Returns an array of all the container listeners registered on this container.

Gets the cursor set in the component. If the component does not have a cursor set, the cursor of its parent is returned. If no cursor is set in the entire hierarchy, Cursor.DEFAULT_CURSOR is returned.

Gets the URL of the document in which this applet is embedded. For example, suppose an applet is contained within the document:

    http://java.sun.com/products/jdk/1.2/index.html
 

The document base is:

    http://java.sun.com/products/jdk/1.2/index.html
 

Gets the DropTarget associated with this Component.

Returns the Container which is the focus cycle root of this Component's focus traversal cycle. Each focus traversal cycle has only a single focus cycle root and each Component which is not a Container belongs to only a single focus traversal cycle. Containers which are focus cycle roots belong to two cycles: one rooted at the Container itself, and one rooted at the Container's nearest focus-cycle-root ancestor. For such Containers, this method will return the Container's nearest focus-cycle- root ancestor.

Returns an array of all the focus listeners registered on this component.

Returns the Set of focus traversal keys for a given traversal operation for this Container. (See setFocusTraversalKeys for a full description of each key.)

If a Set of traversal keys has not been explicitly defined for this Container, then this Container's parent's Set is returned. If no Set has been explicitly defined for any of this Container's ancestors, then the current KeyboardFocusManager's default Set is returned.

Returns whether focus traversal keys are enabled for this Component. Components for which focus traversal keys are disabled receive key events for focus traversal keys. Components for which focus traversal keys are enabled do not see these events; instead, the events are automatically converted to traversal operations.

Returns the focus traversal policy that will manage keyboard traversal of this Container's children, or null if this Container is not a focus cycle root. If no traversal policy has been explicitly set for this Container, then this Container's focus-cycle-root ancestor's policy is returned.

Gets the font of this component.

Gets the font metrics for the specified font.

Gets the foreground color of this component.

Creates a graphics context for this component. This method will return null if this component is currently not displayable.

Gets the GraphicsConfiguration associated with this Component. If the Component has not been assigned a specific GraphicsConfiguration, the GraphicsConfiguration of the Component object's top-level container is returned. If the Component has been created, but not yet added to a Container, this method returns null.

Returns the current height of this component. This method is preferable to writing component.getBounds().heightcomponent.getSize().height because it doesn't cause any heap allocations.

Returns an array of all the hierarchy bounds listeners registered on this component.

Returns an array of all the hierarchy listeners registered on this component.

Returns an Image object that can then be painted on the screen. The url that is passed as an argument must specify an absolute URL.

This method always returns immediately, whether or not the image exists. When this applet attempts to draw the image on the screen, the data will be loaded. The graphics primitives that draw the image will incrementally paint on the screen.

Returns an Image object that can then be painted on the screen. The url argument must specify an absolute URL. The name argument is a specifier that is relative to the url argument.

This method always returns immediately, whether or not the image exists. When this applet attempts to draw the image on the screen, the data will be loaded. The graphics primitives that draw the image will incrementally paint on the screen.

Gets the input context used by this component for handling the communication with input methods when text is entered in this component. By default, the input context used for the parent component is returned. Components may override this to return a private input context.

Returns an array of all the input method listeners registered on this component.

Gets the input method request handler which supports requests from input methods for this component. A component that supports on-the-spot text input must override this method to return an InputMethodRequests instance. At the same time, it also has to handle input method events.

Determines the insets of this container, which indicate the size of the container's border.

A Frame object, for example, has a top inset that corresponds to the height of the frame's title bar.

Returns an array of all the key listeners registered on this component.

Gets the layout manager for this container.

Returns an array of all the objects currently registered as FooListeners upon this Container. FooListeners are registered using the addFooListener method.

You can specify the listenerType argument with a class literal, such as FooListener.class. For example, you can query a Container c for its container listeners with the following code:

ContainerListener[] cls = (ContainerListener[])(c.getListeners(ContainerListener.class));

If no such listeners exist, this method returns an empty array.

Gets the Locale for the applet, if it has been set. If no Locale has been set, then the default Locale is returned.

Gets the location of this component in the form of a point specifying the component's top-left corner. The location will be relative to the parent's coordinate space.

