Class ComponentEvent

java.awt.event.ComponentEvent

All Implemented Interfaces:: Serializable

Direct Known Subclasses:: ContainerEvent, FocusEvent, InputEvent, PaintEvent, WindowEvent

public class ComponentEvent extends AWTEvent

A low-level event which indicates that a component moved, changed size, or changed visibility (also, the root class for the other component-level events).

Component events are provided for notification purposes ONLY; The AWT will automatically handle component moves and resizes internally so that GUI layout works properly regardless of whether a program is receiving these events or not.

In addition to serving as the base class for other component-related events (InputEvent, FocusEvent, WindowEvent, ContainerEvent), this class defines the events that indicate changes in a component's size, position, or visibility.

This low-level event is generated by a component object (such as a List) when the component is moved, resized, rendered invisible, or made visible again. The event is passed to every ComponentListener or ComponentAdapter object which registered to receive such events using the component's addComponentListener method. (ComponentAdapter objects implement the ComponentListener interface.) Each such listener object gets this ComponentEvent when the event occurs.

An unspecified behavior will be caused if the id parameter of any particular ComponentEvent instance is not in the range from COMPONENT_FIRST to COMPONENT_LAST.

Since:

1.1

See Also:

Field Summary

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

Constructor	Description
`ComponentEvent(Component source, int id)`	Constructs a `ComponentEvent` object.

Method Summary

Modifier and Type	Method	Description
`Component`	`getComponent()`	Returns the originator of the event.
`String`	`paramString()`	Returns a parameter string identifying this 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()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details

COMPONENT_FIRST

public static final int COMPONENT_FIRST

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

See Also:

COMPONENT_LAST

public static final int COMPONENT_LAST

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

See Also:

COMPONENT_MOVED

@Native public static final int COMPONENT_MOVED

This event indicates that the component's position changed.

See Also:

COMPONENT_RESIZED

@Native public static final int COMPONENT_RESIZED

This event indicates that the component's size changed.

See Also:

COMPONENT_SHOWN

@Native public static final int COMPONENT_SHOWN

This event indicates that the component was made visible.

See Also:

COMPONENT_HIDDEN

@Native public static final int COMPONENT_HIDDEN

This event indicates that the component was rendered invisible.

See Also:

Constructor Details

ComponentEvent

public ComponentEvent(Component source, int id)

Constructs a ComponentEvent object.

This method throws an IllegalArgumentException if source is null.

Parameters:

source - The Component that originated the event

id - An integer indicating the type of event. For information on allowable values, see the class description for ComponentEvent

Throws:

IllegalArgumentException - if source is null

See Also:

Method Details

getComponent

public Component getComponent()

Returns the originator of the event.

Returns:: the Component object that originated the event, or null if the object is not a Component.

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 AWTEvent
Returns:: a string identifying the event and its attributes

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