java.awt.event
Class ContainerEvent
java.lang.Object
|
+--java.util.EventObject
|
+--java.awt.AWTEvent
|
+--java.awt.event.ComponentEvent
|
+--java.awt.event.ContainerEvent
- 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.
- Since:
- 1.1
- See Also:
ContainerAdapter
,
ContainerListener
,
Tutorial: Writing a Container Listener,
Reference: The Java Class Libraries (update file)
Field Summary |
static int |
COMPONENT_ADDED
This event indicates that a component was added to the container. |
static int |
COMPONENT_REMOVED
This event indicates that a component was removed from the container. |
static int |
CONTAINER_FIRST
The first number in the range of ids used for container events. |
static int |
CONTAINER_LAST
The last number in the range of ids used for container events. |
Fields inherited from class java.awt.AWTEvent |
ACTION_EVENT_MASK, ADJUSTMENT_EVENT_MASK, COMPONENT_EVENT_MASK, consumed, CONTAINER_EVENT_MASK, FOCUS_EVENT_MASK, id, ITEM_EVENT_MASK, KEY_EVENT_MASK, MOUSE_EVENT_MASK, MOUSE_MOTION_EVENT_MASK, RESERVED_ID_MAX, TEXT_EVENT_MASK, WINDOW_EVENT_MASK |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
CONTAINER_FIRST
public static final int CONTAINER_FIRST
- The first number in the range of ids used for container events.
Value 300 is assigned to CONTAINER_FIRST.
CONTAINER_LAST
public static final int CONTAINER_LAST
- The last number in the range of ids used for container events.
Value 301 is assigned to CONTAINER_LAST.
COMPONENT_ADDED
public static final int COMPONENT_ADDED
- This event indicates that a component was added to the container.
Value CONTAINER_FIRST is assigned to COMPONENT_ADDED.
COMPONENT_REMOVED
public static final int COMPONENT_REMOVED
- This event indicates that a component was removed from the container.
Value CONTAINER_FIRST + 1 is assigned to COMPONENT_REMOVED.
ContainerEvent
public ContainerEvent(Component source,
int id,
Component child)
- Constructs a ContainerEvent object.
- Parameters:
source
- the Component object (container) that originated the eventid
- an integer indicating the type of eventchild
- the component that was added or removed
getContainer
public Container getContainer()
- Returns the originator of the event.
- Returns:
- the Container object that originated the event
getChild
public Component getChild()
- Returns the component that was affected by the event.
- Returns:
- the Component object that was added or removed
paramString
public java.lang.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