/*
* @(#)List.java 1.84 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package java.awt;
import java.util.Vector;
import sun.awt.peer.ListPeer;
import sun.awt.PeerBasedToolkit;
import java.awt.event.*;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.awt.AWTEventMulticaster;
import java.util.EventListener;
/**
* The <code>List</code> component presents the user with a
* scrolling list of text items. The list can be set up so that
* the user can choose either one item or multiple items.
* <p>
* For example, the code . . .
* <p>
* <hr><blockquote><pre>
* List lst = new List(4, false);
* lst.add("Mercury");
* lst.add("Venus");
* lst.add("Earth");
* lst.add("JavaSoft");
* lst.add("Mars");
* lst.add("Jupiter");
* lst.add("Saturn");
* lst.add("Uranus");
* lst.add("Neptune");
* lst.add("Pluto");
* cnt.add(lst);
* </pre></blockquote><hr>
* <p>
* where <code>cnt</code> is a container, produces the following
* scrolling list:
* <p>
* <img src="doc-files/List-1.gif"
* ALIGN=center HSPACE=10 VSPACE=7>
* <p>
* Clicking on an item that isn't selected selects it. Clicking on
* an item that is already selected deselects it. In the preceding
* example, only one item from the scrolling list can be selected
* at a time, since the second argument when creating the new scrolling
* list is <code>false</code>. Selecting an item causes any other
* selected item to be automatically deselected.
* <p>
* Beginning with Java 1.1, the Abstract Window Toolkit
* sends the <code>List</code> object all mouse, keyboard, and focus events
* that occur over it. (The old AWT event model is being maintained
* only for backwards compatibility, and its use is discouraged.)
* <p>
* When an item is selected or deselected, AWT sends an instance
* of <code>ItemEvent</code> to the list.
* When the user double-clicks on an item in a scrolling list,
* AWT sends an instance of <code>ActionEvent</code> to the
* list following the item event. AWT also generates an action event
* when the user presses the return key while an item in the
* list is selected.
* <p>
* If an application wants to perform some action based on an item
* in this list being selected or activated, it should implement
* <code>ItemListener</code> or <code>ActionListener</code>
* as appropriate and register the new listener to receive
* events from this list.
* <p>
* For multiple-selection scrolling lists, it is considered a better
* user interface to use an external gesture (such as clicking on a
* button) to trigger the action.
* @version 1.77, %G
* @author Sami Shaio
* @see java.awt.event.ItemEvent
* @see java.awt.event.ItemListener
* @see java.awt.event.ActionEvent
* @see java.awt.event.ActionListener
* @since JDK1.0
*/
public class List extends Component implements ItemSelectable {
/**
* A vector created to contain items which will become
* part of the List Component.
*
* @serial
* @see addItem()
* @see getItem()
*/
Vector items = new Vector();
/**
* This field will represent the number of rows in the
* List Component. It is specified only once, and
* that is when the list component is actually
* created. It will never change.
*
* @serial
* @see getRows()
*/
int rows = 0;
/**
* <code>multipleMode</code> is a variable that will
* be set to <code>true</code> if a list component is to be set to
* multiple selection mode, that is where the user can
* select more than one item in a list at one time.
* <code>multipleMode</code> will be set to false if the
* list component is set to single selection, that is where
* the user can only select one item on the list at any
* one time.
*
* @serial
* @see isMultipleMode()
* @see setMultipleMode()
*/
boolean multipleMode = false;
/**
* <code>selected</code> is an array that will contain
* the indices of items that have been selected.
*
* @serial
* @see getSelectedIndexes()
* @see getSelectedIndex()
*/
int selected[] = new int[0];
/**
* This variable contains the value that will be used
* when trying to make a particular list item visible.
*
* @serial
* @see makeVisible()
*/
int visibleIndex = -1;
transient ActionListener actionListener;
transient ItemListener itemListener;
private static final String base = "list";
private static int nameCounter = 0;
/*
* JDK 1.1 serialVersionUID
*/
private static final long serialVersionUID = -3304312411574666869L;
/**
* Creates a new scrolling list.
* By default, there are four visible lines and multiple selections are
* not allowed.