Due to the asynchronous nature of native event handling, this method can return outdated values (for instance, after several calls of setLocation() in rapid succession). For this reason, the recommended method of obtaining a component's position is within java.awt.event.ComponentListener.componentMoved(), which is called after the operating system has finished moving the component.

Stores the x,y origin of this component into "return value" rv and return rv. If rv is null a new Point is allocated. This version of getLocation is useful if the caller wants to avoid allocating a new Point object on the heap.

Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.

Returns the maximum size of this container.

Returns the minimum size of this container.

Returns an array of all the mouse listeners registered on this component.

Returns an array of all the mouse motion listeners registered on this component.

Returns the position of the mouse pointer in this Component's coordinate space if the Component is directly under the mouse pointer, otherwise returns null. If the Component is not showing on the screen, this method returns null even if the mouse pointer is above the area where the Component would be displayed. If the Component is partially or fully obscured by other Components or native windows, this method returns a non-null value only if the mouse pointer is located above the unobscured part of the Component.

For Containers it returns a non-null value if the mouse is above the Container itself or above any of its descendants. Use if you need to exclude children.

Sometimes the exact mouse coordinates are not important, and the only thing that matters is whether a specific Component is under the mouse pointer. If the return value of this method is null, mouse pointer is not directly above the Component.

Returns the position of the mouse pointer in this Container's coordinate space if the Container is under the mouse pointer, otherwise returns null. This method is similar to with the exception that it can take the Container's children into account. If allowChildren is false, this method will return a non-null value only if the mouse pointer is above the Container directly, not above the part obscured by children. If allowChildren is true, this method returns a non-null value if the mouse pointer is above Container or any of its descendants.

Returns an array of all the mouse wheel listeners registered on this component.

Gets the name of the component.

Returns the value of the named parameter in the HTML tag. For example, if this applet is specified as

 <applet code="Clock" width=50 height=50>
 <param name=Color value="blue">
 </applet>
 

then a call to getParameter("Color") returns the value "blue".

The name argument is case insensitive.

Returns information about the parameters that are understood by this applet. An applet should override this method to return an array of Strings describing these parameters.

Each element of the array should be a set of three Strings containing the name, the type, and a description. For example:

 String pinfo[][] = {
	 {"fps",    "1-10",    "frames per second"},
	 {"repeat", "boolean", "repeat image loop"},
	 {"imgs",   "url",     "images directory"}
 };
 

The implementation of this method provided by the Applet class returns null.

Gets the parent of this component.

Returns the preferred size of this container.

Returns an array of all the property change listeners registered on this component.

Returns an array of all the listeners which have been associated with the named property.

Returns the size of this component in the form of a Dimension object. The height field of the Dimension object contains this component's height, and the width field of the Dimension object contains this component's width.

Stores the width/height of this component into "return value" rv and return rv. If rv is null a new Dimension object is allocated. This version of getSize is useful if the caller wants to avoid allocating a new Dimension object on the heap.

Gets the toolkit of this component. Note that the frame that contains a component controls which toolkit is used by that component. Therefore if the component is moved from one frame to another, the toolkit it uses may change.

Gets this component's locking object (the object that owns the thread sychronization monitor) for AWT component-tree and layout operations.

Returns the current width of this component. This method is preferable to writing component.getBounds().width, or component.getSize().width because it doesn't cause any heap allocations.

Returns the current x coordinate of the components origin. This method is preferable to writing component.getBounds().x, or component.getLocation().x because it doesn't cause any heap allocations.

Returns the current y coordinate of the components origin. This method is preferable to writing component.getBounds().y, or component.getLocation().y because it doesn't cause any heap allocations.

Returns true if this Component is the focus owner. This method is obsolete, and has been replaced by isFocusOwner().

Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java^TM programming language.)

Repaints the component when the image has changed. This imageUpdate method of an ImageObserver is called when more information about an image which had been previously requested using an asynchronous routine such as the drawImage method of Graphics becomes available. See the definition of imageUpdate for more information on this method and its arguments.

The imageUpdate method of Component incrementally draws an image on the component as more of the bits of the image are available.

If the system property awt.image.incrementaldraw is missing or has the value true, the image is incrementally drawn. If the system property has any other value, then the image is not drawn until it has been completely loaded.

