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 }