*/
public List() {
this(0, false);
}
/**
* Creates a new scrolling list initialized with the specified
* number of visible lines. By default, multiple selections are
* not allowed.
* @param rows the number of items to show.
* @since JDK1.1
*/
public List(int rows) {
this(rows, false);
}
/**
* The default number of visible rows is 4. A list with
* zero rows is unusable and unsightly.
*/
final static int DEFAULT_VISIBLE_ROWS = 4;
/**
* Creates a new scrolling list initialized to display the specified
* number of rows. If the value of <code>multipleMode</code> is
* <code>true</code>, then the user can select multiple items from
* the list. If it is <code>false</code>, only one item at a time
* can be selected.
* @param rows the number of items to show.
* @param multipleMode if <code>true</code>,
* then multiple selections are allowed;
* otherwise, only one item can be selected at a time.
*/
public List(int rows, boolean multipleMode) {
this.rows = (rows != 0) ? rows : DEFAULT_VISIBLE_ROWS;
this.multipleMode = multipleMode;
}
/**
* Construct a name for this component. Called by getName() when the
* name is null.
*/
String constructComponentName() {
return base + nameCounter++;
}
/**
* Creates the peer for the list. The peer allows us to modify the
* list's appearance without changing its functionality.
*/
public void addNotify() {
synchronized (getTreeLock()) {
if (peer == null)
peer = ((PeerBasedToolkit) getToolkit()).createList(this);
super.addNotify();
visibleIndex = -1;
}
}
/**
* Removes the peer for this list. The peer allows us to modify the
* list's appearance without changing its functionality.
*/
public void removeNotify() {
synchronized (getTreeLock()) {
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
selected = peer.getSelectedIndexes();
}
super.removeNotify();
}
}
/**
* Gets the number of items in the list.
* @return the number of items in the list.
* @see java.awt.List#getItem
* @since JDK1.1
*/
public int getItemCount() {
return countItems();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>getItemCount()</code>.
*/
public int countItems() {
return items.size();
}
/**
* Gets the item associated with the specified index.
* @return an item that is associated with
* the specified index.
* @param index the position of the item.
* @see java.awt.List#getItemCount
*/
public String getItem(int index) {
return (String) items.elementAt(index);
}
/**
* Gets the items in the list.
* @return a string array containing items of the list.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
* @since JDK1.1
*/
public synchronized String[] getItems() {
String itemCopies[] = new String[items.size()];
items.copyInto(itemCopies);
return itemCopies;
}
/**
* Adds the specified item to the end of scrolling list.
* @param item the item to be added.
* @since JDK1.1
*/
public void add(String item) {
addItem(item);
}
/**
* @deprecated replaced by <code>add(String)</code>.
*/
public void addItem(String item) {
addItem(item, -1);
}
/**
* Adds the specified item to the the scrolling list
* at the position indicated by the index. The index is
* zero-based. If the value of the index is less than zero,
* or if the value of the index is greater than or equal to
* the number of items in the list, then the item is added
* to the end of the list.
* @param item the item to be added.
* If this parameter is null then the item is
* treated as an empty string, <code>""</code>.
* @param index the position at which to add the item.
* @since JDK1.1
*/
public void add(String item, int index) {
addItem(item, index);
}
/**
* @deprecated replaced by <code>add(String, int)</code>.
*/
public synchronized void addItem(String item, int index) {
if (index < -1 || index >= items.size()) {
index = -1;
}
if (item == null)
item = "";
if (index == -1) {
items.addElement(item);
} else {
items.insertElementAt(item, index);
}
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.add(item, index);
}
}
/**
* Replaces the item at the specified index in the scrolling list
* with the new string.
* @param newValue a new string to replace an existing item.
* @param index the position of the item to replace.
*/
public synchronized void replaceItem(String newValue, int index) {
remove(index);
add(newValue, index);
}
/**
* Removes all items from this list.
* @see #remove
* @see #delItems
* @since JDK1.1
*/
public void removeAll() {
clear();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>removeAll()</code>.
*/
public synchronized void clear() {
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.removeAll();
}
items = new Vector();
selected = new int[0];
}
/**
* Removes the first occurrence of an item from the list.
