Java example source code file (BasicComboPopup.java)
The BasicComboPopup.java Java example source code
/*
* Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code 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. 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 javax.swing.plaf.basic;
import javax.accessibility.AccessibleContext;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.LineBorder;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import java.io.Serializable;
/**
* This is a basic implementation of the <code>ComboPopup interface.
*
* This class represents the ui for the popup portion of the combo box.
* <p>
* All event handling is handled by listener classes created with the
* <code>createxxxListener() methods and internal classes.
* You can change the behavior of this class by overriding the
* <code>createxxxListener() methods and supplying your own
* event listeners or subclassing from the ones supplied in this class.
* <p>
* <strong>Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeans™
* has been added to the <code>java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @author Tom Santos
* @author Mark Davidson
*/
public class BasicComboPopup extends JPopupMenu implements ComboPopup {
// An empty ListMode, this is used when the UI changes to allow
// the JList to be gc'ed.
private static class EmptyListModelClass implements ListModel<Object>, Serializable {
public int getSize() { return 0; }
public Object getElementAt(int index) { return null; }
public void addListDataListener(ListDataListener l) {}
public void removeListDataListener(ListDataListener l) {}
};
static final ListModel EmptyListModel = new EmptyListModelClass();
private static Border LIST_BORDER = new LineBorder(Color.BLACK, 1);
protected JComboBox comboBox;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the accessor methods instead.
*
* @see #getList
* @see #createList
*/
protected JList list;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead
*
* @see #createScroller
*/
protected JScrollPane scroller;
/**
* As of Java 2 platform v1.4 this previously undocumented field is no
* longer used.
*/
protected boolean valueIsAdjusting = false;
// Listeners that are required by the ComboPopup interface
/**
* Implementation of all the listener classes.
*/
private Handler handler;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the accessor or create methods instead.
*
* @see #getMouseMotionListener
* @see #createMouseMotionListener
*/
protected MouseMotionListener mouseMotionListener;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the accessor or create methods instead.
*
* @see #getMouseListener
* @see #createMouseListener
*/
protected MouseListener mouseListener;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the accessor or create methods instead.
*
* @see #getKeyListener
* @see #createKeyListener
*/
protected KeyListener keyListener;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead.
*
* @see #createListSelectionListener
*/
protected ListSelectionListener listSelectionListener;
// Listeners that are attached to the list
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead.
*
* @see #createListMouseListener
*/
protected MouseListener listMouseListener;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead
*
* @see #createListMouseMotionListener
*/
protected MouseMotionListener listMouseMotionListener;
// Added to the combo box for bound properties
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead
*
* @see #createPropertyChangeListener
*/
protected PropertyChangeListener propertyChangeListener;
// Added to the combo box model
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead
*
* @see #createListDataListener
*/
protected ListDataListener listDataListener;
/**
* This protected field is implementation specific. Do not access directly
* or override. Use the create method instead
*
* @see #createItemListener
*/
protected ItemListener itemListener;
/**
* This protected field is implementation specific. Do not access directly
* or override.
*/
protected Timer autoscrollTimer;
protected boolean hasEntered = false;
protected boolean isAutoScrolling = false;
protected int scrollDirection = SCROLL_UP;
protected static final int SCROLL_UP = 0;
protected static final int SCROLL_DOWN = 1;
//========================================
// begin ComboPopup method implementations
//
/**
* Implementation of ComboPopup.show().
*/
public void show() {
comboBox.firePopupMenuWillBecomeVisible();
setListSelection(comboBox.getSelectedIndex());
Point location = getPopupLocation();
show( comboBox, location.x, location.y );
}
/**
* Implementation of ComboPopup.hide().
*/
public void hide() {
MenuSelectionManager manager = MenuSelectionManager.defaultManager();
MenuElement [] selection = manager.getSelectedPath();
for ( int i = 0 ; i < selection.length ; i++ ) {
if ( selection[i] == this ) {
manager.clearSelectedPath();
break;
}
}
if (selection.length > 0) {
comboBox.repaint();
}
}
/**
* Implementation of ComboPopup.getList().
