/*
* @(#)Choice.java 1.15 95/09/08 Sami Shaio
*
* Copyright (c) 1994-1995 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for NON-COMMERCIAL purposes and without
* fee is hereby granted provided that this copyright notice
* appears in all copies. Please refer to the file "copyright.html"
* for further important copyright and licensing information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
*/
package java.awt;
import java.util.*;
import java.awt.peer.ChoicePeer;
/**
* The Choice class is a pop-up menu of choices. The current choice is
* displayed as the title of the menu.
*
* @version 1.15 08 Sep 1995
* @author Sami Shaio
* @author Arthur van Hoff
*/
public class Choice extends Component {
/**
* The items for the Choice.
*/
Vector pItems;
/**
* The index of the current choice for this Choice.
*/
int selectedIndex = -1;
/**
* Constructs a new Choice.
*/
public Choice() {
pItems = new Vector();
}
/**
* Creates the Choice's peer. This peer allows us to change the look
* of the Choice without changing its functionality.
*/
public synchronized void addNotify() {
peer = getToolkit().createChoice(this);
super.addNotify();
}
/**
* Returns the number of items in this Choice.
* @see #getItem
*/
public int countItems() {
return pItems.size();
}
/**
* Returns the String at the specified index in the Choice.
* @param index the index to begin at
* @see #countItems
*/
public String getItem(int index) {
return (String)pItems.elementAt(index);
}
/**
* Adds an item to this Choice.
* @param item the item to be added
* @exception NullPointerException If the item's value is equal to null.
*/
public synchronized void addItem(String item) {
if (item == null) {
throw new NullPointerException();
}
pItems.addElement(item);
ChoicePeer peer = (ChoicePeer)this.peer;
if (peer != null) {
peer.addItem(item, pItems.size() - 1);
}
if (selectedIndex < 0) {
select(0);
}
}
/**
* Returns a String representation of the current choice.
* @see #getSelectedIndex
*/
public String getSelectedItem() {
int selectedIndex = this.selectedIndex;
return (selectedIndex >= 0) ? getItem(selectedIndex) : null;
}
/**
* Returns the index of the currently selected item.
* @see #getSelectedItem
*/
public int getSelectedIndex() {
return selectedIndex;
}
/**
* Selects the item with the specified postion.
* @param pos the choice item position
* @exception IllegalArgumentException If the choice item position is
* invalid.
* @see #getSelectedItem
* @see #getSelectedIndex
*/
public synchronized void select(int pos) {
if (pos >= pItems.size()) {
throw new IllegalArgumentException("illegal Choice item position: " + pos);
}
if (pItems.size() > 0) {
selectedIndex = pos;
ChoicePeer peer = (ChoicePeer)this.peer;
if (peer != null) {
peer.select(pos);
}
}
}
/**
* Selects the item with the specified String.
* @param str the specified String
* @see #getSelectedItem
* @see #getSelectedIndex
*/
public void select(String str) {
int index = pItems.indexOf(str);
if (index >= 0) {
select(index);
}
}
/**
* Returns the parameter String of this Choice.
*/
protected String paramString() {
return super.paramString() + ",current=" + getSelectedItem();
}
}