basiccomboboxui.java

java1.6众多例子参考

/*
 * @(#)BasicComboBoxUI.java	1.192 08/05/29
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.swing.plaf.basic;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.accessibility.*;
import javax.swing.plaf.*;
import javax.swing.border.*;
import javax.swing.text.*;
import javax.swing.event.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import sun.awt.AppContext;
import sun.swing.DefaultLookup;
import sun.swing.UIAction;

/**
 * Basic UI implementation for JComboBox. 
 * <p>
 * The combo box is a compound component which means that it is an agregate of
 * many simpler components. This class creates and manages the listeners
 * on the combo box and the combo box model. These listeners update the user 
 * interface in response to changes in the properties and state 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>
 * For adding specific actions, 
 * overide <code>installKeyboardActions</code> to add actions in response to
 * KeyStroke bindings. See the article <a href="http://java.sun.com/products/jfc/tsc/special_report/kestrel/keybindings.html">Keyboard Bindings in Swing</a>
 * at <a href="http://java.sun.com/products/jfc/tsc"><em>The Swing Connection</em></a>.
 *
 * @version 1.192 05/29/08
 * @author Arnaud Weber
 * @author Tom Santos
 * @author Mark Davidson
 */
public class BasicComboBoxUI extends ComboBoxUI {
    protected JComboBox comboBox;
    /**
     * This protected field is implementation specific. Do not access directly
     * or override. 
     */
    protected boolean   hasFocus = false;

    // Control the selection behavior of the JComboBox when it is used
    // in the JTable DefaultCellEditor. 
    private boolean isTableCellEditor = false;
    private static final String IS_TABLE_CELL_EDITOR = "JComboBox.isTableCellEditor";

    // This list is for drawing the current item in the combo box.
    protected JList   listBox;

    // Used to render the currently selected item in the combo box.
    // It doesn't have anything to do with the popup's rendering.
    protected CellRendererPane currentValuePane = new CellRendererPane();

    // The implementation of ComboPopup that is used to show the popup.
    protected ComboPopup popup;

    // The Component that the ComboBoxEditor uses for editing
    protected Component editor;

    // The arrow button that invokes the popup.
    protected JButton   arrowButton;

    // Listeners that are attached to the JComboBox
    /**
     * This protected field is implementation specific. Do not access directly
     * or override. Override the listener construction method instead.
     *
     * @see #createKeyListener
     */
    protected KeyListener keyListener;
    /**
     * This protected field is implementation specific. Do not access directly
     * or override. Override the listener construction method instead.
     *
     * @see #createFocusListener
     */
    protected FocusListener focusListener;
    /**
     * This protected field is implementation specific. Do not access directly
     * or override. Override the listener construction method instead.
     *
     * @see #createPropertyChangeListener
     */
    protected PropertyChangeListener propertyChangeListener;

    /**
     * This protected field is implementation specific. Do not access directly
     * or override. Override the listener construction method instead.
     *
     * @see #createItemListener
     */
    protected ItemListener itemListener;

    // Listeners that the ComboPopup produces.
    protected MouseListener popupMouseListener;
    protected MouseMotionListener popupMouseMotionListener;
    protected KeyListener popupKeyListener;

    // This is used for knowing when to cache the minimum preferred size.
    // If the data in the list changes, the cached value get marked for recalc.
    // Added to the current JComboBox model
    /**
     * This protected field is implementation specific. Do not access directly
     * or override. Override the listener construction method instead.
     *
     * @see #createListDataListener
     */
    protected ListDataListener listDataListener;

    /**
     * Implements all the Listeners needed by this class, all existing
     * listeners redirect to it.
     */
    private Handler handler;

    /**
     * The time factor to treate the series of typed alphanumeric key
     * as prefix for first letter navigation.
     */
    private long timeFactor = 1000L;

    /**
     * This is tricky, this variables is needed for DefaultKeySelectionManager
     * to take into account time factor.
     */
    private long lastTime = 0L;
    private long time = 0L;		