*/
public JList getList() {
return list;
}
/**
* Implementation of ComboPopup.getMouseListener().
*
* @return a <code>MouseListener or null
* @see ComboPopup#getMouseListener
*/
public MouseListener getMouseListener() {
if (mouseListener == null) {
mouseListener = createMouseListener();
}
return mouseListener;
}
/**
* Implementation of ComboPopup.getMouseMotionListener().
*
* @return a <code>MouseMotionListener or null
* @see ComboPopup#getMouseMotionListener
*/
public MouseMotionListener getMouseMotionListener() {
if (mouseMotionListener == null) {
mouseMotionListener = createMouseMotionListener();
}
return mouseMotionListener;
}
/**
* Implementation of ComboPopup.getKeyListener().
*
* @return a <code>KeyListener or null
* @see ComboPopup#getKeyListener
*/
public KeyListener getKeyListener() {
if (keyListener == null) {
keyListener = createKeyListener();
}
return keyListener;
}
/**
* Called when the UI is uninstalling. Since this popup isn't in the component
* tree, it won't get it's uninstallUI() called. It removes the listeners that
* were added in addComboBoxListeners().
*/
public void uninstallingUI() {
if (propertyChangeListener != null) {
comboBox.removePropertyChangeListener( propertyChangeListener );
}
if (itemListener != null) {
comboBox.removeItemListener( itemListener );
}
uninstallComboBoxModelListeners(comboBox.getModel());
uninstallKeyboardActions();
uninstallListListeners();
// We do this, otherwise the listener the ui installs on
// the model (the combobox model in this case) will keep a
// reference to the list, causing the list (and us) to never get gced.
list.setModel(EmptyListModel);
}
//
// end ComboPopup method implementations
//======================================
/**
* Removes the listeners from the combo box model
*
* @param model The combo box model to install listeners
* @see #installComboBoxModelListeners
*/
protected void uninstallComboBoxModelListeners( ComboBoxModel model ) {
if (model != null && listDataListener != null) {
model.removeListDataListener(listDataListener);
}
}
protected void uninstallKeyboardActions() {
// XXX - shouldn't call this method
// comboBox.unregisterKeyboardAction( KeyStroke.getKeyStroke( KeyEvent.VK_ENTER, 0 ) );
}
//===================================================================
// begin Initialization routines
//
public BasicComboPopup( JComboBox combo ) {
super();
setName("ComboPopup.popup");
comboBox = combo;
setLightWeightPopupEnabled( comboBox.isLightWeightPopupEnabled() );
// UI construction of the popup.
list = createList();
list.setName("ComboBox.list");
configureList();
scroller = createScroller();
scroller.setName("ComboBox.scrollPane");
configureScroller();
configurePopup();
installComboBoxListeners();
installKeyboardActions();
}
// Overriden PopupMenuListener notification methods to inform combo box
// PopupMenuListeners.
protected void firePopupMenuWillBecomeVisible() {
super.firePopupMenuWillBecomeVisible();
// comboBox.firePopupMenuWillBecomeVisible() is called from BasicComboPopup.show() method
// to let the user change the popup menu from the PopupMenuListener.popupMenuWillBecomeVisible()
}
protected void firePopupMenuWillBecomeInvisible() {
super.firePopupMenuWillBecomeInvisible();
comboBox.firePopupMenuWillBecomeInvisible();
}
protected void firePopupMenuCanceled() {
super.firePopupMenuCanceled();
comboBox.firePopupMenuCanceled();
}
/**
* Creates a listener
* that will watch for mouse-press and release events on the combo box.
*
* <strong>Warning:
* When overriding this method, make sure to maintain the existing
* behavior.
*
* @return a <code>MouseListener which will be added to
* the combo box or null
*/
protected MouseListener createMouseListener() {
return getHandler();
}
/**
* Creates the mouse motion listener which will be added to the combo
* box.
*
* <strong>Warning:
* When overriding this method, make sure to maintain the existing
* behavior.
*
* @return a <code>MouseMotionListener which will be added to
* the combo box or null
*/
protected MouseMotionListener createMouseMotionListener() {
return getHandler();
}
/**
* Creates the key listener that will be added to the combo box. If
* this method returns null then it will not be added to the combo box.
