src/share/classes/java/awt/DefaultKeyboardFocusManager.java

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  32 import java.lang.ref.WeakReference;
  33 import java.util.LinkedList;
  34 import java.util.Iterator;
  35 import java.util.ListIterator;
  36 import java.util.Set;
  37 
  38 import sun.util.logging.PlatformLogger;
  39 
  40 import sun.awt.AppContext;
  41 import sun.awt.SunToolkit;
  42 import sun.awt.AWTAccessor;
  43 import sun.awt.CausedFocusEvent;
  44 import sun.awt.TimedWindowEvent;
  45 
  46 /**
  47  * The default KeyboardFocusManager for AWT applications. Focus traversal is
  48  * done in response to a Component's focus traversal keys, and using a
  49  * Container's FocusTraversalPolicy.
  50  * <p>
  51  * Please see
  52  * <a href="http://java.sun.com/docs/books/tutorial/uiswing/misc/focus.html">
  53  * How to Use the Focus Subsystem</a>,
  54  * a section in <em>The Java Tutorial</em>, and the
  55  * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
  56  * for more information.
  57  *
  58  * @author David Mendenhall
  59  *
  60  * @see FocusTraversalPolicy
  61  * @see Component#setFocusTraversalKeys
  62  * @see Component#getFocusTraversalKeys
  63  * @since 1.4
  64  */
  65 public class DefaultKeyboardFocusManager extends KeyboardFocusManager {
  66     private static final PlatformLogger focusLog = PlatformLogger.getLogger("java.awt.focus.DefaultKeyboardFocusManager");
  67 
  68     // null weak references to not create too many objects
  69     private static final WeakReference<Window> NULL_WINDOW_WR =
  70         new WeakReference<Window>(null);
  71     private static final WeakReference<Component> NULL_COMPONENT_WR =
  72         new WeakReference<Component>(null);




  32 import java.lang.ref.WeakReference;
  33 import java.util.LinkedList;
  34 import java.util.Iterator;
  35 import java.util.ListIterator;
  36 import java.util.Set;
  37 
  38 import sun.util.logging.PlatformLogger;
  39 
  40 import sun.awt.AppContext;
  41 import sun.awt.SunToolkit;
  42 import sun.awt.AWTAccessor;
  43 import sun.awt.CausedFocusEvent;
  44 import sun.awt.TimedWindowEvent;
  45 
  46 /**
  47  * The default KeyboardFocusManager for AWT applications. Focus traversal is
  48  * done in response to a Component's focus traversal keys, and using a
  49  * Container's FocusTraversalPolicy.
  50  * <p>
  51  * Please see
  52  * <a href="http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
  53  * How to Use the Focus Subsystem</a>,
  54  * a section in <em>The Java Tutorial</em>, and the
  55  * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
  56  * for more information.
  57  *
  58  * @author David Mendenhall
  59  *
  60  * @see FocusTraversalPolicy
  61  * @see Component#setFocusTraversalKeys
  62  * @see Component#getFocusTraversalKeys
  63  * @since 1.4
  64  */
  65 public class DefaultKeyboardFocusManager extends KeyboardFocusManager {
  66     private static final PlatformLogger focusLog = PlatformLogger.getLogger("java.awt.focus.DefaultKeyboardFocusManager");
  67 
  68     // null weak references to not create too many objects
  69     private static final WeakReference<Window> NULL_WINDOW_WR =
  70         new WeakReference<Window>(null);
  71     private static final WeakReference<Component> NULL_COMPONENT_WR =
  72         new WeakReference<Component>(null);