1 /*
   2  * Copyright (c) 1997, 2004, 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 package javax.swing;
  26 
  27 import java.awt.*;
  28 
  29 
  30 /**
  31  * This class has been obsoleted by the 1.4 focus APIs. While client code may
  32  * still use this class, developers are strongly encouraged to use
  33  * <code>java.awt.KeyboardFocusManager</code> and
  34  * <code>java.awt.DefaultKeyboardFocusManager</code> instead.
  35  * <p>
  36  * Please see
  37  * <a href="http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
  38  * How to Use the Focus Subsystem</a>,
  39  * a section in <em>The Java Tutorial</em>, and the
  40  * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
  41  * for more information.
  42  *
  43  * @see <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
  44  *
  45  * @author Arnaud Weber
  46  * @author David Mendenhall
  47  */
  48 public abstract class FocusManager extends DefaultKeyboardFocusManager {
  49 
  50     /**
  51      * This field is obsolete, and its use is discouraged since its
  52      * specification is incompatible with the 1.4 focus APIs.
  53      * The current FocusManager is no longer a property of the UI.
  54      * Client code must query for the current FocusManager using
  55      * <code>KeyboardFocusManager.getCurrentKeyboardFocusManager()</code>.
  56      * See the Focus Specification for more information.
  57      *
  58      * @see java.awt.KeyboardFocusManager#getCurrentKeyboardFocusManager
  59      * @see <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
  60      */
  61     public static final String FOCUS_MANAGER_CLASS_PROPERTY =
  62         "FocusManagerClassName";
  63 
  64     private static boolean enabled = true;
  65 
  66     /**
  67      * Returns the current <code>KeyboardFocusManager</code> instance
  68      * for the calling thread's context.
  69      *
  70      * @return this thread's context's <code>KeyboardFocusManager</code>
  71      * @see #setCurrentManager
  72      */
  73     public static FocusManager getCurrentManager() {
  74         KeyboardFocusManager manager =
  75             KeyboardFocusManager.getCurrentKeyboardFocusManager();
  76         if (manager instanceof FocusManager) {
  77             return (FocusManager)manager;
  78         } else {
  79             return new DelegatingDefaultFocusManager(manager);
  80         }
  81     }
  82 
  83     /**
  84      * Sets the current <code>KeyboardFocusManager</code> instance
  85      * for the calling thread's context. If <code>null</code> is
  86      * specified, then the current <code>KeyboardFocusManager</code>
  87      * is replaced with a new instance of
  88      * <code>DefaultKeyboardFocusManager</code>.
  89      * <p>
  90      * If a <code>SecurityManager</code> is installed,
  91      * the calling thread must be granted the <code>AWTPermission</code>
  92      * "replaceKeyboardFocusManager" in order to replace the
  93      * the current <code>KeyboardFocusManager</code>.
  94      * If this permission is not granted,
  95      * this method will throw a <code>SecurityException</code>,
  96      * and the current <code>KeyboardFocusManager</code> will be unchanged.
  97      *
  98      * @param aFocusManager the new <code>KeyboardFocusManager</code>
  99      *     for this thread's context
 100      * @see #getCurrentManager
 101      * @see java.awt.DefaultKeyboardFocusManager
 102      * @throws SecurityException if the calling thread does not have permission
 103      *         to replace the current <code>KeyboardFocusManager</code>
 104      */
 105     public static void setCurrentManager(FocusManager aFocusManager)
 106         throws SecurityException
 107     {
 108         // Note: This method is not backward-compatible with 1.3 and earlier
 109         // releases. It now throws a SecurityException in an applet, whereas
 110         // in previous releases, it did not. This issue was discussed at
 111         // length, and ultimately approved by Hans.
 112         KeyboardFocusManager toSet =
 113             (aFocusManager instanceof DelegatingDefaultFocusManager)
 114                 ? ((DelegatingDefaultFocusManager)aFocusManager).getDelegate()
 115                 : aFocusManager;
 116         KeyboardFocusManager.setCurrentKeyboardFocusManager(toSet);
 117     }
 118 
 119     /**
 120      * Changes the current <code>KeyboardFocusManager</code>'s default
 121      * <code>FocusTraversalPolicy</code> to
 122      * <code>DefaultFocusTraversalPolicy</code>.
 123      *
 124      * @see java.awt.DefaultFocusTraversalPolicy
 125      * @see java.awt.KeyboardFocusManager#setDefaultFocusTraversalPolicy
 126      * @deprecated as of 1.4, replaced by
 127      * <code>KeyboardFocusManager.setDefaultFocusTraversalPolicy(FocusTraversalPolicy)</code>
 128      */
 129     @Deprecated
 130     public static void disableSwingFocusManager() {
 131         if (enabled) {
 132             enabled = false;
 133             KeyboardFocusManager.getCurrentKeyboardFocusManager().
 134                 setDefaultFocusTraversalPolicy(
 135                     new DefaultFocusTraversalPolicy());
 136         }
 137     }
 138 
 139     /**
 140      * Returns whether the application has invoked
 141      * <code>disableSwingFocusManager()</code>.
 142      *
 143      * @see #disableSwingFocusManager
 144      * @deprecated As of 1.4, replaced by
 145      *   <code>KeyboardFocusManager.getDefaultFocusTraversalPolicy()</code>
 146      */
 147     @Deprecated
 148     public static boolean isFocusManagerEnabled() {
 149         return enabled;
 150     }
 151 }