*
* @return a <code>KeyListener or null
*/
protected KeyListener createKeyListener() {
return null;
}
/**
* Creates a list selection listener that watches for selection changes in
* the popup's list. If this method returns null then it will not
* be added to the popup list.
*
* @return an instance of a <code>ListSelectionListener or null
*/
protected ListSelectionListener createListSelectionListener() {
return null;
}
/**
* Creates a list data listener which will be added to the
* <code>ComboBoxModel. If this method returns null then
* it will not be added to the combo box model.
*
* @return an instance of a <code>ListDataListener or null
*/
protected ListDataListener createListDataListener() {
return null;
}
/**
* Creates a mouse listener that watches for mouse events in
* the popup's list. If this method returns null then it will
* not be added to the combo box.
*
* @return an instance of a <code>MouseListener or null
*/
protected MouseListener createListMouseListener() {
return getHandler();
}
/**
* Creates a mouse motion listener that watches for mouse motion
* events in the popup's list. If this method returns null then it will
* not be added to the combo box.
*
* @return an instance of a <code>MouseMotionListener or null
*/
protected MouseMotionListener createListMouseMotionListener() {
return getHandler();
}
/**
* Creates a <code>PropertyChangeListener which will be added to
* the combo box. If this method returns null then it will not
* be added to the combo box.
*
* @return an instance of a <code>PropertyChangeListener or null
*/
protected PropertyChangeListener createPropertyChangeListener() {
return getHandler();
}
/**
* Creates an <code>ItemListener which will be added to the
* combo box. If this method returns null then it will not
* be added to the combo box.
* <p>
* Subclasses may override this method to return instances of their own
* ItemEvent handlers.
*
* @return an instance of an <code>ItemListener or null
*/
protected ItemListener createItemListener() {
return getHandler();
}
private Handler getHandler() {
if (handler == null) {
handler = new Handler();
}
return handler;
}
/**
* Creates the JList used in the popup to display
* the items in the combo box model. This method is called when the UI class
* is created.
*
* @return a <code>JList used to display the combo box items
*/
protected JList createList() {
return new JList( comboBox.getModel() ) {
public void processMouseEvent(MouseEvent e) {
if (BasicGraphicsUtils.isMenuShortcutKeyDown(e)) {
// Fix for 4234053. Filter out the Control Key from the list.
// ie., don't allow CTRL key deselection.
Toolkit toolkit = Toolkit.getDefaultToolkit();
e = new MouseEvent((Component)e.getSource(), e.getID(), e.getWhen(),
e.getModifiers() ^ toolkit.getMenuShortcutKeyMask(),
e.getX(), e.getY(),
e.getXOnScreen(), e.getYOnScreen(),
e.getClickCount(),
e.isPopupTrigger(),
MouseEvent.NOBUTTON);
}
super.processMouseEvent(e);
}
};
}
/**
* Configures the list which is used to hold the combo box items in the
* popup. This method is called when the UI class
* is created.
*
* @see #createList
*/
protected void configureList() {
list.setFont( comboBox.getFont() );
list.setForeground( comboBox.getForeground() );
list.setBackground( comboBox.getBackground() );
list.setSelectionForeground( UIManager.getColor( "ComboBox.selectionForeground" ) );
list.setSelectionBackground( UIManager.getColor( "ComboBox.selectionBackground" ) );
list.setBorder( null );
list.setCellRenderer( comboBox.getRenderer() );
list.setFocusable( false );
list.setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
setListSelection( comboBox.getSelectedIndex() );
installListListeners();
}
/**
* Adds the listeners to the list control.