Also, if incremental drawing is in effect, the value of the system property awt.image.redrawrate is interpreted as an integer to give the maximum redraw rate, in milliseconds. If the system property is missing or cannot be interpreted as an integer, the redraw rate is once every 100ms.

The interpretation of the x, y, width, and height arguments depends on the value of the infoflags argument.

Called by the browser or applet viewer to inform this applet that it has been loaded into the system. It is always called before the first time that the start method is called.

A subclass of Applet should override this method if it has initialization to perform. For example, an applet with threads would use the init method to create the threads and the destroy method to kill them.

The implementation of this method provided by the Applet class does nothing.

Invalidates the container. The container and all parents above it are marked as needing to be laid out. This method can be called often, so it needs to execute quickly.

Determines if this applet is active. An applet is marked active just before its start method is called. It becomes inactive just before its stop method is called.

Checks if the component is contained in the component hierarchy of this container.

Returns whether the background color has been explicitly set for this Component. If this method returns false, this Component is inheriting its background color from an ancestor.

Returns whether the cursor has been explicitly set for this Component. If this method returns false, this Component is inheriting its cursor from an ancestor.

Determines whether this component is displayable. A component is displayable when it is connected to a native screen resource.

A component is made displayable either when it is added to a displayable containment hierarchy or when its containment hierarchy is made displayable. A containment hierarchy is made displayable when its ancestor window is either packed or made visible.

A component is made undisplayable either when it is removed from a displayable containment hierarchy or when its containment hierarchy is made undisplayable. A containment hierarchy is made undisplayable when its ancestor window is disposed.

Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later. Component subclasses that support double buffering should override this method to return true if double buffering is enabled.

Determines whether this component is enabled. An enabled component can respond to user input and generate events. Components are enabled initially by default. A component may be enabled or disabled by calling its setEnabled method.

Returns whether this Component can be focused.

Returns whether this Container is the root of a focus traversal cycle. Once focus enters a traversal cycle, typically it cannot leave it via focus traversal unless one of the up- or down-cycle keys is pressed. Normal traversal is limited to this Container, and all of this Container's descendants that are not descendants of inferior focus cycle roots. Note that a FocusTraversalPolicy may bend these restrictions, however. For example, ContainerOrderFocusTraversalPolicy supports implicit down-cycle traversal.

Returns whether the specified Container is the focus cycle root of this Container's focus traversal cycle. Each focus traversal cycle has only a single focus cycle root and each Container which is not a focus cycle root belongs to only a single focus traversal cycle. Containers which are focus cycle roots belong to two cycles: one rooted at the Container itself, and one rooted at the Container's nearest focus-cycle-root ancestor. This method will return true for both such Containers in this case.

Returns true if this Component is the focus owner.

Returns whether this Component can become the focus owner.

Returns whether this container provides focus traversal policy. If this property is set to true then when keyboard focus manager searches container hierarchy for focus traversal policy and encounters this container before any other container with this property as true or focus cycle roots then its focus traversal policy will be used instead of focus cycle root's policy.

Returns whether the focus traversal policy has been explicitly set for this Container. If this method returns false, this Container will inherit its focus traversal policy from an ancestor.

Returns whether the font has been explicitly set for this Component. If this method returns false, this Component is inheriting its font from an ancestor.

Returns whether the foreground color has been explicitly set for this Component. If this method returns false, this Component is inheriting its foreground color from an ancestor.

A lightweight component doesn't have a native toolkit peer. Subclasses of Component and Container, other than the ones defined in this package like Button or Scrollbar, are lightweight. All of the Swing components are lightweights.

This method will always return false if this component is not displayable because it is impossible to determine the weight of an undisplayable component.

Returns true if the maximum size has been set to a non-null value otherwise returns false.

Returns whether or not setMinimumSize has been invoked with a non-null value.

Returns true if this component is completely opaque, returns false by default.

An opaque component paints every pixel within its rectangular region. A non-opaque component paints only some of its pixels, allowing the pixels underneath it to "show through". A component that does not fully paint its pixels therefore provides a degree of transparency. Only lightweight components can be transparent.

