Index: java/awt/KeyboardFocusManager.java
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/awt/KeyboardFocusManager.java,v
retrieving revision 1.2.24.4
diff -u -r1.2.24.4 KeyboardFocusManager.java
--- java/awt/KeyboardFocusManager.java 24 Aug 2004 22:00:26 -0000 1.2.24.4
+++ java/awt/KeyboardFocusManager.java 23 Sep 2004 07:34:07 -0000
@@ -55,20 +55,64 @@
import java.util.Map;
import java.util.Set;
-// FIXME: finish documentation
-
/**
- *
- * FIXME: discuss applet contexts and thread groups and codebases
- * being insulated.
- *
- * FIXME: discuss where default focus traversal key sets apply
- * (inherited by child Components etc.)
+ * The KeyboardFocusManager handles the focusing of
+ * windows for receiving keyboard events. The manager handles
+ * the dispatch of all FocusEvents and
+ * KeyEvents, along with WindowEvents
+ * relating to the focused window. Users can use the manager
+ * to ascertain the current focus owner and fire events.
+ *
+ *
+ * The focus owner is the Component that receives
+ * key events. The focus owner is either the currently focused
+ * window or a component within this window.
+ *
+ *
+ * The underlying native windowing system may denote the active
+ * window or its children with special decorations (e.g. a highlighted
+ * title bar). The active window is always either a Frame
+ * or Dialog, and is either the currently focused
+ * window or its owner.
+ *
+ *
+ * Applets may be partitioned into different applet contexts, according
+ * to their code base. In this case, each context has its own
+ * KeyboardFocusManager, as opposed to the global
+ * manager maintained by applets which share the same context.
+ * Each context is insulated from the others, and they don't interact.
+ * The resulting behaviour, as with context division, depends on the browser
+ * supporting the applets. Regardless, there can only ever be
+ * one focused window, one active window and one focus owner
+ * per ClassLoader.
+ *
+ *
+ * To support this separation of focus managers, the manager instances
+ * and the internal state information is grouped by the
+ * ThreadGroup to which it pertains. With respect to
+ * applets, each code base has its own ThreadGroup, so the
+ * isolation of each context is enforced within the manager.
+ *
+ *
+ * By default, the manager defines TAB and Ctrl+TAB as the
+ * forward focus traversal keys and Shift+TAB and Ctrl+Shift+TAB
+ * as the backward focus traversal keys. No up or down cycle
+ * traversal keys are defined by default. Traversal takes effect
+ * on the firing of a relevant KEY_PRESSED event.
+ * However, all other key events related to the use of the
+ * defined focus traversal key sequence are consumed and not
+ * dispatched.
+ *
+ *
+ * These default traversal keys come into effect on all windows
+ * for which no alternative set of keys is defined. This also
+ * applies recursively to any child components of such a window,
+ * which define no traversal keys of their own.
*
* @author Eric Blake
* @author Thomas Fitzsimmons
+ * @author Andrew John Hughes
* @since 1.4
- * @status partially updated to 1.4, needs documentation.
*/
public abstract class KeyboardFocusManager
implements KeyEventDispatcher, KeyEventPostProcessor
@@ -182,7 +226,14 @@
Collections.EMPTY_SET, Collections.EMPTY_SET
};
+ /**
+ * A utility class to support the handling of events relating to property changes.
+ */
private final PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport (this);
+
+ /**
+ * A utility class to support the handling of events relating to vetoable changes.
+ */
private final VetoableChangeSupport vetoableChangeSupport = new VetoableChangeSupport (this);
/** A list of {@link KeyEventDispatcher}s that process {@link
@@ -623,29 +674,99 @@
setGlobalObject (currentFocusCycleRoots, cycleRoot, "currentFocusCycleRoot");
}
+ /**
+ * Registers the supplied property change listener for receiving
+ * events caused by the following property changes:
+ *
+ *
+ * - the current focus owner ("focusOwner")
+ * - the permanent focus owner ("permanentFocusOwner")
+ * - the focused window ("focusedWindow")
+ * - the active window ("activeWindow")
+ * - the default focus traversal policy ("defaultFocusTraversalPolicy")
+ * - the default set of forward traversal keys ("forwardDefaultFocusTraversalKeys")
+ * - the default set of backward traversal keys ("backwardDefaultFocusTraversalKeys")
+ * - the default set of up cycle traversal keys ("upCycleDefaultFocusTraversalKeys")
+ * - the default set of down cycle traversal keys ("downCycleDefaultFocusTraversalKeys")
+ * - the current focus cycle root ("currentFocusCycleRoot")
+ *
+ *
+ * If the supplied listener is null, nothing occurs.
