1 /* 2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.swing; 27 28 import java.awt.*; 29 30 import sun.awt.ModalExclude; 31 import sun.awt.SunToolkit; 32 33 /** 34 * Popups are used to display a {@code Component} to the user, typically 35 * on top of all the other {@code Component}s in a particular containment 36 * hierarchy. {@code Popup}s have a very small life cycle. Once you 37 * have obtained a {@code Popup}, and hidden it (invoked the 38 * {@code hide} method), you should no longer 39 * invoke any methods on it. This allows the {@code PopupFactory} to cache 40 * {@code Popup}s for later use. 41 * <p> 42 * The general contract is that if you need to change the size of the 43 * {@code Component}, or location of the {@code Popup}, you should 44 * obtain a new {@code Popup}. 45 * <p> 46 * {@code Popup} does not descend from {@code Component}, rather 47 * implementations of {@code Popup} are responsible for creating 48 * and maintaining their own {@code Component}s to render the 49 * requested {@code Component} to the user. 50 * <p> 51 * You typically do not explicitly create an instance of {@code Popup}, 52 * instead obtain one from a {@code PopupFactory}. 53 * 54 * @see PopupFactory 55 * 56 * @since 1.4 57 */ 58 public class Popup { 59 /** 60 * The Component representing the Popup. 61 */ 62 private Component component; 63 64 /** 65 * Creates a {@code Popup} for the Component {@code owner} 66 * containing the Component {@code contents}. {@code owner} 67 * is used to determine which {@code Window} the new 68 * {@code Popup} will parent the {@code Component} the 69 * {@code Popup} creates to. 70 * A null {@code owner} implies there is no valid parent. 71 * {@code x} and 72 * {@code y} specify the preferred initial location to place 73 * the {@code Popup} at. Based on screen size, or other paramaters, 74 * the {@code Popup} may not display at {@code x} and 75 * {@code y}. 76 * 77 * @param owner Component mouse coordinates are relative to, may be null 78 * @param contents Contents of the Popup 79 * @param x Initial x screen coordinate 80 * @param y Initial y screen coordinate 81 * @exception IllegalArgumentException if contents is null 82 */ 83 protected Popup(Component owner, Component contents, int x, int y) { 84 this(); 85 if (contents == null) { 86 throw new IllegalArgumentException("Contents must be non-null"); 87 } 88 reset(owner, contents, x, y); 89 } 90 91 /** 92 * Creates a {@code Popup}. This is provided for subclasses. 93 */ 94 protected Popup() { 95 } 96 97 /** 98 * Makes the {@code Popup} visible. If the {@code Popup} is 99 * currently visible, this has no effect. 100 */ 101 102 @SuppressWarnings("deprecation") 103 public void show() { 104 Component component = getComponent(); 105 106 if (component != null) { 107 component.show(); 108 } 109 } 110 111 /** 112 * Hides and disposes of the {@code Popup}. Once a {@code Popup} 113 * has been disposed you should no longer invoke methods on it. A 114 * {@code dispose}d {@code Popup} may be reclaimed and later used 115 * based on the {@code PopupFactory}. As such, if you invoke methods 116 * on a {@code disposed Popup}, indeterminate 117 * behavior will result. 118 */ 119 120 @SuppressWarnings("deprecation") 121 public void hide() { 122 Component component = getComponent(); 123 124 if (component instanceof JWindow) { 125 component.hide(); 126 ((JWindow)component).getContentPane().removeAll(); 127 } 128 dispose(); 129 } 130 131 /** 132 * Frees any resources the {@code Popup} may be holding onto. 133 */ 134 void dispose() { 135 Component component = getComponent(); 136 Window window = SwingUtilities.getWindowAncestor(component); 137 138 if (component instanceof JWindow) { 139 ((Window)component).dispose(); 140 component = null; 141 } 142 // If our parent is a DefaultFrame, we need to dispose it, too. 143 if (window instanceof DefaultFrame) { 144 window.dispose(); 145 } 146 } 147 148 /** 149 * Resets the {@code Popup} to an initial state. 150 */ 151 void reset(Component owner, Component contents, int ownerX, int ownerY) { 152 if (getComponent() == null) { 153 component = createComponent(owner); 154 } 155 156 Component c = getComponent(); 157 158 if (c instanceof JWindow) { 159 JWindow component = (JWindow)getComponent(); 160 161 component.setLocation(ownerX, ownerY); 162 component.getContentPane().add(contents, BorderLayout.CENTER); 163 component.invalidate(); 164 component.validate(); 165 if(component.isVisible()) { 166 // Do not call pack() if window is not visible to 167 // avoid early native peer creation 168 pack(); 169 } 170 } 171 } 172 173 174 /** 175 * Causes the {@code Popup} to be sized to fit the preferred size 176 * of the {@code Component} it contains. 177 */ 178 void pack() { 179 Component component = getComponent(); 180 181 if (component instanceof Window) { 182 ((Window)component).pack(); 183 } 184 } 185 186 /** 187 * Returns the {@code Window} to use as the parent of the 188 * {@code Window} created for the {@code Popup}. This creates 189 * a new {@code DefaultFrame}, if necessary. 190 */ 191 private Window getParentWindow(Component owner) { 192 Window window = null; 193 194 if (owner instanceof Window) { 195 window = (Window)owner; 196 } 197 else if (owner != null) { 198 window = SwingUtilities.getWindowAncestor(owner); 199 } 200 if (window == null) { 201 window = new DefaultFrame(); 202 } 203 return window; 204 } 205 206 /** 207 * Creates the Component to use as the parent of the {@code Popup}. 208 * The default implementation creates a {@code Window}, subclasses 209 * should override. 210 */ 211 Component createComponent(Component owner) { 212 if (GraphicsEnvironment.isHeadless()) { 213 // Generally not useful, bail. 214 return null; 215 } 216 return new HeavyWeightWindow(getParentWindow(owner)); 217 } 218 219 /** 220 * Returns the {@code Component} returned from 221 * {@code createComponent} that will hold the {@code Popup}. 222 */ 223 Component getComponent() { 224 return component; 225 } 226 227 228 /** 229 * Component used to house window. 230 */ 231 @SuppressWarnings("serial") // Superclass is not serializable across versions 232 static class HeavyWeightWindow extends JWindow implements ModalExclude { 233 HeavyWeightWindow(Window parent) { 234 super(parent); 235 setFocusableWindowState(false); 236 setType(Window.Type.POPUP); 237 238 // Popups are typically transient and most likely won't benefit 239 // from true double buffering. Turn it off here. 240 getRootPane().setUseTrueDoubleBuffering(false); 241 // Try to set "always-on-top" for the popup window. 242 // Applets usually don't have sufficient permissions to do it. 243 // In this case simply ignore the exception. 244 try { 245 setAlwaysOnTop(true); 246 } catch (SecurityException se) { 247 // setAlwaysOnTop is restricted, 248 // the exception is ignored 249 } 250 } 251 252 public void update(Graphics g) { 253 paint(g); 254 } 255 256 @SuppressWarnings("deprecation") 257 public void show() { 258 this.pack(); 259 if (getWidth() > 0 && getHeight() > 0) { 260 super.show(); 261 } 262 } 263 } 264 265 266 /** 267 * Used if no valid Window ancestor of the supplied owner is found. 268 * <p> 269 * PopupFactory uses this as a way to know when the Popup shouldn't 270 * be cached based on the Window. 271 */ 272 @SuppressWarnings("serial") // JDK-implementation class 273 static class DefaultFrame extends Frame { 274 } 275 }