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/OpenJDK 21

Class 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.

An unspecified behavior will be caused if the id parameter of any particular ContainerEvent instance is not in the range from CONTAINER_FIRST to CONTAINER_LAST.

Since:
1.1
See Also:

Field Summary

Modifier and Type Field Description
static final int COMPONENT_ADDED
This event indicates that a component was added to the container.
static final int COMPONENT_REMOVED
This event indicates that a component was removed from the container.
static final int CONTAINER_FIRST
The first number in the range of ids used for container events.
static final int CONTAINER_LAST
The last number in the range of ids used for container events.

Fields declared in class java.util.EventObject

source

Constructor Summary

Constructor Description
ContainerEvent(Component source, int id, Component child)
Constructs a ContainerEvent object.

Method Summary

Modifier and Type Method Description
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 declared in class java.awt.event.ComponentEvent

getComponent

Methods declared in class java.awt.AWTEvent

consume, getID, isConsumed, setSource, toString

Methods declared in class java.util.EventObject

getSource

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

CONTAINER_FIRST

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

CONTAINER_LAST

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

COMPONENT_ADDED

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

COMPONENT_REMOVED

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

Constructor Details

ContainerEvent

public ContainerEvent(Component source, int id, Component child)
Constructs a ContainerEvent object.

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. For information on allowable values, see the class description for ContainerEvent
child - the component that was added or removed
Throws:
IllegalArgumentException - if source is null
See Also:

Method Details

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

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/java/awt/event/ContainerEvent.html