Class ContainerEvent

java.lang.Object

java.util.EventObject

java.awt.AWTEvent

java.awt.event.ComponentEvent

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.

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:

• ContainerAdapter
• ContainerListener
• Tutorial: Writing a Container Listener
• Serialized Form

Field Summary

Fields

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 ComponentEvent

COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN

Modifier and Type	Field	Description
static final int	COMPONENT_FIRST	The first number in the range of ids used for component events.
static final int	COMPONENT_HIDDEN	This event indicates that the component was rendered invisible.
static final int	COMPONENT_LAST	The last number in the range of ids used for component events.
static final int	COMPONENT_MOVED	This event indicates that the component's position changed.
static final int	COMPONENT_RESIZED	This event indicates that the component's size changed.
static final int	COMPONENT_SHOWN	This event indicates that the component was made visible.

Fields declared in class 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

Modifier and Type	Field	Description
static final long	ACTION_EVENT_MASK	The event mask for selecting action events.
static final long	ADJUSTMENT_EVENT_MASK	The event mask for selecting adjustment events.
static final long	COMPONENT_EVENT_MASK	The event mask for selecting component events.
protected boolean	consumed	Controls whether or not the event is sent back down to the peer once the source has processed it - false means it's sent to the peer; true means it's not.
static final long	CONTAINER_EVENT_MASK	The event mask for selecting container events.
static final long	FOCUS_EVENT_MASK	The event mask for selecting focus events.
static final long	HIERARCHY_BOUNDS_EVENT_MASK	The event mask for selecting hierarchy bounds events.
static final long	HIERARCHY_EVENT_MASK	The event mask for selecting hierarchy events.
protected int	id	The event's id.
static final long	INPUT_METHOD_EVENT_MASK	The event mask for selecting input method events.
static final long	INVOCATION_EVENT_MASK	The event mask for selecting invocation events.
static final long	ITEM_EVENT_MASK	The event mask for selecting item events.
static final long	KEY_EVENT_MASK	The event mask for selecting key events.
static final long	MOUSE_EVENT_MASK	The event mask for selecting mouse events.
static final long	MOUSE_MOTION_EVENT_MASK	The event mask for selecting mouse motion events.
static final long	MOUSE_WHEEL_EVENT_MASK	The event mask for selecting mouse wheel events.
static final long	PAINT_EVENT_MASK	The event mask for selecting paint events.
static final int	RESERVED_ID_MAX	The maximum value for reserved AWT event IDs.
static final long	TEXT_EVENT_MASK	The event mask for selecting text events.
static final long	WINDOW_EVENT_MASK	The event mask for selecting window events.
static final long	WINDOW_FOCUS_EVENT_MASK	The event mask for selecting window focus events.
static final long	WINDOW_STATE_EVENT_MASK	The event mask for selecting window state events.

Fields declared in class EventObject

source

Modifier and Type	Field	Description
protected Object	source	The object on which the Event initially occurred.

Constructor Summary

Constructors

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 ComponentEvent

getComponent

Modifier and Type	Method	Description
Component	getComponent()	Returns the originator of the event.

Methods declared in class AWTEvent

consume, getID, isConsumed, setSource, toString

Modifier and Type	Method	Description
protected void	consume()	Consumes this event, if this event can be consumed.
int	getID()	Returns the event type.
protected boolean	isConsumed()	Returns whether this event has been consumed.
void	setSource(Object newSource)	Retargets an event to a new source.
String	toString()	Returns a String representation of this object.

Methods declared in class EventObject

getSource

Modifier and Type	Method	Description
Object	getSource()	The object on which the Event initially occurred.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Field Details

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 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:

• getContainer()
• AWTEvent.getID()
• getChild()

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