001 /* PopupFactory.java --
002 Copyright (C) 2003 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;
040
041 import java.awt.Component;
042 import java.awt.Dimension;
043 import java.awt.Point;
044
045
046 /**
047 * A factory for <code>Popup</code> objects. These are used to
048 * managed little windows that float over everything else,
049 * typically containing a popup menu.
050 *
051 * @since 1.4
052 *
053 * @author Sascha Brawer (brawer@dandelis.ch)
054 */
055 public class PopupFactory
056 {
057 /**
058 * The shared factory object.
059 *
060 * @see #getSharedInstance
061 * @see #setSharedInstance
062 */
063 private static PopupFactory sharedFactory;
064
065
066 /**
067 * Constructs a new <code>PopupFactory</code>. Usually, a single
068 * <code>PopupFactory</code> is shared among multiple consumers
069 * of <code>Popup</code>. Use {@link #getSharedInstance} to retrieve
070 * the current factory.
071 */
072 public PopupFactory()
073 {
074 // Nothing to do here.
075 }
076
077
078 /**
079 * Sets the shared factory.
080 *
081 * @param factory the PopupFactory that future invocations of
082 * {@link #getSharedInstance} will return.
083 *
084 * @throws IllegalArgumentException if <code>factory</code>
085 * is <code>null</code>.
086 */
087 public static void setSharedInstance(PopupFactory factory)
088 {
089 if (factory == null)
090 throw new IllegalArgumentException();
091
092 /* Swing is not designed to be thread-safe, so there is no
093 * need to synchronize the access to the global variable.
094 */
095 sharedFactory = factory;
096 }
097
098
099 /**
100 * Retrieves the shared factory, creating a new factory if
101 * necessary.
102 *
103 * @return a <code>PopupFactory</code> that can be used
104 * to create <code>Popup</code> objects.
105 */
106 public static PopupFactory getSharedInstance()
107 {
108 /* Swing is not designed to be thread-safe, so there is no
109 * need to synchronize the access to the global variable.
110 */
111 if (sharedFactory == null)
112 sharedFactory = new PopupFactory();
113
114 return sharedFactory;
115 }
116
117
118 /**
119 * Creates a new <code>Popup</code> given its owner,
120 * contents and the screen position where the popup
121 * will appear.
122 *
123 * @param owner the Component to which <code>x</code> and
124 * <code>y</code> are relative, or <code>null</code> for
125 * placing the popup relative to the origin of the screen.
126 *
127 * @param contents the contents that will be displayed inside
128 * the <code>Popup</code>.
129 *
130 * @param x the horizontal position where the Popup will appear.
131 *
132 * @param y the vertical position where the Popup will appear.
133 *
134 * @throws IllegalArgumentException if <code>contents</code>
135 * is <code>null</code>.
136 */
137 public Popup getPopup(Component owner, Component contents,
138 int x, int y)
139 {
140 Popup popup = null;
141 // By default we enable lightweight popups since they are more efficient
142 // than heavyweight popups.
143 boolean lightweightEnabled = true;
144 // Special case JPopupMenu here, since it supports a lightweightEnabled
145 // flag that we must respect.
146 if (contents instanceof JPopupMenu)
147 {
148 JPopupMenu menu = (JPopupMenu) contents;
149 lightweightEnabled = menu.isLightWeightPopupEnabled();
150 }
151
152 // If we have a root pane and the contents fits within the root pane and
153 // lightweight popups are enabled, than we can use a lightweight popup.
154 JRootPane root = SwingUtilities.getRootPane(owner);
155 if (root != null)
156 {
157 Point rootLoc = root.getLocationOnScreen();
158 Dimension contentsSize = contents.getSize();
159 Dimension rootSize = root.getSize();
160 if (x >= rootLoc.x && y > rootLoc.y
161 && (x - rootLoc.x) + contentsSize.width < rootSize.width
162 && (y - rootLoc.y) + contentsSize.height < rootSize.height)
163 popup = new Popup.LightweightPopup(owner, contents, x, y);
164 else
165 popup = new Popup.JWindowPopup(owner, contents, x, y);
166 }
167 else
168 popup = new Popup.JWindowPopup(owner, contents, x, y);
169 return popup;
170 }
171 }