Subclasses that guarantee to always completely paint their contents should override this method and return true. All of the "heavyweight" AWT components are opaque.

Returns true if the preferred size has been set to a non-null value otherwise returns false.

Determines whether this component is showing on screen. This means that the component must be visible, and it must be in a container that is visible and showing.

Determines whether this component is valid. A component is valid when it is correctly sized and positioned within its parent container and all its children are also valid. In order to account for peers' size requirements, components are invalidated before they are first shown on the screen. By the time the parent container is fully realized, all its components will be valid.

Determines whether this component should be visible when its parent is visible. Components are initially visible, with the exception of top level components such as Frame objects.

Prints a listing of this component to the standard system output stream System.out.

Prints a listing of this component to the specified output stream.

Prints a listing of this container to the specified output stream. The listing starts at the specified indentation.

The immediate children of the container are printed with an indentation of indent+1. The children of those children are printed at indent+2 and so on.

Prints a listing to the specified print writer.

Prints out a list, starting at the specified indentation, to the specified print writer.

The immediate children of the container are printed with an indentation of indent+1. The children of those children are printed at indent+2 and so on.

Get an audio clip from the given URL.

Wakes up a single thread that is waiting on this object's monitor. If any threads are waiting on this object, one of them is chosen to be awakened. The choice is arbitrary and occurs at the discretion of the implementation. A thread waits on an object's monitor by calling one of the wait methods.

The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:

• By executing a synchronized instance method of that object.
• By executing the body of a synchronized statement that synchronizes on the object.
• For objects of type Class, by executing a synchronized static method of that class.

Only one thread at a time can own an object's monitor.

Wakes up all threads that are waiting on this object's monitor. A thread waits on an object's monitor by calling one of the wait methods.

The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Paints the container. This forwards the paint to any lightweight components that are children of this container. If this method is reimplemented, super.paint(g) should be called so that lightweight components are properly rendered. If a child component is entirely clipped by the current clipping setting in g, paint() will not be forwarded to that child.

Paints this component and all of its subcomponents.

The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Paints each of the components in this container.

Plays the audio clip at the specified absolute URL. Nothing happens if the audio clip cannot be found.

Plays the audio clip given the URL and a specifier that is relative to it. Nothing happens if the audio clip cannot be found.

Prepares an image for rendering on this component. The image data is downloaded asynchronously in another thread and the appropriate screen representation of the image is generated.

Prepares an image for rendering on this component at the specified width and height.

The image data is downloaded asynchronously in another thread, and an appropriately scaled screen representation of the image is generated.

Prints the container. This forwards the print to any lightweight components that are children of this container. If this method is reimplemented, super.print(g) should be called so that lightweight components are properly rendered. If a child component is entirely clipped by the current clipping setting in g, print() will not be forwarded to that child.

Prints this component and all of its subcomponents.

The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component.

Prints each of the components in this container.

Removes the specified component from this container. This method also notifies the layout manager to remove the component from this container's layout via the removeLayoutComponent method.

Removes the component, specified by index, from this container. This method also notifies the layout manager to remove the component from this container's layout via the removeLayoutComponent method.

Removes the specified popup menu from the component.

Removes all the components from this container. This method also notifies the layout manager to remove the components from this container's layout via the removeLayoutComponent method.

Removes the specified component listener so that it no longer receives component events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified container listener so it no longer receives container events from this container. If l is null, no exception is thrown and no action is performed.

Removes the specified focus listener so that it no longer receives focus events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified input method listener so that it no longer receives input method events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified key listener so that it no longer receives key events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified mouse listener so that it no longer receives mouse events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed.

Removes the specified mouse wheel listener so that it no longer receives mouse wheel events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If l is null, no exception is thrown and no action is performed.

Makes this Container undisplayable by removing its connection to its native screen resource. Making a container undisplayable will cause all of its children to be made undisplayable. This method is called by the toolkit internally and should not be called directly by programs.

Removes a PropertyChangeListener from the listener list. This method should be used to remove PropertyChangeListeners that were registered for all bound properties of this class.

If listener is null, no exception is thrown and no action is performed.

Removes a PropertyChangeListener from the listener list for a specific property. This method should be used to remove PropertyChangeListeners that were registered for a specific bound property.