* @param item the item to remove from the list.
* @exception IllegalArgumentException
* if the item doesn't exist in the list.
* @since JDK1.1
*/
public synchronized void remove(String item) {
int index = items.indexOf(item);
if (index < 0) {
throw new IllegalArgumentException("item " + item +
" not found in list");
} else {
remove(index);
}
}
/**
* Remove the item at the specified position
* from this scrolling list.
* @param position the index of the item to delete.
* @see java.awt.List#add(String, int)
* @since JDK1.1
* @exception ArrayIndexOutOfBoundsException
* if the <code>position</code> is less than 0 or
* greater than <code>getItemCount()-1</code>
*/
public void remove(int position) {
delItem(position);
}
/**
* @deprecated replaced by <code>remove(String)</code>
* and <code>remove(int)</code>.
*/
public void delItem(int position) {
delItems(position, position);
}
/**
* Gets the index of the selected item on the list,
* @return the index of the selected item, or
* <code>-1</code> if no item is selected,
* or if more that one item is selected.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
*/
public synchronized int getSelectedIndex() {
int sel[] = getSelectedIndexes();
return (sel.length == 1) ? sel[0] : -1;
}
/**
* Gets the selected indexes on the list.
* @return an array of the selected indexes
* of this scrolling list. If no items are
* selected, a zero-length array is returned.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
*/
public synchronized int[] getSelectedIndexes() {
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
selected = ((ListPeer) peer).getSelectedIndexes();
}
return selected;
}
/**
* Get the selected item on this scrolling list.
* @return the selected item on the list,
* or null if no item is selected.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
*/
public synchronized String getSelectedItem() {
int index = getSelectedIndex();
return (index < 0) ? null : getItem(index);
}
/**
* Get the selected items on this scrolling list.
* @return an array of the selected items
* on this scrolling list.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
*/
public synchronized String[] getSelectedItems() {
int sel[] = getSelectedIndexes();
String str[] = new String[sel.length];
for (int i = 0; i < sel.length; i++) {
str[i] = getItem(sel[i]);
}
return str;
}
/**
* Returns the selected items on the list in an array of Objects.
* @see ItemSelectable
*/
public Object[] getSelectedObjects() {
return getSelectedItems();
}
/**
* Selects the item at the specified index in the scrolling list.
* @param index the position of the item to select.
* @see java.awt.List#getSelectedItem
* @see java.awt.List#deselect
* @see java.awt.List#isIndexSelected
*/
public void select(int index) {
// Bug #4059614: select can't be synchronized while calling the peer,
// because it is called from the Window Thread. It is sufficient to
// synchronize the code that manipulates 'selected' except for the
// case where the peer changes. To handle this case, we simply
// repeat the selection process.
ListPeer peer;
do {
peer = (ListPeer) this.peer;
if (peer != null) {
peer.select(index);
return;
}
synchronized (this) {
boolean alreadySelected = false;
for (int i = 0; i < selected.length; i++) {
if (selected[i] == index) {
alreadySelected = true;
break;
}
}
if (!alreadySelected) {
if (!multipleMode) {
selected = new int[1];
selected[0] = index;
} else {
int newsel[] = new int[selected.length + 1];
System.arraycopy(selected, 0, newsel, 0,
selected.length);
newsel[selected.length] = index;
selected = newsel;
}
}
}
}
while (peer != this.peer);
}
/**
* Deselects the item at the specified index.
* <p>
* If the item at the specified index is not selected, or if the
* index is out of range, then the operation is ignored.
* @param index the position of the item to deselect.
* @see java.awt.List#select
* @see java.awt.List#getSelectedItem
* @see java.awt.List#isIndexSelected
*/
public synchronized void deselect(int index) {
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.deselect(index);
}
for (int i = 0; i < selected.length; i++) {
if (selected[i] == index) {
int newsel[] = new int[selected.length - 1];
System.arraycopy(selected, 0, newsel, 0, i);
System.arraycopy(selected, i + 1, newsel, i, selected.length - (i + 1));
selected = newsel;
return;
}
}
}
/**
* Determines if the specified item in this scrolling list is
* selected.