*/
protected void installListListeners() {
if ((listMouseListener = createListMouseListener()) != null) {
list.addMouseListener( listMouseListener );
}
if ((listMouseMotionListener = createListMouseMotionListener()) != null) {
list.addMouseMotionListener( listMouseMotionListener );
}
if ((listSelectionListener = createListSelectionListener()) != null) {
list.addListSelectionListener( listSelectionListener );
}
}
void uninstallListListeners() {
if (listMouseListener != null) {
list.removeMouseListener(listMouseListener);
listMouseListener = null;
}
if (listMouseMotionListener != null) {
list.removeMouseMotionListener(listMouseMotionListener);
listMouseMotionListener = null;
}
if (listSelectionListener != null) {
list.removeListSelectionListener(listSelectionListener);
listSelectionListener = null;
}
handler = null;
}
/**
* Creates the scroll pane which houses the scrollable list.
*/
protected JScrollPane createScroller() {
JScrollPane sp = new JScrollPane( list,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER );
sp.setHorizontalScrollBar(null);
return sp;
}
/**
* Configures the scrollable portion which holds the list within
* the combo box popup. This method is called when the UI class
* is created.
*/
protected void configureScroller() {
scroller.setFocusable( false );
scroller.getVerticalScrollBar().setFocusable( false );
scroller.setBorder( null );
}
/**
* Configures the popup portion of the combo box. This method is called
* when the UI class is created.
*/
protected void configurePopup() {
setLayout( new BoxLayout( this, BoxLayout.Y_AXIS ) );
setBorderPainted( true );
setBorder(LIST_BORDER);
setOpaque( false );
add( scroller );
setDoubleBuffered( true );
setFocusable( false );
}
/**
* This method adds the necessary listeners to the JComboBox.
*/
protected void installComboBoxListeners() {
if ((propertyChangeListener = createPropertyChangeListener()) != null) {
comboBox.addPropertyChangeListener(propertyChangeListener);
}
if ((itemListener = createItemListener()) != null) {
comboBox.addItemListener(itemListener);
}
installComboBoxModelListeners(comboBox.getModel());
}
/**
* Installs the listeners on the combo box model. Any listeners installed
* on the combo box model should be removed in
* <code>uninstallComboBoxModelListeners.
*
* @param model The combo box model to install listeners
* @see #uninstallComboBoxModelListeners
*/
protected void installComboBoxModelListeners( ComboBoxModel model ) {
if (model != null && (listDataListener = createListDataListener()) != null) {
model.addListDataListener(listDataListener);
}
}
protected void installKeyboardActions() {
/* XXX - shouldn't call this method. take it out for testing.
ActionListener action = new ActionListener() {
public void actionPerformed(ActionEvent e){
}
};
comboBox.registerKeyboardAction( action,
KeyStroke.getKeyStroke( KeyEvent.VK_ENTER, 0 ),
JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT ); */
}
//
// end Initialization routines
//=================================================================
//===================================================================
// begin Event Listenters
//
/**
* A listener to be registered upon the combo box
* (<em>not its popup menu)
* to handle mouse events
* that affect the state of the popup menu.
* The main purpose of this listener is to make the popup menu
* appear and disappear.
* This listener also helps
* with click-and-drag scenarios by setting the selection if the mouse was
* released over the list during a drag.
*
* <p>
* <strong>Warning:
* We recommend that you <em>not
* create subclasses of this class.
* If you absolutely must create a subclass,
* be sure to invoke the superclass
* version of each method.
*
* @see BasicComboPopup#createMouseListener
*/
protected class InvocationMouseHandler extends MouseAdapter {
/**
* Responds to mouse-pressed events on the combo box.
*
* @param e the mouse-press event to be handled
*/
public void mousePressed( MouseEvent e ) {
getHandler().mousePressed(e);
}
/**
* Responds to the user terminating
* a click or drag that began on the combo box.
*
* @param e the mouse-release event to be handled
*/
public void mouseReleased( MouseEvent e ) {
getHandler().mouseReleased(e);
}
}
/**
* This listener watches for dragging and updates the current selection in the
* list if it is dragging over the list.
*/
protected class InvocationMouseMotionHandler extends MouseMotionAdapter {
public void mouseDragged( MouseEvent e ) {
getHandler().mouseDragged(e);
}
}
/**
* As of Java 2 platform v 1.4, this class is now obsolete and is only included for
* backwards API compatibility. Do not instantiate or subclass.
* <p>
* All the functionality of this class has been included in
* BasicComboBoxUI ActionMap/InputMap methods.
