1 /*
2 * Copyright 2010 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25 package java.awt;
26
27 import java.awt.peer.*;
28 import java.io.IOException;
29 import java.io.ObjectInputStream;
30 import sun.awt.AWTAccessor;
31
32 /**
33 * The <code>DirectoryDialog</code> class displays a dialog window from which
34 * the user can select a directory.
35 * <p>
36 * It is a modal dialog, that blocks the rest of the application until the user
37 * has chosen a file.
38 * </p>
39 *
40 * @author Costantino Cerbo (c.cerbo@gmail.com)
41 * @since 1.7
42 */
43 public class DirectoryDialog extends Dialog {
44
45 static {
46 AWTAccessor
47 .setDirectoryDialogAccessor(new AWTAccessor.DirectoryDialogAccessor() {
48
49 public void setDirectory(DirectoryDialog directoryDialog,
50 String directory) {
51 directoryDialog.dir = ("".equals(directory)) ? null
52 : directory;
53 }
54 });
55 }
56
57 static {
58 /* ensure that the necessary native libraries are loaded */
59 Toolkit.loadLibraries();
60 GraphicsEnvironment.isHeadless();
61 }
62 /*
63 * The string specifying the directory to display in the file dialog. This
64 * variable may be <code>null</code>.
65 *
66 * @serial
67 *
68 * @see getDirectory()
69 *
70 * @see setDirectory()
71 */
72 private String dir;
73
74 /**
75 * Creates a dialog for selecting a directory. The title of the file dialog
76 * is initially empty.
77 *
78 * @param parent
79 * the owner of the dialog
80 * @since 1.7
81 */
82 public DirectoryDialog(Frame parent) {
83 super(parent, true);
84 }
85
86 /**
87 * Creates a dialog for selecting a directory.
88 *
89 * @param parent
90 * the owner of the dialog
91 * @param title
92 * the title of the dialog
93 * @since 1.7
94 */
95 public DirectoryDialog(Frame parent, String title) {
96 super(parent, title, true);
97 }
98
99 /**
100 * Creates a dialog for selecting a directory. The title of the file dialog
101 * is initially empty.
102 *
103 * @param parent
104 * the owner of the dialog
105 * @since 1.7
106 */
107 public DirectoryDialog(Dialog parent) {
108 super(parent, "", true);
109 }
110
111 /**
112 * Creates a dialog for selecting a directory.
113 *
114 * @param parent
115 * the owner of the dialog
116 * @param title
117 * the title of the dialog
118 * @since 1.7
119 */
120 public DirectoryDialog(Dialog parent, String title) {
121 super(parent, title, true);
122 }
123
124 /**
125 * Gets the directory of this file dialog.
126 *
127 * @return the (potentially <code>null</code> or invalid) directory of this
128 * <code>FileDialog</code>
129 * @see java.awt.FileDialog#setDirectory
130 */
131 public String getDirectory() {
132 return dir;
133 }
134
135 /**
136 * Sets the directory of this file dialog window to be the specified
137 * directory. Specifying a <code>null</code> or an invalid directory implies
138 * an implementation-defined default. This default will not be realized,
139 * however, until the user has selected a file. Until this point,
140 * <code>getDirectory()</code> will return the value passed into this
141 * method.
142 * <p>
143 * Specifying "" as the directory is exactly equivalent to specifying
144 * <code>null</code> as the directory.
145 *
146 * @param dir
147 * the specified directory
148 * @see java.awt.DirectoryDialog#getDirectory
149 */
150 public void setDirectory(String dir) {
151 this.dir = (dir != null && dir.equals("")) ? null : dir;
152 if (peer != null) {
153 ((DirectoryDialogPeer) this.peer).setDirectory(this.dir);
154 }
155 }
156
157 /**
158 * Creates the file dialog's peer. The peer allows us to change the look of
159 * the file dialog without changing its functionality.
160 */
161 @Override
162 public void addNotify() {
163 synchronized (getTreeLock()) {
164 if (parent != null && parent.getPeer() == null) {
165 parent.addNotify();
166 }
167 if (peer == null) {
168 peer = getToolkit().createDirectoryDialog(this);
169 }
170 super.addNotify();
171 }
172 }
173
174 /**
175 * Returns a string representing the state of this <code>FileDialog</code>
176 * window. This method is intended to be used only for debugging purposes,
177 * and the content and format of the returned string may vary between
178 * implementations. The returned string may be empty but may not be
179 * <code>null</code>.
180 *
181 * @return the parameter string of this file dialog window
182 */
183 @Override
184 protected String paramString() {
185 String str = super.paramString();
186 str += ",dir= " + dir;
187 return str;
188 }
189
190 /**
191 * Reads the <code>ObjectInputStream</code> and performs a backwards
192 * compatibility check by converting either a <code>dir</code> or a
193 * <code>file</code> equal to an empty string to <code>null</code>.
194 *
195 * @param s
196 * the <code>ObjectInputStream</code> to read
197 */
198 private void readObject(ObjectInputStream s) throws ClassNotFoundException,
199 IOException {
200 s.defaultReadObject();
201 }
202 }