- All Implemented Interfaces:
Serializable
- Direct Known Subclasses:
ContainerEvent
,FocusEvent
,InputEvent
,PaintEvent
,WindowEvent
public class ComponentEvent extends AWTEvent
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:
ComponentAdapter
,ComponentListener
, Tutorial: Writing a Component Listener, Serialized Form
-
Field Summary
Fields Modifier and Type Field Description static int
COMPONENT_FIRST
The first number in the range of ids used for component events.static int
COMPONENT_HIDDEN
This event indicates that the component was rendered invisible.static int
COMPONENT_LAST
The last number in the range of ids used for component events.static int
COMPONENT_MOVED
This event indicates that the component's position changed.static int
COMPONENT_RESIZED
This event indicates that the component's size changed.static int
COMPONENT_SHOWN
This event indicates that the component was made visible.Fields declared in 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 declared in class java.util.EventObject
source
-
Constructor Summary
Constructors Constructor Description ComponentEvent(Component source, int id)
Constructs aComponentEvent
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 java.util.EventObject
getSource
-
Field Details
-
COMPONENT_FIRST
public static final int COMPONENT_FIRSTThe first number in the range of ids used for component events.- See Also:
- Constant Field Values
-
COMPONENT_LAST
public static final int COMPONENT_LASTThe last number in the range of ids used for component events.- See Also:
- Constant Field Values
-
COMPONENT_MOVED
This event indicates that the component's position changed.- See Also:
- Constant Field Values
-
COMPONENT_RESIZED
This event indicates that the component's size changed.- See Also:
- Constant Field Values
-
COMPONENT_SHOWN
This event indicates that the component was made visible.- See Also:
- Constant Field Values
-
COMPONENT_HIDDEN
This event indicates that the component was rendered invisible.- See Also:
- Constant Field Values
-
-
Constructor Details
-
ComponentEvent
Constructs aComponentEvent
object.This method throws an
IllegalArgumentException
ifsource
isnull
.- Parameters:
source
- TheComponent
that originated the eventid
- An integer indicating the type of event. For information on allowable values, see the class description forComponentEvent
- Throws:
IllegalArgumentException
- ifsource
is null- See Also:
getComponent()
,AWTEvent.getID()
-
-
Method Details
-
getComponent
Returns the originator of the event.- Returns:
- the
Component
object that originated the event, ornull
if the object is not aComponent
.
-
paramString
Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.- Overrides:
paramString
in classAWTEvent
- Returns:
- a string identifying the event and its attributes
-