Class ItemEvent
java.lang.Object
java.util.EventObject
java.awt.AWTEvent
java.awt.event.ItemEvent
- All Implemented Interfaces:
Serializable
A semantic event which indicates that an item was selected or deselected.
This high-level event is generated by an ItemSelectable object (such as a
List) when an item is selected or deselected by the user.
The event is passed to every
ItemListener
object which
registered to receive such events using the component's
addItemListener
method.
The object that implements the ItemListener
interface gets
this ItemEvent
when the event occurs. The listener is
spared the details of processing individual mouse movements and mouse
clicks, and can instead process a "meaningful" (semantic) event like
"item selected" or "item deselected".
An unspecified behavior will be caused if the id
parameter
of any particular ItemEvent
instance is not
in the range from ITEM_FIRST
to ITEM_LAST
.
The stateChange
of any ItemEvent
instance takes one of the following
values:
-
ItemEvent.SELECTED
-
ItemEvent.DESELECTED
- Since:
- 1.1
- See Also:
-
Field Summary
Modifier and TypeFieldDescriptionstatic final int
This state-change-value indicates that a selected item was deselected.static final int
The first number in the range of ids used for item events.static final int
The last number in the range of ids used for item events.static final int
This event id indicates that an item's state changed.static final int
This state-change value indicates that an item was selected.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
ConstructorDescriptionItemEvent
(ItemSelectable source, int id, Object item, int stateChange) Constructs anItemEvent
object. -
Method Summary
Modifier and TypeMethodDescriptiongetItem()
Returns the item affected by the event.Returns the originator of the event.int
Returns the type of state change (selected or deselected).Returns a parameter string identifying this item event.Methods inherited from class java.util.EventObject
getSource
-
Field Details
-
ITEM_FIRST
public static final int ITEM_FIRSTThe first number in the range of ids used for item events.- See Also:
-
ITEM_LAST
public static final int ITEM_LASTThe last number in the range of ids used for item events.- See Also:
-
ITEM_STATE_CHANGED
public static final int ITEM_STATE_CHANGEDThis event id indicates that an item's state changed.- See Also:
-
SELECTED
public static final int SELECTEDThis state-change value indicates that an item was selected.- See Also:
-
DESELECTED
public static final int DESELECTEDThis state-change-value indicates that a selected item was deselected.- See Also:
-
-
Constructor Details
-
ItemEvent
Constructs anItemEvent
object.This method throws an
IllegalArgumentException
ifsource
isnull
.- Parameters:
source
- TheItemSelectable
object that originated the eventid
- The integer that identifies the event type. For information on allowable values, see the class description forItemEvent
item
- An object -- the item affected by the eventstateChange
- An integer that indicates whether the item was selected or deselected. For information on allowable values, see the class description forItemEvent
- Throws:
IllegalArgumentException
- ifsource
is null- See Also:
-
-
Method Details
-
getItemSelectable
Returns the originator of the event.- Returns:
- the ItemSelectable object that originated the event.
-
getItem
Returns the item affected by the event.- Returns:
- the item (object) that was affected by the event
-
getStateChange
public int getStateChange()Returns the type of state change (selected or deselected).- Returns:
- an integer that indicates whether the item was selected or deselected
- See Also:
-
paramString
Returns a parameter string identifying this item event. This method is useful for event-logging and for debugging.- Overrides:
paramString
in classAWTEvent
- Returns:
- a string identifying the event and its attributes
-