001 /* PopupMenuUI.java --
002 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing.plaf;
040
041 import java.awt.event.MouseEvent;
042
043 import javax.swing.JPopupMenu;
044 import javax.swing.Popup;
045 import javax.swing.PopupFactory;
046
047 /**
048 * An abstract base class for delegates that implement the pluggable
049 * look and feel for a <code>JPopupMenu</code>.
050 *
051 * @see javax.swing.JPopupMenu
052 *
053 * @author Andrew Selkirk (aselkirk@sympatico.ca)
054 * @author Sascha Brawer (brawer@dandelis.ch)
055 */
056 public abstract class PopupMenuUI extends ComponentUI
057 {
058 /**
059 * Constructs a new <code>PopupMenuUI</code>.
060 */
061 public PopupMenuUI()
062 {
063 // Nothing to do here.
064 }
065
066
067 /**
068 * Tests whether or not a mouse event triggers a popup menu.
069 *
070 * <p>The default implementation calls
071 * <code>event.isPopupTrigger()</code>, which checks for the gesture
072 * that is common for the platform on which the application runs. If
073 * a look and feel wants to employ non-standard conventions for
074 * triggering a popup menu, it can override this method.
075 *
076 * @param event the event to check.
077 *
078 * @return <code>true</code> if the event triggers a popup menu;
079 * <code>false</code> otherwise.
080 *
081 * @since 1.3
082 */
083 public boolean isPopupTrigger(MouseEvent event)
084 {
085 return event.isPopupTrigger();
086 }
087
088
089 /**
090 * Creates a <code>Popup</code> for displaying the popup menu. The
091 * default implementation uses the {@link javax.swing.PopupFactory}
092 * for retrieving a suitable <code>Popup</code>, but subclasses
093 * might want to override this method if a LookAndFeel needs special
094 * Popups.
095 *
096 * @param popup the <code>JPopupMenu</code> for whose display
097 * a <code>Popup</code> is needed.
098 *
099 * @param x the horizontal position where the popup will be
100 * displayed.
101 *
102 * @param y the vertical position where the popup will be
103 * displayed.
104 *
105 * @return a <code>Popup</code> for showing and hiding
106 * the menu.
107 *
108 * @since 1.4
109 */
110 public Popup getPopup(JPopupMenu popup, int x, int y)
111 {
112 return PopupFactory.getSharedInstance().getPopup(
113 /* origin/owner of the popup */ popup.getInvoker(),
114 /* contents */ popup,
115 x, y);
116 }
117 }