If propertyName or listener is null, no exception is thrown and no action is taken.

Repaints this component.

If this component is a lightweight component, this method causes a call to this component's paint method as soon as possible. Otherwise, this method causes a call to this component's update method as soon as possible.

Note: For more information on the paint mechanisms utilitized by AWT and Swing, including information on how to write the most efficient painting code, see Painting in AWT and Swing.

Repaints the specified rectangle of this component.

If this component is a lightweight component, this method causes a call to this component's paint method as soon as possible. Otherwise, this method causes a call to this component's update method as soon as possible.

Note: For more information on the paint mechanisms utilitized by AWT and Swing, including information on how to write the most efficient painting code, see Painting in AWT and Swing.

Repaints the component. If this component is a lightweight component, this results in a call to paint within tm milliseconds.

Note: For more information on the paint mechanisms utilitized by AWT and Swing, including information on how to write the most efficient painting code, see Painting in AWT and Swing.

Repaints the specified rectangle of this component within tm milliseconds.

If this component is a lightweight component, this method causes a call to this component's paint method. Otherwise, this method causes a call to this component's update method.

Note: For more information on the paint mechanisms utilitized by AWT and Swing, including information on how to write the most efficient painting code, see Painting in AWT and Swing.

Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window. This component must be displayable, visible, and focusable for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event. If this request is denied because this Component's top-level Window cannot become the focused Window, the request will be remembered and will be granted when the Window is later focused by the user.

This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead.

Because the focus behavior of this method is platform-dependent, developers are strongly encouraged to use requestFocusInWindow when possible.

Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window. This component must be displayable, visible, and focusable for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event.

This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the Component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event.

This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead.

The focus behavior of this method can be implemented uniformly across platforms, and thus developers are strongly encouraged to use this method over requestFocus when possible. Code which relies on requestFocus may exhibit different focus behavior on different platforms.

Requests that this applet be resized.

Requests that this applet be resized.

Sets the background color of this component.

The background color affects each component differently and the parts of the component that are affected by the background color may differ between operating systems.

Moves and resizes this component. The new location of the top-left corner is specified by x and y, and the new size is specified by width and height.

Moves and resizes this component to conform to the new bounding rectangle r. This component's new position is specified by r.x and r.y, and its new size is specified by r.width and r.height

Sets the language-sensitive orientation that is to be used to order the elements or text within this component. Language-sensitive LayoutManager and Component subclasses will use this property to determine how to lay out and draw components.

At construction time, a component's orientation is set to ComponentOrientation.UNKNOWN, indicating that it has not been specified explicitly. The UNKNOWN orientation behaves the same as ComponentOrientation.LEFT_TO_RIGHT.

To set the orientation of a single component, use this method. To set the orientation of an entire component hierarchy, use applyComponentOrientation .

Moves the specified component to the specified z-order index in the container. The z-order determines the order that components are painted; the component with the highest z-order paints first and the component with the lowest z-order paints last. Where components overlap, the component with the lower z-order paints over the component with the higher z-order.

If the component is a child of some other container, it is removed from that container before being added to this container. The important difference between this method and java.awt.Container.add(Component, int) is that this method doesn't call removeNotify on the component while removing it from its previous container unless necessary and when allowed by the underlying native windowing system. This way, if the component has the keyboard focus, it maintains the focus when moved to the new position.

This property is guaranteed to apply only to lightweight non-Container components.

Note: Not all platforms support changing the z-order of heavyweight components from one container into another without the call to removeNotify. There is no way to detect whether a platform supports this, so developers shouldn't make any assumptions.

Sets the cursor image to the specified cursor. This cursor image is displayed when the contains method for this component returns true for the current cursor location, and this Component is visible, displayable, and enabled. Setting the cursor of a Container causes that cursor to be displayed within all of the container's subcomponents, except for those that have a non-null cursor.

Associate a DropTarget with this component. The Component will receive drops only if it is enabled.

Enables or disables this component, depending on the value of the parameter b. An enabled component can respond to user input and generate events. Components are enabled initially by default.

Note: Disabling a lightweight component does not prevent it from receiving MouseEvents.

