Java™ Platform
Standard Ed. 6

java.awt.event
Class ItemEvent

java.lang.Object
  extended by java.util.EventObject
      extended by java.awt.AWTEvent
          extended by java.awt.event.ItemEvent
All Implemented Interfaces:
Serializable

public class ItemEvent
extends AWTEvent

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".

Since:
1.1
See Also:
ItemSelectable, ItemListener, Tutorial: Writing an Item Listener, Serialized Form

Field Summary
static int DESELECTED
          This state-change-value indicates that a selected item was deselected.
static int ITEM_FIRST
          The first number in the range of ids used for item events.
static int ITEM_LAST
          The last number in the range of ids used for item events.
static int ITEM_STATE_CHANGED
          This event id indicates that an item's state changed.
static int SELECTED
          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
ItemEvent(ItemSelectable source, int id, Object item, int stateChange)
          Constructs an ItemEvent object.
 
Method Summary
 Object getItem()
          Returns the item affected by the event.
 ItemSelectable getItemSelectable()
          Returns the originator of the event.
 int getStateChange()
          Returns the type of state change (selected or deselected).
 String paramString()
          Returns a parameter string identifying this item event.
 
Methods inherited from class java.awt.AWTEvent
consume, getID, isConsumed, setSource, toString
 
Methods inherited from class java.util.EventObject
getSource
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

ITEM_FIRST

public static final int ITEM_FIRST
The first number in the range of ids used for item events.

See Also:
Constant Field Values

ITEM_LAST

public static final int ITEM_LAST
The last number in the range of ids used for item events.

See Also:
Constant Field Values

ITEM_STATE_CHANGED

public static final int ITEM_STATE_CHANGED
This event id indicates that an item's state changed.

See Also:
Constant Field Values

SELECTED

public static final int SELECTED
This state-change value indicates that an item was selected.

See Also:
Constant Field Values

DESELECTED

public static final int DESELECTED
This state-change-value indicates that a selected item was deselected.

See Also:
Constant Field Values
Constructor Detail

ItemEvent

public ItemEvent(ItemSelectable source,
                 int id,
                 Object item,
                 int stateChange)
Constructs an ItemEvent object.

Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the ItemSelectable object that originated the event
id - an integer that identifies the event type
item - an object -- the item affected by the event
stateChange - an integer that indicates whether the item was selected or deselected
Throws:
IllegalArgumentException - if source is null
Method Detail

getItemSelectable

public ItemSelectable getItemSelectable()
Returns the originator of the event.

Returns:
the ItemSelectable object that originated the event.

getItem

public Object 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:
SELECTED, DESELECTED

paramString

public String paramString()
Returns a parameter string identifying this item event. This method is useful for event-logging and for debugging.

Overrides:
paramString in class AWTEvent
Returns:
a string identifying the event and its attributes

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.

Scripting on this page tracks web page traffic, but does not change the content in any way.