+ *
+ * @param l the new listener to register.
+ * @see KeyboardFocusManager#addPropertyChangeListener(String, java.beans.PropertyChangeListener)
+ */
public void addPropertyChangeListener(PropertyChangeListener l)
{
if (l != null)
propertyChangeSupport.addPropertyChangeListener(l);
}
+ /**
+ * Removes the supplied property change listener from the list
+ * of registered listeners. If the supplied listener is null,
+ * nothing occurs.
+ *
+ * @param l the listener to remove.
+ */
public void removePropertyChangeListener(PropertyChangeListener l)
{
if (l != null)
propertyChangeSupport.removePropertyChangeListener(l);
}
+ /**
+ * Returns the currently registered property change listeners
+ * in array form. The returned array is empty if no listeners are
+ * currently registered.
+ *
+ * @return an array of registered property change listeners.
+ */
public PropertyChangeListener[] getPropertyChangeListeners()
{
return propertyChangeSupport.getPropertyChangeListeners();
}
+ /**
+ * Registers a property change listener for receiving events relating
+ * to a change to a specified property. The supplied property name can be
+ * either user-defined or one from the following list of properties
+ * relevant to this class:
+ *
+ *
+ * - the current focus owner ("focusOwner")
+ * - the permanent focus owner ("permanentFocusOwner")
+ * - the focused window ("focusedWindow")
+ * - the active window ("activeWindow")
+ * - the default focus traversal policy ("defaultFocusTraversalPolicy")
+ * - the default set of forward traversal keys ("forwardDefaultFocusTraversalKeys")
+ * - the default set of backward traversal keys ("backwardDefaultFocusTraversalKeys")
+ * - the default set of up cycle traversal keys ("upCycleDefaultFocusTraversalKeys")
+ * - the default set of down cycle traversal keys ("downCycleDefaultFocusTraversalKeys")
+ * - the current focus cycle root ("currentFocusCycleRoot")
+ *
+ *
+ * Nothing occurs if a null listener is supplied. null is regarded as a valid property name.
+ *
+ * @param name the name of the property to handle change events for.
+ * @param l the listener to register for changes to the specified property.
+ * @see KeyboardFocusManager#addPropertyChangeListener(java.beans.PropertyChangeListener)
+ */
public void addPropertyChangeListener(String name, PropertyChangeListener l)
{
if (l != null)
propertyChangeSupport.addPropertyChangeListener(name, l);
}
+ /**
+ * Removes the supplied property change listener registered for the
+ * specified property from the list of registered listeners. If the
+ * supplied listener is null, nothing occurs.
+ *
+ * @param name the name of the property the listener is
+ * monitoring changes to.
+ * @param l the listener to remove.
+ */
public void removePropertyChangeListener(String name,
PropertyChangeListener l)
{
@@ -653,39 +774,117 @@
propertyChangeSupport.removePropertyChangeListener(name, l);
}
+ /**
+ * Returns the currently registered property change listeners
+ * in array form, which listen for changes to the supplied property.
+ * The returned array is empty, if no listeners are currently registered
+ * for events pertaining to the supplied property.
+ *
+ * @param name The property the returned listeners monitor for changes.
+ * @return an array of registered property change listeners which
+ * listen for changes to the supplied property.
+ */
public PropertyChangeListener[] getPropertyChangeListeners(String name)
{
return propertyChangeSupport.getPropertyChangeListeners(name);
}
+ /**
+ * Fires a property change event as a response to a change to
+ * to the specified property. The event is only fired if a
+ * change has actually occurred (i.e. o and n are different).
+ *
+ * @param name The name of the property to which a change occurred.
+ * @param o The old value of the property.
+ * @param n The new value of the property.
+ */
protected void firePropertyChange(String name, Object o, Object n)
{
propertyChangeSupport.firePropertyChange(name, o, n);
}
+ /**
+ * Registers a vetoable property change listener for receiving events
+ * relating to the following properties:
+ *
+ *
+ * - the current focus owner ("focusOwner")
+ * - the permanent focus owner ("permanentFocusOwner")
+ * - the focused window ("focusedWindow")
+ * - the active window ("activeWindow")
+ *
+ *
+ * Nothing occurs if a null listener is supplied.
