/* * @(#)BasicComboPopup.java	1.85 07/10/25 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */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</code> 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()</code> methods and internal classes. * You can change the behavior of this class by overriding the * <code>createxxxListener()</code> methods and supplying your own * event listeners or subclassing from the ones supplied in this class. * <p> * <strong>Warning:</strong> * 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<sup><font size="-2">TM</font></sup> * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @version 1.85 10/25/07 * @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,                                                        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() {	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</code> or null     * @see ComboPopup#getMouseListener     */    public MouseListener getMouseListener() {	if (mouseListener == null) {	    mouseListener = createMouseListener();	}        return mouseListener;    }    /**     * Implementation of ComboPopup.getMouseMotionListener().     *     * @return a <code>MouseMotionListener</code> or null     * @see ComboPopup#getMouseMotionListener     */    public MouseMotionListener getMouseMotionListener() {	if (mouseMotionListener == null) {	    mouseMotionListener = createMouseMotionListener();	}        return mouseMotionListener;    }    /**     * Implementation of ComboPopup.getKeyListener().     *     * @return a <code>KeyListener</code> 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();    }        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:</strong>     * When overriding this method, make sure to maintain the existing     * behavior.     *     * @return a <code>MouseListener</code> 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:</strong>     * When overriding this method, make sure to maintain the existing     * behavior.     *     * @return a <code>MouseMotionListener</code> 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</code> 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</code> or null     */    protected ListSelectionListener createListSelectionListener() {        return null;    }    /**     * Creates a list data listener which will be added to the     * <code>ComboBoxModel</code>. If this method returns null then     * it will not be added to the combo box model.     *     * @return an instance of a <code>ListDataListener</code> 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</code> 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</code> or null     */    protected MouseMotionListener createListMouseMotionListener() {        return getHandler();    }    /**