*/
public class InvocationKeyHandler extends KeyAdapter {
public void keyReleased( KeyEvent e ) {}
}
/**
* As of Java 2 platform v 1.4, this class is now obsolete, doesn't do anything, and
* is only included for backwards API compatibility. Do not call or
* override.
*/
protected class ListSelectionHandler implements ListSelectionListener {
public void valueChanged( ListSelectionEvent e ) {}
}
/**
* As of 1.4, this class is now obsolete, doesn't do anything, and
* is only included for backwards API compatibility. Do not call or
* override.
* <p>
* The functionality has been migrated into <code>ItemHandler.
*
* @see #createItemListener
*/
public class ListDataHandler implements ListDataListener {
public void contentsChanged( ListDataEvent e ) {}
public void intervalAdded( ListDataEvent e ) {
}
public void intervalRemoved( ListDataEvent e ) {
}
}
/**
* This listener hides the popup when the mouse is released in the list.
*/
protected class ListMouseHandler extends MouseAdapter {
public void mousePressed( MouseEvent e ) {
}
public void mouseReleased(MouseEvent anEvent) {
getHandler().mouseReleased(anEvent);
}
}
/**
* This listener changes the selected item as you move the mouse over the list.
* The selection change is not committed to the model, this is for user feedback only.
*/
protected class ListMouseMotionHandler extends MouseMotionAdapter {
public void mouseMoved( MouseEvent anEvent ) {
getHandler().mouseMoved(anEvent);
}
}
/**
* This listener watches for changes to the selection in the
* combo box.
*/
protected class ItemHandler implements ItemListener {
public void itemStateChanged( ItemEvent e ) {
getHandler().itemStateChanged(e);
}
}
/**
* This listener watches for bound properties that have changed in the
* combo box.
* <p>
* Subclasses which wish to listen to combo box property changes should
* call the superclass methods to ensure that the combo popup correctly
* handles property changes.
*
* @see #createPropertyChangeListener
*/
protected class PropertyChangeHandler implements PropertyChangeListener {
public void propertyChange( PropertyChangeEvent e ) {
getHandler().propertyChange(e);
}
}
private class AutoScrollActionHandler implements ActionListener {
private int direction;
AutoScrollActionHandler(int direction) {
this.direction = direction;
}
public void actionPerformed(ActionEvent e) {
if (direction == SCROLL_UP) {
autoScrollUp();
}
else {
autoScrollDown();
}
}
}
private class Handler implements ItemListener, MouseListener,
MouseMotionListener, PropertyChangeListener,
Serializable {
//
// MouseListener
// NOTE: this is added to both the JList and JComboBox
//
public void mouseClicked(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {
if (e.getSource() == list) {
return;
}
if (!SwingUtilities.isLeftMouseButton(e) || !comboBox.isEnabled())
return;
if ( comboBox.isEditable() ) {
Component comp = comboBox.getEditor().getEditorComponent();
if ((!(comp instanceof JComponent)) || ((JComponent)comp).isRequestFocusEnabled()) {
comp.requestFocus();
}
}
else if (comboBox.isRequestFocusEnabled()) {
comboBox.requestFocus();
}
togglePopup();
}
public void mouseReleased(MouseEvent e) {
if (e.getSource() == list) {
if (list.getModel().getSize() > 0) {
// JList mouse listener
if (comboBox.getSelectedIndex() == list.getSelectedIndex()) {
comboBox.getEditor().setItem(list.getSelectedValue());
}
comboBox.setSelectedIndex(list.getSelectedIndex());
}
comboBox.setPopupVisible(false);
// workaround for cancelling an edited item (bug 4530953)
if (comboBox.isEditable() && comboBox.getEditor() != null) {
comboBox.configureEditor(comboBox.getEditor(),
comboBox.getSelectedItem());
}
return;
}
// JComboBox mouse listener
Component source = (Component)e.getSource();