    /**
     * The default key selection manager
     */
    JComboBox.KeySelectionManager keySelectionManager;

    // Flag for recalculating the minimum preferred size.
    protected boolean isMinimumSizeDirty = true;

    // Cached minimum preferred size.
    protected Dimension cachedMinimumSize = new Dimension( 0, 0 );

    // Flag for calculating the display size
    private boolean isDisplaySizeDirty = true;
    
    // Cached the size that the display needs to render the largest item
    private Dimension cachedDisplaySize = new Dimension( 0, 0 );

    // Key used for lookup of the DefaultListCellRenderer in the AppContext.
    private static final Object COMBO_UI_LIST_CELL_RENDERER_KEY =
                        new StringBuffer("DefaultListCellRendererKey");

    static final StringBuffer HIDE_POPUP_KEY
                  = new StringBuffer("HidePopupKey");

    /**
     * Whether or not all cells have the same baseline.
     */
    private boolean sameBaseline;
    
    /**
     * Indicates whether or not the combo box button should be square.
     * If square, then the width and height are equal, and are both set to
     * the height of the combo (minus appropriate insets).
     */
    private boolean squareButton = true;
    
    /**
     * Optional: if specified, these insets act as padding around the cell
     * renderer when laying out and painting the "selected" item in the 
     * combo box. BasicComboBoxUI uses a single combo box renderer for rendering
     * both the main combo box item and also all the items in the dropdown
     * for the combo box. padding allows you to specify addition insets in
     * addition to those specified by the cell renderer.
     */
    private Insets padding;

    // Used for calculating the default size.
    private static ListCellRenderer getDefaultListCellRenderer() {
        ListCellRenderer renderer = (ListCellRenderer)AppContext.
                         getAppContext().get(COMBO_UI_LIST_CELL_RENDERER_KEY);

        if (renderer == null) {
            renderer = new DefaultListCellRenderer();
            AppContext.getAppContext().put(COMBO_UI_LIST_CELL_RENDERER_KEY,
                                           new DefaultListCellRenderer());
        }
        return renderer;
    }

    /**
     * Populates ComboBox's actions.
     */
    static void loadActionMap(LazyActionMap map) {
	map.put(new Actions(Actions.HIDE));
	map.put(new Actions(Actions.PAGE_DOWN));
	map.put(new Actions(Actions.PAGE_UP));
	map.put(new Actions(Actions.HOME));
	map.put(new Actions(Actions.END));
	map.put(new Actions(Actions.DOWN));
	map.put(new Actions(Actions.DOWN_2));
	map.put(new Actions(Actions.TOGGLE));
	map.put(new Actions(Actions.TOGGLE_2));
	map.put(new Actions(Actions.UP));
	map.put(new Actions(Actions.UP_2));
	map.put(new Actions(Actions.ENTER));
    }

    //========================
    // begin UI Initialization
    //

    public static ComponentUI createUI(JComponent c) {
        return new BasicComboBoxUI();
    }

    @Override
    public void installUI( JComponent c ) {
        isMinimumSizeDirty = true;

        comboBox = (JComboBox)c;
        installDefaults();
        popup = createPopup();
        listBox = popup.getList();

	// Is this combo box a cell editor?
        Boolean inTable = (Boolean)c.getClientProperty(IS_TABLE_CELL_EDITOR );
	if (inTable != null) {
	    isTableCellEditor = inTable.equals(Boolean.TRUE) ? true : false;
	}

        if ( comboBox.getRenderer() == null || comboBox.getRenderer() instanceof UIResource ) {
            comboBox.setRenderer( createRenderer() );
        }

        if ( comboBox.getEditor() == null || comboBox.getEditor() instanceof UIResource ) {
            comboBox.setEditor( createEditor() );
        }

        installListeners();
        installComponents();

        comboBox.setLayout( createLayoutManager() );

        comboBox.setRequestFocusEnabled( true );

	installKeyboardActions();

        comboBox.putClientProperty("doNotCancelPopup", HIDE_POPUP_KEY);

        if (keySelectionManager == null || keySelectionManager instanceof UIResource) {
            keySelectionManager = new DefaultKeySelectionManager();
	}
	comboBox.setKeySelectionManager(keySelectionManager);
    }