* @param index the item to be checked.
* @return <code>true</code> if the specified item has been
* selected; <code>false</code> otherwise.
* @see java.awt.List#select
* @see java.awt.List#deselect
* @since JDK1.1
*/
public boolean isIndexSelected(int index) {
return isSelected(index);
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>isIndexSelected(int)</code>.
*/
public boolean isSelected(int index) {
int sel[] = getSelectedIndexes();
for (int i = 0; i < sel.length; i++) {
if (sel[i] == index) {
return true;
}
}
return false;
}
/**
* Get the number of visible lines in this list.
* @return the number of visible lines in this scrolling list.
*/
public int getRows() {
return rows;
}
/**
* Determines whether this list allows multiple selections.
* @return <code>true</code> if this list allows multiple
* selections; otherwise, <code>false</code>.
* @see java.awt.List#setMultipleMode
* @since JDK1.1
*/
public boolean isMultipleMode() {
return allowsMultipleSelections();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>isMultipleMode()</code>.
*/
public boolean allowsMultipleSelections() {
return multipleMode;
}
/**
* Sets the flag that determines whether this list
* allows multiple selections.
* @param b if <code>true</code> then multiple selections
* are allowed; otherwise, only one item from
* the list can be selected at once.
* @see java.awt.List#isMultipleMode
* @since JDK1.1
*/
public void setMultipleMode(boolean b) {
setMultipleSelections(b);
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>setMultipleMode(boolean)</code>.
*/
public synchronized void setMultipleSelections(boolean b) {
if (b != multipleMode) {
multipleMode = b;
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.setMultipleMode(b);
}
}
}
/**
* Gets the index of the item that was last made visible by
* the method <code>makeVisible</code>.
* @return the index of the item that was last made visible.
* @see java.awt.List#makeVisible
*/
public int getVisibleIndex() {
return visibleIndex;
}
/**
* Makes the item at the specified index visible.
* @param index the position of the item.
* @see java.awt.List#getVisibleIndex
*/
public synchronized void makeVisible(int index) {
visibleIndex = index;
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.makeVisible(index);
}
}
/**
* Gets the preferred dimensions for a list with the specified
* number of rows.
* @param rows number of rows in the list.
* @return the preferred dimensions for displaying this scrolling list
* given that the specified number of rows must be visible.
* @see java.awt.Component#getPreferredSize
* @since JDK1.1
*/
public Dimension getPreferredSize(int rows) {
return preferredSize(rows);
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>getPreferredSize(int)</code>.
*/
public Dimension preferredSize(int rows) {
synchronized (getTreeLock()) {
ListPeer peer = (ListPeer) this.peer;
return (peer != null) ?
peer.getPreferredSize(rows) :
super.preferredSize();
}
}
/**
* Gets the preferred size of this scrolling list.
* @return the preferred dimensions for displaying this scrolling list.
* @see java.awt.Component#getPreferredSize
* @since JDK1.1
*/
public Dimension getPreferredSize() {
return preferredSize();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>getPreferredSize()</code>.
*/
public Dimension preferredSize() {
synchronized (getTreeLock()) {
return (rows > 0) ?
preferredSize(rows) :
super.preferredSize();
}
}
/**
* Gets the minumum dimensions for a list with the specified
* number of rows.
* @param rows number of rows in the list.
* @return the minimum dimensions for displaying this scrolling list
* given that the specified number of rows must be visible.
* @see java.awt.Component#getMinimumSize
* @since JDK1.1
*/
public Dimension getMinimumSize(int rows) {
return minimumSize(rows);
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>getMinimumSize(int)</code>.
*/
public Dimension minimumSize(int rows) {
synchronized (getTreeLock()) {
ListPeer peer = (ListPeer) this.peer;
return (peer != null) ?
peer.getMinimumSize(rows) :
super.minimumSize();
}
}
/**
* Determines the minimum size of this scrolling list.
* @return the minimum dimensions needed
* to display this scrolling list.