+ *
+ * @param l the listener to register.
+ * @see KeyboardFocusManager#addVetoableChangeListener(String, java.beans.VetoableChangeListener)
+ */
public void addVetoableChangeListener(VetoableChangeListener l)
{
if (l != null)
vetoableChangeSupport.addVetoableChangeListener(l);
}
+ /**
+ * Removes the supplied vetoable property change listener from
+ * the list of registered listeners. If the supplied listener
+ * is null, nothing occurs.
+ *
+ * @param l the listener to remove.
+ */
public void removeVetoableChangeListener(VetoableChangeListener l)
{
if (l != null)
vetoableChangeSupport.removeVetoableChangeListener(l);
}
+ /**
+ * Returns the currently registered vetoable property change listeners
+ * in array form. The returned array is empty if no listeners are
+ * currently registered.
+ *
+ * @return an array of registered vetoable property change listeners.
+ * @since 1.4
+ */
public VetoableChangeListener[] getVetoableChangeListeners()
{
return vetoableChangeSupport.getVetoableChangeListeners();
}
+ /**
+ * Registers a vetoable property change listener for receiving events relating
+ * to a vetoable change to a specified property. The supplied property name can be
+ * either user-defined or one from the following list of properties
+ * relevant to this class:
+ *
+ *
+ * - the current focus owner ("focusOwner")
+ * - the permanent focus owner ("permanentFocusOwner")
+ * - the focused window ("focusedWindow")
+ * - the active window ("activeWindow")
+ *
+ *
+ * Nothing occurs if a null listener is supplied. null is regarded as a valid property name.
+ *
+ * @param name the name of the property to handle change events for.
+ * @param l the listener to register for changes to the specified property.
+ * @see KeyboardFocusManager#addVetoableChangeListener(java.beans.VetoableChangeListener)
+ */
public void addVetoableChangeListener(String name, VetoableChangeListener l)
{
if (l != null)
vetoableChangeSupport.addVetoableChangeListener(name, l);
}
+ /**
+ * Removes the supplied vetoable property change listener registered
+ * for the specified property from the list of registered listeners.
+ * If the supplied listener is null, nothing occurs.
+ *
+ * @param name the name of the vetoable property the listener is
+ * monitoring changes to.
+ * @param l the listener to remove.
+ */
public void removeVetoableChangeListener(String name,
VetoableChangeListener l)
{
@@ -693,51 +892,210 @@
vetoableChangeSupport.removeVetoableChangeListener(name, l);
}
+ /**
+ * Returns the currently registered vetoable property change listeners
+ * in array form, which listen for changes to the supplied property.
+ * The returned array is empty, if no listeners are currently registered
+ * for events pertaining to the supplied property.
+ *
+ * @param name The property the returned listeners monitor for changes.
+ * @return an array of registered property change listeners which
+ * listen for changes to the supplied property.
+ * @since 1.4
+ */
public VetoableChangeListener[] getVetoableChangeListeners(String name)
{
return vetoableChangeSupport.getVetoableChangeListeners(name);
}
+ /**
+ * Fires a property change event as a response to a vetoable change to
+ * to the specified property. The event is only fired if a
+ * change has actually occurred (i.e. o and n are different).
+ * In the event that the property change is vetoed, the following
+ * occurs:
+ *
+ *
+ * -
+ * This method throws a
PropertyVetoException to
+ * the proposed change.
+ *
+ * -
+ * A new event is fired to reverse the previous change.
+ *
+ * -
+ * This method again throws a
PropertyVetoException
+ * in response to the reversion.
+ *
+ *
+ *
+ * @param name The name of the property to which a change occurred.
+ * @param o The old value of the property.
+ * @param n The new value of the property.
+ * @throws PropertyVetoException if one of the listeners vetos
+ * the change by throwing this exception.
+ */
protected void fireVetoableChange(String name, Object o, Object n)
throws PropertyVetoException
{
vetoableChangeSupport.fireVetoableChange(name, o, n);
}
+ /**
+ * Adds a key event dispatcher to the list of registered dispatchers.
+ * When a key event is fired, each dispatcher's dispatchKeyEvent
+ * method is called in the order that they were added, prior to the manager
+ * dispatching the event itself. Notifications halt when one of the
+ * dispatchers returns true.