    @Override
    public void uninstallUI( JComponent c ) {
        setPopupVisible( comboBox, false);
        popup.uninstallingUI();

        uninstallKeyboardActions();

        comboBox.setLayout( null );

        uninstallComponents();
        uninstallListeners();
        uninstallDefaults();

        if ( comboBox.getRenderer() == null || comboBox.getRenderer() instanceof UIResource ) {
            comboBox.setRenderer( null );
        }

        ComboBoxEditor comboBoxEditor = comboBox.getEditor(); 
        if (comboBoxEditor instanceof UIResource ) { 
            if (comboBoxEditor.getEditorComponent().hasFocus()) { 
                // Leave focus in JComboBox.
                comboBox.requestFocusInWindow();
            }
            comboBox.setEditor( null );
        }

        if (keySelectionManager instanceof UIResource) {
	    comboBox.setKeySelectionManager(null);
	}

        handler = null;
        keyListener = null;
        focusListener = null;
        listDataListener = null;
        propertyChangeListener = null;
        popup = null;
        listBox = null;
        comboBox = null;
    }

    /**
     * Installs the default colors, default font, default renderer, and default
     * editor into the JComboBox.
     */
    protected void installDefaults() {
        LookAndFeel.installColorsAndFont( comboBox,
                                          "ComboBox.background",
                                          "ComboBox.foreground",
                                          "ComboBox.font" );
        LookAndFeel.installBorder( comboBox, "ComboBox.border" );
        LookAndFeel.installProperty( comboBox, "opaque", Boolean.TRUE);

        Long l = (Long)UIManager.get("ComboBox.timeFactor");
        timeFactor = l == null ? 1000L : l.longValue();
        
        //NOTE: this needs to default to true if not specified
        Boolean b = (Boolean)UIManager.get("ComboBox.squareButton");
        squareButton = b == null ? true : b;
        
        padding = UIManager.getInsets("ComboBox.padding");
    }

    /**
     * Create and install the listeners for the combo box and its model.
     * This method is called when the UI is installed.
     */
    protected void installListeners() {
	if ( (itemListener = createItemListener()) != null) {
	    comboBox.addItemListener( itemListener );
	}
        if ( (propertyChangeListener = createPropertyChangeListener()) != null ) {
            comboBox.addPropertyChangeListener( propertyChangeListener );
        }
        if ( (keyListener = createKeyListener()) != null ) {
            comboBox.addKeyListener( keyListener );
        }
        if ( (focusListener = createFocusListener()) != null ) {
            comboBox.addFocusListener( focusListener );
        }
	if ((popupMouseListener = popup.getMouseListener()) != null) {
	    comboBox.addMouseListener( popupMouseListener );
	}
	if ((popupMouseMotionListener = popup.getMouseMotionListener()) != null) {
	    comboBox.addMouseMotionListener( popupMouseMotionListener );
	}
	if ((popupKeyListener = popup.getKeyListener()) != null) {
	    comboBox.addKeyListener(popupKeyListener);
	}

        if ( comboBox.getModel() != null ) {
            if ( (listDataListener = createListDataListener()) != null ) {
                comboBox.getModel().addListDataListener( listDataListener );
            }
        }
    }

    /**
     * Uninstalls the default colors, default font, default renderer, and default
     * editor into the JComboBox.
     */
    protected void uninstallDefaults() {
        LookAndFeel.installColorsAndFont( comboBox,
                                          "ComboBox.background",
                                          "ComboBox.foreground",
                                          "ComboBox.font" );
        LookAndFeel.uninstallBorder( comboBox );
    }

    /**