java.lang.Object
- java.awt.FocusTraversalPolicy
- - java.awt.ContainerOrderFocusTraversalPolicy
  - - java.awt.DefaultFocusTraversalPolicy

All Implemented Interfaces:

java.io.Serializable

public class DefaultFocusTraversalPolicy extends ContainerOrderFocusTraversalPolicy

A FocusTraversalPolicy that determines traversal order based on the order of child Components in a Container. From a particular focus cycle root, the policy makes a pre-order traversal of the Component hierarchy, and traverses a Container's children according to the ordering of the array returned by Container.getComponents(). Portions of the hierarchy that are not visible and displayable will not be searched.
If client code has explicitly set the focusability of a Component by either overriding Component.isFocusTraversable() or Component.isFocusable(), or by calling Component.setFocusable(), then a DefaultFocusTraversalPolicy behaves exactly like a ContainerOrderFocusTraversalPolicy. If, however, the Component is relying on default focusability, then a DefaultFocusTraversalPolicy will reject all Components with non-focusable peers. This is the default FocusTraversalPolicy for all AWT Containers.
The focusability of a peer is implementation-dependent. Sun recommends that all implementations for a particular native platform construct peers with the same focusability. The recommendations for Windows and Unix are that Canvases, Labels, Panels, Scrollbars, ScrollPanes, Windows, and lightweight Components have non-focusable peers, and all other Components have focusable peers. These recommendations are used in the Sun AWT implementations. Note that the focusability of a Component's peer is different from, and does not impact, the focusability of the Component itself.
Please see How to Use the Focus Subsystem, a section in The Java Tutorial, and the Focus Specification for more information.

Since:

1.4

See Also:
Container.getComponents(), Component.isFocusable(), Component.setFocusable(boolean), Serialized Form

Constructors
Constructor and Description

DefaultFocusTraversalPolicy

DefaultFocusTraversalPolicy()

public DefaultFocusTraversalPolicy()

Constructors
	Constructor and Description
	DefaultFocusTraversalPolicy	DefaultFocusTraversalPolicy() public DefaultFocusTraversalPolicy()

