1 /*
2 * Copyright (c) 1999, 2008, 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</code> to the user, typically
35 * on top of all the other <code>Component</code>s in a particular containment
36 * hierarchy. <code>Popup</code>s have a very small life cycle. Once you
37 * have obtained a <code>Popup</code>, and hidden it (invoked the
38 * <code>hide</code> method), you should no longer
39 * invoke any methods on it. This allows the <code>PopupFactory</code> to cache
40 * <code>Popup</code>s for later use.
41 * <p>
42 * The general contract is that if you need to change the size of the
43 * <code>Component</code>, or location of the <code>Popup</code>, you should
44 * obtain a new <code>Popup</code>.
45 * <p>
46 * <code>Popup</code> does not descend from <code>Component</code>, rather
47 * implementations of <code>Popup</code> are responsible for creating
48 * and maintaining their own <code>Component</code>s to render the
49 * requested <code>Component</code> to the user.
50 * <p>
51 * You typically do not explicitly create an instance of <code>Popup</code>,
52 * instead obtain one from a <code>PopupFactory</code>.
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</code> for the Component <code>owner</code>
66 * containing the Component <code>contents</code>. <code>owner</code>
67 * is used to determine which <code>Window</code> the new
68 * <code>Popup</code> will parent the <code>Component</code> the
69 * <code>Popup</code> creates to.
70 * A null <code>owner</code> implies there is no valid parent.
71 * <code>x</code> and
72 * <code>y</code> specify the preferred initial location to place
73 * the <code>Popup</code> at. Based on screen size, or other paramaters,
74 * the <code>Popup</code> may not display at <code>x</code> and
75 * <code>y</code>.
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</code>. This is provided for subclasses.
93 */
94 protected Popup() {
95 }
96
97 /**
98 * Makes the <code>Popup</code> visible. If the <code>Popup</code> is
99 * currently visible, this has no effect.
100 */
101 public void show() {
102 Component component = getComponent();
103
104 if (component != null) {
105 component.show();
106 }
107 }
108
109 /**
110 * Hides and disposes of the <code>Popup</code>. Once a <code>Popup</code>
111 * has been disposed you should no longer invoke methods on it. A
112 * <code>dispose</code>d <code>Popup</code> may be reclaimed and later used
113 * based on the <code>PopupFactory</code>. As such, if you invoke methods
114 * on a <code>disposed</code> <code>Popup</code>, indeterminate
115 * behavior will result.
116 */
117 public void hide() {
118 Component component = getComponent();
119
120 if (component instanceof JWindow) {
121 component.hide();
122 ((JWindow)component).getContentPane().removeAll();
123 }
124 dispose();
125 }
126
127 /**
128 * Frees any resources the <code>Popup</code> may be holding onto.
129 */
130 void dispose() {
131 Component component = getComponent();
132 Window window = SwingUtilities.getWindowAncestor(component);
133
134 if (component instanceof JWindow) {
135 ((Window)component).dispose();
136 component = null;
137 }
138 // If our parent is a DefaultFrame, we need to dispose it, too.
139 if (window instanceof DefaultFrame) {
140 window.dispose();
141 }
142 }
143
144 /**
145 * Resets the <code>Popup</code> to an initial state.
146 */
147 void reset(Component owner, Component contents, int ownerX, int ownerY) {
148 if (getComponent() == null) {
149 component = createComponent(owner);
150 }
151
152 Component c = getComponent();
153
154 if (c instanceof JWindow) {
155 JWindow component = (JWindow)getComponent();
156
157 component.setLocation(ownerX, ownerY);
158 component.getContentPane().add(contents, BorderLayout.CENTER);
159 component.invalidate();
160 component.validate();
161 if(component.isVisible()) {
162 // Do not call pack() if window is not visible to
163 // avoid early native peer creation
164 pack();
165 }
166 }
167 }
168
169
170 /**
171 * Causes the <code>Popup</code> to be sized to fit the preferred size
172 * of the <code>Component</code> it contains.
173 */
174 void pack() {
175 Component component = getComponent();
176
177 if (component instanceof Window) {
178 ((Window)component).pack();
179 }
180 }
181
182 /**
183 * Returns the <code>Window</code> to use as the parent of the
184 * <code>Window</code> created for the <code>Popup</code>. This creates
185 * a new <code>DefaultFrame</code>, if necessary.
186 */
187 private Window getParentWindow(Component owner) {
188 Window window = null;
189
190 if (owner instanceof Window) {
191 window = (Window)owner;
192 }
193 else if (owner != null) {
194 window = SwingUtilities.getWindowAncestor(owner);
195 }
196 if (window == null) {
197 window = new DefaultFrame();
198 }
199 return window;
200 }
201
202 /**
203 * Creates the Component to use as the parent of the <code>Popup</code>.
204 * The default implementation creates a <code>Window</code>, subclasses
205 * should override.
206 */
207 Component createComponent(Component owner) {
208 if (GraphicsEnvironment.isHeadless()) {
209 // Generally not useful, bail.
210 return null;
211 }
212 return new HeavyWeightWindow(getParentWindow(owner));
213 }
214
215 /**
216 * Returns the <code>Component</code> returned from
217 * <code>createComponent</code> that will hold the <code>Popup</code>.
218 */
219 Component getComponent() {
220 return component;
221 }
222
223
224 /**
225 * Component used to house window.
226 */
227 static class HeavyWeightWindow extends JWindow implements ModalExclude {
228 HeavyWeightWindow(Window parent) {
229 super(parent);
230 setFocusableWindowState(false);
231 setType(Window.Type.POPUP);
232
233 // Popups are typically transient and most likely won't benefit
234 // from true double buffering. Turn it off here.
235 getRootPane().setUseTrueDoubleBuffering(false);
236 // Try to set "always-on-top" for the popup window.
237 // Applets usually don't have sufficient permissions to do it.
238 // In this case simply ignore the exception.
239 try {
240 setAlwaysOnTop(true);
241 } catch (SecurityException se) {
242 // setAlwaysOnTop is restricted,
243 // the exception is ignored
244 }
245 }
246
247 public void update(Graphics g) {
248 paint(g);
249 }
250
251 public void show() {
252 this.pack();
253 if (getWidth() > 0 && getHeight() > 0) {
254 super.show();
255 }
256 }
257 }
258
259
260 /**
261 * Used if no valid Window ancestor of the supplied owner is found.
262 * <p>
263 * PopupFactory uses this as a way to know when the Popup shouldn't
264 * be cached based on the Window.
265 */
266 static class DefaultFrame extends Frame {
267 }
268 }