Class ContainerEvent
- All Implemented Interfaces:
Serializable
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:
-
Field Summary
Modifier and TypeFieldDescriptionstatic final int
This event indicates that a component was added to the container.static final int
This event indicates that a component was removed from the container.static final int
The first number in the range of ids used for container events.static final int
The last number in the range of ids used for container events.Fields inherited from class java.awt.event.ComponentEvent
COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN
Fields inherited from 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 inherited from class java.util.EventObject
source
-
Constructor Summary
ConstructorDescriptionContainerEvent
(Component source, int id, Component child) Constructs aContainerEvent
object. -
Method Summary
Modifier and TypeMethodDescriptiongetChild()
Returns the component that was affected by the event.Returns the originator of the event.Returns a parameter string identifying this event.Methods inherited from class java.awt.event.ComponentEvent
getComponent
Methods inherited from class java.util.EventObject
getSource
-
Field Details
-
CONTAINER_FIRST
public static final int CONTAINER_FIRSTThe first number in the range of ids used for container events.- See Also:
-
CONTAINER_LAST
public static final int CONTAINER_LASTThe last number in the range of ids used for container events.- See Also:
-
COMPONENT_ADDED
public static final int COMPONENT_ADDEDThis event indicates that a component was added to the container.- See Also:
-
COMPONENT_REMOVED
public static final int COMPONENT_REMOVEDThis event indicates that a component was removed from the container.- See Also:
-
-
Constructor Details
-
ContainerEvent
Constructs aContainerEvent
object.This method throws an
IllegalArgumentException
ifsource
isnull
.- Parameters:
source
- TheComponent
object (container) that originated the eventid
- An integer indicating the type of event. For information on allowable values, see the class description forContainerEvent
child
- the component that was added or removed- Throws:
IllegalArgumentException
- ifsource
is null- See Also:
-
-
Method Details
-
getContainer
Returns the originator of the event.- Returns:
- the
Container
object that originated the event, ornull
if the object is not aContainer
.
-
getChild
Returns the component that was affected by the event.- Returns:
- the Component object that was added or removed
-
paramString
Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.- Overrides:
paramString
in classComponentEvent
- Returns:
- a string identifying the event and its attributes
-