Sets the focusable state of this Component to the specified value. This value overrides the Component's default focusability.

Sets whether this Container is the root of a focus traversal cycle. Once focus enters a traversal cycle, typically it cannot leave it via focus traversal unless one of the up- or down-cycle keys is pressed. Normal traversal is limited to this Container, and all of this Container's descendants that are not descendants of inferior focus cycle roots. Note that a FocusTraversalPolicy may bend these restrictions, however. For example, ContainerOrderFocusTraversalPolicy supports implicit down-cycle traversal.

The alternative way to specify the traversal order of this Container's children is to make this Container a focus traversal policy provider.

Sets the focus traversal keys for a given traversal operation for this Container.

The default values for a Container's focus traversal keys are implementation-dependent. Sun recommends that all implementations for a particular native platform use the same default values. The recommendations for Windows and Unix are listed below. These recommendations are used in the Sun AWT implementations.

Identifier	Meaning	Default
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS	Normal forward keyboard traversal	TAB on KEY_PRESSED, CTRL-TAB on KEY_PRESSED
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS	Normal reverse keyboard traversal	SHIFT-TAB on KEY_PRESSED, CTRL-SHIFT-TAB on KEY_PRESSED
KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS	Go up one focus traversal cycle	none
KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS		Go down one focus traversal cycle	none

To disable a traversal key, use an empty Set; Collections.EMPTY_SET is recommended.

Using the AWTKeyStroke API, client code can specify on which of two specific KeyEvents, KEY_PRESSED or KEY_RELEASED, the focus traversal operation will occur. Regardless of which KeyEvent is specified, however, all KeyEvents related to the focus traversal key, including the associated KEY_TYPED event, will be consumed, and will not be dispatched to any Container. It is a runtime error to specify a KEY_TYPED event as mapping to a focus traversal operation, or to map the same event to multiple default focus traversal operations.

If a value of null is specified for the Set, this Container inherits the Set from its parent. If all ancestors of this Container have null specified for the Set, then the current KeyboardFocusManager's default Set is used.

Sets whether focus traversal keys are enabled for this Component. Components for which focus traversal keys are disabled receive key events for focus traversal keys. Components for which focus traversal keys are enabled do not see these events; instead, the events are automatically converted to traversal operations.

Sets the focus traversal policy that will manage keyboard traversal of this Container's children, if this Container is a focus cycle root. If the argument is null, this Container inherits its policy from its focus- cycle-root ancestor. If the argument is non-null, this policy will be inherited by all focus-cycle-root children that have no keyboard- traversal policy of their own (as will, recursively, their focus-cycle- root children).

If this Container is not a focus cycle root, the policy will be remembered, but will not be used or inherited by this or any other Containers until this Container is made a focus cycle root.

Sets whether this container will be used to provide focus traversal policy. Container with this property as true will be used to acquire focus traversal policy instead of closest focus cycle root ancestor.

Sets the font of this container.

Sets the foreground color of this component.

Sets whether or not paint messages received from the operating system should be ignored. This does not affect paint events generated in software by the AWT, unless they are an immediate response to an OS-level paint message.

This is useful, for example, if running under full-screen mode and better performance is desired, or if page-flipping is used as the buffer strategy.

Sets the layout manager for this container.

Sets the locale of this component. This is a bound property.

Moves this component to a new location. The top-left corner of the new location is specified by the x and y parameters in the coordinate space of this component's parent.

Moves this component to a new location. The top-left corner of the new location is specified by point p. Point p is given in the parent's coordinate space.

Sets the maximum size of this component to a constant value. Subsequent calls to getMaximumSize will always return this value. Setting the maximum size to null restores the default behavior.

Sets the minimum size of this component to a constant value. Subsequent calls to getMinimumSize will always return this value. Setting the minimum size to null restores the default behavior.

Sets the name of the component to the specified string.

Sets the preferred size of this component to a constant value. Subsequent calls to getPreferredSize will always return this value. Setting the preferred size to null restores the default behavior.

Resizes this component so that it has width d.width and height d.height.

Resizes this component so that it has width width and height height.

Sets this applet's stub. This is done automatically by the system.

