java.lang.Object
- java.awt.FocusTraversalPolicy

Direct Known Subclasses:

ContainerOrderFocusTraversalPolicy, InternalFrameFocusTraversalPolicy
```
public abstract class FocusTraversalPolicy
extends Object
```
A FocusTraversalPolicy defines the order in which Components with a particular focus cycle root are traversed. Instances can apply the policy to arbitrary focus cycle roots, allowing themselves to be shared across Containers. They do not need to be reinitialized when the focus cycle roots of a Component hierarchy change.
The core responsibility of a FocusTraversalPolicy is to provide algorithms determining the next and previous Components to focus when traversing forward or backward in a UI. Each FocusTraversalPolicy must also provide algorithms for determining the first, last, and default Components in a traversal cycle. First and last Components are used when normal forward and backward traversal, respectively, wraps. The default Component is the first to receive focus when traversing down into a new focus traversal cycle. A FocusTraversalPolicy can optionally provide an algorithm for determining a Window's initial Component. The initial Component is the first to receive focus when a Window is first made visible.
FocusTraversalPolicy takes into account focus traversal policy providers. When searching for first/last/next/previous Component, if a focus traversal policy provider is encountered, its focus traversal policy is used to perform the search operation.
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.setFocusTraversalPolicy(java.awt.FocusTraversalPolicy), Container.getFocusTraversalPolicy(), Container.setFocusCycleRoot(boolean), Container.isFocusCycleRoot(java.awt.Container), Container.setFocusTraversalPolicyProvider(boolean), Container.isFocusTraversalPolicyProvider(), KeyboardFocusManager.setDefaultFocusTraversalPolicy(java.awt.FocusTraversalPolicy), KeyboardFocusManager.getDefaultFocusTraversalPolicy()

Constructor Summary

Constructors
Constructor and Description

FocusTraversalPolicy()

Eerste pagina van API Java Inhoudsopgave Haut

Method Summary

Methods
Modifier and Type	Method and Description
`abstract Component`	`getComponentAfter(Container aContainer, Component aComponent)` Returns the Component that should receive the focus after aComponent.
`abstract Component`	`getComponentBefore(Container aContainer, Component aComponent)` Returns the Component that should receive the focus before aComponent.
`abstract Component`	`getDefaultComponent(Container aContainer)` Returns the default Component to focus.
`abstract Component`	`getFirstComponent(Container aContainer)` Returns the first Component in the traversal cycle.
`Component`	`getInitialComponent(Window window)` Returns the Component that should receive the focus when a Window is made visible for the first time.
`abstract Component`	`getLastComponent(Container aContainer)` Returns the last Component in the traversal cycle.

Eerste pagina van API Java Inhoudsopgave Haut

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

- Constructor Detail
  - FocusTraversalPolicy
```
public FocusTraversalPolicy()
```
- Method Detail
  - getComponentAfter
```
public abstract Component getComponentAfter(Container aContainer,
                          Component aComponent)
```
    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.
    
    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 after aComponent, or null if no suitable Component can be found
    
    Throws:
    
    IllegalArgumentException - if aContainer is not a focus cycle root of aComponent or a focus traversal policy provider, or if either aContainer or aComponent is null
  - getComponentBefore
```
public abstract Component getComponentBefore(Container aContainer,
                           Component aComponent)
```
    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.
    
    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:
    
    IllegalArgumentException - if aContainer is not a focus cycle root of aComponent or a focus traversal policy provider, or if either aContainer or aComponent is null
  - getFirstComponent
```
public abstract Component getFirstComponent(Container aContainer)
```
    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.
    
    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:
    
    IllegalArgumentException - if aContainer is null
  - getLastComponent
```
public abstract Component getLastComponent(Container aContainer)
```
    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.
    
    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:
    
    IllegalArgumentException - if aContainer is null
  - getDefaultComponent
```
public abstract Component getDefaultComponent(Container aContainer)
```
    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.
    
    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:
    
    IllegalArgumentException - if aContainer is null
  - getInitialComponent
```
public Component getInitialComponent(Window window)
```
    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:
    
    IllegalArgumentException - if window is null
    See Also:
    getDefaultComponent(java.awt.Container), Window.getMostRecentFocusOwner()

Nederlandse vertaling

U hebt gevraagd om deze site in het Nederlands te bezoeken. Voor nu wordt alleen de interface vertaald, maar nog niet alle inhoud.

Als je me wilt helpen met vertalingen, is je bijdrage welkom. Het enige dat u hoeft te doen, is u op de site registreren en mij een bericht sturen waarin u wordt gevraagd om u toe te voegen aan de groep vertalers, zodat u de gewenste pagina's kunt vertalen. Een link onderaan elke vertaalde pagina geeft aan dat u de vertaler bent en heeft een link naar uw profiel.

Bij voorbaat dank.

Document heeft de 11/06/2005 gemaakt, de laatste keer de 04/03/2020 gewijzigd
Bron van het afgedrukte document:https://www.gaudry.be/nl/java-api-rf-java/awt/focustraversalpolicy.html

De infobrol is een persoonlijke site waarvan de inhoud uitsluitend mijn verantwoordelijkheid is. De tekst is beschikbaar onder CreativeCommons-licentie (BY-NC-SA). Meer info op de gebruiksvoorwaarden en de auteur.

Referenties

Manuel PHP : https://docs.oracle.com

Deze verwijzingen en links verwijzen naar documenten die geraadpleegd zijn tijdens het schrijven van deze pagina, of die aanvullende informatie kunnen geven, maar de auteurs van deze bronnen kunnen niet verantwoordelijk worden gehouden voor de inhoud van deze pagina.
De auteur Deze site is als enige verantwoordelijk voor de manier waarop de verschillende concepten, en de vrijheden die met de referentiewerken worden genomen, hier worden gepresenteerd. Vergeet niet dat u meerdere broninformatie moet doorgeven om het risico op fouten te verkleinen.

Inhoudsopgave Haut

Class FocusTraversalPolicy

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FocusTraversalPolicy

Method Detail

getComponentAfter

getComponentBefore

getFirstComponent

getLastComponent

getDefaultComponent

getInitialComponent

Referenties