTEvent
From class java.util.EventObject
Public Constructors
ContainerEvent(Component source, int id, Component child)
Constructs a ContainerEvent object.
Public Methods
Component getChild()
Returns the component that was affected by the event.
Container getContainer()
Returns the originator of the event.
String paramString()
Returns a parameter string identifying this event.
[Expand]
Inherited Methods
From class java.awt.event.ComponentEvent
From class java.awt.AWTEvent
From class java.util.EventObject
From class java.lang.Object

Constants

public static final int COMPONENT_ADDED

This event indicates that a component was added to the container.

Constant Value: 300 (0x0000012c)

public static final int COMPONENT_REMOVED

This event indicates that a component was removed from the container.

Constant Value: 301 (0x0000012d)

public static final int CONTAINER_FIRST

The first number in the range of ids used for container events.

Constant Value: 300 (0x0000012c)

public static final int CONTAINER_LAST

The last number in the range of ids used for container events.

Constant Value: 301 (0x0000012d)

Public Constructors

public ContainerEvent (Component source, int id, Component child)

Constructs a ContainerEvent object.

Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.

Parameters
source the Component object (container) that originated the event
id an integer indicating the type of event
child the component that was added or removed
Throws
IllegalArgumentException if source is null

Public Methods

public Component getChild ()

Returns the component that was affected by the event.

Returns
  • the Component object that was added or removed

public Container getContainer ()

Returns the originator of the event.

Returns
  • the Container object that originated the event, or null if the object is not a Container.

public String paramString ()

Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.

Returns
  • a string identifying the event and its attributes