* @see java.awt.Component#getMinimumSize()
* @since JDK1.1
*/
public Dimension getMinimumSize() {
return minimumSize();
}
/**
* @deprecated As of JDK version 1.1,
* replaced by <code>getMinimumSize()</code>.
*/
public Dimension minimumSize() {
synchronized (getTreeLock()) {
return (rows > 0) ? minimumSize(rows) : super.minimumSize();
}
}
/**
* Adds the specified item listener to receive item events from
* this list.
* If l is null, no exception is thrown and no action is performed.
*
* @param l the item listener.
* @see java.awt.event.ItemEvent
* @see java.awt.event.ItemListener
* @see java.awt.List#removeItemListener
* @since JDK1.1
*/
public synchronized void addItemListener(ItemListener l) {
itemListener = AWTEventMulticaster.add(itemListener, l);
newEventsOnly = true;
}
/**
* Removes the specified item listener so that it no longer
* receives item events from this list.
* If l is null, no exception is thrown and no action is performed.
*
* @param l the item listener.
* @see java.awt.event.ItemEvent
* @see java.awt.event.ItemListener
* @see java.awt.List#addItemListener
* @since JDK1.1
*/
public synchronized void removeItemListener(ItemListener l) {
itemListener = AWTEventMulticaster.remove(itemListener, l);
}
/**
* Returns an array of all the item listeners
* registered on this list.
*
* @return all of this list's <code>ItemListener</code>s
* or an empty array if no item
* listeners are currently registered
*
* @see #addItemListener
* @see #removeItemListener
* @see java.awt.event.ItemEvent
* @see java.awt.event.ItemListener
* @since 1.4
*/
public synchronized ItemListener[] getItemListeners() {
return (ItemListener[])AWTEventMulticaster.getListeners(
(EventListener)itemListener,
ItemListener.class);
}
/**
* Adds the specified action listener to receive action events from
* this list. Action events occur when a user double-clicks
* on a list item.
* If l is null, no exception is thrown and no action is performed.
*
* @param l the action listener.
* @see java.awt.event.ActionEvent
* @see java.awt.event.ActionListener
* @see java.awt.List#removeActionListener
* @since JDK1.1
*/
public synchronized void addActionListener(ActionListener l) {
actionListener = AWTEventMulticaster.add(actionListener, l);
newEventsOnly = true;
}
/**
* Removes the specified action listener so that it no longer
* receives action events from this list. Action events
* occur when a user double-clicks on a list item.
* If l is null, no exception is thrown and no action is performed.
*
* @param l the action listener.
* @see java.awt.event.ActionEvent
* @see java.awt.event.ActionListener
* @see java.awt.List#addActionListener
* @since JDK1.1
*/
public synchronized void removeActionListener(ActionListener l) {
actionListener = AWTEventMulticaster.remove(actionListener, l);
}
/**
* Returns an array of all the action listeners
* registered on this list.
*
* @return all of this list's <code>ActionListener</code>s
* or an empty array if no action
* listeners are currently registered
*
* @see #addActionListener
* @see #removeActionListener
* @see java.awt.event.ActionEvent
* @see java.awt.event.ActionListener
* @since 1.4
*/
public synchronized ActionListener[] getActionListeners() {
return (ActionListener[]) AWTEventMulticaster.getListeners(
(EventListener)actionListener,
ActionListener.class);
}
// NOTE: remove when filtering is done at lower level
boolean eventEnabled(AWTEvent e) {
switch (e.id) {
case ActionEvent.ACTION_PERFORMED:
if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 ||
actionListener != null) {
return true;
}
return false;
case ItemEvent.ITEM_STATE_CHANGED:
if ((eventMask & AWTEvent.ITEM_EVENT_MASK) != 0 ||
itemListener != null) {
return true;
}
return false;
default:
break;
}
return super.eventEnabled(e);
}
/**
* Processes events on this scrolling list. If an event is
* an instance of <code>ItemEvent</code>, it invokes the
* <code>processItemEvent</code> method. Else, if the
* event is an instance of <code>ActionEvent</code>,
* it invokes <code>processActionEvent</code>.
* If the event is not an item event or an action event,
* it invokes <code>processEvent</code> on the superclass.
* @param e the event.
