basicmenubarui.java

java1.6众多例子参考

/*
 * @(#)BasicMenuBarUI.java	1.81 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.swing.plaf.basic;

import sun.swing.DefaultLookup;
import sun.swing.UIAction;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.*;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.border.*;
import javax.swing.plaf.*;


/**
 * A default L&F implementation of MenuBarUI.  This implementation
 * is a "combined" view/controller.
 *
 * @version 1.81 11/17/05
 * @author Georges Saab
 * @author David Karlton
 * @author Arnaud Weber
 */
public class BasicMenuBarUI extends MenuBarUI  {
    protected JMenuBar              menuBar = null;
    protected ContainerListener     containerListener;
    protected ChangeListener        changeListener;
    private Handler handler;

    public static ComponentUI createUI(JComponent x) {
	return new BasicMenuBarUI();
    }

    static void loadActionMap(LazyActionMap map) {
        map.put(new Actions(Actions.TAKE_FOCUS));
    }

    public void installUI(JComponent c) {
	menuBar = (JMenuBar) c;

	installDefaults();
        installListeners();
        installKeyboardActions();

    }

    protected void installDefaults() {
	if (menuBar.getLayout() == null ||
	    menuBar.getLayout() instanceof UIResource) {
            menuBar.setLayout(new DefaultMenuLayout(menuBar,BoxLayout.LINE_AXIS));
        }
  
	LookAndFeel.installProperty(menuBar, "opaque", Boolean.TRUE);
	LookAndFeel.installBorder(menuBar,"MenuBar.border");
	LookAndFeel.installColorsAndFont(menuBar,
					      "MenuBar.background",
					      "MenuBar.foreground",
					      "MenuBar.font");
    }

    protected void installListeners() {
        containerListener = createContainerListener();
        changeListener = createChangeListener();
	
        for (int i = 0; i < menuBar.getMenuCount(); i++) {
            JMenu menu = menuBar.getMenu(i);
	    if (menu!=null)
		menu.getModel().addChangeListener(changeListener);        
	}
	menuBar.addContainerListener(containerListener);
    }

    protected void installKeyboardActions() {
	InputMap inputMap = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);

	SwingUtilities.replaceUIInputMap(menuBar,
			   JComponent.WHEN_IN_FOCUSED_WINDOW, inputMap);

        LazyActionMap.installLazyActionMap(menuBar, BasicMenuBarUI.class,
                                           "MenuBar.actionMap");
    } 

    InputMap getInputMap(int condition) {
	if (condition == JComponent.WHEN_IN_FOCUSED_WINDOW) {
	    Object[] bindings = (Object[])DefaultLookup.get
		                (menuBar, this, "MenuBar.windowBindings");
	    if (bindings != null) {
		return LookAndFeel.makeComponentInputMap(menuBar, bindings);
	    }
	}
	return null;
    }

    public void uninstallUI(JComponent c) {
        uninstallDefaults();
        uninstallListeners();
        uninstallKeyboardActions();

	menuBar = null;
    }

    protected void uninstallDefaults() {
	if (menuBar!=null) {
	    LookAndFeel.uninstallBorder(menuBar);
	}
    }

    protected void uninstallListeners() {
	menuBar.removeContainerListener(containerListener);

        for (int i = 0; i < menuBar.getMenuCount(); i++) {
	    JMenu menu = menuBar.getMenu(i);
	    if (menu !=null)
		menu.getModel().removeChangeListener(changeListener);
        }

	containerListener = null;
	changeListener = null;
        handler = null;
    }

    protected void uninstallKeyboardActions() {
	SwingUtilities.replaceUIInputMap(menuBar, JComponent.
				       WHEN_IN_FOCUSED_WINDOW, null);
	SwingUtilities.replaceUIActionMap(menuBar, null);
    }

    protected ContainerListener createContainerListener() {
	return getHandler();
    }

    protected ChangeListener createChangeListener() {
        return getHandler();
    }

    private Handler getHandler() {
        if (handler == null) {
            handler = new Handler();
        }
        return handler;
    }


    public Dimension getMinimumSize(JComponent c) {
        return null;
    }

    public Dimension getMaximumSize(JComponent c) {
        return null;
    }

    private class Handler implements ChangeListener, ContainerListener {
        //
        // ChangeListener
        //
	public void stateChanged(ChangeEvent e) {
	    int i,c;
	    for(i=0,c = menuBar.getMenuCount() ; i < c ; i++) {
		JMenu menu = menuBar.getMenu(i);
		if(menu !=null && menu.isSelected()) {
		    menuBar.getSelectionModel().setSelectedIndex(i);
		    break;
		}
	    }
	}

        //
        // ContainerListener
        //
	public void componentAdded(ContainerEvent e) {
	    Component c = e.getChild();
	    if (c instanceof JMenu)
		((JMenu)c).getModel().addChangeListener(changeListener);
	}
	public void componentRemoved(ContainerEvent e) {
	    Component c = e.getChild();
	    if (c instanceof JMenu)
		((JMenu)c).getModel().removeChangeListener(changeListener);
	}
    }


    private static class Actions extends UIAction {
        private static final String TAKE_FOCUS = "takeFocus";

        Actions(String key) {
            super(key);
	}

	public void actionPerformed(ActionEvent e) {
            // TAKE_FOCUS
	    JMenuBar menuBar = (JMenuBar)e.getSource();
            MenuSelectionManager defaultManager = MenuSelectionManager.defaultManager();
	    MenuElement me[];
	    MenuElement subElements[];
	    JMenu menu = menuBar.getMenu(0);
	    if (menu!=null) {
		    me = new MenuElement[3];
		    me[0] = (MenuElement) menuBar;
		    me[1] = (MenuElement) menu;
		    me[2] = (MenuElement) menu.getPopupMenu();
		    defaultManager.setSelectedPath(me);
	    }
	}
    }
}