+ *
+ *
+ * The same dispatcher can exist multiple times within the list
+ * of registered dispatchers, and there is no limit on the length
+ * of this list. A null dispatcher is simply ignored.
+ *
+ * @param dispatcher The dispatcher to register.
+ */
public void addKeyEventDispatcher(KeyEventDispatcher dispatcher)
{
if (dispatcher != null)
keyEventDispatchers.add(dispatcher);
}
+ /**
+ * Removes the specified key event dispatcher from the list of
+ * registered dispatchers. The manager always dispatches events,
+ * regardless of its existence within the list. The manager
+ * can be added and removed from the list, as with any other
+ * dispatcher, but this does not affect its ability to dispatch
+ * key events. Non-existent and null dispatchers are simply ignored
+ * by this method.
+ *
+ * @param dispatcher The dispatcher to remove.
+ */
public void removeKeyEventDispatcher(KeyEventDispatcher dispatcher)
{
keyEventDispatchers.remove(dispatcher);
}
+ /**
+ * Returns the currently registered key event dispatchers in List
+ * form. At present, this only includes dispatchers explicitly registered
+ * via the addKeyEventDispatcher() method, but this behaviour
+ * is subject to change and should not be depended on. The manager itself
+ * may be a member of the list, but only if explicitly registered. If no
+ * dispatchers have been registered, the list will be empty.
+ *
+ * @return A list of explicitly registered key event dispatchers.
+ * @see KeyboardFocusManager#addKeyEventDispatcher(java.awt.KeyEventDispatcher)
+ */
protected List getKeyEventDispatchers ()
{
return (List) keyEventDispatchers.clone ();
}
+ /**
+ * Adds a key event post processor to the list of registered post processors.
+ * Post processors work in the same way as key event dispatchers, except
+ * that they are invoked after the manager has dispatched the key event,
+ * and not prior to this. Each post processor's postProcessKeyEvent
+ * method is called to see if any post processing needs to be performed. THe
+ * processors are called in the order in which they were added to the list,
+ * and notifications continue until one returns true. As with key event
+ * dispatchers, the manager is implicitly called following this process,
+ * regardless of whether or not it is present within the list.
+ *
+ *
+ * The same post processor can exist multiple times within the list
+ * of registered post processors, and there is no limit on the length
+ * of this list. A null post processor is simply ignored.
+ *
+ * @param postProcessor the post processor to register.
+ * @see KeyboardFocusManager#addKeyEventDispatcher(java.awt.KeyEventDispatcher)
+ */
public void addKeyEventPostProcessor (KeyEventPostProcessor postProcessor)
{
if (postProcessor != null)
keyEventPostProcessors.add (postProcessor);
}
+ /**
+ * Removes the specified key event post processor from the list of
+ * registered post processors. The manager always post processes events,
+ * regardless of its existence within the list. The manager
+ * can be added and removed from the list, as with any other
+ * post processor, but this does not affect its ability to post process
+ * key events. Non-existent and null post processors are simply ignored
+ * by this method.
+ *
+ * @param postProcessor the post processor to remove.
+ */
public void removeKeyEventPostProcessor (KeyEventPostProcessor postProcessor)
{
keyEventPostProcessors.remove (postProcessor);
}
+ /**
+ * Returns the currently registered key event post processors in List
+ * form. At present, this only includes post processors explicitly registered
+ * via the addKeyEventPostProcessor() method, but this behaviour
+ * is subject to change and should not be depended on. The manager itself
+ * may be a member of the list, but only if explicitly registered. If no
+ * post processors have been registered, the list will be empty.
+ *
+ * @return A list of explicitly registered key event post processors.
+ * @see KeyboardFocusManager#addKeyEventPostProcessor(java.awt.KeyEventPostProcessor)
+ */
protected List getKeyEventPostProcessors ()
{
return (List) keyEventPostProcessors.clone ();
}
+ /**
+ * The AWT event dispatcher uses this method to request that the manager
+ * handle a particular event. If the manager fails or refuses to
+ * dispatch the supplied event (this method returns false), the
+ * AWT event dispatcher will try to dispatch the event itself.
+ *
+ *
+ * The manager is expected to handle all FocusEvents
+ * and KeyEvents, and WindowEvents
+ * relating to the focus. Dispatch is done with regard to the
+ * the focus owner and the currently focused and active windows.
+ * In handling the event, the source of the event may be overridden.
