1 /*
2 * Copyright (c) 2011, 2018, 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
27 package sun.lwawt;
28
29 import java.awt.*;
30 import java.awt.event.ItemEvent;
31 import java.awt.event.ItemListener;
32 import java.awt.peer.ChoicePeer;
33
34 import javax.accessibility.Accessible;
35 import javax.swing.*;
36
37 /**
38 * Lightweight implementation of {@link ChoicePeer}. Delegates most of the work
39 * to the {@link JComboBox}.
40 */
41 final class LWChoicePeer extends LWComponentPeer<Choice, JComboBox<String>>
42 implements ChoicePeer, ItemListener {
43
44 /**
45 * According to Choice specification item events are sent in response to
46 * user input, but not in response to calls to select(). But JComboBox are
47 * sent item events in both cases. Should be used under delegateLock.
48 */
49 private boolean skipPostMessage;
50
51 LWChoicePeer(final Choice target,
52 final PlatformComponent platformComponent) {
53 super(target, platformComponent);
54 }
55
56 @Override
57 JComboBox<String> createDelegate() {
58 return new JComboBoxDelegate();
59 }
60
61 @Override
62 void initializeImpl() {
63 super.initializeImpl();
64 final Choice choice = getTarget();
65 final JComboBox<String> combo = getDelegate();
66 synchronized (getDelegateLock()) {
67 final int count = choice.getItemCount();
68 for (int i = 0; i < count; ++i) {
69 combo.addItem(choice.getItem(i));
70 }
71 select(choice.getSelectedIndex());
72
73 // NOTE: the listener must be added at the very end, otherwise it
74 // fires events upon initialization of the combo box.
75 combo.addItemListener(this);
76 }
77 }
78
79 @Override
80 public void itemStateChanged(final ItemEvent e) {
81 // AWT Choice sends SELECTED event only whereas JComboBox
82 // sends both SELECTED and DESELECTED.
83 if (e.getStateChange() == ItemEvent.SELECTED) {
84 synchronized (getDelegateLock()) {
85 if (skipPostMessage) {
86 return;
87 }
88 getTarget().select(getDelegate().getSelectedIndex());
89 }
90 postEvent(new ItemEvent(getTarget(), ItemEvent.ITEM_STATE_CHANGED,
91 e.getItem(), ItemEvent.SELECTED));
92 }
93 }
94
95 @Override
96 public void add(final String item, final int index) {
97 synchronized (getDelegateLock()) {
98 getDelegate().insertItemAt(item, index);
99 }
100 }
101
102 @Override
103 public void remove(final int index) {
104 synchronized (getDelegateLock()) {
105 // We shouldn't post event, if selected item was removed.
106 skipPostMessage = true;
107 getDelegate().removeItemAt(index);
108 skipPostMessage = false;
109 }
110 }
111
112 @Override
113 public void removeAll() {
114 synchronized (getDelegateLock()) {
115 getDelegate().removeAllItems();
116 }
117 }
118
119 @Override
120 public void select(final int index) {
121 synchronized (getDelegateLock()) {
122 if (index != getDelegate().getSelectedIndex()) {
123 skipPostMessage = true;
124 getDelegate().setSelectedIndex(index);
125 skipPostMessage = false;
126 }
127 }
128 }
129
130 @Override
131 public boolean isFocusable() {
132 return true;
133 }
134
135 @SuppressWarnings("serial")// Safe: outer class is non-serializable.
136 private final class JComboBoxDelegate extends JComboBox<String> {
137
138 @Override
139 public boolean hasFocus() {
140 return getTarget().hasFocus();
141 }
142
143 //Needed for proper popup menu location
144 @Override
145 public Point getLocationOnScreen() {
146 return LWChoicePeer.this.getLocationOnScreen();
147 }
148
149 /**
150 * We should post ITEM_STATE_CHANGED event when the same element is
151 * reselected.
152 */
153 @Override
154 public void setSelectedItem(final Object anObject) {
155 final Object oldSelection = selectedItemReminder;
156 if (oldSelection != null && oldSelection.equals(anObject)) {
157 selectedItemChanged();
158 }
159 super.setSelectedItem(anObject);
160 }
161
162 @Override
163 public void firePopupMenuWillBecomeVisible() {
164 super.firePopupMenuWillBecomeVisible();
165 SwingUtilities.invokeLater(() -> {
166 JPopupMenu popupMenu = getPopupMenu();
167 // Need to override the invoker for proper grab handling
168 if (popupMenu != null
169 && popupMenu.isShowing()
170 && popupMenu.getInvoker() != getTarget()) {
171 // The popup is now visible with correct location
172 // Save it and restore after toggling visibility and changing invoker
173 Point loc = popupMenu.getLocationOnScreen();
174 SwingUtilities.convertPointFromScreen(loc, this);
175 popupMenu.setVisible(false);
176 popupMenu.show(getTarget(), loc.x, loc.y);
177 }
178 });
179 }
180
181 private JPopupMenu getPopupMenu() {
182 for (int i = 0; i < getAccessibleContext().getAccessibleChildrenCount(); i++) {
183 Accessible child = getAccessibleContext().getAccessibleChild(i);
184 if (child instanceof JPopupMenu) {
185 return (JPopupMenu) child;
186 }
187 }
188 return null;
189 }
190 }
191 }