Dimension size = source.getSize();
Rectangle bounds = new Rectangle( 0, 0, size.width - 1, size.height - 1 );
if ( !bounds.contains( e.getPoint() ) ) {
MouseEvent newEvent = convertMouseEvent( e );
Point location = newEvent.getPoint();
Rectangle r = new Rectangle();
list.computeVisibleRect( r );
if ( r.contains( location ) ) {
if (comboBox.getSelectedIndex() == list.getSelectedIndex()) {
comboBox.getEditor().setItem(list.getSelectedValue());
}
comboBox.setSelectedIndex(list.getSelectedIndex());
}
comboBox.setPopupVisible(false);
}
hasEntered = false;
stopAutoScrolling();
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
//
// MouseMotionListener:
// NOTE: this is added to both the List and ComboBox
//
public void mouseMoved(MouseEvent anEvent) {
if (anEvent.getSource() == list) {
Point location = anEvent.getPoint();
Rectangle r = new Rectangle();
list.computeVisibleRect( r );
if ( r.contains( location ) ) {
updateListBoxSelectionForEvent( anEvent, false );
}
}
}
public void mouseDragged( MouseEvent e ) {
if (e.getSource() == list) {
return;
}
if ( isVisible() ) {
MouseEvent newEvent = convertMouseEvent( e );
Rectangle r = new Rectangle();
list.computeVisibleRect( r );
if ( newEvent.getPoint().y >= r.y && newEvent.getPoint().y <= r.y + r.height - 1 ) {
hasEntered = true;
if ( isAutoScrolling ) {
stopAutoScrolling();
}
Point location = newEvent.getPoint();
if ( r.contains( location ) ) {
updateListBoxSelectionForEvent( newEvent, false );
}
}
else {
if ( hasEntered ) {
int directionToScroll = newEvent.getPoint().y < r.y ? SCROLL_UP : SCROLL_DOWN;
if ( isAutoScrolling && scrollDirection != directionToScroll ) {
stopAutoScrolling();
startAutoScrolling( directionToScroll );
}
else if ( !isAutoScrolling ) {
startAutoScrolling( directionToScroll );
}
}
else {
if ( e.getPoint().y < 0 ) {
hasEntered = true;
startAutoScrolling( SCROLL_UP );
}
}
}
}
}
//
// PropertyChangeListener
//
public void propertyChange(PropertyChangeEvent e) {
JComboBox comboBox = (JComboBox)e.getSource();
String propertyName = e.getPropertyName();
if ( propertyName == "model" ) {
ComboBoxModel oldModel = (ComboBoxModel)e.getOldValue();
ComboBoxModel newModel = (ComboBoxModel)e.getNewValue();
uninstallComboBoxModelListeners(oldModel);
installComboBoxModelListeners(newModel);
list.setModel(newModel);
if ( isVisible() ) {
hide();
}
}
else if ( propertyName == "renderer" ) {
list.setCellRenderer( comboBox.getRenderer() );
if ( isVisible() ) {
hide();
}
}
else if (propertyName == "componentOrientation") {
// Pass along the new component orientation
// to the list and the scroller
ComponentOrientation o =(ComponentOrientation)e.getNewValue();
JList list = getList();
if (list!=null && list.getComponentOrientation()!=o) {
list.setComponentOrientation(o);
}
if (scroller!=null && scroller.getComponentOrientation()!=o) {
scroller.setComponentOrientation(o);
}
if (o!=getComponentOrientation()) {
setComponentOrientation(o);
}
}
else if (propertyName == "lightWeightPopupEnabled") {
setLightWeightPopupEnabled(comboBox.isLightWeightPopupEnabled());
}
}
//
// ItemListener
//
public void itemStateChanged( ItemEvent e ) {
if (e.getStateChange() == ItemEvent.SELECTED) {
JComboBox comboBox = (JComboBox)e.getSource();
setListSelection(comboBox.getSelectedIndex());
}
}
}
//
// end Event Listeners
//=================================================================
/**
* Overridden to unconditionally return false.
*/
public boolean isFocusTraversable() {
return false;
}
//===================================================================
// begin Autoscroll methods
//
/**
* This protected method is implementation specific and should be private.
* do not call or override.