+ *
+ *
+ * The actual dispatching is performed by calling
+ * redispatchEvent(). This avoids the infinite recursion
+ * of dispatch requests which may occur if this method is called on
+ * the target component.
+ *
+ * @param e the event to dispatch.
+ * @return true if the event was dispatched.
+ * @see KeyboardFocusManager#redispatchEvent(java.awt.Component, java.awt.AWTEvent)
+ * @see KeyEvent
+ * @see FocusEvent
+ * @see WindowEvent
+ */
public abstract boolean dispatchEvent (AWTEvent e);
+ /**
+ * Handles redispatching of an event so that recursion of
+ * dispatch requests does not occur. Event dispatch methods
+ * within this manager (dispatchEvent()) and
+ * the key event dispatchers should use this method to handle
+ * dispatching rather than the dispatch method of the target
+ * component.
+ *
+ *
+ *
+ * This method is not intended for general consumption, and is
+ * only for the use of the aforementioned classes.
+ *
+ *
+ * @param target the target component to which the event is
+ * dispatched.
+ * @param e the event to dispatch.
+ */
public final void redispatchEvent (Component target, AWTEvent e)
{
synchronized (e)
@@ -747,42 +1105,203 @@
}
}
+ /**
+ * Attempts to dispatch key events for which no key event dispatcher
+ * has so far succeeded. This method is usually called by
+ * dispatchEvent() following the sending of the key
+ * event to any registered key event dispatchers. If the key
+ * event reaches this stage, none of the dispatchers returned
+ * true. This is, of course, always the case if there are no
+ * registered dispatchers.
+ *
+ *
+ * If this method also fails to handle the key event, then
+ * false is returned to the caller. In the case of
+ * dispatchEvent(), the calling method may try
+ * to handle the event itself or simply forward on the
+ * false result to its caller. When the event is dispatched
+ * by this method, a true result is propogated through the
+ * calling methods.
+ *
+ * @param e the key event to dispatch.
+ * @return true if the event was dispatched successfully.
+ */
public abstract boolean dispatchKeyEvent (KeyEvent e);
+ /**
+ * Handles the post processing of key events. By default,
+ * this method will map unhandled key events to appropriate
+ * MenuShortcuts. The event is consumed
+ * in the process and the shortcut is activated. This
+ * method is usually called by dispatchKeyEvent.
+ *
+ * @param e the key event to post process.
+ * @return true by default, as the event was handled.
+ */
public abstract boolean postProcessKeyEvent (KeyEvent e);
+ /**
+ * Handles focus traversal operations for key events which
+ * represent focus traversal keys in relation to the supplied
+ * component. The supplied component is assumed to have the
+ * focus, whether it does so or not, and the operation is
+ * carried out as appropriate, with this in mind.
+ *
+ * @param focused the component on which to perform focus traversal,
+ * on the assumption that this component has the focus.
+ * @param e the possible focus traversal key event.
+ */
public abstract void processKeyEvent (Component focused, KeyEvent e);
+ /**
+ * Delays all key events following the specified timestamp until the
+ * supplied component has focus. The AWT calls this method when it is
+ * determined that a focus change may occur within the native windowing
+ * system. Any key events which occur following the time specified by
+ * after are delayed until a FOCUS_GAINED event is received
+ * for the untilFocused component. The manager is responsible for ensuring
+ * this takes place.
+ *
+ * @param after the timestamp beyond which all key events are delayed until
+ * the supplied component gains focus.
+ * @param untilFocused the component to wait on gaining focus.
+ */
protected abstract void enqueueKeyEvents (long after, Component untilFocused);
+ /**
+ * Removes the key event block specified by the supplied timestamp and component.
+ * All delayed key events are released for normal dispatching following its
+ * removal and subsequent key events that would have been blocked are now
+ * immediately dispatched. If the specified timestamp is below 0, then
+ * the request with the oldest timestamp is removed.
+ *
+ * @param after the timestamp of the key event block to be removed, or a
+ * value smaller than 0 if the oldest is to be removed.
+ * @param untilFocused the component of the key event block to be removed.
+ */
protected abstract void dequeueKeyEvents (long after, Component untilFocused);
+ /**
+ * Discards all key event blocks relating to focus requirements for
+ * the supplied component, regardless of timestamp.
+ *
+ * @param comp the component of the key event block(s) to be removed.