* @see java.awt.event.ActionEvent
* @see java.awt.event.ItemEvent
* @see java.awt.List#processActionEvent
* @see java.awt.List#processItemEvent
* @since JDK1.1
*/
protected void processEvent(AWTEvent e) {
if (e instanceof ItemEvent) {
processItemEvent((ItemEvent) e);
return;
} else if (e instanceof ActionEvent) {
processActionEvent((ActionEvent) e);
return;
}
super.processEvent(e);
}
/**
* Processes item events occurring on this list by
* dispatching them to any registered
* <code>ItemListener</code> objects.
* <p>
* This method is not called unless item events are
* enabled for this component. Item events are enabled
* when one of the following occurs:
* <p><ul>
* <li>An <code>ItemListener</code> object is registered
* via <code>addItemListener</code>.
* <li>Item events are enabled via <code>enableEvents</code>.
* </ul>
* @param e the item event.
* @see java.awt.event.ItemEvent
* @see java.awt.event.ItemListener
* @see java.awt.List#addItemListener
* @see java.awt.Component#enableEvents
* @since JDK1.1
*/
protected void processItemEvent(ItemEvent e) {
if (itemListener != null) {
itemListener.itemStateChanged(e);
}
}
/**
* Processes action events occurring on this component
* by dispatching them to any registered
* <code>ActionListener</code> objects.
* <p>
* This method is not called unless action events are
* enabled for this component. Action events are enabled
* when one of the following occurs:
* <p><ul>
* <li>An <code>ActionListener</code> object is registered
* via <code>addActionListener</code>.
* <li>Action events are enabled via <code>enableEvents</code>.
* </ul>
* @param e the action event.
* @see java.awt.event.ActionEvent
* @see java.awt.event.ActionListener
* @see java.awt.List#addActionListener
* @see java.awt.Component#enableEvents
* @since JDK1.1
*/
protected void processActionEvent(ActionEvent e) {
if (actionListener != null) {
actionListener.actionPerformed(e);
}
}
/**
* Returns the parameter string representing the state of this
* scrolling list. This string is useful for debugging.
* @return the parameter string of this scrolling list.
*/
protected String paramString() {
return super.paramString() + ",selected=" + getSelectedItem();
}
/**
* @deprecated As of JDK version 1.1,
* Not for public use in the future.
* This method is expected to be retained only as a package
* private method.
*/
public synchronized void delItems(int start, int end) {
for (int i = end; i >= start; i--) {
items.removeElementAt(i);
}
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
peer.delItems(start, end);
}
}
/*
* Serialization support. Since the value of the selected
* field isn't neccessarily up to date we sync it up with the
* peer before serializing.
*/
private int listSerializedDataVersion = 1;
/**
* Writes default serializable fields to stream. Writes
* a list of serializable ItemListener(s) as optional data.
* The non-serializable ItemListner(s) are detected and
* no attempt is made to serialize them.
*
* @serialData Null terminated sequence of 0 or more pairs.
* The pair consists of a String and Object.
* The String indicates the type of object and
* is one of the following :
* itemListenerK indicating and ItemListener object.
*
* @see AWTEventMulticaster.save(ObjectOutputStream, String, EventListener)
* @see java.awt.Component.itemListenerK
*/
private void writeObject(ObjectOutputStream s)
throws IOException {
synchronized (this) {
ListPeer peer = (ListPeer) this.peer;
if (peer != null) {
selected = peer.getSelectedIndexes();
}
}
s.defaultWriteObject();
AWTEventMulticaster.save(s, itemListenerK, itemListener);
AWTEventMulticaster.save(s, actionListenerK, actionListener);
s.writeObject(null);
}
private void readObject(ObjectInputStream s)
throws ClassNotFoundException, IOException {
s.defaultReadObject();
Object keyOrNull;
while (null != (keyOrNull = s.readObject())) {
String key = ((String) keyOrNull).intern();
if (itemListenerK == key)
addItemListener((ItemListener) (s.readObject()));
else if (actionListenerK == key)
addActionListener((ActionListener) (s.readObject()));
else // skip value for unrecognized key
s.readObject();
}
}
}