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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.awt.event;
import java.awt.AWTEvent;
import java.awt.ItemSelectable;
/**
* 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 <code>ItemListener</code> object which
* registered to receive such events using the component's
* <code>addItemListener</code> method.
* <P>
* The object that implements the <code>ItemListener</code> interface gets
* this <code>ItemEvent</code> 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".
*
* @author Carl Quinn
*
* @see java.awt.ItemSelectable
* @see ItemListener
* @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/itemlistener.html">Tutorial: Writing an Item Listener</a>
*
* @since 1.1
*/
public class ItemEvent extends AWTEvent {
/**
* The first number in the range of ids used for item events.
*/
public static final int ITEM_FIRST = 701;
/**
* The last number in the range of ids used for item events.
*/
public static final int ITEM_LAST = 701;
/**
* This event id indicates that an item's state changed.
*/
public static final int ITEM_STATE_CHANGED = ITEM_FIRST; //Event.LIST_SELECT
/**
* This state-change value indicates that an item was selected.
*/
public static final int SELECTED = 1;
/**
* This state-change-value indicates that a selected item was deselected.
*/
public static final int DESELECTED = 2;
/**
* The item whose selection state has changed.
*
* @serial
* @see #getItem()
*/
Object item;
/**
* <code>stateChange</code> indicates whether the <code>item</code>
* was selected or deselected.
*
* @serial
* @see #getStateChange()
*/
int stateChange;
/*
* JDK 1.1 serialVersionUID
*/
private static final long serialVersionUID = -608708132447206933L;
/**
* Constructs an <code>ItemEvent</code> object.
* <p>Note that passing in an invalid <code>id</code> results in
* unspecified behavior. This method throws an
* <code>IllegalArgumentException</code> if <code>source</code>
* is <code>null</code>.
*
* @param source the <code>ItemSelectable</code> object
* that originated the event
* @param id an integer that identifies the event type
* @param item an object -- the item affected by the event
* @param stateChange
* an integer that indicates whether the item was
* selected or deselected
* @throws IllegalArgumentException if <code>source</code> is null
*/
public ItemEvent(ItemSelectable source, int id, Object item, int stateChange) {
super(source, id);
this.item = item;
this.stateChange = stateChange;
}
/**
* Returns the originator of the event.
*
* @return the ItemSelectable object that originated the event.
*/
public ItemSelectable getItemSelectable() {
return (ItemSelectable)source;
}
/**
* Returns the item affected by the event.
*
* @return the item (object) that was affected by the event
*/
public Object getItem() {
return item;
}
/**
* Returns the type of state change (selected or deselected).
*
* @return an integer that indicates whether the item was selected
* or deselected
*
* @see #SELECTED
* @see #DESELECTED
*/
public int getStateChange() {
return stateChange;
}
/**
* Returns a parameter string identifying this item event.
* This method is useful for event-logging and for debugging.
*
* @return a string identifying the event and its attributes
*/
public String paramString() {
String typeStr;
switch(id) {
case ITEM_STATE_CHANGED:
typeStr = "ITEM_STATE_CHANGED";
break;
default:
typeStr = "unknown type";
}
String stateStr;
switch(stateChange) {
case SELECTED:
stateStr = "SELECTED";
break;
case DESELECTED:
stateStr = "DESELECTED";
break;
default:
stateStr = "unknown type";
}
return typeStr + ",item="+item + ",stateChange="+stateStr;
}
}