*/
protected void startAutoScrolling( int direction ) {
// XXX - should be a private method within InvocationMouseMotionHandler
// if possible.
if ( isAutoScrolling ) {
autoscrollTimer.stop();
}
isAutoScrolling = true;
if ( direction == SCROLL_UP ) {
scrollDirection = SCROLL_UP;
Point convertedPoint = SwingUtilities.convertPoint( scroller, new Point( 1, 1 ), list );
int top = list.locationToIndex( convertedPoint );
list.setSelectedIndex( top );
autoscrollTimer = new Timer( 100, new AutoScrollActionHandler(
SCROLL_UP) );
}
else if ( direction == SCROLL_DOWN ) {
scrollDirection = SCROLL_DOWN;
Dimension size = scroller.getSize();
Point convertedPoint = SwingUtilities.convertPoint( scroller,
new Point( 1, (size.height - 1) - 2 ),
list );
int bottom = list.locationToIndex( convertedPoint );
list.setSelectedIndex( bottom );
autoscrollTimer = new Timer(100, new AutoScrollActionHandler(
SCROLL_DOWN));
}
autoscrollTimer.start();
}
/**
* This protected method is implementation specific and should be private.
* do not call or override.
*/
protected void stopAutoScrolling() {
isAutoScrolling = false;
if ( autoscrollTimer != null ) {
autoscrollTimer.stop();
autoscrollTimer = null;
}
}
/**
* This protected method is implementation specific and should be private.
* do not call or override.
*/
protected void autoScrollUp() {
int index = list.getSelectedIndex();
if ( index > 0 ) {
list.setSelectedIndex( index - 1 );
list.ensureIndexIsVisible( index - 1 );
}
}
/**
* This protected method is implementation specific and should be private.
* do not call or override.
*/
protected void autoScrollDown() {
int index = list.getSelectedIndex();
int lastItem = list.getModel().getSize() - 1;
if ( index < lastItem ) {
list.setSelectedIndex( index + 1 );
list.ensureIndexIsVisible( index + 1 );
}
}
//
// end Autoscroll methods
//=================================================================
//===================================================================
// begin Utility methods
//
/**
* Gets the AccessibleContext associated with this BasicComboPopup.
* The AccessibleContext will have its parent set to the ComboBox.
*
* @return an AccessibleContext for the BasicComboPopup
* @since 1.5
*/
public AccessibleContext getAccessibleContext() {
AccessibleContext context = super.getAccessibleContext();
context.setAccessibleParent(comboBox);
return context;
}
/**
* This is is a utility method that helps event handlers figure out where to
* send the focus when the popup is brought up. The standard implementation
* delegates the focus to the editor (if the combo box is editable) or to
* the JComboBox if it is not editable.
*/
protected void delegateFocus( MouseEvent e ) {
if ( comboBox.isEditable() ) {
Component comp = comboBox.getEditor().getEditorComponent();
if ((!(comp instanceof JComponent)) || ((JComponent)comp).isRequestFocusEnabled()) {
comp.requestFocus();
}
}
else if (comboBox.isRequestFocusEnabled()) {
comboBox.requestFocus();
}
}
/**
* Makes the popup visible if it is hidden and makes it hidden if it is
* visible.
*/
protected void togglePopup() {
if ( isVisible() ) {
hide();
}
else {
show();
}
}
/**
* Sets the list selection index to the selectedIndex. This
* method is used to synchronize the list selection with the
* combo box selection.
*
* @param selectedIndex the index to set the list
*/
private void setListSelection(int selectedIndex) {
if ( selectedIndex == -1 ) {
list.clearSelection();
}
else {
list.setSelectedIndex( selectedIndex );
list.ensureIndexIsVisible( selectedIndex );
}
}
protected MouseEvent convertMouseEvent( MouseEvent e ) {
Point convertedPoint = SwingUtilities.convertPoint( (Component)e.getSource(),
e.getPoint(), list );
MouseEvent newEvent = new MouseEvent( (Component)e.getSource(),
e.getID(),
e.getWhen(),
e.getModifiers(),
convertedPoint.x,
convertedPoint.y,
e.getXOnScreen(),
e.getYOnScreen(),
e.getClickCount(),
e.isPopupTrigger(),
MouseEvent.NOBUTTON );
return newEvent;
}
/**
* Retrieves the height of the popup based on the current
* ListCellRenderer and the maximum row count.
