java.awt.event
Class ItemEvent
- java.lang.Object
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- java.util.EventObject
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- java.awt.AWTEvent
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- java.awt.event.ItemEvent
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- 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 everyItemListenerobject which registered to receive such events using the component'saddItemListenermethod.The object that implements the
ItemListenerinterface gets thisItemEventwhen 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
idparameter of any particularItemEventinstance is not in the range fromITEM_FIRSTtoITEM_LAST.The
stateChangeof anyItemEventinstance takes one of the following values:ItemEvent.SELECTEDItemEvent.DESELECTED
- Since:
- 1.1
- See Also:
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ItemSelectable,ItemListener, Tutorial: Writing an Item Listener, Serialized Form
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Field Summary
Fields Modifier and Type Field and Description static intDESELECTEDThis state-change-value indicates that a selected item was deselected.static intITEM_FIRSTThe first number in the range of ids used for item events.static intITEM_LASTThe last number in the range of ids used for item events.static intITEM_STATE_CHANGEDThis event id indicates that an item's state changed.static intSELECTEDThis 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
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Fields inherited from class java.util.EventObject
source
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Constructor Summary
Constructors Constructor and Description ItemEvent(ItemSelectable source, int id, Object item, int stateChange)Constructs anItemEventobject.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method and Description ObjectgetItem()Returns the item affected by the event.ItemSelectablegetItemSelectable()Returns the originator of the event.intgetStateChange()Returns the type of state change (selected or deselected).StringparamString()Returns a parameter string identifying this item event.-
Methods inherited from class java.util.EventObject
getSource
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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
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Constructor Detail
ItemEvent
public ItemEvent(ItemSelectable source, int id, Object item, int stateChange)
Constructs anItemEventobject.This method throws an
IllegalArgumentExceptionifsourceisnull.- Parameters:
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source- TheItemSelectableobject that originated the event -
id- 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 event -
stateChange- An integer that indicates whether the item was selected or deselected. For information on allowable values, see the class description forItemEvent - Throws:
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IllegalArgumentException- ifsourceis null - See Also:
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getItemSelectable(),AWTEvent.getID(),getStateChange()
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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:
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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:
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paramStringin classAWTEvent - Returns:
- a string identifying the event and its attributes
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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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