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.
ComponentAdapter,
ComponentListener,
Tutorial: Writing a Component Listener,
Serialized Form| Modifier and Type | Field and 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.
|
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| Constructor and Description |
|---|
ComponentEvent(Component source,
int id)
Constructs a
ComponentEvent object. |
| Modifier and Type | Method and Description |
|---|---|
Component |
getComponent()
Returns the originator of the event.
|
java.lang.String |
paramString()
Returns a parameter string identifying this event.
|
ComponentEvent object.
This method throws an
IllegalArgumentException if source
is null.
source - The Component that originated the eventid - An integer indicating the type of event.
For information on allowable values, see
the class description for ComponentEventjava.lang.IllegalArgumentException - if source is nullgetComponent(),
AWTEvent.getID()Component object that originated
the event, or null if the object is not a
Component.paramString in class AWTEvent