*/
protected int getPopupHeightForRowCount(int maxRowCount) {
// Set the cached value of the minimum row count
int minRowCount = Math.min( maxRowCount, comboBox.getItemCount() );
int height = 0;
ListCellRenderer renderer = list.getCellRenderer();
Object value = null;
for ( int i = 0; i < minRowCount; ++i ) {
value = list.getModel().getElementAt( i );
Component c = renderer.getListCellRendererComponent( list, value, i, false, false );
height += c.getPreferredSize().height;
}
if (height == 0) {
height = comboBox.getHeight();
}
Border border = scroller.getViewportBorder();
if (border != null) {
Insets insets = border.getBorderInsets(null);
height += insets.top + insets.bottom;
}
border = scroller.getBorder();
if (border != null) {
Insets insets = border.getBorderInsets(null);
height += insets.top + insets.bottom;
}
return height;
}
/**
* Calculate the placement and size of the popup portion of the combo box based
* on the combo box location and the enclosing screen bounds. If
* no transformations are required, then the returned rectangle will
* have the same values as the parameters.
*
* @param px starting x location
* @param py starting y location
* @param pw starting width
* @param ph starting height
* @return a rectangle which represents the placement and size of the popup
*/
protected Rectangle computePopupBounds(int px,int py,int pw,int ph) {
Toolkit toolkit = Toolkit.getDefaultToolkit();
Rectangle screenBounds;
// Calculate the desktop dimensions relative to the combo box.
GraphicsConfiguration gc = comboBox.getGraphicsConfiguration();
Point p = new Point();
SwingUtilities.convertPointFromScreen(p, comboBox);
if (gc != null) {
Insets screenInsets = toolkit.getScreenInsets(gc);
screenBounds = gc.getBounds();
screenBounds.width -= (screenInsets.left + screenInsets.right);
screenBounds.height -= (screenInsets.top + screenInsets.bottom);
screenBounds.x += (p.x + screenInsets.left);
screenBounds.y += (p.y + screenInsets.top);
}
else {
screenBounds = new Rectangle(p, toolkit.getScreenSize());
}
Rectangle rect = new Rectangle(px,py,pw,ph);
if (py+ph > screenBounds.y+screenBounds.height
&& ph < screenBounds.height) {
rect.y = -rect.height;
}
return rect;
}
/**
* Calculates the upper left location of the Popup.
*/
private Point getPopupLocation() {
Dimension popupSize = comboBox.getSize();
Insets insets = getInsets();
// reduce the width of the scrollpane by the insets so that the popup
// is the same width as the combo box.
popupSize.setSize(popupSize.width - (insets.right + insets.left),
getPopupHeightForRowCount( comboBox.getMaximumRowCount()));
Rectangle popupBounds = computePopupBounds( 0, comboBox.getBounds().height,
popupSize.width, popupSize.height);
Dimension scrollSize = popupBounds.getSize();
Point popupLocation = popupBounds.getLocation();
scroller.setMaximumSize( scrollSize );
scroller.setPreferredSize( scrollSize );
scroller.setMinimumSize( scrollSize );
list.revalidate();
return popupLocation;
}
/**
* A utility method used by the event listeners. Given a mouse event, it changes
* the list selection to the list item below the mouse.
*/
protected void updateListBoxSelectionForEvent(MouseEvent anEvent,boolean shouldScroll) {
// XXX - only seems to be called from this class. shouldScroll flag is
// never true
Point location = anEvent.getPoint();
if ( list == null )
return;
int index = list.locationToIndex(location);
if ( index == -1 ) {
if ( location.y < 0 )
index = 0;
else
index = comboBox.getModel().getSize() - 1;
}
if ( list.getSelectedIndex() != index ) {
list.setSelectedIndex(index);
if ( shouldScroll )
list.ensureIndexIsVisible(index);
}
}
//
// end Utility methods
//=================================================================
}
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