If there is a security manager, its checkPermission method is called with the AWTPermission("setAppletStub") permission if a stub has already been set.

Shows or hides this component depending on the value of parameter b.

Requests that the argument string be displayed in the "status window". Many browsers and applet viewers provide such a window, where the application can inform users of its current state.

Called by the browser or applet viewer to inform this applet that it should start its execution. It is called after the init method and each time the applet is revisited in a Web page.

A subclass of Applet should override this method if it has any operation that it wants to perform each time the Web page containing it is visited. For example, an applet with animation might want to use the start method to resume animation, and the stop method to suspend the animation.

Note: some methods, such as getLocationOnScreen, can only provide meaningful results if the applet is showing. Because isShowing returns false when the applet's start is first called, methods requiring isShowing to return true should be called from a ComponentListener.

The implementation of this method provided by the Applet class does nothing.

Called by the browser or applet viewer to inform this applet that it should stop its execution. It is called when the Web page that contains this applet has been replaced by another page, and also just before the applet is to be destroyed.

A subclass of Applet should override this method if it has any operation that it wants to perform each time the Web page containing it is no longer visible. For example, an applet with animation might want to use the start method to resume animation, and the stop method to suspend the animation.

The implementation of this method provided by the Applet class does nothing.

Returns a string representation of this component and its values.

Transfers the focus to the next component, as though this Component were the focus owner.

Transfers the focus down one focus traversal cycle. If this Container is a focus cycle root, then the focus owner is set to this Container's default Component to focus, and the current focus cycle root is set to this Container. If this Container is not a focus cycle root, then no focus traversal operation occurs.

Transfers the focus up one focus traversal cycle. Typically, the focus owner is set to this Component's focus cycle root, and the current focus cycle root is set to the new focus owner's focus cycle root. If, however, this Component's focus cycle root is a Window, then the focus owner is set to the focus cycle root's default Component to focus, and the current focus cycle root is unchanged.

Updates the container. This forwards the update to any lightweight components that are children of this container. If this method is reimplemented, super.update(g) should be called so that lightweight components are properly rendered. If a child component is entirely clipped by the current clipping setting in g, update() will not be forwarded to that child.

Validates this container and all of its subcomponents.

The validate method is used to cause a container to lay out its subcomponents again. It should be invoked when this container's subcomponents are modified (added to or removed from the container, or layout-related information changed) after the container has been displayed.

Causes current thread to wait until another thread invokes the method or the method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method. The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait();
         ... // Perform action appropriate to condition
     }
 

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Causes current thread to wait until either another thread invokes the method or the method for this object, or a specified amount of time has elapsed.

The current thread must own this object's monitor.

This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:

• Some other thread invokes the notify method for this object and thread T happens to be arbitrarily chosen as the thread to be awakened.
• Some other thread invokes the notifyAll method for this object.
• Some other thread interrupts thread T.
• The specified amount of real time has elapsed, more or less. If timeout is zero, however, then real time is not taken into consideration and the thread simply waits until notified.

The thread T is then removed from the wait set for this object and re-enabled for thread scheduling. It then competes in the usual manner with other threads for the right to synchronize on the object; once it has gained control of the object, all its synchronization claims on the object are restored to the status quo ante - that is, to the situation as of the time that the wait method was invoked. Thread T then returns from the invocation of the wait method. Thus, on return from the wait method, the synchronization state of the object and of thread T is exactly as it was when the wait method was invoked.

A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout);
         ... // Perform action appropriate to condition
     }
 

(For more information on this topic, see Section 3.2.3 in Doug Lea's "Concurrent Programming in Java (Second Edition)" (Addison-Wesley, 2000), or Item 50 in Joshua Bloch's "Effective Java Programming Language Guide" (Addison-Wesley, 2001).

If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.

Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Causes current thread to wait until another thread invokes the method or the method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

This method is similar to the wait method of one argument, but it allows finer control over the amount of time to wait for a notification before giving up. The amount of real time, measured in nanoseconds, is given by:

 1000000*timeout+nanos

In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:

• Another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method.
• The timeout period, specified by timeout milliseconds plus nanos nanoseconds arguments, has elapsed.

The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout, nanos);
         ... // Perform action appropriate to condition
     }
 

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.