Java™ Platform
Standard Ed. 6

java.awt.event
Class ContainerEvent

java.lang.Object
  extended by java.util.EventObject
      extended by java.awt.AWTEvent
          extended by java.awt.event.ComponentEvent
              extended by java.awt.event.ContainerEvent
All Implemented Interfaces:
Serializable

public class ContainerEvent
extends ComponentEvent

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.

Since:
1.1
See Also:
ContainerAdapter, ContainerListener, Tutorial: Writing a Container Listener, Serialized Form

Field Summary
static int COMPONENT_ADDED
          This event indicates that a component was added to the container.
static int COMPONENT_REMOVED
          This event indicates that a component was removed from the container.
static int CONTAINER_FIRST
          The first number in the range of ids used for container events.
static int CONTAINER_LAST
          The last number in the range of ids used for container events.
 
Fields inherited from class java.awt.event.ComponentEvent
COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN
 
Fields inherited from class java.awt.AWTEvent
ACTION_EVENT_MASK, ADJUSTMENT_EVENT_MASK, COMPONENT_EVENT_MASK, consumed, CONTAINER_EVENT_MASK, FOCUS_EVENT_MASK, HIERARCHY_BOUNDS_EVENT_MASK, HIERARCHY_EVENT_MASK, id, INPUT_METHOD_EVENT_MASK, INVOCATION_EVENT_MASK, ITEM_EVENT_MASK, KEY_EVENT_MASK, MOUSE_EVENT_MASK, MOUSE_MOTION_EVENT_MASK, MOUSE_WHEEL_EVENT_MASK, PAINT_EVENT_MASK, RESERVED_ID_MAX, TEXT_EVENT_MASK, WINDOW_EVENT_MASK, WINDOW_FOCUS_EVENT_MASK, WINDOW_STATE_EVENT_MASK
 
Fields inherited from class java.util.EventObject
source
 
Constructor Summary
ContainerEvent(Component source, int id, Component child)
          Constructs a ContainerEvent object.
 
Method Summary
 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.
 
Methods inherited from class java.awt.event.ComponentEvent
getComponent
 
Methods inherited from class java.awt.AWTEvent
consume, getID, isConsumed, setSource, toString
 
Methods inherited from class java.util.EventObject
getSource
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

CONTAINER_FIRST

public static final int CONTAINER_FIRST
The first number in the range of ids used for container events.

See Also:
Constant Field Values

CONTAINER_LAST

public static final int CONTAINER_LAST
The last number in the range of ids used for container events.

See Also:
Constant Field Values

COMPONENT_ADDED

public static final int COMPONENT_ADDED
This event indicates that a component was added to the container.

See Also:
Constant Field Values

COMPONENT_REMOVED

public static final int COMPONENT_REMOVED
This event indicates that a component was removed from the container.

See Also:
Constant Field Values
Constructor Detail

ContainerEvent

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
Method Detail

getContainer

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.

getChild

public Component getChild()
Returns the component that was affected by the event.

Returns:
the Component object that was added or removed

paramString

public String paramString()
Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.

Overrides:
paramString in class ComponentEvent
Returns:
a string identifying the event and its attributes

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.

Scripting on this page tracks web page traffic, but does not change the content in any way.