basiccombopopup.java

JAVA 所有包

     * 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 getHandler();
    }

    /**
     * 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 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</code> used to display the combo box items
     */
    protected JList createList() {
	return new JList( comboBox.getModel() ) {
            public void processMouseEvent(MouseEvent e)  {
                if (e.isControlDown())  {
                    // Fix for 4234053. Filter out the Control Key from the list. 
                    // ie., don't allow CTRL key deselection.
                    e = new MouseEvent((Component)e.getSource(), e.getID(), e.getWhen(), 
                                       e.getModifiers() ^ InputEvent.CTRL_MASK,
                                       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</code>.
     *
     * @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</em> 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:</strong>
     * We recommend that you <em>not</em> 
     * 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</code>.
     *
     * @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.setSelectedIndex( list.getSelectedIndex() );
                    } else {
                        comboBox.getEditor().setItem( list.getSelectedValue() );
                    }
                }
                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.setSelectedIndex( list.getSelectedIndex() );
                    } else {
                        comboBox.getEditor().setItem( list.getSelectedValue() );
                    }
                }
		comboBox.setPopupVisible(false);
            }
            hasEntered = false;
            stopAutoScrolling();
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }