basiccomboboxui.java

java jdk 1.4的源码

/*
 * @(#)BasicComboBoxUI.java	1.155 03/01/23
 *
 * Copyright 2003 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.FocusManager;
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;

/**
 * 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 1.155 01/23/03
 * @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;

    private FocusListener editorFocusListener;
    private ActionListener editorActionListener;

    /**
     * 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;

    // 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");

    // 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;
    }

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

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

    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();
    }

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

        keyListener = null;
        focusListener = null;
        listDataListener = null;
        propertyChangeListener = null;
	editorActionListener = null;
	editorFocusListener = 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" );
    }

    /**
     * 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 );
    }

    /**
     * Remove the installed listeners from the combo box and its model.
     * The number and types of listeners removed and in this method should be
     * the same that was added in <code>installListeners</code>
     */
    protected void uninstallListeners() {
        if ( keyListener != null ) {
            comboBox.removeKeyListener( keyListener );
        }
	if ( itemListener != null) {
	    comboBox.removeItemListener( itemListener );
	}
        if ( propertyChangeListener != null ) {
            comboBox.removePropertyChangeListener( propertyChangeListener );
        }
        if ( focusListener != null) {
            comboBox.removeFocusListener( focusListener );
        }
	if ( popupMouseListener != null) {
	    comboBox.removeMouseListener( popupMouseListener );
	}
	if ( popupMouseMotionListener != null) {
	    comboBox.removeMouseMotionListener( popupMouseMotionListener );
	}
	if (popupKeyListener != null) {
	    comboBox.removeKeyListener(popupKeyListener);
	}
        if ( comboBox.getModel() != null ) {
            if ( listDataListener != null ) {
                comboBox.getModel().removeListDataListener( listDataListener );
            }
        }
    }

    /**
     * Creates the popup portion of the combo box.
     *
     * @return an instance of <code>ComboPopup</code>
     * @see ComboPopup
     */
    protected ComboPopup createPopup() {
        BasicComboPopup popup = new BasicComboPopup( comboBox );
        popup.getAccessibleContext().setAccessibleParent(comboBox);
        return popup;
    }

    /**
     * Creates a <code>KeyListener</code> 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 <code>KeyListener</code> or null
     */
    protected KeyListener createKeyListener() {
        return new KeyHandler();
    } 

    /**
     * Creates a <code>FocusListener</code> 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>FocusListener</code> or null
     */
    protected FocusListener createFocusListener() {
        return new FocusHandler();
    }

    /**
     * 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 new ListDataHandler();
    }

    /**
     * Creates an <code>ItemListener</code> 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</code> or null
     */
    protected ItemListener createItemListener() {
        return null;
    }

    /**
     * Creates a <code>PropertyChangeListener</code> 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</code> or null
     */
    protected PropertyChangeListener createPropertyChangeListener() {
        return new PropertyChangeHandler();
    }

    /**
     * Creates a layout manager for managing the components which make up the 
     * combo box.
     * 
     * @return an instance of a layout manager
     */
    protected LayoutManager createLayoutManager() {
        return new ComboBoxLayoutManager();
    }

    /**
     * Creates the default renderer that will be used in a non-editiable combo 
     * box. A default renderer will used only if a renderer has not been