+ */
protected abstract void discardKeyEvents (Component comp);
- public abstract void focusNextComponent (Component comp);
-
- public abstract void focusPreviousComponent (Component comp);
-
- public abstract void upFocusCycle (Component comp);
-
- public abstract void downFocusCycle (Container cont);
+ /**
+ * Moves the current focus to the next component following
+ * comp, based on the current focus traversal policy. By
+ * default, only visible, displayable, accepted components
+ * can receive focus. Canvases, Panels,
+ * Labels, ScrollPanes, Scrollbars,
+ * Windows and lightweight components are judged
+ * to be unacceptable by default. See the
+ * DefaultFocusTraversalPolicy for more details.
+ *
+ * @param comp the component prior to the one which will
+ * become the focus, following execution of this method.
+ * @see DefaultFocusTraversalPolicy
+ */
+ public abstract void focusNextComponent(Component comp);
+
+ /**
+ * Moves the current focus to the previous component, prior to
+ * comp, based on the current focus traversal policy. By
+ * default, only visible, displayable, accepted components
+ * can receive focus. Canvases, Panels,
+ * Labels, ScrollPanes, Scrollbars,
+ * Windows and lightweight components are judged
+ * to be unacceptable by default. See the
+ * DefaultFocusTraversalPolicy for more details.
+ *
+ * @param comp the component following the one which will
+ * become the focus, following execution of this method.
+ * @see DefaultFocusTraversalPolicy
+ */
+ public abstract void focusPreviousComponent(Component comp);
+
+ /**
+ * Moves the current focus upwards by one focus cycle.
+ * Both the current focus owner and current focus cycle root
+ * become the focus cycle root of the supplied component.
+ * However, in the case of a Window, the default
+ * focus component becomes the focus owner and the focus cycle
+ * root is not changed.
+ *
+ * @param comp the component used as part of the focus traversal.
+ */
+ public abstract void upFocusCycle(Component comp);
- public final void focusNextComponent ()
+ /**
+ * Moves the current focus downwards by one focus cycle.
+ * If the supplied container is a focus cycle root, then this
+ * becomes the current focus cycle root and the focus goes
+ * to the default component of the specified container.
+ * Nothing happens for non-focus cycle root containers.
+ *
+ * @param comp the component used as part of the focus traversal.
+ */
+ public abstract void downFocusCycle(Container cont);
+
+ /**
+ * Moves the current focus to the next component, based on the
+ * current focus traversal policy. By default, only visible,
+ * displayable, accepted component can receive focus.
+ * Canvases, Panels,
+ * Labels, ScrollPanes, Scrollbars,
+ * Windows and lightweight components are judged
+ * to be unacceptable by default. See the
+ * DefaultFocusTraversalPolicy for more details.
+ *
+ * @see DefaultFocusTraversalPolicy
+ */
+ public final void focusNextComponent()
{
focusNextComponent (null);
}
- public final void focusPreviousComponent ()
+ /**
+ * Moves the current focus to the previous component, based on the
+ * current focus traversal policy. By default, only visible,
+ * displayable, accepted component can receive focus.
+ * Canvases, Panels,
+ * Labels, ScrollPanes, Scrollbars,
+ * Windows and lightweight components are judged
+ * to be unacceptable by default. See the
+ * DefaultFocusTraversalPolicy for more details.
+ *
+ * @see DefaultFocusTraversalPolicy
+ */
+ public final void focusPreviousComponent()
{
focusPreviousComponent (null);
}
- public final void upFocusCycle ()
+ /**
+ * Moves the current focus upwards by one focus cycle,
+ * so that the new focus owner is the focus cycle root
+ * of the current owner. The current focus cycle root then
+ * becomes the focus cycle root of the new focus owner.
+ * However, in the case of the focus cycle root of the
+ * current focus owner being a Window, the default
+ * component of this window becomes the focus owner and the
+ * focus cycle root is not changed.
+ */
+ public final void upFocusCycle()
{
upFocusCycle (null);
}
- public final void downFocusCycle ()
+ /**
+ * Moves the current focus downwards by one focus cycle,
+ * iff the current focus cycle root is a Container.
+ * Usually, the new focus owner is set to the default component
+ * of the container and the current focus cycle root is set
+ * to the current focus owner. Nothing occurs if the current
+ * focus cycle root is not a container.
+ */
+ public final void downFocusCycle()
{
Component focusOwner = getGlobalFocusOwner ();
if (focusOwner instanceof Container