gcc/libjava/classpath/javax/swing/plaf/basic/BasicMenuBarUI.java

/* BasicMenuBarUI.java --
   Copyright (C) 2002, 2004, 2005  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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any later version.

GNU Classpath is distributed in the hope that it will be useful, but
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package javax.swing.plaf.basic;

import java.awt.Dimension;
import java.awt.event.ContainerEvent;
import java.awt.event.ContainerListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.BoxLayout;
import javax.swing.JComponent;
import javax.swing.JMenuBar;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.MenuBarUI;

/**
 * UI Delegate for JMenuBar.
 */
public class BasicMenuBarUI extends MenuBarUI
{
  protected ChangeListener changeListener;

  /*ContainerListener that listens to the ContainerEvents fired from menu bar*/
  protected ContainerListener containerListener;

  /*Property change listeners that listener to PropertyChangeEvent from menu bar*/
  protected PropertyChangeListener propertyChangeListener;

  /* menu bar for which this UI delegate is for*/
  protected JMenuBar menuBar;

  /**
   * Creates a new BasicMenuBarUI object.
   */
  public BasicMenuBarUI()
  {
    changeListener = createChangeListener();
    containerListener = createContainerListener();
    propertyChangeListener = new PropertyChangeHandler();
  }

  /**
   * Creates ChangeListener
   *
   * @return The ChangeListener
   */
  protected ChangeListener createChangeListener()
  {
    return new ChangeHandler();
  }

  /**
   * Creates ContainerListener() to listen for ContainerEvents
   * fired by JMenuBar.
   *
   * @return The ContainerListener
   */
  protected ContainerListener createContainerListener()
  {
    return new ContainerHandler();
  }

  /**
   * Factory method to create a BasicMenuBarUI for the given {@link
   * JComponent}, which should be a {@link JMenuBar}.
   *
   * @param x The {@link JComponent} a UI is being created for.
   *
   * @return A BasicMenuBarUI for the {@link JComponent}.
   */
  public static ComponentUI createUI(JComponent x)
  {
    return new BasicMenuBarUI();
  }

  /**
   * Returns maximum size for the specified menu bar
   *
   * @param c component for which to get maximum size
   *
   * @return  Maximum size for the specified menu bar
   */
  public Dimension getMaximumSize(JComponent c)
  {
    // let layout manager calculate its size
    return null;
  }

  /**
   * Returns maximum allowed size of JMenuBar.
   *
   * @param c menuBar for which to return maximum size
   *
   * @return Maximum size of the give menu bar.
   */
  public Dimension getMinimumSize(JComponent c)
  {
    // let layout manager calculate its size
    return null;
  }

  /**
   * Returns preferred size of JMenuBar.
   *
   * @param c menuBar for which to return preferred size
   *
   * @return Preferred size of the give menu bar.
   */
  public Dimension getPreferredSize(JComponent c)
  {
    // let layout manager calculate its size
    return null;
  }

  /**
   * Initializes any default properties that this UI has from the defaults for
   * the Basic look and feel.
   */
  protected void installDefaults()
  {
    UIDefaults defaults = UIManager.getLookAndFeelDefaults();

    menuBar.setBackground(defaults.getColor("MenuBar.background"));
    menuBar.setBorder(defaults.getBorder("MenuBar.border"));
    menuBar.setFont(defaults.getFont("MenuBar.font"));
    menuBar.setForeground(defaults.getColor("MenuBar.foreground"));
    menuBar.setOpaque(true);
  }

  /**
   * This method installs the keyboard actions for the JMenuBar.
   */
  protected void installKeyboardActions()
  {
    // FIXME: implement
  }

  /**
   * This method installs the listeners needed for this UI to function.
   */
  protected void installListeners()
  {
    menuBar.addContainerListener(containerListener);
    menuBar.addPropertyChangeListener(propertyChangeListener);
  }

  /**
  * Installs and initializes all fields for this UI delegate. Any properties
  * of the UI that need to be initialized and/or set to defaults will be
  * done now. It will also install any listeners necessary.
  *
  * @param c The {@link JComponent} that is having this UI installed.
  */
  public void installUI(JComponent c)
  {
    super.installUI(c);
    menuBar = (JMenuBar) c;
    menuBar.setLayout(new BoxLayout(menuBar, BoxLayout.X_AXIS));
    installDefaults();
    installListeners();
    installKeyboardActions();
  }

  /**
   * This method uninstalls the defaults and nulls any objects created during
   * install.
   */
  protected void uninstallDefaults()
  {
    menuBar.setBackground(null);
    menuBar.setBorder(null);
    menuBar.setFont(null);
    menuBar.setForeground(null);
  }

  /**
   * This method reverses the work done in installKeyboardActions.
   */
  protected void uninstallKeyboardActions()
  {
    // FIXME: implement. 
  }

  /**
   * Unregisters all the listeners that this UI delegate was using.
   */
  protected void uninstallListeners()
  {
    menuBar.removeContainerListener(containerListener);
    menuBar.removePropertyChangeListener(propertyChangeListener);
  }

  /**
   * Performs the opposite of installUI. Any properties or resources that need
   * to be cleaned up will be done now. It will also uninstall any listeners
   * it has. In addition, any properties of this UI will be nulled.
   *
   * @param c The {@link JComponent} that is having this UI uninstalled.
   */
  public void uninstallUI(JComponent c)
  {
    uninstallDefaults();
    uninstallListeners();
    uninstallKeyboardActions();
    menuBar = null;
  }

  protected class ChangeHandler implements ChangeListener
  {
    public void stateChanged(ChangeEvent event)
    {
    }
  }

  /**
   * This class handles ContainerEvents fired by JMenuBar. It revalidates
   * and repaints menu bar whenever menu is added or removed from it.
   */
  protected class ContainerHandler implements ContainerListener
  {
    /**
     * This method is called whenever menu is added to the menu bar
     *
     * @param e The ContainerEvent.
     */
    public void componentAdded(ContainerEvent e)
    {
      menuBar.revalidate();
      menuBar.repaint();
    }

    /**
     * This method is called whenever menu is removed from the menu bar.
     *
     * @param e The ContainerEvent.
     */
    public void componentRemoved(ContainerEvent e)
    {
      menuBar.revalidate();
      menuBar.repaint();
    }
  }

  /**
   * This class handles PropertyChangeEvents fired from the JMenuBar
   */
  protected class PropertyChangeHandler implements PropertyChangeListener
  {
    /**
     * This method is called whenever one of the properties of the MenuBar
     * changes.
     *
     * @param e The PropertyChangeEvent.
     */
    public void propertyChange(PropertyChangeEvent e)
    {
      if (e.getPropertyName().equals("borderPainted"))
        menuBar.repaint();
      if (e.getPropertyName().equals("margin"))
        menuBar.repaint();
    }
  }
}