Methods
	Modifier and Type	Method and Description
	accept	`protected boolean` accept(Component aComponent) Determines whether a Component is an acceptable choice as the new focus owner. protected boolean accept(Component aComponent) Determines whether a Component is an acceptable choice as the new focus owner. The Component must be visible, displayable, and enabled to be accepted. If client code has explicitly set the focusability of the Component by either overriding `Component.isFocusTraversable()` or `Component.isFocusable()`, or by calling `Component.setFocusable()`, then the Component will be accepted if and only if it is focusable. If, however, the Component is relying on default focusability, then all Canvases, Labels, Panels, Scrollbars, ScrollPanes, Windows, and lightweight Components will be rejected. Overrides: `accept` in class `ContainerOrderFocusTraversalPolicy` Parameters: `aComponent` - the Component whose fitness as a focus owner is to be tested Returns: `true` if aComponent meets the above requirements; `false` otherwise
	getComponentAfter	`Component` getComponentAfter(Container aContainer, Component aComponent) Returns the Component that should receive the focus after aComponent. public Component getComponentAfter(Container aContainer, Component aComponent) Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns the Component that should receive the focus after aComponent. aContainer must be a focus cycle root of aComponent or a focus traversal policy provider. By default, ContainerOrderFocusTraversalPolicy implicitly transfers focus down-cycle. That is, during normal forward focus traversal, the Component traversed after a focus cycle root will be the focus-cycle- root's default Component to focus. This behavior can be disabled using the `setImplicitDownCycleTraversal` method. If aContainer is focus traversal policy provider, the focus is always transferred down-cycle. Specified by: `getComponentAfter` in class `FocusTraversalPolicy` Parameters: `aContainer` - a focus cycle root of aComponent or a focus traversal policy provider `aComponent` - a (possibly indirect) child of aContainer, or aContainer itself Returns: the Component that should receive the focus after aComponent, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if aContainer is not a focus cycle root of aComponent or focus traversal policy provider, or if either aContainer or aComponent is null
	getComponentBefore	`Component` getComponentBefore(Container aContainer, Component aComponent) Returns the Component that should receive the focus before aComponent. public Component getComponentBefore(Container aContainer, Component aComponent) Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns the Component that should receive the focus before aComponent. aContainer must be a focus cycle root of aComponent or a focus traversal policy provider. Specified by: `getComponentBefore` in class `FocusTraversalPolicy` Parameters: `aContainer` - a focus cycle root of aComponent or focus traversal policy provider `aComponent` - a (possibly indirect) child of aContainer, or aContainer itself Returns: the Component that should receive the focus before aComponent, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if aContainer is not a focus cycle root of aComponent or focus traversal policy provider, or if either aContainer or aComponent is null
	getDefaultComponent	`Component` getDefaultComponent(Container aContainer) Returns the default Component to focus. public Component getDefaultComponent(Container aContainer) Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns the default Component to focus. This Component will be the first to receive focus when traversing down into a new focus traversal cycle rooted at aContainer. The default implementation of this method returns the same Component as `getFirstComponent`. Specified by: `getDefaultComponent` in class `FocusTraversalPolicy` Parameters: `aContainer` - the focus cycle root or focus traversal policy provider whose default Component is to be returned Returns: the default Component in the traversal cycle of aContainer, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if aContainer is null See Also: `ContainerOrderFocusTraversalPolicy.getFirstComponent(java.awt.Container)`
	getFirstComponent	`Component` getFirstComponent(Container aContainer) Returns the first Component in the traversal cycle. public Component getFirstComponent(Container aContainer) Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns the first Component in the traversal cycle. This method is used to determine the next Component to focus when traversal wraps in the forward direction. Specified by: `getFirstComponent` in class `FocusTraversalPolicy` Parameters: `aContainer` - the focus cycle root or focus traversal policy provider whose first Component is to be returned Returns: the first Component in the traversal cycle of aContainer, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if aContainer is null
	getImplicitDownCycleTraversal	`boolean` getImplicitDownCycleTraversal() Returns whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly. public boolean getImplicitDownCycleTraversal() Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly. If `true`, during normal forward focus traversal, the Component traversed after a focus cycle root will be the focus-cycle-root's default Component to focus. If `false`, the next Component in the focus traversal cycle rooted at the specified focus cycle root will be traversed instead. Returns: whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly See Also: `ContainerOrderFocusTraversalPolicy.setImplicitDownCycleTraversal(boolean)`, `ContainerOrderFocusTraversalPolicy.getFirstComponent(java.awt.Container)`
	getInitialComponent	`Component` getInitialComponent(Window window) Returns the Component that should receive the focus when a Window is made visible for the first time. public Component getInitialComponent(Window window) Description copied from class: `FocusTraversalPolicy` Returns the Component that should receive the focus when a Window is made visible for the first time. Once the Window has been made visible by a call to `show()` or `setVisible(true)`, the initial Component will not be used again. Instead, if the Window loses and subsequently regains focus, or is made invisible or undisplayable and subsequently made visible and displayable, the Window's most recently focused Component will become the focus owner. The default implementation of this method returns the default Component. Parameters: `window` - the Window whose initial Component is to be returned Returns: the Component that should receive the focus when window is made visible for the first time, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if window is null See Also: `FocusTraversalPolicy.getDefaultComponent(java.awt.Container)`, `Window.getMostRecentFocusOwner()`
	getLastComponent	`Component` getLastComponent(Container aContainer) Returns the last Component in the traversal cycle. public Component getLastComponent(Container aContainer) Description copied from class: `ContainerOrderFocusTraversalPolicy` Returns the last Component in the traversal cycle. This method is used to determine the next Component to focus when traversal wraps in the reverse direction. Specified by: `getLastComponent` in class `FocusTraversalPolicy` Parameters: `aContainer` - the focus cycle root or focus traversal policy provider whose last Component is to be returned Returns: the last Component in the traversal cycle of aContainer, or null if no suitable Component can be found Throws: `java.lang.IllegalArgumentException` - if aContainer is null
	setImplicitDownCycleTraversal	`void` setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) Sets whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly. public void setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) Description copied from class: `ContainerOrderFocusTraversalPolicy` Sets whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly. If `true`, during normal forward focus traversal, the Component traversed after a focus cycle root will be the focus-cycle-root's default Component to focus. If `false`, the next Component in the focus traversal cycle rooted at the specified focus cycle root will be traversed instead. The default value for this property is `true`. Parameters: `implicitDownCycleTraversal` - whether this ContainerOrderFocusTraversalPolicy transfers focus down-cycle implicitly See Also: `ContainerOrderFocusTraversalPolicy.getImplicitDownCycleTraversal()`, `ContainerOrderFocusTraversalPolicy.getFirstComponent(java.awt.Container)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

SourceForge

Class DefaultFocusTraversalPolicy

Methods inherited from class java.lang.Object