/*

 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

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.

 *

 * @author Georges Saab

 * @author David Karlton

 * @author Arnaud Weber

 */

public class BasicMenuBarUI extends MenuBarUI  {

    /**

     * The instance of {@code JMenuBar}.

     */

    protected JMenuBar              menuBar = null;

    /**

     * The instance of {@code ContainerListener}.

     */

    protected ContainerListener     containerListener;

    /**

     * The instance of {@code ChangeListener}.

     */

    protected ChangeListener        changeListener;

    private Handler handler;

    /**

     * Returns a new instance of {@code BasicMenuBarUI}.

     *

     * @param x a component

     * @return a new instance of {@code BasicMenuBarUI}

     */

    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();

    }

    /**

     * Installs default properties.

     */

    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");

    }

    /**

     * Registers listeners.

     */

    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);

    }

    /**

     * Registers keyboard actions.

     */

    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;

    }

    /**

     * Uninstalls default properties.

     */

    protected void uninstallDefaults() {

        if (menuBar!=null) {

            LookAndFeel.uninstallBorder(menuBar);

        }

    }

    /**

     * Unregisters listeners.

     */

    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;

    }

    /**

     * Unregisters keyboard actions.

     */

    protected void uninstallKeyboardActions() {

        SwingUtilities.replaceUIInputMap(menuBar, JComponent.

                                       WHEN_IN_FOCUSED_WINDOW, null);

        SwingUtilities.replaceUIActionMap(menuBar, null);

    }

    /**

     * Returns an instance of {@code ContainerListener}.

     *

     * @return an instance of {@code ContainerListener}

     */

    protected ContainerListener createContainerListener() {

        return getHandler();

    }

    /**

     * Returns an instance of {@code ChangeListener}.

     *

     * @return an instance of {@code ChangeListener}

     */

    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);

            }

        }

    }

}